Natural Heritage System for the Lake Simcoe Watershed

Transcription

Natural Heritage System for the
Lake Simcoe Watershed
Phase 1: Components and Policy Templates
Prepared for:
Lake Simcoe Region Conservation Authority
A Collaboration of:
Lake Simcoe Region Conservation Authority and
Beacon Environmental
July 2007
Acknowledgements
The development of the Lake Simcoe Watershed Natural Heritage System was a
collaborative effort between the Lake Simcoe Region Conservation Authority and
Beacon Environmental.
We are grateful to the LSEMS partners who provided useful review comments that
contributed to the successful conclusion of this project.
We would particularly like to thank Environment Canada (Canadian Wildlife Service) for
permission to use excerpts from their publications. We also thank Bird Studies Canada
(Jon McCracken) for providing timely data on colonial nesting birds in the watershed.
Three workshops were undertaken which were well-attended by a wide-variety of
stakeholders which included: several provincial ministries, municipalities, conservation
authorities, land development industry, non-governmental organizations (such as Ducks
Unlimited Canada) and citizen interest groups amongst others. In addition to their verbal
comments and feedback, many of these stakeholders have also provided valuable written
comments. We are truly grateful for all of these contributions which have greatly
improved the product.
The data contained in the maps in this report have been compiled from various sources.
While every effort has been made to accurately depict the information, data mapping
errors may exist. Some data are © Queens Printer for Ontario, 2007. Reproduced with
Permission.
The opinions and recommendations herein remain those of the authors.
Suggested Citation:
Beacon Environmental and the Lake Simcoe Region Conservation Authority. 2007. Natural Heritage
System for the Lake Simcoe Watershed. Prepared for the Lake Simcoe Region Conservation Authority and
the Lake Simcoe Environmental Management Strategy. 142 pp plus appendices.
Profiles of Primary Members of the Study Team
Beacon Environmental, Markham, Ontario
Brian Henshaw
Ecologist and principal of Beacon Environmental, Brian was the project manager of this study
for Beacon, and was a primary author of this report. He has been consulting in Ontario for 18
years. He has a wide range of experience relating to analysis of features and functions relating to
wildlife, wetlands and landscape connectivity. He has undertaken several important review
projects including an update to the Environment Canada publication “How Much Habitat is
Enough?” and a review of urban effects on forest birds.
Adèle Labbé B.Sc.
Biologist at Beacon Environmental, Adele was a contributing author, responsible for the
research elements and for organization of the project at Beacon, preparation of report writing,
ELC field checking, liaison among the project team members. Adele also assisted with mapping
quality control.
Donald M. Fraser M.Sc.
Ecologist and principal at Beacon Environmental, with 25 years experience in natural heritage
assessment and environmental planning, Don has undertaken several landscape-level ecological
analyses. He was responsible for quality assurance and review of the component analyses. Don
contributed to the development of policy and provided ongoing support as required.
Lake Simcoe Region Conservation Authority, Newmarket, Ontario
Kimberley Baker B.Sc.
Senior Natural Heritage Biologist with the Authority, Kim has over a decade of experience in
natural heritage planning and plan review. Kim was a primary author and was responsible for
the co-ordination of the contribution of Authority staff to the project and provided input into the
policy development and oversaw the mapping and analysis components.
Michael Dennis B.A.
As GIS Analyst, Michael was responsible for the data management of the project and provided
on-going GIS support in the form of analysis and graphical representations.
Christine Deschamps M.Sc.
As Natural Heritage Ecologist, Christine undertook ELC field checking, data acquisition and
contributed to the quality control of the mapping.
Rob Baldwin B.Sc., Manager Watershed Science, was the LSRCA’s project manager and acted
as the liaison with the other Authority partners.
Janice Bennett B.Sc., provided her GIS skills and expertise with the regulation mapping to
identify and digitize the significant valleylands component of the system.
Darren Campbell B.A., GIS co-ordinator, provided data and graphics related to the woodland
data.
Jeff Andersen, Senior Fisheries Biologist, assisted with the Habitat for Fish analysis.
Table of Contents
Executive Summary ................................................................................................1
1.0
Introduction.............................................................................................5
2.0
Policy Background ..................................................................................9
3.0
Goals and Objectives ............................................................................10
4.0
Approach
4.1 Literature Review ........................................................................11
4.2 Component Discussion Papers....................................................11
4.3 Development of GIS Mapping ....................................................12
4.4 Policy Development......................................................................12
Natural Heritage System Components
5.0
Significant Habitat for Endangered and Threatened Species
5.1 Introduction..................................................................................15
5.2 Why are Endangered and Threatened Species Important? ....16
5.3 Endangered and Threatened Species in the Lake Simcoe
Watershed.....................................................................................16
5.4 Criteria..........................................................................................17
5.5 Literature Cited ...........................................................................18
6.0
Significant Wetlands
6.1 Wetlands in the Lake Simcoe Watershed ..................................19
6.2 Wetland Types in the Watershed ...............................................21
6.3 Why are Wetlands Important?...................................................23
6.4 Policy Framework........................................................................26
6.5 Criteria..........................................................................................27
6.6 Literature Cited ..........................................................................33
7.0
Significant Woodlands
7.1 History of Woodland Cover ........................................................34
7.2 Woodland Functions....................................................................35
7.3 Overview of Science .....................................................................36
7.4 Socially Significant Woodlands ..................................................40
7.5 Woodlands in the Lake Simcoe Watershed ...............................41
7.6 Policy Framework .......................................................................48
7.7 Review of Criteria ........................................................................49
7.8 Criteria for the Lake Simcoe Watershed NHS.........................53
7.9 Literature Cited ..........................................................................63
8.0
Significant Valleylands
8.1 Valleylands in the Lake Simcoe Watershed ..............................68
8.2 Why are Valleylands Important? ...............................................68
8.3 The Identification of Significant Valleylands ............................69
8.5 Criteria..........................................................................................71
9.0
Significant Wildlife Habitat
9.1 Background: What is Significant Wildlife Habitat? ................75
9.2 Why is Wildlife Habitat Important? ..........................................75
9.3 Use of the Significant Wildlife Habitat Designation .................77
9.5 Criteria..........................................................................................79
10.0
Areas of Natural and Scientific Interest
10.1 Background ..................................................................................87
10.2 Why are ANSIs Important?........................................................87
10.3 Life Science ANSIs in the Lake Simcoe Watershed..................88
10.5 Criteria..........................................................................................91
11.0
Habitat for Fish
11.1 Background: What is Habitat for Fish? ....................................94
11.2 The Importance of Habitat for Fish ...........................................94
11.3 Habitat for Fish in the Lake Simcoe Watershed.......................95
11.5 Criteria..........................................................................................98
11.6 Literature Cited .........................................................................100
12.0
Linkages
12.1 Overview .....................................................................................101
12.2 Key Assumptions........................................................................101
12.3 Differing Perspectives on Connectivity....................................102
12.4 Policy Framework......................................................................105
12.5 Criteria........................................................................................105
12.6 Literature Cited .........................................................................109
13.0
Suggested Policy Templates
13.1 Lake Simcoe Region Conservation Authority
Suggested Policies.......................................................................111
13.2 Suggested Implementation Policies for Official Plans............119
14.0
Mapping Interpretation......................................................................127
15.0
Where Do We Go From Here? ..........................................................128
16.0
Conclusions..........................................................................................129
17.0
Additional Literature Cited ...............................................................135
List of Figures
Figure 1.1
Figure 6.1
Figure 7.1
Figure 7.2
Figure 7.3
Figure 7.4
Figure 7.5
Figure 7.6
Figure 7.7
Figure 8.1
Figure 9.1
Figure 10.1
Figure 11.1
Figure 12.1
Figure 16.1
Figure 16.2
Lake Simcoe Watershed..........................................................................8
Example of Significant Wetlands in the
Lake Simcoe Watershed NHS...............................................................32
Ecodistricts .............................................................................................43
Woodland Patch Analysis – Whole Watershed...................................45
Woodland Patch Analysis – Black River Subwatershed ....................47
Woodland Patch Analysis – Barrie Creeks Subwatershed
Group......................................................................................................47
Subwatershed Woodland Cover ...........................................................58
Big Woods Policy Areas ........................................................................59
Example of Significant Woodlands in the Lake Simcoe
Watershed NHS .....................................................................................62
Example of Significant Valleylands in the Lake Simcoe
Watershed NHS .....................................................................................74
Example of Significant Wildlife Habitat in the Lake Simcoe
Watershed NHS .....................................................................................84
Example of ANSIs in the Lake Simcoe Watershed NHS....................92
Example of Habitat for Fish in the Lake Simcoe
Watershed NHS .....................................................................................99
Example of Linkages ...........................................................................108
Example of GIS Mapping Product.....................................................131
Lake Simcoe Watershed Natural Heritage System...........................132
List of Tables
Table 1.1
Table 4.1
Table 5.1
Table 6.1
Table 6.2
Table 6.3
Table 6.4
Table 7.1
Table 7.2
Table 7.3
Table 7.4
LSRCA Municipalities ............................................................................7
Recommended Policy Levels.................................................................14
NHIC Endangered and Threatened Element Occurrences
for the Lake Simcoe Watershed ...........................................................17
Distribution of Wetlands in the Lake Simcoe Watershed..................20
Wetland Analysis by Ecodistrict ..........................................................21
Status of Wetland Designations in the Watershed..............................27
Summary of Significant Wetland Criteria for the Lake Simcoe
Watershed...............................................................................................31
Woodland Cover by Type in the Watershed .......................................41
Woodland Cover Analysis by Ecodistrict............................................42
Total Woodland Cover by Subwatershed Areas.................................44
Criteria Recommended by Others for the Identification
of Significant Woodlands in Southern Ontario...................................50
Table 7.5
Table 7.6
Table 8.1
Table 9.1
Table 10.1
Table 10.2
Table 10.3
Table 11.1
Table 12.1
Table 12.2
Table 12.3
Table 16.1
Table 16.2
Criteria Used for the Determination of Significant
Woodlands in Southern Ontario ..........................................................51
Summary of Significant Woodland Criteria for the Lake
Simcoe Watershed .................................................................................61
Summary of Significant Valleylands Criteria in the Lake
Simcoe Watershed .................................................................................73
Summary Criteria for the Identification of SWH
in the Lake Simcoe Watershed .............................................................83
Provincially Significant Life Science ANSIs
Regionally Significant Life Science ANSIs
Summary of ANSI Criteria
Summary of Habitat for Fish Criteria
Key Woodland Habitat Criteria for
Woodland Breeding Birds (taken from EC 2007).............................103
Corridor Pros and Cons......................................................................104
Summary of Linkage Criteria for the Lake Simcoe
Watershed.............................................................................................107
The Natural Heritage System by Subwatershed Area......................130
Area of the Natural Heritage System Components ..........................133
List of Photographs
Photograph 6.1
Photograph 6.2
Photograph 6.3
Photograph 7.1
Photograph 10.1
A marsh in the Town of Innisfil (the rare
Great Egret, a white heron, can be seen centre left)................22
Locally rare Swamp Pink or Calapogon Orchids in
Gibson Hill Fen, one of the few fens in the
Lake Simcoe Watershed.............................................................25
Derryville Bog, one of the very few true bogs in the
Lake Simcoe Watershed. Note the die-back caused
by stress that limits the growth of the trees to below
25% cover....................................................................................29
An example of an isolated remnant woodlot, which
has largely developed since the landscape was settled ............35
A seared pine in the provincially significant life
science ANSI – DeGrassi Point Tallgrass Relict ......................88
List of Appendices
Appendix 1.
Appendix 2.
Appendix 3.
Appendix 4.
Appendix 5.
Appendix 6.
Appendix 7.
Ecological Land Classification Methodology ....................................139
Blind Field Checking of LSRCA ELC Data......................................143
Technical Methodology for Determining Significant
Valleylands in the Lake Simcoe Watershed ......................................155
Terms of Reference: Environmental Impact Study..........................159
Acronyms..............................................................................................165
Summary of NHS Components and their Policy
Recommendations................................................................................167
Glossary ................................................................................................169
Executive Summary
The Lake Simcoe Region Conservation Authority (LSRCA) partnered with Beacon
Environmental to develop a Natural Heritage System (NHS) for the 350,000 ha Lake Simcoe
Watershed. The development of the system was initiated to provide the information required for
the Lake Simcoe Comprehensive Basin Wide Plan, subwatershed plans in development, as well
as support to the plan and development review activities.
The Natural Heritage System has two phases: Phase 1 Components and Policy Templates, and
Phase 2 Restoration, Enhancement and Securement Strategy. The latter will be completed in the
future.
The goal of Phase 1 will be achieved by fulfilling the following objectives:
1) Develop criteria that help define significant areas;
2) Identify existing ecological linkages between significant areas;
3) Create an interactive system map in a GIS platform;
4) Review and incorporate key provincial legislation and policy that will assist in the
protection of natural heritage features and functions and policy development; and
5) Review existing municipal and LSRCA natural heritage policies and develop suggested
policy templates for use with the NHS that may be adopted by the LSRCA, as well as its
member municipalities.
The foundation of this NHS is the Provincial Policy Statement 2005, as it is the principal tool
designed by the Province to incorporate natural heritage planning across the watershed. Science
is the support structure of the NHS and it will serve to provide comprehensive criteria based on
recent scientific concepts in order to identify lands of ecological value within the watershed.
Policy suggestions will guide the implementation of the NHS with a four-tiered strategy,
proposing policies for application by the LSRCA, as well as policies for use by the partner
municipalities.
A literature review included formal scientific literature, existing natural heritage policies, as
well as other Natural Heritage System approaches and recommended approaches. The review
explored in detail several components of the NHS, especially those that are still the subject of
debate. In addition, studies on the identification of significant woodlands undertaken by
individual municipalities (e.g., Region of York, City of Hamilton) were reviewed.
The components that comprise the Lake Simcoe Watershed NHS are described and include:
Significant Habitat for Endangered and Threatened Species; Significant Wetlands; Significant
Woodlands; Significant Valleylands; Significant Wildlife Habitat; Areas of Natural and
Scientific Interest; Habitat for Fish; and Linkages. This led to the development of criteria to
determine provincial and watershed significance for system components.
The NHS was based on the Ecological Land Classification (ELC) and land use mapping that has
been undertaken over the past five years by the LSRCA for the entire watershed. GIS techniques
were used to further develop criteria, and for some components (e.g., valleylands) GIS became
the primary mechanism for developing a process with which to identify elements of the
component. Once criteria were developed, GIS algorithms were used to create the NHS
mapping. Each component was mapped as a GIS layer, which were overlain onto the base
watershed map. The maps were fine-tuned with reviews of the final product. The component
layers were then integrated into one final layer which retains each of the components.
Following the development of criteria for each of the components an initial draft of this
document was circulated and comments were received from a wide variety of stakeholders. The
LSRCA also hosted two well-attended and constructive workshops which provided further
feedback and important suggestions for improvements.
Following these discussions with stakeholders and receipt of further review comments,
substantial changes were made to the NHS. For example, a four-tiered (rather than a threetiered) policy approach was used to direct the protection of the natural features of the NHS. The
first two levels of this policy approach are assigned a “provincially significant” designation and
are considered to be those features that would be identified if following the guidelines and intent
of the PPS. Level 3 features are determined to represent significance at the watershed level,
while Level 4 – supporting features are considered to be supporting elements of the natural
heritage system within the watershed. Where features fit into more than one Policy Level, the
highest Level will prevail. The policy levels are summarized in the following table.
Recommended Policy Levels
Significance
Provincially
Significant
Watershed
Significant
Policy Level
NHS Intent
Level 1
•
•
Retain
No development or land
use change
Level 2
•
•
Retain
No negative impact
Level 3
•
Generally retain and
avoid, some flexibility
No net negative
impact
Supporting features
•
Supporting
Level 4
•
Big Woods
Policy Areas
BWPA
•
•
Retain
No net loss of
woodland
Implications for Replacement
Replacement can be considered for
impacts due to projects associated with
non-Planning Act mechanisms such as
Environmental Assessments
When there is no “negative impact”,
replacement can be considered for loss of
area or function
Retention preferred but replacement
acceptable
Not a development constraint, replacement
encouraged
Target area for replacement, restoration
and stewardship priorities
The following table provides a summary of the NHS by discrete subwatershed area and by policy
level.
The Natural Heritage System by Subwatershed Areas
Area of
Subwatershed
(ha)
Maskinonge River
Barrie creeks
Hewitt’s Creek
West Holland
East Holland
Innisfil creeks
Lover’s Creek
Beaver River
White’s Creek
Ramara creeks
Talbot River
Georgina creeks
Uxbridge Brook
Oro South creeks
Oro North creeks
Pefferlaw Brook
Black River
Hawkestone Creek
Islands in Lake
Simcoe combined
Total
Percent of
Subwatershed in
NHS
Percent of Subwatershed by Component Level
Level 1
Level 2
Level 3
7,179
3781
1,751
35,410
23,910
10,757
5,995
32,724
10,520
14,350
7,056
4,946
17,495
5,769
8,344
28,482
37,536
3,971
1,912
18.7
19.3
22.3
30.5
33.1
33.3
34.0
36.0
38.4
41.6
42.3
42.3
44.5
44.5
45.2
49.6
52.0
54.4
87.1
10.7
7.1
10.5
21.6
24.2
17.4
21.8
17.0
19.3
28.9
21.5
28.2
31.0
25.6
31.8
35.7
37.5
40.7
63.1
2.8
4.2
3.1
2.2
2.5
5.6
5.2
10.7
8.2
2.6
6.5
3.0
8.7
9.2
3.1
8.4
8.8
5.3
7.4
2.6
6.1
6.9
3.8
3.6
6.0
3.4
5.3
6.7
5.8
7.0
3.2
2.2
5.6
5.3
2.5
3.0
4.1
1.8
Level 4 supporting
2.6
1.9
1.8
2.9
2.8
4.3
3.6
3.0
4.2
4.3
7.3
7.9
2.6
4.1
5.0
3.0
2.7
4.3
14.8
261,887
40.2%
26.4%
6.3%
4.1%
3.4%
This document also provides two suggested implementation policy templates designed to assist
the LSRCA and planning authorities.
The identification and description of the Natural Heritage System provides a tool to:
•
Protect natural heritage resources and move towards the sustainability of ecosystem
services;
•
Examine landscape change over time;
•
Refine existing municipal natural heritage systems;
•
Guide the scope of environmental studies and assess the impacts of proposed
developments;
•
Guide future ecological planning initiatives (e.g., wetland evaluations);
•
Help identify priority communities/subwatersheds/planning
restoration or enhancement opportunities;
•
Identify high value restoration or enhancement areas (i.e., those locations where the
greatest ecological benefit can be realized for the least amount of dollars); and
•
Identify land acquisition targets for conservation organizations.
jurisdictions
for
It is the belief of the authors of this report that it reflects both the most recent science and a
pragmatic approach, which should enable a wide range of stakeholders to lend support to this
initiative. In the future, it is hoped that new scientific research, watershed data, updates and
revisions can further improve the NHS.
The Conservation Authority intends to adopt the NHS as a tool for plan review, providing
advice to its municipal partners and members of the public. This will also further and foster
partnerships and land stewardship, as well as contributing to protection and research
initiatives across the watershed.
It is recommended that the planning authorities within the Lake Simcoe Watershed use the
NHS as a basis to identify sustainable natural heritage systems within their jurisdictions as
well as to amend and adopt supporting implementation policies and to embed these within
their respective Official Plans.
Based on the experiences of the project team, the following recommendations are offered:
1. The development of a restoration and enhancement strategy that includes the restoration
of linkages and integrates stewardship initiatives;
2. The NHS be used to further refine land acquisition strategies and priority areas in the
watershed;
3. The Conservation Authority maintain and upgrade the ELC and land use mapping on a
regular basis;
4. Efforts be established to improve knowledge of Species at Risk in the watershed;
5. The Authority prepare “watershed rare” lists for all faunal groups; and
6. The NHS be used to direct targeted wetland evaluations under the Ontario Wetland
Evaluation System.
1.0
Introduction
The Lake Simcoe Region Conservation Authority (LSRCA) is an environmental agency working
to protect, restore and manage the natural resources of the Lake Simcoe Watershed (Figure 1.1).
The Lake Simcoe Watershed drains 261,887 ha of land into the 72,252 ha lake and is home to
approximately 350,000 people. The LSRCA has been active for over 50 years under the
Conservation Authorities Act and has gained many municipal partners along the way (Table 1.1).
The LSRCA mission (2006) is:
…to provide leadership in the restoration and protection of the environmental health
and quality of Lake Simcoe and its watershed with our Community, Municipal and
other Government partners.
The LSRCA has partnered with Beacon Environmental to develop a Natural Heritage System
(NHS) for the Lake Simcoe Watershed, which will provide information required for the Lake
Simcoe Comprehensive Basin Wide Plan, subwatershed plans, as well as to support plan and
development review.
In addition to the intrinsic values associated with flora and fauna, protection of the natural
features and ecological functions of the watershed will aid to improve air quality (OMNR 2006),
provide safe drinking water (Gabor et al. 2001) and maintain a better quality of life (MPIR 2006)
for its many human inhabitants.
Natural Heritage Systems generally consist of core conservation lands and waters linked by
natural corridors, and are identified as landscape networks for the conservation of biological
diversity, natural processes, and viable populations of indigenous species and ecosystems (Riley
and Mohr 1994).
Landscapes across the world are a matrix of agricultural, rural, urban and natural areas. A major
challenge when confronted with land use change is ensuring that appropriate long-range planning
is in place. The consequence of current trends in land use is that humans appropriate an everlarger fraction of the biosphere’s goods and services while simultaneously diminishing the
capacity of global ecosystems to sustain food production, maintain freshwater and forest
resources, regulate climate and air quality, and mediate infectious disease (Foley et al. 2005).
As the population of Ontario continues to increase, the associated stress of the effects of land use
change also continues to increase. There has been a long history of concern for the loss of
biodiversity and this has often been addressed with the establishment of greenways (Pierce et al.
2005). Some examples of greenways in Ontario are identified in the Niagara Escarpment Plan,
the Oak Ridges Moraine Conservation Plan, the Ontario Greenbelt Plan and the National Capital
Commissions Greenbelt in Ottawa.
It has long been common practice to set aside parcels of land to preserve their natural values, as
exemplified by Algonquin Park, the first wildlife sanctuary established in Canada in 1893.
However, early conservation practice in Ontario mainly consisted of protected areas created for
recreational use such as Point Pelee National Park and Rondeau Provincial Park (Environment
Canada 2005). This ‘islands of green’ approach was a pillar in the movement to preserve lands,
but did not necessarily conserve on the basis of ecological value. Rather, land was often acquired
because it was considered to represent a rare feature in the landscape or that was habitat for rare
species (Hilts et al. 1986). The practice of conservation planning has generally not been
systematic and protected lands have often been located in places that do not contribute to the
representation of biodiversity (Margules and Pressey 2000). Systematic conservation planning
was first introduced in Ontario during the early 1990s as Natural Heritage Systems. This core
and natural corridor approach, as defined by Riley and Mohr (1994), played a role in the
development of the Provincial Policy Statement 1997 and began to connect conservation science
to implementation policy.
The concept of a Natural Heritage System is two-fold. First, it aims to identify, by using sound
scientific concepts, the important natural features of a landscape in order to preserve
biodiversity. Second, the system attempts to respect these scientific principles with the use of
direct policy tools, such as directed development and land use policies to implement the
protection of important natural features through municipal official plans. Natural Heritage
Systems contribute as part of an integrative land use planning approach to conservation biology.
The preservation of biodiversity has become an international objective with respect to
conservation (Redford and Richter 1999) through initiatives such as the United Nations
Convention on Biological Diversity and the Ontario Biodiversity Strategy (2005). The term
biodiversity has become somewhat ambiguous due to its use across a wide range of disciplines
such as ecology, policy development, and planning. For the purpose of this study we have
adopted the definition of the Ontario Ministry of Natural Resources (OMNR 1999) definition of
“biodiversity”, which is:
…the variability among organisms from all sources including terrestrial, marine
and other aquatic ecosystems and the ecological complexes of which they are part;
this includes diversity within species, between species and of ecosystems.
Not all natural heritage features are protected on the basis of their ecological function. Some
features are preserved on the basis of social values. For example, small woodlands in urban areas
are often valued for providing improved air quality, buffering extreme temperatures and noise,
providing an aesthetic value as well as their contribution to the physical and psychological wellbeing of residents (FON 2006). It can be beneficial in many respects to integrate social criteria
into a Natural Heritage System. Preserving natural features in urban centres can maintain a
healthy link between the heritage of indigenous knowledge and biodiversity-based tradition that
still exists amongst many rural migrants who may now live in urban centres (Pierce et al. 2005).
Economic, social, and ecological systems all have interconnecting parts (Polasky 2006).
Associating an economic value to ecological function is a more recent approach to protecting
natural features. Ducks Unlimited Canada (DUC) has been a leader in promoting the concept of
Ecological Goods and Services (EG&S). Ecological Goods and Services are the benefits that
society derives from healthy ecosystems such as the purification of air and water, groundwater
recharge, wildlife habitat and carbon sequestration (Ducks Unlimited Canada 2006). It is likely
that in sometime in the not too far distant future it will be possible to establish a dollar value on
the Natural Heritage System of the Lake Simcoe Watershed that will help to demonstrate the
importance of these ecosystems to the public.
This report identifies a Natural Heritage System for the Lake Simcoe Watershed using an
integrated approach, as follows:
1) The foundation of this NHS is the Provincial Policy Statement 2005, as it is the principal
tool designed by the Province to incorporate natural heritage planning across the
watershed;
2) Science is the support structure of the NHS and it will serve to provide comprehensive
criteria based on recent scientific concepts in order to identify lands of ecological value
within the watershed;
3) Policy recommendations will guide the implementation of the NHS with a four-tiered
strategy, proposing policies for application by the LSRCA, as well as policies for use by
the partner municipalities (Table 1.1); and
4) Although the NHS is based on the two cornerstones of science and policy, it also draws
heavily on common sense, thereby ensuring that the NHS is a reasonable, understandable
and defensible system.
Table 1.1 LSRCA Municipalities
Regional Municipality of York
Regional Municipality of Durham
County of Simcoe
Town of Aurora
Town of Newmarket
Town of East Gwillimbury
Town of Georgina
Town of Whitchurch-Stouffville
Township of King
Township of Uxbridge
Township of Brock
Township of Scugog
Town of Bradford-West Gwillimbury
Town of Innisfil
Township of Oro-Medonte
Township of Ramara
Town of New Tecumseth
City of Barrie
City of Orillia*
City of Kawartha Lakes
*Note: the City of Orillia and a very small portion of the Town of Caledon are within the
physical watershed of Lake Simcoe, but are not within the Conservation Authority’s jurisdiction.
2.0
Policy Background
The LSRCA has taken action to identify and designate a Natural Heritage System to fulfill
information requirements for the Comprehensive Basin Wide Plan, other subwatershed plans,
and to support plan and development review. The Comprehensive Basin Wide Plan is a
requirement of the Lake Simcoe Environmental Management Strategy (LSEMS). LSEMS is a
partnership of all levels of government, first nations and community groups. The partnership
includes one Conservation Authority (LSRCA), one federal department (Department of Fisheries
and Oceans [DFO], four provincial ministries (i.e., Ministry of the Environment [MOE],
Ministry of Natural Resources [MNR], Ministry of Municipal Affairs and Housing [MMAH],
Ontario Ministry of Public Infrastructure Renewal [MPIR], Ontario Ministry of Agriculture and
Food [OMAF]), the Cities of Orillia, Barrie and Kawartha Lakes, three upper tier municipalities,
14 lower tier municipalities, as well as one first nations group (the Chippewas of Georgina First
Nations).
The partnership began in response to the deteriorating health of Lake Simcoe, particularly the
loss of natural coldwater fisheries as a consequence of nutrient overload caused by surrounding
land use practices. Designating and protecting a Natural Heritage System is a specific objective
of LSEMS in support of their mandate. The LSEMS (2006) mandate is:
to improve and protect the health of the Lake Simcoe watershed ecosystem and
improve associated recreational opportunities.
In Ontario, land use planning responsibilities lie with the approval authority, which depends on
what approval has been delegated by the Province of Ontario. There are some planning decisions
that are approved by the Province, mainly Official Plans and Official Plan updates. There are
also some planning approvals likewise delegated from the County/Region to the lower tier
municipality. For instance, some Counties/Regions have delegated approval of subdivisions to
some lower tier municipalities. In this document and for the purposes of the Lake Simcoe
Watershed Natural Heritage System policy recommendations, the term “planning authority”
refers to the upper and lower tier municipal governments and the Cities of Barrie, Orillia and
Kawartha Lakes.
Natural heritage planning is now more usually undertaken on a watershed basis and therefore one
study area may span several planning jurisdictions. Since planning authorities are the decisionmakers, it is beneficial to involve them in natural heritage planning in order to ensure stakeholder
input and to promote implementation.
The government of Ontario has attempted to direct land use change with recent legislation such
as the Oak Ridges Moraine Conservation Act, 2001, the Greenbelt Act, 2005 and the Places to
Grow Act, 2005. However, 36% of the Lake Simcoe Watershed is outside of the Greenbelt and
Oak Ridges Moraine, and even within these areas, the components of Natural Heritage (e.g.,
significant woodlands) have not always been identified by the province or the planning
authorities. For example, the Greenbelt Plan delineates a Natural System, but does not define the
specific natural heritage features within that system, although technical guidelines for doing so
are anticipated in the near future.
The Growth Plan sets out a vision and strategic policy direction for managing growth in the
Greater Golden Horseshoe, which includes the Lake Simcoe Watershed. The Plan contains
policies that encourage the development of more compact and complete communities, with the
right mix of housing, jobs and community services. This type of development will make more
efficient use of infrastructure and ensure that important natural heritage features and agricultural
lands are protected from urban sprawl.
The Provincial Policy Statement 2005 (PPS) is the underlying foundation for Natural Heritage
System planning in Ontario. The PPS 2005 (MMAH 2005) defines a Natural Heritage System as:
features and areas linked by corridors that are necessary to maintain biological
and geological diversity, natural functions, viable populations of indigenous
species and ecosystems. These systems can include lands that have been restored
and areas with the potential to be restored to a natural state.
Section 3 of The Planning Act confirms that all decisions pertaining to planning “shall be
consistent with” the Provincial Policy Statement 2005.
The Growth Plan for the Greater Golden Horseshoe, 2006, which was established under the
Places to Grow Act, 2005, sets out a vision and strategic policy direction for managing growth in
the Greater Golden Horseshoe, which includes Lake Simcoe. The PPS 2005 infers that a healthy
Ontarian landscape is dependent upon protecting natural heritage, water, agricultural, mineral
and cultural heritage. Section 2.1 of the PPS 2005 outlines the policies that identify and protect
natural heritage features from development. Section 4.5 of the PPS 2005 notes that municipal
Official Plans are the most important vehicle for the implementation of the PPS.
3.0
Goal and Objectives
The goal of this project is to identify a Natural Heritage System (NHS) within the Lake Simcoe
Watershed and to develop suggested policy templates to assist in protecting its functions and
features.
This goal will be achieved by fulfilling the following objectives:
1) Develop criteria that help define the components of the NHS;
2) Identify existing ecological linkages between significant areas;
3) Create an interactive system map in a GIS platform;
4) Review and incorporate key provincial legislation and policy that will assist in the
protection of natural heritage features and functions and policy development; and
5) Review existing municipal and LSRCA natural heritage policies and develop suggested
policy templates for use with the NHS that may be adopted by the LSRCA, as well as
member municipalities.
4.0
Approach
The goals and objectives outlined above were addressed through several project phases. First was
a literature review to provide a solid scientific backbone to the design of the system components.
Next was the development of the criteria and interaction with the LSRCA Geographic
Information Systems (GIS) team. The mapping process required the development of appropriate
algorithms in the ArcGIS format.
The subsequent development of policy recommendations and templates involved a firm
understanding of the policy background, including those of the partner municipalities within the
watershed.
4.1
Literature Review
The literature review included formal scientific literature, existing natural heritage policies, as
well as other Natural Heritage System approaches and recommended approaches.
The scientific review explored in detail several components of the NHS, especially those that are
still the subject of debate. In addition, studies on the identification of significant woodlands
undertaken by individual municipalities (e.g., Region of York, City of Hamilton) were reviewed.
4.2
Component Discussion Papers
The literature review led to the development of each system component (i.e., woodlands,
wetlands, etc.) described as a separate entity through eight independent discussion papers. The
discussion papers allowed a detailed interpretation of each component in relation to Natural
Heritage planning and facilitated an understanding as to how they interact in the system. The
discussion papers were then incorporated into the final report as separate chapters. For each
component, criteria were developed to identify a feature as significant. These criteria were then
translated into a GIS platform to produce the mapping.
The components that comprise the Lake Simcoe Natural Heritage System are described in
Sections 5.0 through 12.0 of this document and are the following:
•
•
•
•
Significant Habitat of Endangered and Threatened Species;
Significant Wetlands;
Significant Woodlands;
Significant Valleylands;
•
•
•
•
4.3
Significant Wildlife Habitat;
Areas of Natural and Scientific Interest;
Habitat for Fish; and
Linkages.
Development of GIS Mapping
The Natural Heritage System was largely based on the Ecological Land Classification (ELC) and
Land Use Mapping (Appendix 1) that has been undertaken over the past five years by the
LSRCA for the entire watershed. A blind field checking protocol was developed and executed to
confirm the accuracy of the base mapping (Appendix 2).
GIS techniques were used to further develop criteria, and for some components (e.g.,
valleylands) GIS became the primary mechanism for developing a process with which to identify
components.
Once criteria were developed, algorithms were used to create the mapping. Each component was
mapped as a GIS layer, which were overlain onto the base watershed map. The maps were finetuned with a review of the final product.
4.4
Policy Development
Following discussions with stakeholders and receipt of review comments, a four-tiered policy
approach was used to direct the protection of the natural features of the Natural Heritage System
(Table 4.1). This four level approach was largely based on the PPS. The first two levels of this
policy approach are assigned a “provincially significant” designation and are considered to be
those features that would be identified if following the guidelines and intent of the PPS. Level 3
of this approach is determined to represent significance at the watershed level, while Level 4 –
supporting features are those features that are considered to be supporting features within the
watershed. The following paragraphs expand on these policy levels.
Level 1 features are considered to be provincially significant and they represent critical
components of the Lake Simcoe Watershed NHS, whose maintenance and longevity are
imperative to the health and the function of the watershed and of Lake Simcoe. These features
are to be retained on the landscape and an EIS is required to demonstrate that there are no
negative impacts on the natural features when development is proposed adjacent. The EIS will
recommend an ecologically defensible limit of development adjacent to the feature. When
negative impacts or land use changes are permitted, such as they may be through an
Environmental Assessment process, replacement measures are required. These could include
creation, enhancement or restoration on or off site.
Level 2 features are also considered to be provincially significant components of the Natural
Heritage System. These features and their ecological functions should be retained on the
landscape. When development or land use change is proposed within or adjacent to a Level 2
feature, an EIS is required to demonstrate that there are no “negative impacts”, consistent with
the terms and definitions of the PPS. If it is demonstrated that there are no negative impacts (or
when negative impacts are permitted, such as through an Environmental Assessment process),
and the loss of part or all of a feature area can be contemplated, subject to the identification of
measures to replace lost areas or functions. These could include creation, enhancement or
restoration on or off site.
Level 3 features are considered to be significant at the watershed level. It is the overall intent that
these features should be retained on the landscape. However, flexibility is contemplated in the
way in which these features are addressed when a land use change or other development is
considered. An EIS is required to demonstrate that there are no net negative impacts on the
Natural Heritage System. Mitigation for the loss of a natural heritage feature, or an identified
impact, is intended through replacement. This could include creation, enhancement or restoration
on or off site.
Level 4 - supporting features are considered to be supporting Level 1, 2 and 3 NHS features.
Retention of these features is encouraged, though they are not necessarily a constraint to land use
change. Replacement mechanisms are encouraged and could include enhancement or restoration
on or off site for impingement on the feature or its functions.
The Big Woods Policy Areas are those areas where there is a high percentage of woodland cover
and large woodland patches. These areas are considered most likely at the landscape scale to
represent high ecological function, diversity, connectivity and are priority natural areas within
the Lake Simcoe Watershed. Special efforts will be directed at protecting the long-term integrity
of these areas by ensuring that there is no net loss of woodland cover through an approved EIS.
Restoration and stewardship initiatives are encouraged and when appropriate, by preferentially
directing replacement toward these policy areas.
Areas within the watershed that are regulated by provincial planning tools such as the Oak
Ridges Moraine Conservation Plan 2002 (ORMCP) and the Greenbelt Plan 2005 supersede the
NHS. There is a structural hierarchy within the planning process, which this document does not
override. The ORMCP and the Greenbelt Plan and their requirements apply to all lands within
their respective jurisdiction. Similarly, regulations of the Conservation Authorities Act and the
LSRCA Regulations under the Act (whereby, for example, all wetlands and watercourses are
regulated by the Authority) and the federal Fisheries Act also apply.
For example, the ORMCP has a suite of technical papers that serve to aid planning authorities
with the identification and delineation of the Key Natural Heritage Features found within the
ORMCP plan area. The Province is presently producing a similar set of technical papers for the
Greenbelt Plan.
Two separate policy templates were developed in order to facilitate the implementation of the
system, as follows:
1) For the LSRCA, to provide suggested policy approaches for integrating the NHS into
watershed policy documents of the Authority; and
2) For planning authorities to provide suggested policy approaches to assist in the
integration of the NHS into their Official Plans.
The policy templates take into account the Provincial Policy Statement (2005), the Oak Ridges
Moraine Conservation Plan (2002) and the Greenbelt Plan (2005).
Table 4.1 Recommended Policy Levels
Significance
Provincially
Significant
Watershed
Significant
Policy Level
Level 1
NHS Intent
• Retain
• No development
or land use
change
Level 2
•
•
Retain
No negative
impact
Level 3
•
Generally retain,
some flexibility
No net negative
impact
Supporting
features
•
Supporting
Level 4 –
supporting
•
Big Woods
Policy Areas
BWPA
•
•
Retain
No net loss of
woodland
Implications for Replacement
• Replacement can be
considered for impacts
due to projects associated
with non-Planning Act
mechanisms such as
Environmental
Assessments
• When there is no
“negative impact”, but
there is a loss of area or
reduction in function,
replacement can be
considered
• Retention preferred but
replacement acceptable
• No net loss of area or
function
• Not necessarily a
development constraint,
replacement encouraged
• Target area for
replacement, restoration
and stewardship priorities
Natural Heritage System Components
The following chapters of the report provide the criteria for each of the components, along
with a discussion, rationale and a cited literature section.
5.0
5.1
Significant Habitat of Endangered and Threatened Species
Introduction
The significant habitat of endangered and threatened species is a major component of the Natural
Heritage section of the Provincial Policy Statement (PPS). The PPS (MMAH 2005) states that:
Development and site alteration shall not be permitted in significant habitat of
endangered species and threatened species.
The PPS (MMAH 2005) defines Endangered and Threatened (E&T) species as the following:
Endangered species:
means a species that is listed or categorized as an “Endangered Species”
on the Ontario Ministry of Natural Resources’ official species at risk list, as
updated and amended from time to time.
Threatened species:
means a species that is listed or categorized as a “Threatened Species” on
the Ontario Ministry of Natural Resources’ official species at risk list, as
updated and amended from time to time.
Note that the definition of “Endangered” within the PPS now encompasses both regulated and
non-regulated Endangered species, which it did not prior to the 2005 PPS update.
Significant in regard to the habitat of endangered species and threatened species means:
the habitat, as approved by the Ontario Ministry of Natural Resources, that
is necessary for the maintenance, survival, and/or the recovery of naturally
occurring or reintroduced populations of endangered species or threatened
species, and where those areas of occurrence are occupied or habitually
occupied by the species during all or any part(s) of its life cycle.
The Ontario Ministry of Natural Resources (MNR) is responsible for the identification,
evaluation and listing of E&T species, but not for the assessment of the “significant habitat of”.
The Natural Heritage Reference Manual is a guide to the application of Section 2.l - Natural
Heritage Section 2.1 of the PPS (OMNR 1999). The Natural Heritage Reference Manual states
that the planning authority may wish to have assessments reviewed by MNR staff. However, the
15
definition within the PPS (MMAH 2005), reproduced above, implies that MNR must approve
such assessments.
The concept of E&T species is already well-represented within the application of the PPS. This
is because the occurrence of one of these species within any part of an evaluated wetland almost
always results in the entire wetland being considered Provincially Significant (PSW). In addition,
many approaches to the designation of significant woodlands (another PPS component) include
an automatic designation of “significant” with the occurrence of such species. To some extent,
this means that E&T species are given greater planning weight. For example, the occurrence of
the endangered Butternut (Juglans cinerea) within an evaluated wetland unit would make the
wetland a PSW and in many cases, the woodlot within which it is located a significant woodland,
plus any Natural Heritage System (NHS) designation specifically aimed at addressing “the
significant habitat” of that Butternut tree or population.
5.2
Why are Endangered and Threatened Species Important?
There is general consensus among ecologists that special efforts should be made to protect
species that are at a risk of becoming extirpated from a region or province. This is related to
objectives of maintaining or enhancing biodiversity at regional, provincial and national levels.
In the Natural Heritage Reference Manual (OMNR 1999), MNR notes that the protection of
endangered and threatened species is necessary in order to slow or prevent the loss of species
from the province, and in some cases, their extinction on a global basis.
The MNR coordinates the development of recovery plans for designated species that are only or
predominantly found in Ontario, which can either be single or multi-species plans, or even
watershed or ecosystem based plans. As of September 2006, no single or multi-species plans
were available on the MNR website (OMNR 2006); although several are in preparation. One
recovery plan for a watershed was available. The Species at Risk Act (SARA) public registry is
also a source to check for recovery strategies.
5.3
Endangered and Threatened Species in the Lake Simcoe Watershed
Within the Lake Simcoe Watershed, the only reliable and easily accessible source for
information on these species is the MNR’s Natural Heritage Information Centre (NHIC) on-line
database and follow-up detailed data requests from the relevant District Office of the MNR. The
District Office of the MNR may also have additional data, but in practice, rarely are E&T records
readily available from any other source (such as reports provided by consultants).
Information on the occurrence elements of E&T species was requested from MNR for the Lake
Simcoe Watershed. These data were displayed on a GIS platform. Records for extinct or
extirpated species were deleted.
Historical records that were 20 years or older were not used. This is consistent with the typical
approach taken by others when using element occurrences that incorporate older records.
16
In total, 15 “current” element occurrences of E&T species were provided for the watershed.
These are indicated in Table 5.1.
Table 5.1 NHIC Endangered and Threatened Element Occurrences for the
Common Name
Eastern Prairie
Fringed-orchid
Purple Twayblade
King Rail
Loggerhead Shrike
Loggerhead Shrike
Least Bittern
Least Bittern
Least Bittern
Least Bittern
Least Bittern
Redside Dace
Redside Dace
Redside Dace
Blanding's Turtle
L. Simcoe Whitefish
Scientific Name
Platanthera leucophaea
Prov.
S-Rank
S2
MNR
Status
END-NR
Subwatershed
West Holland
Liparis lilifolia
Rallus elegans
Lanius ludovicianus
Lanius ludovicianus
Ixobrychus exilis
Ixobrychus exilis
Ixobrychus exilis
Ixobrychus exilis
Ixobrychus exilis
Clinostomus elongatus
Emydoideas blandingii
Coregonus clupeaformis
S2
S2B,SZN
S2B,SZN
S2B,SZN
S3B,SZN
S3B,SZN
S3B,SZN
S3B,SZN
S3B,SZN
S3
S3
S3
S3?
S?
END-NR
END-R
END-R
END-R
THR
THR
THR
THR
THR
THR
THR
THR
THR
THR
West Holland
West Holland
East Holland
Talbot River
West Holland
Beaver River
West Holland
Beaver River
East Holland
West Holland
East Holland
West Holland
Black River
Lake Simcoe
Of these 15 element occurrences, 13 (87%) are captured within the proposed Natural Heritage
System (this includes the Lake Simcoe whitefish for which no recent record was available). The
two that are not captured within the NHS are the two records of Loggerhead Shrike (from 1989
and 1996).
Extensive areas within the Lake Simcoe Watershed have not had extensive, intensive or even any
recent field investigations. Therefore, it is common for the known occurrences of E&T species to
be from evaluated wetlands, designated ANSIs, or areas where development applications have
resulted in detailed field investigations or data collection efforts from local naturalists. This lack
of data in general and strong bias towards “investigated areas” doubtless reflects, at least to some
extent, the real distribution of these species, but it may also underestimate the importance of
other habitat patches within the watershed that have been lightly surveyed or not surveyed at all.
5.4
Criteria
Including E&T species on the basis that they might indicate areas of particular biodiversity that
should be included in the NHS was considered. Indicator groups (such as landscape features) or
“keystone species” have been touted as a means to identify biodiversity “hotspots” or the likely
locations of otherwise undocumented rare species. However, these approaches have met with
mixed success.
17
The use of rare or “at-risk” species in particular, has been investigated to see if they represent
good surrogates for the identification of biodiversity. One study found that only where data on
distributions of at-risk species are available were at-risk species good candidate indicators for
selecting sites to represent biodiversity (Lawler et al. 2003).
The concept of building a transparent NHS in a GIS environment upon the principal PPS
components also created another challenge, as areas that harbour E&T species would need to be
identified, which would be problematic as this practice is not supported by MNR as it might lead
to increased disturbance of some sites. Further, the extent of “significant habitat of” could not be
determined without site-specific data, analysis and approval by MNR and/or the planning
authority.
For these reasons, and the related issue of creating a bias away from areas that have not been
surveyed in the past, the NHS does not directly incorporate E&T species distribution data as a
component. Clearly, where these species contribute to the designation of other features such as
PSWs or ANSIs, they will, in fact, be included.
It is important to note that the presence of an E&T species anywhere in the watershed will still
trigger protection under the Planning Act and the PPS (and, where appropriate, the Endangered
Species Act or the federal Species at Risk Act). This mechanism will be related in the NHS
through suggested policies addressing the preparation of Environmental Impact Studies and the
consideration of supporting parts of the system that have not been directly addressed (e.g.,
adjacent lands, indirect fish habitat), but that nevertheless will be required. Clearly the presence
of E&T species must be addressed through on-site investigations when development or land use
change is contemplated. As previously discussed, the data available from the NHIC were
overlain on the proposed NHS and 87% of the records were located within the system.
5.5
Literature Cited
Lawler, J.J., D. White, J.C. Sifneos and L. L. Master. 2003.
Rare species and the use of indicator groups for conservation planning. Conservation Biology 17:
875-882.
Ontario Ministry of Natural Resources. 1999.
Natural Heritage Reference Manual for Policy 2.3 of the Provincial Policy Statement. Ontario
Ministry of Natural Resources. Peterborough. 127 pp.
Natural Heritage Information Centre. Available online: http://nhic.mnr.gov.on.ca/nhic_.cfm
Species at Risk. Available online:
http://www.mnr.gov.on.ca/MNR/speciesatrisk/links.html
Ministry of Municipal Housing and Affairs. 2005.
Provincial Policy Statement 2005. Ministry of Municipal Housing and Affairs. Toronto.
18
6.0
6.1
Wetlands in the Lake Simcoe Watershed
Wetlands define the interface of open water and terrestrial habitats. They consist of a wide
variety of habitats that are generally classified as those within which 50% or more of the plant
cover is hydrophytic, or in other words, adapted to water (OMNR 2002). In total, there are
approximately 35,251 ha of wetlands within the watershed, which is approximately 13.5% of the
watershed (excluding the lake).
Evaluated wetlands in the watershed have been evaluated using the Ontario Wetland Evaluation
System (OMNR 2002). Unevaluated wetlands in the watershed are identified using the following
Ecological Land Classification codes (Lee et al. 1998): fen (FEO, FES), bog (BOO, BOS, BOT),
marsh (MAM, MAS, SAS, SAM, SAF), and swamp (SWT, SWD, SWM, SWC) (see Appendix
1, Section 4.0).
The distribution of wetlands across the Lake Simcoe Watershed is not uniform. Table 6.1
provides a breakdown of wetlands by subwatershed grouping. Also indicated is the percentage of
wetlands that have not been evaluated using the Ontario Wetland Evaluation System (OMNR
1994) or are not Oak Ridges Moraine wetlands (which are largely protected by the ORMCP).
Although an assessment of wetland cover should more correctly be made against both historical
and current wetland patterns across the subwatersheds (Bedford 1999; Detenbeck et al. 1999)
watersheds with over 10% wetland cover are in relatively fair shape from a hydrological and
biological perspective (although the distribution of wetland within the watershed is also
important) (Environment Canada 2004). For example, one study found that having 15% of a
watershed in wetlands resulted in a reduction of phosphorus loadings by 66% (Wang and Mitch
1995 cited in Environment Canada 2004), while another found that percentage land use
determines the water and sediment quality of 22 marshes in the Great Lakes Basin (Crosbie and
Chow-Fraser 1999).
Although guidelines are general in nature, and each watershed has unique characteristics, the
literature strongly suggests that those subwatersheds with less than 10% wetland cover are much
less likely to be in good condition from a hydrological and biological perspective. Clearly,
further wetland loss within those subwatersheds listed in the upper half of Table 6.1 would be
more likely to result in deleterious effects on subwatershed function and water quality.
19
Table 6.1 Distribution of Wetlands in the Lake Simcoe Watershed
Barrie creeks
Hewitt’s Creek
Maskinonge River
Talbot River
West Holland River
East Holland River
Oro creeks (north)
Oro creeks (south)
Innisfil creeks
Lover’s Creek
Uxbridge Brook
Georgina creeks
Pefferlaw Brook
Beaver River
White’s Creek
Black River
Hawkestone Creek
Ramara creeks
Islands in Lake
Simcoe combined
Totals
Area of
Subwatershed
(ha)
Total Wetland
Area by
Subwatershed
(ha)
Total
Wetlands by
Subwatershed
(% of
subwatershed)
Unevaluated
Wetland Area
by
Subwatershed
(ha)
Unevaluated
Wetlands by
Subwatershed
(% of
wetlands)
3,781
1,751
7,179
7,056
35,410
23,910
8,344
87,431
5,769
10,757
5,995
17,495
4,946
28,482
32,724
10,520
37,536
3,971
14,350
109
70
451
533
2,935
2,124
805
7,027
599
1,145
647
1,950
627
4,133
5,378
1,926
7,392
862
3,200
2.9
4.0
6.3
7.6
8.3
8.9
9.7
8%
10.4
10.6
10.8
11.1
12.7
14.5
16.4
18.3
19.7
21.7
22.3
82
25
36
490
647
410
216
74.9
36.0
8.1
91.9
22.1
19.3
26.8
390
597
88
620
84
1,390
1,393
1,045
2,097
191
775
65.1
52.1
13.6
31.8
13.4
33.6
25.9
54.3
28.4
22.2
24.2
1,912
261,887
663
35,596
34.7
13.6%
182
10,747
27.5
30.2%
The right-hand column of Table 6.1 also indicates that there are a number of subwatersheds in
the Lake Simcoe Watershed in which a relatively high percentage of the wetlands have not been
formally evaluated (e.g., Talbot River, Oro south, White’s Creek), suggesting where future
wetland evaluations might be a valuable contribution to natural heritage planning.
Distribution of wetlands by ecodistrict does not appear to demonstrate any strong bias (Table
6.2). Note that site district 6E-7 is the Oak Ridges Moraine, an environment where wetlands are
naturally scarce due to the porous sandy soils. There is a high percentage of unevaluated
wetlands on the Moraine.
20
Table 6.2 Wetland Analysis by Ecodistrict
Ecodistrict
6E-6
6E-7
6E-8
6E-9
6.2
Area of
Ecodistrict
(excl. the
lake) (ha)
156,684
33,603
65,433
6,166
Percent of
watershed
All wetlands
Area (ha)
Percent of
Ecodistrict
60%
13%
25%
2%
21, 515
2, 041
10, 237
1, 803
13.7%
6.1%
15.6%
29.2%
Unevaluated wetlands
Area (ha)
Percent of
wetlands in
Ecodistrict
5, 831
1, 051
3, 219
645
27.1%
51.5%
31.4%
35.8%
Wetland Types in the Watershed
When asked to describe a wetland, most people will likely describe open water environments
that are dominated by bulrushes, cattails and water-lilies. The habitat of several types of herons,
waterfowl and perhaps, Canada Geese (Branta canadensis) would also be described. Other
wildlife such as American Beaver (Castor canadensis), Muskrat (Ondatra zibethicus) or even
River Otter (Lutra canadensis) are also strongly associated with wetlands. There are four types
of wetlands represented in the Lake Simcoe Watershed: marshes, fens, bogs and swamps.
Open shallow water wetlands are called Marshes. Marshes are often (but not always)
characterized by the presence of open water and are subject to fluctuations in this water level,
which may bring with them relatively high levels of nutrients. Marshes are commonly associated
with lakes, ponds, rivers and creeks; they make up approximately 10% of all wetlands in
southern Ontario and 12.6% of the wetlands within the Lake Simcoe Watershed. In Ontario,
wetlands are generally classified when aquatic vegetation is present to a maximum depth of 2 m
water. At depths greater than 2 m they are described as open water systems (e.g., the open water
of the lake itself).
Two of the other wetland types are rare in the Lake Simcoe Watershed. The first is the Fen. Fens
are primarily characterized by specific kinds of plants that are found only in these habitats (and
are therefore often referred to as “fen indicators”). In the Lake Simcoe Watershed, almost all
known fens are peat-based and there are approximately 450 ha of this wetland type currently
identified. These peat-based systems are sometimes referred to as “poor” fens, as compared to
the “rich” fens that can develop on mineral-rich limestone systems (which are commonly found
on the Bruce Peninsula). Fens occasionally develop along the sides of slow moving rivers or
around kettle lakes. Fens are typically found in areas of slow constant drainage (such as seepage
areas). Regardless of whether “rich” or “poor”, all fens are characterized by these stable water
conditions, which are therefore usually maintained through groundwater inputs (as opposed to
surface water, which tends to be fluctuating, leading to the development of other wetland types
such as mashes). In Ontario, and by definition, wetland communities with 25% tree cover (at 6 m
tall) are not classified as fens, but are known as swamps (see below).
21
Photograph 6.1 A marsh in the Town of Innisfil
(the rare Great Egret, a white heron, can be seen centre left).
The second of the two other rare wetland types in Lake Simcoe is the Bog. Although the word
“Bog” is often attached to wetlands as part of their proper name (e.g., Wilfred Bog), no more
than a handful of wetlands actually meet the very precise definition for this very rare wetland
type within the watershed; only 25 ha of true bogs have been identified within the Lake Simcoe
Watershed.
Bogs are unusual in that all of their nutrients are delivered by rainfall (a condition referred to as
“ombrotrophic”); consequently they are nutrient poor and the pH is often very acidic (e.g., 3.9 –
4.2), further reducing the availability of nutrients to plants. Wetlands which receive groundwater
inputs, or receive nutrients through a floating mat around a lake or pond, are actually more often
some other wetland type (i.e., a fen, marsh or swamp) rather than a “kettle bog”, which they are
sometimes described as.
Unlike fens, bogs are not characterized by any particular assemblage of indicator plant species.
Rather, they are characterized by a distinct lack of plant species richness. Rarely are more than
14 species of vascular plants (i.e., not including non-vascular plants such as mosses) found in a
true bog. Stunted trees (typically Black Spruce [Picea mariana], rather than Tamarack [Larix
laricina]) less than 6 m tall are often found in bogs. In Ontario, and by definition, bogs with
more than 25% tree cover (at a height of 6 m) are actually classified as swamps.
22
The Swamp is the only other wetland type in Ontario. It is generally defined as a community with
at least 25% cover by woody vegetation (i.e., trees or shrubs). Swamps can be very wet, or
alternatively surface water can be absent. Many treed swamps (with species such as soft maples,
Black Ash [Fraxinus nigra] and Green Ash [F. pennsylvanica]), are quite dry by July and
walking through them in the fall, one might not realize that they were wetlands, were it not for
the species of plants that are present.
Swamps dominated by shrubs tend to be wetter than treed swamps. Typically, as conditions get
wetter, the treed swamp communities give way to shrub swamps, then to grass and sedge marsh
communities, and finally to open water.
Many of the wetlands away from Lake Simcoe are treed swamps, and up to 86% of all remaining
wetlands in the basin are swamps. They have developed or persisted in seasonally wet areas (i.e.,
during the spring) that have not been farmed, although some are used for livestock grazing and
shade in the summer and fall. It can be difficult to differentiate between treed swamps and moist
upland forest, especially in disturbed and regenerating areas. In these cases, specially trained
biologists determine whether a community is wetland or upland based on the dominance of
hydrophytic plants and sometimes by using soil properties (moisture and composition) as
additional evidence.
In summary, there are four wetland types. The most familiar, the marsh, is characterized by
grasses, sedges and open water communities with water-lilies, cattails and bulrushes. The second
and third, fens and bogs, are specialized communities that are rare in the Lake Simcoe
Watershed. The fourth, and most common of all, is the swamp, which can be treed or
characterized by shrubs, which vary from wet to almost dry and can be very similar to moist
uplands.
6.3
Why are Wetlands Important?
Wetlands have been used, abused and drained extensively in southern Ontario over the past two
centuries. In some parts of the province wetland loss has been in the order of 90 to 100% (Snell
1987 as cited in Detenbeck et al., 1999). Given this, one could conclude that wetlands are not
important. However, the consequences of wetland loss and degradation are just beginning to be
felt both by people and the ecosystems that they support. These costs are directly related to longterm sustainability of human activities and the health and sustainability of our natural heritage
systems.
Hydrology and Water Quality
In preparing a submission for the Walkerton Inquiry, Ducks Unlimited Canada produced a
review and summary of wetland functions and values for water quality and quantity
(http://vm.ducks.ca/aboutduc/news/archives/pdf/pipefull.pdf) (Gabor et al., 2001). This
document reviewed the current literature and summarized a series of wetland functions as
follows:
23
Hydrological Functions
• Water storage and flood reduction
• Erosion prevention
• Groundwater recharge and discharge
Water Quality Functions
• Nutrient Assimilation (Nitrogen, Phosphorus)
• Sediment removal
• Pathogen removal
• Pesticide loss and dissipation
Not all wetlands perform all of these functions simultaneously. For example, wetlands can
provide seasonal storage for flood water, such as in a treed swamp during the fall. But the same
treed swamp might have no water storage capacity in the spring, during snow melt. Many
wetlands can both recharge and discharge groundwater, depending on the season and fluctuations
in the water table. Nutrient flows within wetlands are also complex, and they too vary by season.
Some functions ascribed to wetlands, such as sediment removal or pesticide dissipation, can be
detrimental to other aspects of wetland ecology. For example, sedimentation is one of the leading
causes of impairment to wetland function and it is also one of the three leading causes of outright
wetland loss.
Clearly, these wetland hydrologic and water quality functions are complex and dependant on a
wide range of variables, both spatial and temporal. It is certain however, that wetlands contribute
towards the sustenance of freshwater resources, which are used by humans and wildlife alike.
Wildlife Values
Many of Ontario’s fish, fauna and flora species use wetlands during all or part of their lifecycles. A high proportion of the designated “Species At Risk” are wetland-associated species.
This is not surprising given that wetland loss within the Great Lakes Basin is estimated at 68%
south of the pre-Cambrian shield (Snell 1987 as cited in Detenbeck et al., 1999). Within the Lake
Simcoe Watershed, Detenbeck et al. (1999) provide a map summary that indicates wetland loss
within the 26 to 50% range.
Marshes are often critical fish nursery and spawning areas. They also provide habitat for a wide
range of other obligate aquatic species that have relatively narrow habitat niches (i.e., they need
permanent water). This includes a wide variety of insects, birds, reptiles and amphibians.
Extensive marshes are now relatively rare and only 10% of southern Ontario wetlands have been
estimated to represent marsh (Riley 1989). Within the Lake Simcoe Watershed, only 1.7% of the
total land area is currently marsh, while marsh comprises 12.6% of all wetland areas.
Fens and bogs are rare and represent habitat for relatively specialized species. Consequently, a
variety of plants can be found in these communities that are rare at various levels (i.e., locally,
24
regionally, provincially and nationally). They also provide specialized habitat for other species
(e.g., non-vascular plants and insects).
Photograph 6.2 Locally rare Swamp Pink or Calapogon Orchids in Gibson Hill Fen, one
of the few fens in the Lake Simcoe Watershed.
Within the Lake Simcoe Watershed there are only 25 ha of bog (and some of this may actually
be poor fen). This is one of the rarest habitats of any type in the watershed. There are more fens,
but even this wetland type represents only 1.3% (about 448 ha) of all the wetlands identified
within the watershed. Both of these wetland types are exceedingly rare and together comprise
less than 0.2% of the total land cover of the watershed.
Swamps support a wide variety of habitat niches due to the structural diversity that they exhibit.
This structural diversity includes: tall canopies, tree cavities, dense shrub layers, dense winter
cover (from conifers), pits and mounds on the forest floor and seasonal pools. In turn, these
features can provide habitat for a wide range of attributes such as area-sensitive forest breeding
birds, winter deer yards, amphibian breeding pools and even seasonal fish spawning when
swamps are flooded by wetland riverine systems. Within the Lake Simcoe Watershed (and
excluding the lake itself), swamps represent 11.5 % of the total land area and 86% of all wetland
areas.
25
6.4
Policy Framework
Wetland protection has been one of the more successful aspects of the natural heritage policies
within the Provincial Policy Statement (PPS). Partly, this is because the initial push to evaluate
wetlands was undertaken by the province rather than the planning authorities.
However, wetlands evaluated as provincially significant are only protected by the PPS under the
Planning Act. Therefore, wetlands continue to be lost to projects such as road and other
infrastructure construction that fall under the Environmental Assessment Act, by agricultural
projects such as drainage improvements and peat extraction, and by existing zoning provisions
that pre-date wetland protection.
As the NHS closely follows the building blocks established through application of the natural
heritage policies of the PPS, Provincially Significant Wetlands are a major component of the
system.
The PPS 2005 defines wetlands as:
lands that are seasonally or permanently covered by shallow water as well as
lands where the water table is close to or at the surface. In either case the presence
of abundant water has caused the formation of hydric soils and has favored the
dominance of either hydrophytic plants or water tolerant plants. The four major
types of wetlands are swamps, marshes, bogs and fens.
The PPS defines a significant wetland as:
an area identified as provincially significant by the Ministry of Natural Resources
using evaluation procedures established by the province, as amended from time to
time.
Section 2.1.3 of the Provincial Policy Statement 2005 specifies that:
development and site alteration shall not be permitted in significant wetlands in
Ecoregions 5E, 6E and 7E.
The Ontario Wetlands Evaluation System (OWES) was developed by the Ontario Ministry of
Natural Resources in 1984 and has been periodically updated since (OMNR 1994). The OWES
evaluates the importance of a wetland based on a scoring system where four principal
components (i.e., biological, social, hydrological, and special features) each worth a maximum of
250 points, combine for a total of 1,000 possible points. Subcomponents and attributes receive a
varying number of possible points dependent on predetermined criteria.
Once evaluated, a wetland can become either a provincially significant wetland (PSW), or an
evaluated non-provincially significant wetland (non-PSW). Planning authorities sometimes
designate non-PSWs as “Locally Significant Wetlands” in their Official Plans.
26
Approximately three-quarters of all wetlands in the Lake Simcoe Watershed have either been
evaluated using OWES and/or are protected wetlands on the Oak Ridges Moraine. This leaves
approximately 25% of all the watershed’s wetlands (or almost 9,300 ha) unevaluated (Table 6.3).
Many of the existing evaluated non-PSWs were originally evaluated under the first or second
edition of OWES. Based on recent updates in the watershed, it is likely that many of these nonPSWs would attain PSW status if they were reevaluated in accordance with the updates and
methodological changes to OWES that are reflected in its current edition.
Table 6.3 Status of Wetland Designations in the Watershed
Evaluated Wetlands (OWES)
Wetlands Identified but not
Evaluated (non-ORM)
Non-evaluated Wetlands on
the Oak Ridges Moraine
Total
6.5
Area (ha)
Percent of all
wetlands
24,951
9,306
70.7
25.4
Percent of
watershed (not
incl. the lake)
9.9%
3.6%
1,445
3.9
0.6%
36,702
100%
13.5%
Criteria
As is the case with other components of the Lake Simcoe NHS, significant wetlands may reside
within more than one designated criteria. For example, a significant swamp forest might also
meet the definition of significant woodland.
The criteria for the designation of significant wetlands in the NHS have been based primarily on
the existing policy framework. However, the NHS must go beyond just addressing evaluated
wetlands, as 25% of all wetlands in the watershed have not been evaluated. These criteria are
discussed in the following sections.
Evaluated PSWs
All PSWs will be included within the NHS as Level 1 features.
Evaluated non-Provincially Significant Wetlands and Planning Authority Designated Locally
The MNR does not designate “Locally Significant Wetlands” (LSWs). This status can only be
assigned by the planning authority. A review of the Official Plans of municipalities within the
watershed was undertaken to examine how each had addressed non-PSWs.
Some planning authorities, perhaps assuming that MNR-designated “non-provincially significant
wetlands” were synonymous with LSWs, identified them for some level of protection in the text
portion of the Official Plan policies, but did not actually identify the locations of these features
27
on a schedule. Other Official Plans did not address this group of wetlands at all, or were not
explicit in their intentions. Some planning authorities afforded all of these wetland designations
(LSW, PSW, non-PSW) some protection.
Given this wide range of municipal approaches within the watershed, the following criteria have
been applied:
1.
Where local planning authorities have designated Locally Significant Wetlands in
their existing or draft Official Plans, they will be included as Level 3 NHS
features.
2.
Non-Provincially Significant Evaluated Wetlands will appear as Level 3 NHS
features.
Fens and Bogs
All ELC or OWES identified fens and bogs will be included within the NHS. Fens and bogs will
also be included under Significant Wildlife Habitat on account of their rarity and contribution to
biodiversity, regardless of their status as significant wetlands.
Unevaluated Wetlands
Unevaluated wetlands are found in many parts of the Lake Simcoe Watershed. Indeed,
approximately 11,000 ha of wetland within the watershed remain unevaluated.
The criteria listed below reflect a need to capture unevaluated wetlands when they might be
supporting other NHS components or are sufficiently extensive to be included in their own right
(but have not been evaluated). The 10 ha criterion was used as the limit in part based on the
experiences of the authors in reviewing and evaluating wetlands under the updated Ontario
Wetland Evaluation System. Once wetlands approach this size they are now quite likely to
become provincially significant. This is especially the case when one considers that through
complexing wetlands units of 10 ha in area could be added to others that are functionally related
(and within 750 m). In addition, all wetlands are regulated by the LSRCA and interference with
them is prohibited except where permitted.
The criteria are also loosely based on those selected for significant woodlands (and many of the
unevaluated swamp forests will also be designated as significant woodlands) and are as follows:
1. All PSWs are Level 1 features;
2. Any unevaluated wetland that is contiguous with a designated PSW will be included as a
Level 2 feature (but if and when it is incorporated into the PSW boundary by MNR it will
become a Level 1 feature);
3. All evaluated Non-PSWs and designated Locally Significant Wetlands are included Level
3 features;
28
Photograph 6.3 Derryville Bog, one of the very few true bogs in the Watershed. Note the
die-back caused by stress that limits the growth of trees to below 25% cover.
4. Any unevaluated wetland that is contiguous with an Evaluated Non-PSW or a designated
Locally Significant Wetland will be included as a Level 3 feature;
5. Unevaluated wetlands that are 10 ha or greater in area will be designated as a Level 2
feature;
6. The entirety of any wetland greater than or equal to 0.5 ha that overlaps with or falls
within 30 m of any identified Level 1, Level 2 and /or Level 3 NHS feature is designated
a Level 3 feature;
7. Any other wetland unit that is greater than 0.5 ha but less than 10 ha is recognized as a
supporting habitat feature in the watershed, but not as part of the NHS (i.e., Level 4 –
supporting).
Wetlands that are 10 ha or greater in extent have been automatically included in Level 2, rather
than Level 3. This might appear to be counterintuitive as evaluated non-PSWs and designated
LSWs are only assigned Level 3. This precautionary approach is appropriate, as wetlands that
29
have not been formerly evaluated could turn out to be provincially significant, if upon evaluation
they are not, then they can be determined to be Level 3 features.
The policy direction of this NHS identifies a mechanism for updated or new evaluations to be
incorporated into the NHS in the future. The policy implications of each level (Level 1, Level 2,
Level 3 and Level 4 - Supporting) can be found in Section 13.0 Suggested Policy Templates.
Greenbelt Plan Wetlands
Within the Greenbelt Plan area, the Greenbelt Plan definition of a Key Natural Heritage Feature
or Key Hydrologic Feature is used for wetlands, as determined through criteria established by the
MNR. As these criteria were not available at the time of writing, wetlands within Greenbelt have
not specifically been identified as key natural heritage or key hydrologic features. Wetlands that
meet the criteria will be considered Level 1 features as the Greenbelt Plan tales precedence over
the NHS.
Oak Ridges Moraine Wetlands
Within the Oak Ridges Moraine (ORM) portion of the Lake Simcoe Watershed, the Oak Ridges
Moraine Conservation Plan (ORMCP) definition of a Key Natural Heritage Feature is used, and
replaces the wetland criteria presented above.
While some of the ORMCP criteria are easily mapped (such as evaluated wetlands), some other
criteria cannot be applied as a mapping product for the NHS, as determining the presence of the
“Key Natural Heritage Features” or “Hydrologically Sensitive Features” within the Oak Ridges
Moraine Plan Area requires detailed site-specific investigations. It is important to note however,
that the requirements and definition (including the draft technical guidelines) apply to the
identification of all wetlands on the Moraine whether or not they are illustrated as part of the
NHS in Authority maps.
Regardless of these challenges, to the extent possible these features were mapped for the
regulated ORM area. However, this mapping is intended as a guide only, and confirmation of a
feature boundary and the presence of any other wetlands will be required to ensure conformity
with the ORMCP. For example, when a wetland is discovered on a property it is subject to the
ORMCP, regardless of whether it appears on any map.
On the ORM, all wetlands, including those less than 0.5 ha have been mapped as Level 1
features, upon detailed investigation, these 0.5 ha wetlands may not remain as a Level 1
constraint in accordance with the direction of the current draft ORMCP technical guidelines.
The Lake Simcoe Region Conservation Authority Ontario Regulation 179/06
Under Ontario Regulation 179/06, the LSRCA regulates (among other ‘hazard lands’) wetlands
and their adjacent lands. In accordance with the Regulation:
30
Section 2(1):
No personal shall undertake development, or permit another person to undertake
development in or on the areas with the jurisdiction of the Authority that
are,…wetlands, or other areas where development could interfere with the hydrologic
function of a wetland, including areas within 120m of all provincially significant
wetlands and areas within 30m of all other wetlands….
Section 3 (1):
The Authority may grant permission for development in or on the areas described in
subsection 2 (1) if, it its opinion, the control of flooding, erosion, dynamic beaches,
pollution or the conservation of land will not be affected by the development.
The Lake Simcoe Watershed NHS significant wetlands criteria are summarized in Table 6.4.
Figure 6.1 depicts a mapping example.
Table 6.4 Summary of Significant Wetland Criteria for the Lake Simcoe Watershed
Feature
Lake Simcoe Watershed NHS Criterion
Provincially Significant All PSWs
Wetland
Evaluated Non-PSWs; All Non-PSWs and designated LSWs
plus designated Locally
Unevaluated wetlands contiguous to
evaluated non-PSWs and designated LSWs
Unevaluated wetlands
The entirety of any wetland ≥ 0.5 ha that
overlaps with or falls within 30 m of any
identified Level 1, Level 2 and/or Level 3
NHS feature
Any other wetland unit that is ≥ 10 ha in
area
Unevaluated wetlands contiguous to PSWs
Level
Level 1
Attribute
Name
WE1
Level 3
WE3-A
Level 3
WE3-B
Level 3
WE3-C
Level 2
WE2-A
Level 2
(until
formally
incorporated
into PSW)
Any other wetland unit that is ≥ 0.5 ha and
Level 4 < 10 ha is recognized as a supporting supporting
habitat feature in the watershed
Greenbelt Plan Area
Wetlands consistent with the definition of
Level 1
the Greenbelt Plan
Oak Ridges Moraine ORM wetlands consistent with the draft
Level 1
Wetlands
ORMCP Technical Paper
31
WE2-B
WE4
NA
MWE
32
6.6
Literature Cited
Bedford, B. 1999.
Cummulative effects on wetland landscapes: links to wetland restoration in the United
States and southern Canada. Wetlands 19:775-788.
Crosbie, B. and P. Chow-Fraser. 1999.
Percentage land use in the watershed determines the water and sediment quality of 22
marshes in the Great Lakes Basin. Canadian Journal of Aquatic Science 56: 1781-1791.
Detenbeck, N.E., S.M. Galatowitsch, J. Atkinson and H. Ball. 1999.
Evaluating perturbations and developing restoration strategies for inland wetlands in the
Great Lakes Basin. Wetlands 19: 789-820.
Environment Canada, Canadian Wildlife Service. 2004.
How Much Habitat is Enough? A Framework for Guiding Habitat Rehabilitation in Great
Lakes Areas of Concern (Second Edition). Minister of Public Works and Government
Services Canada. 80 pp.
Gabor, T.S., A.K. North, L.C.M. Ross, H.R. Murkin, J.S. Anderson, and M.A. Turner. 2001.
Beyond the pipe: the importance of wetlands & upland conservation practices in
watershed management: functions and values for water quality and quantity. Prepared for
the Walkerton Inquiry. Ducks Unlimited Canada. Available online:
<http://www.ducks.ca/aboutduc/news/archives/pdf/pipeshrt.pdf>.
Lee, H.T., W.D. Bakowsky, J. Riley, J. Bowles, M. Puddister, P. Uhlig and S. McMurray. 1998.
Ecological Land Classification for Southern Ontario: First Approximation and Its
Application. Ontario Ministry of Natural Resources. SCSS Field Guide FG-02. 225 pp.
Ontario Wetland Evaluation System. Southern Manual. 1993 3rd Edition. Updated.
OMNR # 502254-1.
Riley, J.L. 1989.
Southern Ontario bogs and fens off the Canadian Shield. pp. 355-367. In: Bardecki, M.J.
and N. Patterson (eds.). Wetlands: inertia or momentum? Federation of Ontario
Naturalists, Don Mills, 426 pp.
Snell, E. A. 1987.
Wetland distribution and conversion in southern Ontario. Inland Waters and Lands
Directorate, Environment Canada, Ottawa. Table 6, Working Paper 48, En 73-4/48E.
Wang, N. and W. J. Mitch. 1995.
Estimating phosphorus retention of existing and restored wetlands in the Quanicassee
River watershed, Saginaw Bay, Michigan. Prepared for the Wetland Initiative, Chicago,
Illinois.
33
7.0
7.1
Significant Woodlands
History of Woodland Cover
Prior to European settlement the dominant land cover type of the Lake Simcoe Watershed was
woodlands of various forms. Estimates of total cover were in the 80% range, rather than the more
commonly thought 90%, as Simcoe County was known as one of the most densely settled areas
by aboriginal inhabitants (the Hurons) who may have farmed as much as 20,000 ha (Heidenreich
1971 as cited in Larson et al. 1999).
Some authors have estimated that 70% of woodland cover south and east of the Canadian Shield
has been lost since settlement (Riley and Mohr 1994). Post-settlement forest loss is thought to
have peaked around 1920 and in some areas there has been some recovery since then. In 1978,
woodland cover in Simcoe County was estimated at 29% and in York Region at 18.5% (Larson
et al. 1999).
The original woodlands throughout most of southern Ontario were converted to non-forest uses.
For instance, upland woodlands found on prime agricultural soils have largely been transformed
into agricultural lands, while woodlands once surrounding urban centres have been developed
into residential subdivisions.
34
Photograph 7.1 An example of an isolated remnant woodlot, which has largely
developed since the landscape was settled.
7.2
Woodland Functions
The Natural Heritage Reference Manual (OMNR 1999) lists a variety of important functions
associated with woodlands and Larson et al. (1999) summarize the importance of woodlands.
These important functions can generally be described as follows:
•
•
•
Economic Services and Values
o oxygen production, carbon sequestration, climate moderation, water quality and
quantity improvements, woodland products, economic activity associated with
cultural values
Cultural Values
o education, recreation, tourism, research, spiritual and aesthetic worth
Ecological Values
o diversity of species, structural heterogeneity, energy (photosynthesis), nutrient
and energy cycling.
The Provincial Policy Statement (PPS) (MMAH 2005) definition of woodlands also touches on
these themes:
[Woodlands means]…treed areas that provide environmental and economic
benefit to both the private landowner and the general public, such as erosion
prevention, hydrological and nutrient cycling, provision of clean air and the long-
35
term storage of carbon, provision of wildlife habitat, outdoor recreational
opportunities, and the sustainable harvest of a wide range of woodland products.
Woodlands include treed areas, woodlands or forested areas and vary in their
level of significance at the local, regional and provincial levels.
Structural diversity of habitat is a key driver of biodiversity. In woodlands, habitat niches can
range from microhabitats such as the surfaces of fissured trunks, leaves and rotting logs to
macrohabitat features such as the horizontal layers within the forest (e.g., supercanopy, canopy,
subcanopy). In addition, woodlands are present in a wide variety of topographic settings and soil
and moisture regimes. These can range from talus slopes to heavy clay soils; from saturated
organics to very dry sandy soils. For all of these reasons it is not surprising that many woodland
species are obligates (i.e., they are only found in woodlands), or that woodlands provide habitat
for a wide range of flora and fauna. They form important building blocks of the natural heritage
system.
7.3
Overview of the Science
The following sections discuss some of the relevant literature that was used to develop
appropriate criteria for the selection of significant woodland in the Lake Simcoe Watershed.
Fragmentation
Fragmentation describes the process that results from larger forest patches being separated into
ever smaller patches or fragments.
Fragmentation has many repercussions for forest habitat, such as increased edge effects,
increased predation and decreased species richness (Austen et al. 2001). As well, fragmentation
leads to increased woodlot isolation, which in turn can reduce dispersal, immigration and
recolonization (Burke and Nol 2000; Trzcinski et al. 1999).
Fragmentation can result in habitat blocks that are too small to support certain species of flora or
fauna (e.g., those that are considered to be area-sensitive) or are too small to provide relatively
undisturbed and high quality habitat conditions. Fragmentation can also result in the degradation
of connectivity to a critical habitat type (e.g., an amphibian breeding pond).
However, it can be very difficult to tease apart the relative importance of fragmentation from
patch size, which is confounded by the fact that in real landscapes these two factors are often
interrelated. One review of 134 fragmentation studies showed evidence that the ecological
mechanisms and effects of habitat fragmentation are poorly understood (McGarigal and
Cushman 2002).
36
Patch Size
Many researchers agree that fragmentation can affect woodland composition in terms of species
and vegetation composition, but many have also found that woodland patch size is a more
significant component (Trzcinski et al. 1999; Villard et al. 1999; Austen et al. 2001; Nol et al.
2005).
Larger patches of woodlands tend to have a greater diversity of habitat niches and therefore they
are more likely to support greater biodiversity. Very large patch sizes are also associated with
total forest cover, as these conditions tend to occur simultaneously in real-world landscapes
(Villard et al. 1999).
It is now generally accepted that when it comes to woodland patch size, bigger really is better
(Austen et al. 2001; Burke and Nol 2000; Bayne and Hobson 2002; Margules and Pressey 2000;
Miller and Hobbs 2002; Trzcinski et al. 1999). Large woodlands are more likely to contain a
greater diversity of plant and animal species and communities than smaller woodlands and are
better buffered against the harmful edge effects of agricultural or urban activities than smaller
areas (OMNR 1999).
In a landmark paper, Robbins et al. (1989) determined habitat area requirements for forest birds
(based on presence/absence, not productivity) in the mid-Atlantic states and considered 100 ha as
an absolute minimum guideline for forest patch size. The probability of detecting some of the
more sensitive woodland bird species in 100 ha woodland patches was as low as 20 to 30%.
More recently, some researchers have raised the concept of the “Big Woods” (Mancke and
Gavin 2000; Environment Canada 2004). Few, however, have tackled the idea of establishing
minimum sizes for productive, high quality forest patches in southern Ontario. Burke and Nol
(2000) recommend preservation of tracts that are at least 500 ha in extent to guard against local
population declines in some bird species (notably the Ovenbird [Seiurus aurocapillus]).
Environment Canada (2004) summarized the anticipated response of forest birds to patch size
using data from one area of southern Ontario. It was concluded that 200 ha woodland patches
will support 80% of sensitive species, 100 ha patches 60%, while few were supported at the 50
ha patch level. (Environment Canada [2004] and Environment Canada [in prep] are good sources
for further information on this topic.)
Based on Illinois data, Herkert et al. (1993) suggest that a 400 ha woodland patch was required
to support 75 to 80% of the highly sensitive woodland bird species. They predicted that a 100 ha
patch should contain about 60% of the highly sensitive species.
In Maryland, guidelines suggest that blocks of 3,000 ha of mature forest should be preserved
(Maryland Partners in Flight 1997). Mancke and Gavin (2000) stress the importance of the “Big
Woods” (meaning >5,000 ha) for regional productivity of some forest birds.
Clearly, woodland patch size can be important for many species of flora and fauna. The relative
importance of patch size, patch characteristics and landscape cover varies and so too does the
interaction of these for different species.
37
Habitat Quality
Habitat quality usually relates to a range of metrics such as: shape, interior (usually that which is
more than 100 m from an edge), age, composition, structure and the presence of invasive species.
Today, most of the woodlands in southern Ontario are young (Larson et al. 1999), due to having
been clear-cut, then abandoned and left to regenerate naturally. This has altered the composition
of trees in southern Ontario’s woodlands as well as the composition of species found within
them. Species that use older-growth woodlands or characteristics of old trees (e.g., flyingsquirrels [Glaucomys spp.] and Brown Creepers [Certhia americana]) are now less frequent in
southern Ontario (Larson et al. 1999).
Determination of habitat quality, while a useful exercise, mostly requires detailed field
investigations that are beyond the scope of a regional conservation planning exercise. It is clear
that plantations and cultural woodlands generally do not provide high quality habitat for
woodland flora and fauna. However, they do make valuable contributions to the NHS in other
ways and often serve as nurseries for future woodlands.
There is also some doubt regarding the necessity of gathering detailed, quality-related
information to determine significant woodlands at the landscape level. For example, one study
that did gather detailed data in southern Ontario (UTRCA 2003), ultimately used selection
criteria that were all GIS driven. Where woodland cover falls below critical thresholds (see
following section), it could be argued that all woodlands become important; perhaps
understanding woodland quality becomes more critical when forest cover is high and planning
authorities need to consider which woodlands could be lost to alternate land use.
There is also conflicting evidence in the literature regarding the response of birds to edge
habitats (or lack of interior). Some studies have found evidence that linear habitats may have
higher densities or that edge-use avoidance is linked to overall density of the species within the
patch (Bollinger and Switzer 2002). The literature appears relatively consistent on the increased
negative effects of cowbird nest parasitism and avian predators on edge-nesting birds (Chalfoun
et al. 2002). Edge effects (e.g., predation, disturbance, changes in food supply) may be important
in some circumstances for some species. These effects likely extend from birds to other groups
such as plants (Bowles 1999) and bryophytes (Hylander et al. 2002). However, many of the
empirical data demonstrating the use of “interior forest” do not originate from the temperate
zone. In trying to resolve the question of interior forest functions, it is not possible to draw direct
parallels between temperate and tropical ecosystems. For example, data on skulking Amazonian
breeding birds show that they avoid crossing even relatively small rivers (and with good reason
given the numbers of predators) (various citations in Hilty et al. 2006), whereas most birds that
inhabit temperate ecosystems are either highly mobile or migrate hundreds of kilometres twice a
year.
There is no doubt that habitat quality is an important metric, and it may be as important as patch
size. Recognizing that all these different woodland metrics are interrelated to some extent, the
literature suggests that neither patch size nor habitat quality are as important as overall woodland
cover.
38
Woodland Cover
There is increasing scientific evidence that the total woodland cover of a landscape may exert the
most important influence on biodiversity. Obviously the loss of woodland cover results in a
direct loss of habitat of that type. This reduction in habitat can result in proportionally smaller
population sizes, and animals in habitat remnants may experience altered dispersal rates,
decreased rates of survival, decreased productivity, altered foraging behaviours and decreased
mating opportunities (Brooker and Brooker 2002).
Research that has examined the independent effects of habitat loss versus habitat fragmentation
suggests that habitat loss has a greater effect than habitat fragmentation on the distribution and
abundance of birds (Fahrig 2002). Golet (2001) also found that bird relative abundance was not
related to patch size and that the pattern of distribution of breeding birds was consistent with that
of total forest cover. This is further supported by southern Ontario research that found that
woodland area and edges effects did not significantly affect either nesting success or the
productivity of neotropical songbirds (Friesen et al. 1998).
There is now substantive evidence that total woodland cover is a critical metric (e.g., Austen et
al. 2001; Golet 2001; Fahrig 2002; Lindenmayer et al. 2002; Trzcinski et al. 1999; Friesen et al.
1998, 1999; Rosenburg et al. 1999). Perhaps less clear are the thresholds for biodiversity. These
thresholds, or general patterns, will be influenced by a wide variety of interacting metrics, such
as the quality of woodland, and the type of matrix (meaning the in-between areas, such as
agriculture, exurban or urban land uses). Presumably, where the dominant landscape is
woodland, wildlife will respond primarily to local habitat effects rather than woodland cover
metrics, as described by Lichstein et al. (2002).
What is known with reasonable certainty is that as woodland cover decreases, species fail to
occupy remaining patches and many of those that remain become rare, or fail to successfully
attract mates or reproduce. These two latter concerns are particularly relevant, for the mere
presence of a species in a woodlot does not mean that it is successfully reproducing, and many
studies that examine wildlife use of woodlands rely on presence-absence data, not productivity
data.
Near Ottawa, Ontario, several species of woodland birds disappeared as breeders when woodland
cover declined below 30% (Freemark 1988). There is additional research that supports a 20 to
30% woodland cover threshold beyond which the persistence of bird species was virtually
ensured or that habitat configuration had little or no effect on species richness or abundance
(Fahrig 1997; Andrén 1994 both cited in Villard et al. 1999). In another study woodland bird
species favouring interior habitat conditions continued to increase in number in areas with 20%
to at least 35% woodland cover, depending on the scale of the analysis (Tate 1998).
For one classic woodland bird species, the Scarlet Tanager (Piranga olivacea), research
coordinated by Rosenberg et al. (1999) has established a sliding scale whereby tanagers show
almost no area sensitivity at 70% forest cover (i.e., they were occurring in almost all woodland
patches), but would not be expected to occur in any patches where the forest cover falls much
below 20 to 30%.
39
Woodland patches in regions with higher forest cover have been found to be particularly
important for so-called forest interior species (Austen et al. 2001). Based on the findings of that
study, a priority might be to ensure the presence of larger expanses of woodland within highly
forested landscapes (Austen et al. 2001), which is often the reverse of approaches that seek to
identify significant woodlands.
One interesting study found that agricultural crop damage by voles actually decreased with
increasing forest cover (Delattre et al. 1992 cited in Hilty et al. 2006). This finding could open
up other useful avenues of research.
Overall, the literature indicates that one primary woodland cover threshold is probably
somewhere in the 30 to 40% percent cover range. Currently, there is a preponderance of
evidence supporting the use of 30% as a threshold. The use of this figure probably would not be
described as precautionary.
7.4
Socially Significant Woodlands
The socio-economic value of woodlands is also important. Air and water quality benefits, and
direct economic and recreational uses of woodlands are often recognized, but rarely are they
explicitly explored in details for the development of significant woodland criteria. The aesthetic
and spiritual value to humans should also be expressed in this component. Failure to recognize
the full suite of socio-economic values placed on woodlands can lead to the pressure to designate
relatively small woodland patches as “ecologically significant”, which can be a difficult
scientific position to defend, when the real reasons for their importance may be more often
related to social and economic values.
Ecological values are often incompatible with human use. Separation of woodlands that are
specifically identified for their social values can be important. This avoids the problem of
automatically assuming that areas with the greatest woodland cover can afford to withstand
losses of woodland cover (which is more of a social paradigm), and that woodland patches in
areas with the least woodland cover are ecologically the most important, when the scientific
evidence may be entirely to the contrary.
One source for the economic value of woodlands (e.g., for discussion on services performed such
as air quality improvement) is the American Forests website (www.americanforests.org).
Through the CITYgreen campaign, American Forests puts a dollar value on the air quality
benefits and carbon sequestration of woodlands and urban trees.
In their recent publication Natural Spaces – The Socio-economic Benefits of Southern Ontario’s
Greenspaces (www.naturalspaces.mnr.gov.on.ca), the Ministry of Natural Resources (MNR)
explore this topic in an Ontario context.
40
7.5
Woodlands in the Lake Simcoe Watershed
Woodlands were identified within the Lake Simcoe Watershed through the procedures described
in Appendix 1 – Ecological Land Classification. Woodlands include all treed communities,
whether upland or wetland. The ELC communities that were considered to represent woodlands
are: forest (FOD, FOM, FOC), swamp (SWD, SWM, SWC), and culturally woodlands (CUP,
CUW) as shown in the table (Table 7.1) below. Some woodlands that are designated as
“Significant Woodlands” may also be designated “Significant Wetlands”. The two terms are not
mutually exclusive.
Woodlands of all qualities and types combined comprise approximately 71,000 ha (or 27%), of
the total area of the watershed (excluding the lake itself). Of this area, approximately 9,000 ha
(i.e., 12.7% of the available woodland cover) could be considered to be of lower ecological
quality (i.e., they are plantations, which are standing crops, or cultural woodlands); excluding
these two cover classes, the woodland cover within the watershed is approximately 23.7%.
Table 7.1 Woodland Cover by Type in the Watershed
Class – Woodland Type
Cultural Plantation (CUP)
Cultural Woodland (CUW)*
Conifer Forest (FOC)
Deciduous Forest (FOD)
Mixed Forest (FOM)
Conifer Swamp (SWC)
Deciduous Swamp (SWD)
Mixed Swamp (SWM)
Total
Approximate Area of Watershed
(excl. lake)
Forest Cover
ha
5,788
3,272
4,621
20,310
15,417
3,028
10,825
7,809
71,070
261,887
%
8.1
4.6
6.5
28.6
21.7
4.3
15.2
11.0
100
27.1
*This category includes substantial hedgerows which are continuous with other natural features (ca. 608 ha).
As described in the ELC metadata (Appendix 1), hedgerows were included in the LSRCA ELC
base map layer as Cultural Woodlands (CUW) where they were substantial and continuous with
other natural heritage features, with an attached attribute note indicating that they were
hedgerows. However, for the purpose of the NHS, hedgerows are not intended to be included as
woodlands and therefore unless they are part of another designated feature such as Significant
Wildlife Habitat, are not considered to be a NHS feature.
In addition to the amount of woodland cover within the watershed, there are two ways in which
the distribution of that cover may be examined. The general spatial distribution of cover (for
example by subwatershed, ecodistrict or other spatial characteristic) is most likely uneven.
Another characteristic is the size of forest patches. Both of these spatial parameters will be
discussed in the following sections.
41
Spatial Distribution of Woodland Cover
An analysis of woodland cover was undertaken by ecodistrict. An ecodistrict is an area defined
by the MNR that has a distinct combination of landforms, soils, waters, plants and animals.
Ecodistricts are therefore a useful mechanism to describe biodiversity, as the species associated
within similar community patches would be expected to some extent to reflect the influence of
the ecodistrict. If woodland cover types are well represented within each ecodistrict this can be
expected to maximize biodiversity potential.
Within the Lake Simcoe Watershed there are four ecodistricts (Figure 7.1). Most of the
watershed, and all of the lake itself, are contained within ecodistrict 6E-6, while a quarter of the
watershed is within ecodistrict 6E-8. Only 13% of the watershed is within the Oak Ridges
Moraine (ORM) ecodistrict 6E-7, and a relatively tiny proportion (2.4%) is within ecodistrict 6E9, in the extreme northeast portion of the watershed.
Table 7.2 provides the results of the analysis by ecodistrict. Not surprisingly, woodland cover is
highest in the 6E-7 ORM ecodistrict. However, it is noteworthy that almost one-third of the
woodland cover within that particular ecodistrict is either plantation or cultural woodland.
Without these cultural communities, woodland cover within this 6E-7 would be about 29%.
Woodland cover is notably low (20.5%) in ecodistrict 6E-8, which accounts for approximately
one-quarter of the entire watershed.
Table 7.2 Woodland Cover Analysis by Ecodistrict
6E-6
ha
%
Ecodistrict area (excl.
Lake Simcoe)
Cultural Plantation
Cultural Woodland
Conifer Forest
Deciduous Forest
Mixed Forest
Conifer Swamp
Deciduous Swamp
Mixed Swamp
Total Woodland Cover
Ecodistrict
Woodland Cover %
156,684
1,644
2,020
1,973
12,709
10,044
1,118
8,020
4,329
59.8
3.9
4.8
4.7
30.4
24.0
2.7
19.2
10.3
41,857
6E-7
ha
%
33,603
3,511
715
920
4,824
2,434
411
344
837
12.8
25.1
5.1
6.6
34.5
17.4
2.9
2.5
6.0
13,996
26.7
42
6E-8
ha
%
65,433
587
463
1,703
2,295
2,499
1,402
1,966
2,529
25.0
4.4
3.4
12.7
17.1
18.6
10.4
14.6
18.8
13,445
41.7
6E-9
ha
%
6,166
46
74
25
481
440
97
495
113
2.4
2.6
4.2
1.4
27.2
24.8
5.5
27.9
6.4
1,771
20.5
28.7
43
To provide as complete a picture as possible of the spatial variation in woodland cover, an
analysis was undertaken by subwatershed. For greater clarity, some discrete but proximal
subwatersheds were combined (e.g., “Barrie creeks”). Table 7.3 provides the results of this
analysis.
The data in Table 7.3 have been sorted in ascending order by watershed to show the lowest
percent forest cover at the top of the table, and the greatest percent cover at the bottom.
Subwatersheds vary in area from less than 2,000 ha to more than 40,000 ha and these differences
must be taken into account when examining these data.
Table 7.3 Total Woodland Cover by Subwatershed Areas
Maskinonge River
Barrie Creeks
Hewitt’s Creek
Beaver River
West Holland River
East Holland River
White’s Creek
Innisfil Creeks
Ramara Creeks
Lover’s Creek
Talbot River
Georgina Creeks
Uxbridge Brook
Pefferlaw Brook
Oro South Creeks
Oro North Creeks
Black River
Hawkestone Creek
Islands in Lake Simcoe combined
Area of
Subwatersheds
Woodland
Cover by % of
subwatershed
7,179
3,781
1,751
32,724
35,410
23,910
10,520
10,757
14,350
5,995
7,056
4,946
17,495
28,482
5,769
8,344
37,536
3,971
11.7
14.1
16.8
17.1
20.6
20.9
21.8
25.2
26.9
27.2
27.6
30.3
31.0
35.1
35.4
35.9
37.4
43.4
1,912
68.5
Woodland Patch Size Analysis
A woodland patch is defined here as the total area of a contiguous patch of wooded habitat as
mapped by the LSRCA ELC mapping project. This analysis does not incorporate other
parameters of “quality” that by and large could only be established with detailed field work.
A calculation of the area of “interior” habitat within each subwatershed was not undertaken as
part of this analysis. The presence of interior conditions or habitat is highly variable according to
factors such as the type of woodland, its position in the landscape and the organism of interest
44
(“interior” distances are much different for plants versus birds, for example). The concept of
“interior” breeding bird species is not robust and many species thought to be “interior” are
actually either area-sensitive (requiring large areas of habitat in which to successfully breed) or
require certain specialized habitat conditions (e.g., Brown Creeper). Indeed, some studies have
even found higher densities of forest breeding birds in linear woodlands with limited “interior”
habitat (Bollinger and Switzer 2002) and few studies, if any, have looked at breeding success for
various flora and fauna versus edge effects over several different community patches in
temperate climates.
For this analysis, GIS was used to calculate all contiguous woodland areas and to compute a
graph of the distribution of woodland patch sizes within the watershed. This analysis does not in
any way incorporate the benefits of adjacent or nearby natural areas, nor does it discount
woodland patches that have exurban development envelopes within them. The results of this
analysis are provided in Figure 7.2.
Figure 7.2 Woodland Patch Analysis - Whole Watershed
Watershed
30000
1800
1600
25000
1400
# of
Patches
1000
15000
800
Total Area (ha)
20000
1200
Total Area
10000
600
400
5000
200
0
0
10
0
<=
10
>5
0
0
>
00
0
0
0
<=
50
<=
10
>1
0
<=
50
>5
0
<=
25
>2
5
>2
0
<=
20
>1
5
<=
15
>1
0
<=
10
<=
4
>4
>2
<=
2
<
>0
.5
0.
5
0
Patch Size (ha)
Figure 7.2 demonstrates that for the entire watershed, approximately 9,387 ha of woodland (or
13.2% of the total woodland) are accounted for in the first four columns (i.e., patches up to 10
ha). The (unlikely) total loss of this woodland cover (and without the “recruitment” of new
patches) would reduce the percent of the watershed that is wooded from the current 27.1% to
23.6%.
This analysis also indicates the importance of woodlands over 25 ha in terms of total forest
cover, even as the number of patches declines sharply. Conversely, relatively few hectares (less
45
than 2,000) are encapsulated within the two smallest categories, even though they include over
2,000 patches.
There is only one patch (of approximately 1,100 ha) in the greater than 1,000 ha class. This is
somewhat deceiving, however, as the definition of a break in contiguous cover was
conservatively applied consistent with the ELC methodology employed (Appendix 1).
Considering that the overall size of the watershed is around 260,000 ha, it is perhaps surprising
that there are only ten woodland patches greater than 500 ha. One more patch would be added to
this category if a large contiguous wooded area that extends outside the edge of the Lake Simcoe
Watershed is included. Given that many scientific authorities consider 500 ha wooded patches to
be at the lower end of what is required for successful reproduction by many sensitive species,
this analysis shows that the watershed is not in good shape from a patch size perspective. Three
of these ten larger patches are located on the Oak Ridges Moraine.
Although this analysis was undertaken for all ecodistricts and all subwatershed groupings within
the Lake Simcoe Watershed, only the results of the analysis for the Black River subwatershed
(Figure 7.3) and the Barrie Creeks subwatershed (Figure 7.4) are included below by way of
example.
The Black River subwatershed, with a total woodland cover of almost 38%, shows a distribution
of patch size that includes only 1,321 ha of its woodland cover (3.5%), in the smallest four size
categories (Figure 7.3).
The Barrie Creeks subwatershed grouping shows a much higher percentage of its woodlands in
the smaller patch size group (Figure 7.4). This figure also demonstrates the relative importance
of the six remaining patches within the Barrie creeks area that are greater than 25 ha in area.
46
Figure 7.3 Woodland Patch Analysis – Black River Subwatershed
Black River
9000.00
300
8000.00
250
7000.00
5000.00
150
4000.00
Total Area (ha)
6000.00
200
# of Patches
Total Area
3000.00
100
2000.00
50
1000.00
0.00
<=
10
>1
0
00
<=
50
>5
0
00
<=
10
00
>
10
00
50
>5
0
<=
25
>2
5
<=
20
>2
0
>1
5
<=
<=
15
0
<=
1
>1
0
<=
4
>4
>2
<=
2
<
>0
.5
0.
5
0
Patch Size (ha)
Figure 7.4 Woodland Patch Analysis – Barrie Creeks Subwatershed Group
Barrie Creeks
180.00
70
160.00
60
140.00
50
40
100.00
80.00
30
60.00
20
40.00
10
20.00
0.00
Patch Size (ha)
47
<=
10
00
>
10
00
<=
50
0
>5
00
<=
10
0
>1
00
<=
50
>5
0
>2
5
<=
25
>2
0
<=
20
>1
5
<=
15
>1
0
<=
10
>4
<=
4
>2
<=
2
>0
.5
<
0.
5
0
Total Area (ha)
120.00
# of Patches
Total Area
Big Woods Analysis
Two related metrics were investigated to form the basis of a Big Woods approach. These were
the aggregation of woodland patches and the identification of the largest woodland patches.
A series of GIS queries were run that merged different woodland patches that were within
various stipulated distances from each other (ranging from 12 m to 21 m) into one “patch”. After
several trial runs and comparison to the woodland cover map, use of 18 m was found to represent
areas of high contiguous woodland cover within which Big Woods Policy Areas could be
contemplated. This had the effect of identifying the largest aggregations of woodland patches
within the watershed. The resulting “aggregated patches” were sorted and those that were close
to or exceeded 1,000 ha were overlain on the largest contiguous patches. These largest patches
came from a simple query to identify all patches in the watershed > 500 ha (woodlands extending
outside of the watershed were included).
The result was confirmed with a raster based analysis of woodland cover density based on a 25
m grid. Woodland density was calculated as the area of woodland within a 2 km radius of each
grid cell. The Big Woods Policy Areas identified previously were overlain on the woodland
density map to verify that areas with high forest density (a high proportion of woodland cover
within 2 km) were identified as Big Woods Policy Areas.
7.6
Policy Framework
Over the past decade, the notion of woodland protection has been slowly gathering support
throughout much of southern Ontario. However, unlike the guidance provided by the MNR for
the identification of Provincially Significant Wetlands, detailed technical guidance for the
identification of significant woodlands is not presently available. There is some general guidance
offered in the Natural Heritage Reference Manual (OMNR 1999), which states that:
…the identification and evaluation of significant woodlands is a planning authority
[i.e., municipal] responsibility. Approaches to compiling and assessing woodlands
information will vary depending on the resources of the planning authority,
availability of information, development pressures and the nature and extent of the
woodlands present in the planning authority.
In section 2.1.4 of the PPS 2005 (MMAH 2005), it is specified that:
…development and site alteration shall not be permitted in significant woodlands
south and east of the Canadian Shield, unless it has been demonstrated that there
will be no negative impacts on the natural features or their ecological function.
This level of protection is sometimes approached or met in municipal Official Plans. However, in
some cases the development and implementation of policies to embed protection for significant
48
woodlands within Official Plans have not always kept pace with the actual designation of the
features.
Often, “greenland” or “environmental protection” designations are prescribed to include
significant woodlands among a list of other significant features, but the actual limits of the
features or specific criteria for their identification are lacking. This can lead to piecemeal and
inconsistent levels of protection, and at times, litigation at the Ontario Municipal Board over the
determination of significance for a particular unit on the landscape.
7.7
Review of Criteria
There are two general approaches that have been applied to the development of criteria for the
identification of significant woodlands.
The first method is a scoring system, which demands a high level of knowledge on several
criteria that may include, for example: area, contagion, age, rare or conservative species,
diversity, scenic values, resource values and various disturbance criteria. A score is provided for
each of the criteria, which if desired may then be weighted for relative importance, and a final
score is calculated. Significant woodlands can then be selected by setting a score level similar to
the manner in which the Ontario Wetland Evaluation System works (e.g., Eastern Ontario
Woodland Valuation System [Rowsell 2003]).
In some respects this method is perhaps the most defensible, as decisions to assign significance
are based on a high level of understanding of the features and functions of patches. It is probably
more useful in areas where there is an extensive amount of woodland or in cases where the study
area is relatively small (i.e., at a subwatershed level). Drawbacks associated with this method are
that it requires detailed data gathered from repeated site visits by highly-trained field
investigators. As this method is site-intensive, it can also lead to the underestimation of the role
of the individual woodland in a landscape perspective, such as regional woodland cover.
The second approach involves the identification of a suite of GIS-oriented criteria, whereby if a
woodlot meets any one (or several) of the criteria it is considered to be significant. This approach
has the advantage of being a landscape level of investigation that can be applied efficiently using
GIS tools. Drawbacks are that species-level information is usually lacking and woodland quality
is generally (though not entirely) excluded; a small woodland dominated by non-native species
may be identified for protection as “significant woodland” or conversely, small high quality
woodlands may not. In these approaches criteria are seldom weighted.
Table 7.4 provides criteria that have been recommended by others for the determination of
significant woodlands in southern Ontario. Taken together, the authors of these
recommendations have reviewed a significant body of literature and brought together a wide
range of expertise to provide these guidelines. Of particular note is the report commissioned by
the Federation of Ontario Naturalists (FON) (now Ontario Nature) who undertook an extensive
review of approaches for determining significant woodlands (Reid 2002). This became an
49
important background report for Ontario Nature’s “Suggested Guidelines for the Identification of
Significant Woodlands in Southern Ontario” (FON 2004). The guidelines appear in Table 7.4.
Table 7.4 Criteria Recommended by Others for the Identification of
Significant Woodlands in Southern Ontario
Criteria
Natural Heritage
Reference Manual
(OMNR 1999)
Ontario Nature
(FON 2004)
Patch Size
If percent cover:
<5%, 2 ha;
5-15%, 4 ha;
15-30%, 40 ha (300 m min.
width);
>30%, min. size not
suggested
Forest
Interior /
Shape
More interior better
Proximity/
Connectivity
Closer is better, overlap
with other NH features;
One or more natural
heritage features within
boundary;
Potential to form linkage to
another feature or area
Occupy a substantial part of
a watershed;
Close or adjacent to
groundwater
discharge,
recharge or headwaters
If percent cover:
<5%, all;
5-10%, 2 ha;
11-15%, 4 ha;
16-20%, 10 ha;
20-30%, 15 ha;
31-50%, 25 ha;
>50%, 40 ha
<30% cover: minimum 4 ha
interior using 100 m from edge
criteria; OR
if total forest interior (in the total
forested area) is less than 10%,
any patch containing forest
interior
where >30% woodland cover,
all patches with 4 ha interior
using 200 m edge
Any woodland that falls within
or overlaps with a core or
corridor in any identified natural
heritage system incl. Big Picture
2002
Hydrology/
Groundwater
30 m from streams, wetlands,
lakes, headwaters sources and
catchments of first order
watercourse
Eastern Ontario
Woodland Valuation
System
(Rowsell 2003)*
Urban:
>4 ha (=3)
2-4 ha (=2)
<2 ha (=1)
Rural:
>200 ha (=3)
20-200 ha (=2)
<20 ha (=1)
≥ 4 ha remains after 200
m edge removed (3);
m edge removed (2);
m removed (1 or 0)
Closest edge between
patches: < 100 m (3);
100 - 250 m (2);
>250m (1)
Proximity to water:
<30 m (3);
30-50 m (2);
>50 m (1)
Slope:
>30% (3);
15-30% (2);
<15%(1)
Note: * The Woodlands Valuation System rates the criteria evenly relative to one another (i.e., not weighted) and
then sums up the score from each criterion to give a final number to an individual woodland patch.
Other
Slope: > or equal to 10%;
Soils subject to wind and erosion
For the NHS a limited review of criteria for significant woodlands used or proposed by others in
Official Plans and Natural Heritage Systems was undertaken. The results are presented in Table
7.5.
50
Table 7.5 Criteria Used for the Determination of Significant Woodlands In Southern Ontario
Criteria
Patch Size
Halton Region
(GLL 2002)
Quinte West
/Belleville
(Lower Trent CA
2001)
Hamilton
(City of Hamilton
2004)
York Region
(2005 – draft)
Urban Area: ≥2 ha
> 40 ha
(forest cover in
study area 30.6%)
If percent cover in
planning unit (urban
vs.
rural
by
watershed):
<5%, 1 ha
5-10%, 2 ha
11-15%, 4 ha
16-20%, 10 ha
21-30%, 15 ha
Greater than 100 m
from edge
South of ORM:
≥ 4 ha
North of ORM:
10
ha
≥
(Any woodlands
on the ORM will
follow
the
ORMCP
guidelines)
Since
all
woodlands over
10 ha defined as
significant,
deemed
unnecessary
to
include
criteria
for interior or age
Any
native
woodland over 2
ha:
1) within 100 m
of
another
significant feature
OR
2) that occurs
within
the
Regional
Greenlands
System
Rural:
South of
Escarpment: ≥4 ha
North of
Escarpment ≥10 ha
Forest Interior
/ Shape
4 ha or greater
interior for 100 m,
200 m and 300 m
from perimeter
100 m from edge
and patch width at
least 300 m
Proximity/
Connectivity
Corridors associated
with major creeks
and river valleys
within 50 m of
creek or river edge
Patches adjacent or
overlapping with
other
features
(including PSWs,
ANSIs, ESAs)
Located within 50
m of a significant
natural area
Woodlands within
150 m either side of
the top of the
Niagara Escarpment
(incl. creeks and
rivers designated as
coldwater)
51
Town of Innisfil
(2006)1
≥10 ha
Upper Thames
River C. A.
Natural Heritage
Study (2003)
Any woodland >
10 ha in area or
any
woodland
patch less than 25
ha that contains
forest interior
Couchiching
Conservancy –
The Oro Moraine
Habitat Project
(2005)
Based
on
the
degree of Forest
Cover; >40 ha
Any
woodland
patch
with
a
minimum of 4 ha
of interior habitat,
defined using a
100 m buffer from
the woodland edge
Within 100 m of
another significant
feature
(2
ha
minimum area)
1. Where 50% of
the patch is within
750m of a “core
area”
2.Within 100 m of
a patch ≥ 10 ha
3. For patches
exempt
from
watercourse
criteria any within
a “Big Picture”
corridor along the
n.
branch
of
Any woodland that
falls
within
a
designated core or
corridor
area
defined by the
Bigger
Picture
project
or
a
municipal natural
heritage network is
considered
significant for this
criterion
Criteria
Hydrology/
Groundwater
Age
Other
Halton Region
(GLL 2002)
Quinte West
/Belleville
(Lower Trent CA
2001)
Hamilton
(City of Hamilton
2004)
York Region
(2005 – draft)
Town of Innisfil
(2006)1
Watercourse
passing through or
arising
in
a
woodland (cold and
warm
water
fisheries)
Any woodland > 1
ha adjacent to
watercourse
Within 30 m of any
hydrological
feature,
including
all
streams,
headwater
areas,
wetlands and lakes
Within 30 m of
watercourse,
surface
water
feature or an
evaluated wetland
Within 30 m of
watercourse,
surface
water
feature
or
an
evaluated wetland
(2 ha minimum
area)
100 years or more
100 years or more
G1, G2, G3, S1,
S2, S3 plant or
animal species
G1, G2, G3, S1,
S2, S3 plant or
animal species
Within 30 m of a
watercourse
or
Drainage to firstorder streams
Polygon
average
age >99 years
Core Area: ≥ 25 ha
with core at least 4
ha, 100m from edge
Slope ≥ 10%
Any
woodland
containing
threatened,
endangered, special
concern,
provincially
or
locally rare plant or
wildlife species
Upper Thames
River C. A.
Natural Heritage
Study (2003)
Thames River
1. Any woodland
patch containing or
within 50 m of a
watercourse.
2. Any woodland
on porous soils that
may have sensitive
groundwater
recharge
or
discharge
resources
Couchiching
Conservancy –
The Oro Moraine
Habitat Project
(2005)
If any portion is
within 30 m of a
stream or wetland,
or
within
the
catchment area of
first-order
watercourses,
or
within
recharge,
discharge,
or
shallow
aquifer
areas
Any woodland on
slopes greater than
or equal to 10%, or
on soils subject to
wind and water
erosion
Any
species Any
species
by
designated
by designated
COSEWIC
or COSEWIC
or
COSSARO
as COSSARO
as
or
Threatened
or Threatened
Endangered, or of Endangered, or of
Special Concern
Special Concern
1
Note: according to the source, criteria were based on “other recently completed Significant Woodland studies”, as data on Innisfil woodlands were lacking
52
Lake Simcoe Watershed Natural Heritage System
In addition to the many approaches reviewed by Ontario Nature, and those reviewed in the above
table, the Toronto Region Conservation Authority (TRCA) has also recently completed a
Terrestrial Natural Heritage System Strategy (TRCA 2006). The TRCA selected a weighted
scoring system based on quality (patch area, shape and matrix influence), quantity (% cover) and
distribution (location of natural cover and its quality). This approach evaluates the landscape as
one functional unit and therefore does not evaluate each natural heritage component (e.g.,
woodlands, valleylands and wetlands). The basic unit used is the “habitat patch”, which can be
examined at various scales and under various restoration scenarios, which was a primary goal of
the development of this approach.
7.8
Criteria for the Lake Simcoe Watershed NHS
The development of criteria for the selection of significant woodlands in the Lake Simcoe
Watershed was based on a combination of the following: literature review, approaches
recommended by others, the practical application of criteria elsewhere in southern Ontario, and
professional judgment.
It is important to note that some recommendations made by others for the designation of
significant woodlands were not necessarily made in the context of the development of a multicomponent natural heritage system. For example, recommendations to include woodlands
overlapping with the Big Picture 2002 mapping made by Ontario Nature (Table 7.4), presumably
speak to a desire to ensure a linked system. However, within this NHS, other components (e.g.,
valleyland, wetlands and linkage) will be used to address the development of the system and
subsequent initiatives will build on the NHS.
The same issue applies to the use of rare species (e.g., Endangered and Threatened Species),
which are discussed under two different components (i.e., Endangered and Threatened Species
and Significant Wildlife Habitat).
In a similar vein, the designation of some other features is not a function of a natural heritage
planning exercise. For example, the use of “slope” (as a criterion for the determination of
significant woodland), is more correctly a hazard-related descriptor. As pointed out by North
53
South Environmental Inc. (NSEI) (2005) woodland cover may actually discourage the growth of
dense ground cover (which in turn prevents erosion).
The following paragraphs provide a review of the selected criteria for significant woodlands
within the Lake Simcoe Watershed.
Patch Size – Ecology
The literature indicates that some woodland patches begin to provide some appreciable level of
function for woodland flora and fauna at 10 ha and that area-sensitive breeding birds, for
example, can at least be anticipated to occur at the 25 ha level (depending on other interrelated
factors such as woodland cover and habitat quality). The patch size analysis indicated that
woodland cover within the watershed would be seriously undermined if these classes for patch
size were compromised. The larger woodlands (25 ha or greater) were assigned to Level 1 (for
retention – see Policy Section 13.0). Intermediate-sized woodlands at 10 ha to 25 ha were placed
in Level 2 (i.e., for retention with very limited flexibility). Smaller woodlands (2 – 10 ha) are
identified as Level 4 - supporting features, which have an increasing ecological role as total
forest cover increases. In part, this is reflected in the Big Woods Policy Areas.
54
Patch Size – Socially Significant Woodlands
Recognizing the social importance of woodlands is contemplated by the natural heritage section
of the PPS. Excluding small urban woodlands from protection for socio-economic factors can
lead to weak ecological arguments being advanced for their protection and in their absence to
more “people pressure” on ecologically functional patches that are maintained.
There are few guidelines developed to meet this definition. Within urban areas 0.5 ha has been
used or suggested in other jurisdictions. Following comments from stakeholders the lower
threshold applied in the NHS was 4 ha. The patch size analysis indicates that the amount of
woodland cover represented by patches less than 4 ha within urban areas is small, but this
cumulative area number is obviously biased downwards, as the smaller the patch, the less likely
it is to be mapped using ELC in the first place.
These urban woodlands with an area of 4 ha to 10 ha have been designated a Level 3 feature,
recognizing their significance both socially, to the overall forest cover within the watershed and
limited ecological function, while permitting flexibility in the planning process. Whether or not
these features are dominated by native species is of little consequence, as their value is not being
assessed strictly on an ecological basis.
Contribution to Watershed Cover
Perhaps the most important factor affecting the integrity of the watershed from a woodland
perspective is the total percentage of woodland cover. There is substantive evidence that the key
cover number lies between 20 and 40%, and is probably closer to the higher end of this spread;
the use of 30% as a minimum ecological threshold is becoming widely adopted.
Woodland cover within the Lake Simcoe Watershed is already below this minimum threshold.
The portions of each the four ecodistricts represented within the watershed also fall below the
30% threshold when plantations and cultural woodlands are deducted. With plantations and
cultural woodlands included, only the Oak Ridges Moraine ecodistrict meets the threshold (note
that woodland cover by entire ecodistrict was not considered, just the portion within the Lake
Simcoe Watershed).
However, seven of the 18 Lake Simcoe subwatershed groups (plus the islands) did meet the 30%
threshold (Figure 7.5). In terms of area, these subwatersheds represent approximately 41% of the
land base of the watershed.
For many organisms, it is possible that this “group of seven” contains many of the productive
woodlands and that the presence of sensitive species in other areas may in part be predicated by
the high level of landscape woodland cover in those areas.
Frequently, the approach applied in natural heritage planning exercises is that as forest cover
increases, the recommended minimum patch size (for retention) also increases (e.g., OMNR
1999). In a real landscape and until a lower woodland cover level is reached, this effectively
55
results in a declining amount of woodland cover. It is likely that in similar terrains, patch size
and total woodland cover are also interrelated metrics. The scientific evidence seems to suggest
that this approach is not the best way to maintain functional ecosystems; if productive areas are
those with the largest woodland patches and the highest amounts of cover, then protecting less of
these woodlands will ensure that the landscape is managed to the lowest common denominator.
To recognize the ecological contribution of smaller woodlands to the overall forest cover
threshold, all woodlands 2 ha or larger (to 10 ha) in the entire watershed are recognized as
supporting features (Level 4 - supporting). Although these features do not receive a “significant
woodland” designation, it is intended to recognize the role that these small patches play in
maintaining a healthy landscape.
Note that it is not the intent of the NHS to include typical hedgerows as woodlands, even when
they may have been designated by the ELC mapping as “Cultural Woodlands”. For the purposes
of applying the woodland criteria only, hedgerows are excluded unless they are at least 40 m in
width.
Consistent with other approaches to the designation of significant woodlands, plantations have
been included. Plantations contribute in an important way to overall forest cover, have many
wildlife functions, social functions and provide other services such as the sequestration of
carbon. Many plantations are in various stages of succession to forest cover. Plantations are
difficult to address as many are also intended to act as nurseries for reforestation projects, and
the definition of an “actively managed” plantation (in the context of exclusion from the NHS) is
subjective and requires detailed site-level information. Nothing in the NHS is meant to detract
from the ability of the owners of plantations to legally harvest their crop. Individual planning
authorities may wish to address this issue in further detail based on their individual
circumstances.
The Big Woods
The arguments provided above and the supporting literature speak strongly to source areas of
high aggregations of woodland patches and/or the inclusion of patches which are more than 500
ha in size. The concept here is to recognize and elevate the importance of aggregations of
woodland patches and perhaps to provide guidance for future replacement efforts. The analysis
methods employed resulted in areas of known aggregations overlain with areas of contiguous
patches more than >500 ha.
Several Big Woods Policy Areas were determined relative to these forested areas and were
selected to represent as many ecodistricts as possible and all four quarters of the lake so as to
encompass latitudinal and longitudinal variation (Figure 7.6) (See section 7.5 for methods).
56
Proximity/Connectivity
The interaction (“contagion effects”) of natural heritage patches and components is a constant
theme in the literature. However the science is less than robust when it comes to determining a
distance within which adjacent features should be considered part of the system, based only on
this criterion. This is also consistent with the notion that amount of habitat is more important
than configuration or connectivity.
For the Lake Simcoe Watershed NHS, many of the connectivity issues are being addressed
through the designation of other components, such as Big Woods Policy Areas, habitat for fish,
significant valleylands and linkages. This is a different challenge compared to studies that only
address significant woodlands. Therefore, and in the absence of compelling science to the
contrary, a conservative criterion has been selected that identifies the entirety of any woodland
(≥0.5 ha) that overlaps or is located within 30 m of any other identified Level 1, Level 2 and/or
Level 3 NHS feature. A Level 3 designation will apply to the connected patch.
Greenbelt Plan Woodlands
Within the Greenbelt Plan area, the Greenbelt Plan definition of Significant Woodland takes
precedence over the woodland criteria presented above. At the time of writing, the criteria for
the determination of ‘significant woodland’ within the Greenbelt Plan were not available from
the Province. Once the criteria are available woodlands that meet the Greenbelt criteria and that
are within the Natural Heritage System of the Greenbelt Plan will be identified as Level 1
features. Woodlands outside of the Natural Heritage System of the Greenbelt Plan are subject to
the requirements of the PPS and therefore shall be identified by the LSRCA NHS.
57
58
59
Oak Ridges Moraine Woodlands
For that portion of the Oak Ridges Moraine within the Lake Simcoe Watershed jurisdiction, the
Oak Ridges Moraine Conservation Plan (ORMCP) definition of a Significant Woodland is used,
and replaces the woodland criteria presented above. The ORMCP criteria (OMNR 2004) for
significant woodlands are as follows:
•
4 ha or larger in the Countryside or Settlement Areas;
•
0.5 ha or larger in the Natural Core or Natural linkage Areas.
The following criterion is also used to designate Significant Woodlands on the ORM:
•
When located wholly or partially within key natural heritage or hydrologically sensitive
features or their vegetation protection zones (minimum 0.5 ha).
Unfortunately, these criteria cannot be applied for the purposes of this NHS, as the presence of
the “key natural heritage features” or “hydrologically sensitive features” require detailed sitespecific investigations. Similarly, the definition of woodland on the ORM includes almost all
cultural thickets (CUT) and potentially some cultural meadows, a definition that is not consistent
with the definition of a woodland polygon in this NHS (which strictly follows the ELC system
for southern Ontario).
Regardless of these challenges, to the extent possible ORM woodlands were mapped for the
regulated ORM area. However, this ORM mapping is intended as a rough guide only, as the full
suite of ORMCP criteria as specified in the draft technical paper demands detailed, site-specific
field investigations to ensure conformity with the ORMCP.
The Lake Simcoe Watershed significant woodlands criteria are summarized in Table 7.6. Figure
7.7 depicts a mapping example.
60
Table 7.6 Summary of Significant Woodland Criteria for the Lake Simcoe Watershed
Feature
Patch Size: Ecology
Patch Size: Social
Proximity /
Connectivity
The Big Woods
Contribution to
Watershed
Woodland Cover
Greenbelt Plan
Oak Ridges
Moraine
Woodland patches ≥ 25 ha
Woodland patches ≥ 10-25 ha
Level
Level 1
Level 2
Attribute
Name
WO1
WO2
Cultural Thicket (CUT) units that are contiguous to
Level 1, 2 or 3 woodlands are to be considered part
of the patch for NHS determination purposes (but
not for patch size calculations)
All woodland patches ≥ 4.0 ha to < 10 ha in urban
areas
The entirety of any woodland ≥ 0.5 ha and < 10 ha
that overlaps or is located within 30 m of any
identified Level 1, 2 or 3 feature
As defined in Figure 7.6, designated as Big Woods
Policy Areas
All woodlands ≥ 2.0 ha and < 10 ha
Level 4 –
supporting
WO4-A
Level 3
UWO3
Level 3
WO3
Level 4 supporting
WO4-B
Woodlands consistent with the definition and
criteria of the Greenbelt Plan, within the Greenbelt
NHS
All woodlands that qualify as Key Natural Heritage
Features under the ORMCP and its technical
guidelines
Level 1
NA
Level 1
MWO1
Note:
BWO
For definitions of woodland see Appendix 5.
61
62
7.9
Literature Cited
Austen, M.J.W., C.M. Francis, M.S.W. Bradstreet and D.M. Burke. 2001.
Landscape context and fragmentation effects on forest birds in Southern Ontario. Condor
103:701-714.
Andren, H. 1994.
Effects of habitat fragmentation on birds and mammals in landscapes with different
proportions of suitable habitat: a review. Oikos 71: 355-366.
Bayne, E.M. and K.A. Hobson. 2002.
Apparent survival of male ovenbirds in fragmented and forested boreal landscapes.
Ecology 83: 1307-1316.
Bollinger, E.K. and P.V. Switzer. 2002.
Modelling the impact of edge avoidance on avian nest densities in habitat fragments.
Ecological Applications 12: 1567-1575.
Bowles, J. 1999.
Forest fragments and plants. Southern Ontario Woodlands: The Conservation Challenge.
Conference Casebook. Federation of Ontario Naturalists. 164 pp.
Brooker, L and M. Brooker. 2002.
Dispersal and population dynamics of the blue-breasted fairy wren, Malurus
pulcherrimus, in fragmented habitat in the Western Australian wheatbelt. Wildlife
Research 29: 225-233.
Burke, D.M. and E. Nol. 2000.
Landscape and fragment size effects on reproductive success of forest-breeding birds in
Ontario. Ecological Applications 10: 1749-1761.
Chalfoun, A.D., M.J. Ratnaswamy and F.R. Thompson III. 2002.
Songbird nest predators in forest-pasture edge and forest interior in a fragmented
landscape. Ecological Applications 12: 858-867.
City of Hamilton. 2005.
Discussion Paper #4a: Review of Significant Woodland Criteria Technical Discussion
Paper. 16 pp.
Couchiching Conservancy. 2005.
The Oro Moraine Habitat Project. Available online:
http://www.couchconservancy.ca/oromoraine.htm.
63
Delattre, P., P. Giraudoux, J. Baudry, P. Musard, M. Toussaint, D. Truchetet, P. Stahl et al.
1992.
Land use patterns and types of Common Vole (Microtus arvalis) population kinetics.
Agriculture, Ecosystems and Environment 39:153-168.
Environment Canada, Canadian Wildlife Service. In prep.
Area Sensitive Forest Birds in Urban Areas. Minister of Public Works and Government
Services Canada.
Fahrig, L. 1997.
Relative effects of habitat loss and fragmentation on population extinction. Journal of
Wildlife Management 61:603-610.
Fahrig, L. 2002.
Effect of habitat fragmentation on the extinction threshold: a synthesis. Ecological
Applications 12: 346-353.
Federation of Ontario Naturalists. 2004.
Suggested Guidelines for the Identification of Significant Woodlands in Southern
Ontario. Federation of Ontario Naturalists. Don Mills, Ontario.
Freemark, K. 1988.
Landscape ecology of forest birds in the Northeast. pp. 7-12 in DeGraaf, R.M. and W.M.
Healy (Eds.). United States Department of Agriculture, Northeast Forest Experimental
Station, General Technical Report NE-140. 32 pp.
Friesen, L.E., M. D. Cadman and R. J. MacKay. 1998.
Nesting success of neotropical migrant songbirds in a highly fragmented landscape.
Conservation Biology 13: 338-346.
Friesen, L. E., V. E. Wyatt and M. D. Cadman. 1999.
Pairing success of wood thrushes in a fragmented agricultural landscape. Wilson Bulletin
111: 279-281.
Gartner Lee Limited. 2002.
Final Report: Rationale and Methodology for Determining Significant Woodlands in the
Regional Municipality of Halton. Prepared for the Regional Municipality of Halton. 66
pp. plus appendices.
64
Golet, F.H., Y. Wang, J.D. Merrow and W.R. DeRagon. 2001.
Relationship between habitat and landscape features and the avian community of red
maple swamps in southern Rhode Island. Wilson Bulletin 113: 217-227.
Heidenreich, C. 1971.
Huronia: A History and Geography of the Huron Indians 1600 – 1650. McClelland and
Stewart Ltd., Toronto.
Herkert, J.R., R.E. Szafoni, V.M. Kleen and J.E. Schwegman. 1993.
Habitat establishment, enhancement and management for forest and grassland birds in
Illinois. Natural Heritage Technical Publication #1, Illinois Department of Conservation,
Springfield, Illinois. 22 pp.
Hilty, J. A., W.Z. Lidicker Jr. and A.M. Merenlender. 2006.
Corridor Ecology. Island Press. Washington, D. C.
Hylander, K., B.G. Jonsson and C. Nilsson. 2002.
Evaluating buffer strips along boreal streams using bryophytes as indicators. Ecological
Larson, B.M., J. Riley, E. A. Snell and H. G. Godschalk. 1999.
The Woodland Heritage of Southern Ontario. Federation of Ontario Naturalists. Don
Mills, Ontario. 262 pp.
Lee, H.T., W.D. Bakowsky, J. Riley, J. Bowles, M. Puddister, P. Uhlig and S. McMurray, 1998:
Ecological Land Classification for Southern Ontario: First Approximation and Its
Application. Ontario Ministry of Natural Resources. SCSS Field Guide FG-02. 225 pp.
Lichstein, J.W., T.R. Simons and K.E. Franzreb. 2002.
Landscape effects on breeding songbird abundance in managed forests. Ecological
Lindenmayer, D.B., R.B. Cunningham, C.F. Donnelly, H. Nix and B.D. Lindenmayer. 2002.
Effects of forest fragmentation on bird assemblages in a novel landscape context.
Lower Trent Conservation. 2001.
Natural Heritage Report. 41pp. plus appendices.
Mancke, R.G. and T.A. Gavin. 2000.
Breeding bird density in woodlands: Effects of depth and buildings at the edges.
Margules, C.R. and R.L. Pressey. 2000.
Systematic conservation planning. Nature 405: 243-253.
65
Maryland Partners in Flight Management Committee. 1997.
Habitat management guidelines for the benefit of landbirds in Maryland. U.S. Fish and
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Annapolis
field
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Available
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McGarigal, K. and S.A. Cushman. 2002.
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37 pp.
Miller, J.R. and R.J. Hobbs. 2002.
Conservation where people live and work. Conservation Biology 16: 330-337.
Nol, E., C.M. Francis and D.M. Burke. 2005.
Using distance from putative source woodlands to predict occurrence of forest birds in
putative sinks. Conservation Biology 19: 836-844.
North–South Environmental Inc. 2005.
York Region Significant Woodlands Study Draft Final Report. Prepared for the Regional
Municipality of York, Transportation and Works Department.
Ontario Ministry of Natural Resources. 2004 (draft).
Oak Ridges Moraine Technical Paper 7. Identification and Protection of Significant
Woodlands on the Oak Ridges Moraine. Unpaginated.
Natural Heritage Reference Manual for Policy 2.3 of the Provincial Policy Statement.
Ontario Ministry of Natural Resources. Peterborough. 127 pp.
Reid, R. 2002.
Evaluation of Significant Woodlands in Southern Ontario: A Review of the State of the
Art. Prepared for the Federation of Ontario Naturalists. Pp. 103-125. In Appendix E.
Federation of Ontario Naturalists. 2004. Suggested Guidelines for the Identification of
Significant Woodlands in Southern Ontario. Federation of Ontario Naturalists. Don Mills,
Ontario.
Riley, J. L. and P. Mohr. 1994.
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66
Robbins, C.S., D.K. Dawson and B.A. Dowell. 1989.
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Dhondt. 1999.
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Rowsell, M. 2003.
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67
8.0
Significant Valleylands
8.1
Valleylands in the Lake Simcoe Watershed
A valleyland is a natural depression in the landscape that is often, but not always, associated with
a river or stream. Valleylands act as the framework of a watershed and the landscape of the Lake
Simcoe Watershed is a mosaic of valleylands and tablelands. Valleylands vary in size from tiny
headwater features (which create much debate about the definition of a “valley”) to wide valleys
containing substantial rivers and expansive wetlands that everyone would recognize as a
valleyland.
Most definitions of valleylands refer to one aspect or another of their distinctiveness in the
landscape. Using the methods described in Appendix 3 of this report, significant valleylands
were identified in the Lake Simcoe Watershed. As the landscape of the watershed ranges from
the rolling topography of the Oak Ridges Moraine to the relatively flat landscape of Ramara
Township, so too does the distinctiveness of valleylands.
8.2
Why are Valleylands Important?
The Natural Heritage Reference Manual (OMNR 1999) refers to valleylands as the “backbone”
of a watershed because of the many important ecological functions they perform, such as:
•
•
•
•
•
•
•
•
channeling water and wildlife;
providing a connection between natural heritage features;
providing important migration corridors;
providing microclimates;
transporting sediment and nutrients;
acting as natural drainage areas;
maintaining water levels by acting as floodplains and seepage areas; and
maintaining water quality through riparian vegetation communities.
Valleylands are also often associated with cultural significance. Whether they were the location
of aboriginal travel routes or settlements, or post-settlement development patterns, they often
strongly influence human settlement patterns.
Valleylands are generally not developed because of the inherent hazards associated with them.
Natural hazards such as flooding or bank instability and erosion are common in valleys. This has
left many highly urbanized or agricultural areas with valleylands as the only remaining natural
areas. The fact that valleylands are often relatively undisturbed areas existing in relatively
developed areas also renders them as an important feature in the overall natural heritage system.
68
8.3
The Identification of Significant Valleylands
Despite the importance of valleylands to the mandate of Conservation Authorities, they have
generally not been specifically addressed (except perhaps indirectly as part of connectivity
pathways) when it comes to the development of natural heritage systems. In part, this is related
to the complexity of identifying the limits of valleylands at a landscape scale. However, the
advent of GIS tools has made it possible to use digital elevation models and other analytical
approaches to identify valleylands at a regional scale using chosen design inputs (e.g., depth,
length, height and slope). A precursor of determining valleylands has been the recent update of
the LSRCA regulations.
The Natural Heritage Reference Manual (OMNR 1999) suggests several factors to apply to the
evaluation of the relative importance of valleylands. These are:
•
•
•
•
•
Prominence of a distinctive landform;
Degree of naturalness;
Ecological functions (e.g., habitat, linkage);
Restoration potential; and
Historical-cultural value.
There is at least one example in southern Ontario where the challenge of identifying significant
valleylands was explicitly addressed. As part of the development of a NHS, the Raisin Region
Conservation Authority (RRCA) identified and evaluated valleylands within its watershed (Land
Ethic Group 2005). The RRCA mapped valleylands on the basis of its new (2006) Regulation
and then applied a weighted scoring system based on the following criteria:
•
•
•
•
•
•
•
Prominence as a distinctive landform;
Degree of naturalness;
Habitat value;
Degree of alteration;
Linkage function;
Restoration potential; and
Historical-cultural value.
The valleylands were then classified into one of three categories of importance: lower, medium
and high. However, once this was complete, the RRCA and its steering committee decided that
all valleylands are equally important and included all valleylands in its natural heritage system.
The Oak Ridges Moraine Conservation Plan’s draft technical paper entitled Identification of Key
Natural Heritage Features on the Oak Ridges Moraine (OMNR 2004) chose a more prescriptive
method for the identification of Oak Ridges Moraine Significant Valleylands. The following was
included within the definition of a valley:
•
All streams with well-defined valley morphology having an average width of
25 m or more; or
69
8.4
•
All spillways and ravines with the presence of flowing or standing water, an
average width of 25 m or more, a length of greater than 50 m, two valley walls
with a slope of 15% or greater with a minimum height of 5 m, and an overall
area of 0.5 ha; or
•
Additional features identified by the approval authority that are consistent
with one or more of the functions described [in the draft ORM technical
paper].
Policy Framework
Provincial policy is directed at the identification and protection of significant valleylands.
Section 2.1.4 of the Provincial Policy Statement (PPS) (MMAH 2005) states that:
Development and site alteration shall not be permitted in significant valleylands
south and east of the Canadian Shield...unless it has been demonstrated that there
will be no negative impacts on the natural features or their ecological functions.
Pertinent definitions found within the PPS are as follows:
Valleyland
…[a] natural area that occurs in a valley or other landform depression that has
water flowing through or standing for some period of the year.
Significant
…ecologically important in terms of features, functions, representation or amount,
and contributing to the quality and diversity of an identifiable geographic area or
natural heritage system.
The Lake Simcoe Watershed Development Policies 20061 (LSRCA 2006) define valleylands as:
A depressional feature associated with a river or stream whether or not it contains
a watercourse.
The LSRCA Regulation 179/06 made under the Conservation Authorities Act requires that a
permit be issued by the Authority prior to any development within valleylands. The Authority
mapping (i.e., the Regulation mapping) used to administer the regulation includes “apparent
valleys” which are valley features that are determined using a digital elevation model, along with
a 15 m additional area on either side of the feature.
1
LSRCA Watershed Development Policies (2006) were based on the definitions from the “Guide for
Developing Schedules of Regulated Areas August 2003”.
70
The Greenbelt Plan identifies significant valleylands as Key Natural Heritage Features.
However, at the time of writing, the criteria for determining significant valleylands were not
available from the Province. Once the criteria are available, they and the definitions and policies
of the Greenbelt Plan shall apply.
8.5
Criteria
The LSRCA regulates all valleylands (significant or otherwise) within its jurisdiction and these
valleylands have been identified independently of this NHS definition.
The Authority’s regulatory mapping includes all “apparent” valleylands and while a useful
starting point, does not provide sufficient resolution to separate out a subset of “significant
valleylands” specifically for the purpose of the development of the NHS. For example, many
shallow, “apparent” valley features extend into areas of built urban form, or extend across farm
fields as actively ploughed lands.
To provide further resolution, ArcGIS software (Appendix 3) was used with a variety of
shapefiles to identify valleylands in two areas: off the Oak Ridges Moraine (ORM) and on the
Oak Ridges Moraine, which met the following criteria:
Off the Oak Ridges Moraine
Off the ORM, significant valleylands are defined in the NHS as follows:
•
All physical features with an average width of 25 m or more, a length of greater
than 50 m, two valley walls with a slope of 8% or greater with a minimum height
of 5 m.
These valleys were identified at a large scale (1:60,000) using the “hillshade” shapefile, a slope
classification file and a point layer of stable top of slope. In addition, the “slope erosion” layer,
constructed for the LSRCA’s Regulation, was also used to verify the location of the slope. As
this layer was based on a much broader set of criteria, the valleylands were most often situated
within the slope erosion polygons.
The slope criterion (8%) was also run at various alternate levels (starting at the ORM’s 15%) but
was eventually reduced to 8% after extensive testing of degrees of slope. This percentage was
found to delineate the more prominent valleys that could reasonably be expected to be of
“significance” at the watershed scale. Greater slopes resulted in very few valleylands being
delineated and lesser slopes resulted in many relatively unobtrusive valleys being identified as
significant.
The valleylands were then digitized into polygons to permit greater manipulation and to allow
confirmation that they met the width and length criteria.
71
On the Oak Ridges Moraine
Within the ORM regulated portion of the Lake Simcoe Watershed, the Oak Ridges Moraine
Conservation Plan (ORMCP) definition of a Significant Valleyland is used. A significant
valleyland on the ORM is as follows:
•
All physical features with an average width of 25 m or more, a length of greater
than 50 m, two valley walls with a slope of 15% or greater with a minimum
height of 5 m.
The ORM valleylands were digitized using the same methodology as those off the Moraine.
However the greater slope criteria of the Moraine created smaller, tighter valleylands,
necessitating the digitizing to be done at a much smaller scale (1:5,000).
Once the polygons were produced, there was some degree of subjectivity, such as where the
valley began and ended. Various additional technical GIS tools were used to assist in some of
the more difficult areas.
The guidelines for the identification of “significant valleylands” on the ORM were largely
implemented as recommended in the draft ORMCP technical paper (OMNR 2004). To the extent
possible these features were mapped for the regulated ORM area. However, this ORM mapping
is intended as a guide only, as the full suite of ORMCP criteria requires detailed, site-specific
field investigations to ensure conformity with the ORMCP.
Summary of Criteria
Significant valleylands on the Oak Ridges Moraine were included as Level 1 features.
Significant valleylands in the rest of the watershed (not ORM) were included as Level 2 features.
Undoubtedly there are many valleys within the watershed that have not been identified as
“significant valleylands”, as they did not meet the above criteria. Some of these valleys may be
captured within the NHS as other natural heritage components, such as linkages, significant
wetlands or habitat for fish.
The Lake Simcoe Watershed significant valleylands criteria are summarized in Table 8.1. Figure
8.1 illustrates an example.
72
Table 8.1 Summary of Significant Valleylands Criteria
for the Lake Simcoe Watershed
Feature
Criterion
Details
Lake Simcoe
Watershed NHS
Level
Attribute
Name
Significant
Valleyland off
the Oak
Ridges
Moraine
Width
25 m
Level 2
SVL2
Length
50 m
Slope
8%
Valleylands that
meet these criteria
will be included in
the NHS
Height
5m
Width
25 m
Level 1
MVL1
Length
50 m
Slope
15%
Valleylands that
meet these criteria
will be included in
the NHS
Height
5m
Area
≥ 0.5 ha
Significant
Valleyland on
the Oak
Ridges
Moraine
The LSRCA regulates all valleylands (significant or otherwise) within its jurisdiction and these
valleylands are identified independently of this NHS definition.
8.6
Literature Cited
Lake Simcoe Region Conservation Authority. 2006.
Watershed Development Policies. Resolution No. BOD-06-72. 21 pp plus appendices.
Land Ethic Group. 2005.
Natural Heritage Strategy for the Raisin Region Conservation Authority. 39 pp. plus
maps.
Ontario Ministry of Municipal Housing and Affairs. 2005.
37 pp.
Ontario Wetland Evaluation System. Southern Manual. 3rd Edition. OMNR #502254-1.
Ontario Ministry of Natural Resources. 2004 (draft).
Identification of Key Natural Heritage Features on the Oak Ridges Moraine. Technical
Paper-1.
73
74
9.0
9.1
Background: What is Significant Wildlife Habitat?
In the Provincial Policy Statement 2005 (PPS) (MMAH 2005), wildlife habitat is identified as:
areas where plants, animals and other organisms live and find adequate amounts
of food, water, shelter and space needed to sustain their population. Specific
wildlife habitats of concern may include areas where species concentrate at a
vulnerable point in their annual life cycle; and areas which are important to
migratory or non-migratory species.
Significant Wildlife Habitat (SWH) is an area that is considered to be an important habitat of a
particular species or group of species. Examples of SWH include: hibernation grounds,
waterfowl nesting habitats, amphibian breeding woodland ponds, seeps and springs and unique
habitats (such as bat hibernacula). The importance of SWH is based on the premise that some
habitat types are no longer plentiful and it also encompasses areas where species concentrate to
breed or to hibernate, as well as unique habitat. The scale of importance can vary from national
(e.g., a migratory stopover/concentration area for waterfowl) to local (e.g., an important
amphibian breeding pond) (OMNR 2000).
The Natural Heritage Reference Manual (OMNR 1999), which is currently under review, guides
the identification of natural heritage features. Further guidance is also provided in the Significant
Wildlife Habitat Technical Guide (SWHTG) (OMNR 2000). This document suggests approaches
for defining, identifying and evaluating SWH features.
The evaluation of SWH is challenging, as not all areas that contain a “suggested” feature will be
significant. The technical guide suggests over 30 sub-criteria in order to identify significant
habitats (e.g., winter deer yards, bat hibernacula, mineral licks). Almost all of these sub-criteria
are relative, meaning that some scale of relative importance needs to be applied. This may render
one example significant, while excluding another.
For example, there are many amphibian breeding ponds found in woodlands, but not all will be
identified as “significant”. Only the more important breeding ponds within any given jurisdiction
(e.g., municipality) are to be considered as significant. As this is a relative assessment, extensive
fieldwork to identify all or most of the breeding ponds would be required in order to decide
which ponds might qualify as “significant”. In addition to the requirement for detailed field
investigations, there is some level of subjectivity involved, which further contributes to the
difficulty of SWH evaluation.
9.2
Why is Wildlife Habitat Important?
The driving force for the designation of SWH is the protection of biodiversity. The provision of
habitat is one of the main functions of natural heritage features (OMNR 1999). There are five
principal types of SWH suggested. These are:
75
•
•
•
•
•
Seasonal concentration areas;
Rare vegetation communities;
Specialized habitats for wildlife;
Habitats of species of conservation concern; and
Wildlife movement corridors.
Seasonal concentrations of animals
Areas of seasonal concentrations of animals provide important cover and protection from
inclement weather conditions and predators (OMNR 2000). They may also be areas where there
is an abundance of resources, such as food or breeding sites. These habitats directly influence the
persistence of species. Some examples include: winter deer yards, waterfowl stopover and
staging areas, and reptile hibernacula.
Rare vegetation communities
Rare vegetation communities often provide habitat for rare species that in turn depend on these
habitats for survival (OMNR 2000). If rare vegetation communities are lost, the number of rare
species will increase and therefore further reduce biodiversity. Some examples of rare vegetation
communities in southern Ontario are tallgrass prairies, fens, bogs, and alvars.
Specialized habitats for wildlife
Specialized habitats for wildlife are considered to be those that serve specialized species. Some
species have particular requirements in order to ensure their survival. This is a rather poorly
defined category, but could, for example, include seepage areas that support certain flora and
fauna. These specialized habitats are often of seasonal use.
Habitats of species of conservation concern
This category includes species that may be locally rare or in decline, but that have not reached
the level of rarity that is normally associated with Endangered or Threatened designations. It is
suggested that the highest priority for protection be provided to habitats of the most rare species
(on a scale of global through to local municipality); and that habitats that support large
populations of a species of concern should be considered significant.
Wildlife movement corridors
Movement corridors are included in the Significant Wildlife Habitat Technical Guide (OMNR
2000) as especially important features for those species that require a variety of habitats to
survive. Movement corridors allow animals to travel across the landscape with cover that
76
protects them from predators and provides shelter from harsh weather conditions (OMNR 2000).
However, the provision of connectivity of natural features, natural heritage systems, and the
linkages between and among them is explicitly addressed in the PPS in Section 2.1.2 and will be
treated in its own category (“Linkage”) in the Lake Simcoe NHS.
9.3
Use of the Significant Wildlife Habitat Designation
Rarely has SWH been explicitly determined by planning authorities or others preparing Natural
Heritage Systems. This is generally due to a lack of available data. The Raisin Region
Conservation Authority and the Eastern Ontario Natural Heritage Working Group have both
addressed SWH but concluded that the available data were inadequate (Land Ethic Group 2005;
Stow and Hamill 2003).
The Lower Trent Conservation Authority has addressed SWH more closely than most others, and
included it within its proposed NHS system (Lower Trent Conservation 2001). However, the
inadequacy of available data is highlighted and the SWH component is incomplete.
Natural heritage systems that do not specifically identify the designated components that
collectively comprise the system (e.g., the provincial Greenbelt) imply that SWH is included
within the system. However, without the designation of the specific components of the system, it
is unclear as to which features, if any, are included specifically as SWH, as opposed to other
components. However, many SWH elements are inevitably included in other components. For
example, most important woodland breeding ponds will be captured within designated
Significant Woodlands.
Ideally a planning authority or agency would first compile detailed field data gathered within its
jurisdiction. The planning authority would then determine the criteria that would be applied
using the suggestions of MNR’s Significant Wildlife Habitat Technical Guidelines as a guide.
Many of the suggested criteria do not represent clearly defined thresholds (e.g., for colonial
waterbirds: “permanence of the site” “species representation in the planning area” or “least
disturbed sites”). Therefore this process is probably best informed by the results of the detailed
field data gathering across the jurisdiction.
This example also demonstrates the difficulty of applying the SWH designation at the site level
(e.g., by a proponent or review agency). It is often not possible to determine whether or not a
particular feature on an individual property might represent, for example “a least disturbed site”
or a site with “the highest plant species diversity” in the planning area, as comparative data are
frequently lacking or restricted. Where, during site-specific investigations a feature or function is
located that clearly meets the SWH test as determined by a particular planning authority, it will
be addressed according to the direction within the Official Plan.
It is unlikely that data of the required extent and quality are going to be forthcoming for the Lake
Simcoe Watershed in the near future for either LSRCA or for planning authorities to undertake
this comparative assessment as a jurisdictional scale.
77
9.4
Policy Framework
Provincial Policy Statement
Significant Wildlife Habitat is addressed by Section 2.1.4 of the PPS, which specifies that:
Development and site alteration shall not be permitted in significant wildlife
habitat unless it has been demonstrated that there will be no negative impacts on
the natural features or their ecological functions.
The PPS defines wildlife habitat as significant where it is:
ecologically important in terms of features, functions, representation or amount,
and contributing to the quality and diversity of an identifiable geographic area or
Natural Heritage System.
Generally, there are no municipal Official Plans that have designated significant wildlife habitat,
although some specific elements may have been addressed.
Significant Wildlife Habitat in the Greenbelt Plan Area
The Greenbelt Plan identifies SWH as a Key Natural Heritage Feature. However, at the time of
writing, the criteria for the identification of SWH within the Greenbelt Plan area have not been
made available by the Province. Once the criteria are available, they and the definitions and
policies of the Greenbelt Plan shall apply.
Significant Wildlife Habitat on the Oak Ridges Moraine
On the ORM, SWH is identified by the MNR (OMNR 2004). The identification procedure is
site-specific and follows the suggested guidelines of the draft Significant Wildlife Habitat
Technical Guide (OMNR 2000). The Oak Ridges Moraine Conservation Plan (ORMCP)
includes SWH as a Key Natural Heritage Feature. However, the Significant Wildlife Habitat
Technical Paper (OMNR February 2004) notes that “…a majority of SWH on the ORM can be
found either wholly or partially within the boundaries of other Key Natural Heritage Features or
Hydrologically Sensitive Features”. The technical paper states that municipalities are not
responsible for the identification of SWH, but rather SWH will be identified in response to sitespecific planning and is the responsibility of the proponent. Application of the MNR criteria for
mapping purposes in the NHS would require detailed site-specific investigations.
78
9.5
Criteria
In the Lake Simcoe Watershed sufficient data to designate SWH on a watershed-wide basis are
restricted to four subcomponents based on known information. These are:
•
•
•
•
Winter Deer Yards;
Colonial Waterbird Nesting Sites;
Rare Ecological Land Classification (ELC) communities (e.g., tallgrass prairies,
alvars, fens, and bogs); and
Grassland Communities.
For all other suggested features (e.g., bat hibernacula), extensive and intensive fieldwork would
be required over a large watershed (~250,000 ha), that would likely take many years to complete.
If and when data for analysis become available at the landscape scale then additional criteria can
be added to the SWH component.
Winter Deer Yards
Deer yard mapping is typically undertaken by the MNR. Because White-tailed Deer (Odocoileus
virginianus) do not move well in deep snow, they sometimes remain in sheltered areas during the
winter, or as snow begins to accumulate. Yards typically consist of a core area of coniferous
forest (over 60% canopy cover), surrounded by mixed or deciduous forest. Yards can persist over
many years and the use of specific yards is likely learned by successive generations of deer. The
core area is considered by MNR to represent SWH.
The understory of the deer yard areas usually consists of small trees, especially Eastern White
Cedar (Thuja occidentalis), which serve as winter food. If snowfall is heavy, the deer stay within
the core of the yard. Deer tend to use the same yards year after year and are not highly adaptable
in moving to a new yard. These yards can be critical to the survival of White-tailed Deer in some
parts of the Province (OMNR 2000).
The core deer yard (Stratum 1) mapping provided by the MNR (NRVIS mapping 1999) was used
to designate this component of SWH as a Level 2 feature.
Colonial Waterbird Nesting Sites
Colonially-nesting waterbirds concentrate in relatively small areas for nesting purposes. These
species include cormorants, herons, terns and gulls. Individual colonies may support the entire
breeding population for a given species across a relatively large area. Because colonial
waterbirds typically nest in relatively confined areas, they can be particularly susceptible to
disturbance, disease or habitat destruction.
The Ontario Heronry Inventory database has not been updated for 15 years (Jon McCracken,
Bird Studies Canada, pers. comm., 2006); it also appears that the database of historical
information regarding heronries may not be available. Bird Studies Canada kindly provided
79
information from the Breeding Bird Atlas of Ontario database, which is based on data which
were gathered by volunteers from 2001 to 2005 inclusive. The locations of colonies, as taken
from this database, were mapped and included within the designated SWH as Level 2 features.
The Canadian Wildlife Service (CWS) also gathers information on colonial nesting birds for the
Great Lakes and some additional inland locations. At the time of writing these data were also
unavailable. If these data become available, the locations of the colonies should be mapped and
included within the designated SWH as a Level 2 feature.
Rare Vegetation Communities
Based on the southern Ontario ELC mapping program, rare vegetation communities identified
within the Lake Simcoe Watershed include: alvars, tallgrass prairies, fens and bogs. These
communities are designed SWH as Level 2 features.
Alvars are provincially vulnerable communities (as ranked by the NHIC) that are characterized
by naturally open areas of thin soil over essentially flat limestone or marble rock with trees
absent or at least not forming a continuous canopy (LSEMS 2003). Approximately 27 ha of
alvars have been identified in the Lake Simcoe Watershed, all of which are situated on the
Carden Plain in the northeast portion of the watershed.
Tallgrass prairies are open (or semi-open) plains covered in tall grass, with little to no tree cover.
They are characterized by droughty soil conditions and ground fires. These ecosystems support a
high concentration of rare plants and associated insects. Fifteen percent of the watershed’s rare
plant species are found in tallgrass prairies. Tallgrass prairies once covered sandy areas in the
southwest portion of Lake Simcoe at Holland Landing, DeGrassi Point and Fox Island. These
areas have experienced a long history of occupation by First Nations. It is probable that the First
Nations encouraged the ground fires that are essential for the maintenance of the prairies. These
prairies have become significantly diminished in size due to natural woody succession, which
was once kept in check by the fires (LSEMS 2003). However, in limited areas some
maintenance is being undertaken by conservation groups such as Tallgrass Ontario.
Fens are primarily characterized by specific kinds of plants that are only found in these wetland
habitats (See Section 6.2). In the Lake Simcoe Watershed, almost all known fens are peat-based
and comprise a total of approximately 450 ha.
Bogs are unusual in that all of their nutrients are delivered by rainfall (a condition referred to as
“ombrotrophic”); consequently they are nutrient poor and the pH is often very acidic (e.g., 3.9 –
4.2), further reducing the availability of nutrients to plants. Only 25 ha of this rare wetland type
have been identified within the Lake Simcoe Watershed (See Section 6.2).
Grassland Communities
Grassland communities (which in this case refers to upland ELC communities of Cultural
Meadows [CUM] and Cultural Thickets [CUT]) in the Lake Simcoe Watershed are generally
80
dominated by non-native cool season grasses, native and non-native forbs and a variety of native
and non-native shrubs. Shrub cover may vary from 0 to 100%. Grasslands generally do not
include pasture lands, which, to the extent possible, are mapped separately within the Lake
Simcoe Watershed as an agricultural use (i.e., they are actively grazed by livestock).
Grassland communities are generally not identified as parts of woodlands or wetlands and they
seldom feature as major components of Areas of Natural and Scientific Interest (ANSIs) or other
protected areas. However, despite the fact that grasslands are often dominated by non-native
vegetation species, many native flora and fauna species use them. Indeed, many of these species
(e.g., Bobolink [Dolichonyx oryzivorus] and Eastern Meadowlark [Sturnella magna]) are found
in no other habitat types and are therefore considered habitat specialists. Presumably, in presettlement times these species were confined to habitats such as burns, previously flooded areas,
prairie habitats and then as today human-altered environments.
Today, some of these species attempt to use active agricultural lands, or at least their edges.
However, expansive areas of “less disturbed” grassland communities are critically important for
the productivity of a wide-variety of species, many of which are in decline not only within
southern Ontario but across North America. Some authorities consider that the decline of
grassland birds in North America has been more pronounced than any other group of birds
(McCracken 2005). A Natural Heritage System which seeks to maintain biodiversity should
address this community type, even if its long-term maintenance requires human intervention
(e.g., fire management, cutting, etc.).
Some of the rarest breeding birds in the province occupy grasslands. This includes species such
as Henslow’s Sparrow (Ammodramus henslowii) and Loggerhead Shrike (Lanius ludovicianus),
both of which are rapidly declining and have almost become extirpated from Ontario. Of the 14
Endangered bird species that breed in Ontario, five use this type of habitat. The most recent
addition to the “Threatened” category is also a specialist of younger “old-field” – the declining
Golden-winged Warbler (Vermivora chrysoptera). Across the province many species typical of
these habitats have shown declines. These include species such as Upland Sandpiper (Bartramia
longicauda), Horned Lark (Alpestris eremophila), Brown Thrasher (Toxostoma rufum), Eastern
Meadowlark, Bobolink and Grasshopper Sparrow (Ammodramus savannarum). Some species
that presently are abundant may also be in decline (e.g., Savannah Sparrow [Passerculus
sandwichensis]). A similar picture could probably be described for other grassland flora and
fauna, such as many snake species, Lepidoptera (moths and butterflies), mammals (e.g., weasels)
and native flora with prairie affinities.
Although there appears to be general agreement on the need for including these habitats in
Natural Heritage Systems, very few attempts have been made to explicitly include them. In most
cases it appears that grasslands are generally included within “corridors” or “linkages”.
Environment Canada (2004) did not address grassland habitats in its publication entitled How
Much Habitat is Enough? However, on the Oak Ridges Moraine the MNR (2004) identified
grasslands greater than 10 ha as “Specialized Habitat” which is significant for guilds or
communities of wildlife species. The thresholds established by the MNR (i.e., numbers of pairs
of certain species, such as 15 pairs of thrashers) are rather high compared to typical distributions
of breeding birds found in remaining grasslands and are also provided without reference to the
81
extent of a grassland patch. In addition, areas that meet the criteria are only to be assessed as
“Candidate SWH” when a change in land use is proposed.
There are many smaller patches of grassland habitat which some authors argue may still be
important contributing habitats for grassland species (Davis 2004; Henningsen and Best 2005).
The MNR (2004) provides information indicating that grassland areas 10 ha or larger provide
habitat for many of the above species, with 25 ha required for Upland Sandpiper and 50 ha for
Bobolink. This resulted in the recommended 10 ha threshold for the Oak Ridges Moraine,
described above. McCracken (2005) reviewed the literature and concluded that the optimal size
of a grassland patch cannot be determined, but that patches less than 10 ha were unlikely to be of
great benefit.
Brown Thrasher was found to be rare in habitat patches less than 4 ha (Forman et al. 1976 cited
in Cavitt and Haas 2000). For the Bobolink, larger fields have higher densities than small fields;
fields ≥ 30 ha were found to support more than twice the number of males (per 100 m of
transect) than fields ≤ 10 ha (Bollinger and Gavin 1992). In Maine, the abundance of Vesper
Sparrow (Pooecetes gramineus) was positively correlated with increasing area; the species
reached 50% incidence at 20 ha in grassland barrens (Vickery et al. 1994).
Grasshopper Sparrows are also more likely to occupy large tracts of habitat than small fragments
(Herkert 1994; Vickery et al. 1994). Minimum area requirements in Maine were about 100 ha
(Vickery et al. 1994), but in Illinois were about 30 ha (Herkert 1994). The Endangered
Henslow’s Sparrow, appears to prefer tallgrass fields also of at least 30 ha.
The newly designated “Threatened” Golden-winged Warbler is usually found in early
successional habitat and territories are most often located in habitat patches that are 10 ha to 50
ha (Confer and Knapp 1981).
One of the challenges of incorporating grasslands into the NHS is identifying those areas that are
“less disturbed”. For example, it is not the intent of this NHS to capture lands that are manicured
grassland, hydro-seed grasslands, lawns, high use pasture lands, or intensive or rotational fallow
farmland. The highest quality grasslands for wildlife, and therefore the targets of the NHS, are:
1. marginal farmlands (and therefore usually only lightly grazed, if at all);
2. grassland over shallow bedrock; and
3. very sandy soils that do not support more intensive land uses.
However, the ELC system has a poorly developed cultural grassland/thicket section that does not
permit differentiation among all of these grasslands types which are simply all lumped together
as cultural meadow or cultural thicket. The criteria in this section are meant to apply to the above
three categories and areas that are mapped that do not reflect one or more of these characteristics
are not intended to be part of the NHS.
Overall, while smaller patches of grassland habitat may have an increasing role to play in the
conservation of grassland birds, only substantive habitat patches consisting of 15 ha of meadow
or 15 ha of thicket (as defined through LSRCA’s ELC mapping; see Appendix 1) will be
82
included within the NHS as SWH. For contiguous shrub and meadow patches the threshold is 20
ha. Smaller patches of grassland that are ≥10 ha, but surrounded by other NHS components, will
also be included in the system. These grassland designations will be Level 4 - supporting NHS
components.
Cultural thickets which are contiguous with woodlands or wetlands that are part of this NHS will
be included as Level 4 – supporting features (as they are in Woodlands, see Section 7.8).
Summary of Criteria
As with other components, SWH may well overlap with one or more other designated
components. For example, a SWH area might also be a significant woodland.
Table 9.1 presents a summary of the criteria used to define SWH in the Lake Simcoe Watershed.
Figure 9.1 depicts a mapping example.
Table 9.1 Summary Criteria for the Identification of SWH in the Lake Simcoe Watershed
Feature
Rare Vegetation Communities
(i.e., prairie, alvar, fen and bog)
Core Winter Deer Yards
Colonial Waterbird Nesting
Sites
Grassland Communities
Greenbelt Plan
Oak Ridges Moraine
All ELC communities of these types
Level 2
Attribute
Name
WH2-A
Core yard areas (Stratum 1) as designated by
MNR
Colony sites as mapped by BSC and CWS
Level 2
WH2-B
Level 2
WH2-C
Level 4 –
supporting
Level 4 –
supporting
Level 4 –
supporting
Level 4 –
supporting
WH4-A
Level 4 –
supporting
WH4-E
Cultural Thicket (CUT) ELC communities ≥
15 ha
Cultural Meadow (CUM) ELC communities
≥ 15 ha
Contiguous CUT/CUM communities ≥ 20 ha
CUT or CUM and contiguous CUT/CUM
communities ≥ 10 ha, when surrounded by
other NHS features
CUT communities that are contiguous with
woodland or wetland patches that qualify as
Level 1, 2 or 3 NHS features
SWH criteria will be provided within the
Greenbelt Plan area in the future by the
Province
Features on the ORM were identified using
same
criteria
as
above.
However
determination of SWH must at least be
consistent with the requirements of the draft
ORMCP Technical Paper
83
Level
WH4-B
WH4-C
WH4-D
N/A
N/A
84
9.6
Literature Cited
Cavitt, J. F., and C. A. Haas. 2000.
Brown Thrasher (Toxostoma rufum). In The Birds of North America, No. 557 (A. Poole
and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Bollinger, E.K. and T. A. Gavin. 1992.
Eastern Bobolink populations: ecology and conservation in an agricultural landscape. Pp.
497–506 in Ecology and Conservation of Neotropical Migrant Landbirds (J. M. Hagan III
and D. W. Johnston, eds.). Smithsonian Institute Press, Washington, D.C
Confer, J. L. and K. Knapp. 1981.
Golden-winged Warblers and Blue-winged Warblers: the relative success of a habitat
specialist and a generalist. Auk 98:108 – 114.
Davis, S. K. 2004.
Area sensitivity in grassland passerines: effects of patch size, patch shape and vegetation
structure on bird abundance and occurrence in southern Saskatchewan. Auk 121: 1130 –
1145.
Environment Canada, Canadian Wildlife Services. 2004.
Forman, R.T.T., A. E. Galli and C. F. Leck. 1976.
Forest size and avian diversity in New Jersey woodlands with some land use
implications. Oecologia 26: 1–8.
Herkert, J.R. 1994.
Breeding bird communities of midwestern prairie fragments: the effects of prescribed
burning and habitat-area. Natural Areas Journal 14: 128–135.
Henningsen, J. C. and L. B. Best. 2005.
Grassland bird use of riparian filter strips in southeast Iowa. Journal of Wildlife
Management 69: 198 – 210.
Jones, S. L., and J. E. Cornely. 2002.
Vesper Sparrow (Pooecetes gramineus). In The Birds of North America, No. 624 (A.
Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Lake Simcoe Environmental Management Strategy. 2003.
State of the Lake Simcoe Watershed.
85
Land Ethic Group. 2005.
Natural Heritage Strategy for the Raisin Region Conservation Authority. 39 pp. plus
maps.
Lower Trent Conservation. 2001.
Natural Heritage Report. 41 pp. plus appendices.
McCracken, J. D. 2005.
Where the Bobolinks roam: the light of North America’s grassland birds. Tropical
Conservancy Biodiversity 6: 20 – 29.
McCracken, J. D. 2006.
Personal communication, October 2006. Bird Studies Canada, Port Rowan, Ontario.
37 pp.
Significant Wildlife Habitat Technical Guide. Ontario Ministry of Natural Resources. 151
pp.
Significant Wildlife Habitat Technical Paper for the Oak Ridges Moraine. MNR
Technical Paper-2 (Draft).
Stow, N. and S. Hamill. 2003.
Significant Wildlife Habitat Technical Report. Eastern Ontario Natural Heritage Working
Group. 10 pp.
Vickery, P. D., M. L. Hunter, Jr. and S. M. Melvin. 1994.
Effects of habitat area on the distribution of grassland birds of Maine. Conservation
Biology 8: 1087–1097.
86
10.0
10.1
Significant Areas of Natural and Scientific Interest (ANSI)
Background
A wide variety of natural landscapes rich in natural heritage features are found in southern
Ontario. To encourage the protection of these features and landscapes, the Ontario Ministry of
Natural Resources has led the provincial Areas of Natural and Scientific Interest (ANSI)
program. The ANSI program began in 1983 with regulation through the Ontario Heritage Act to
meet the objective of ultimately achieving Provincial Park protection status for these biologically
or geologically significant areas (OMNR 1988). The evolution of this provincial program led to
the protection of ANSIs under the Provincial Policy Statement (PPS) as natural heritage features.
There are two types of ANSIs: life science and earth science. Life science ANSIs are based on
biological and ecological characteristics. Earth science ANSIs are based on geological landform
characteristics.
The selection criteria used by the MNR to define ANSIs are:
1.
2.
3.
4.
5.
Representation;
Diversity;
Condition;
Ecological function; and
Special features.
ANSIs can be designated within one of two levels of significance: regional and provincial. These
levels are not based on jurisdictional boundaries but rather are based on ecodistricts. Provincial
significance relates to the best representation of a particular feature within an ecodistrict, while
regional significance is good representation within the ecodistrict, but not the best.
Only provincially significant ANSIs are specifically addressed by the PPS 2005 and they are
identified by the MNR using procedures established by the Province. Presently, there are more
than 500 provincially significant ANSIs in Ontario (OMNR 1999).
10.2
Why are ANSIs Important?
ANSIs are important because they are chosen to represent the full range of biological (life
science) and geological (earth science) resources of a particular area. This means that a
provincially significant life science ANSI is especially important for representing Ontario’s
natural diversity. Regional ANSIs were not selected to be provincially significant but are still
significant within the ecodistrict. Protecting the range of biological resources of an area will help
maintain a high diversity of habitat types, which in turn will aid the maintenance of high
biodiversity.
87
With respect to the Natural Heritage System (NHS), only life science ANSIs will be included.
Earth science ANSIs are omitted as they are based on geological criteria and are of tangential
importance to the development of a Natural Heritage System.
Photograph 10.1 A seared pine in the provincially significant life science ANSI DeGrassi Point Tallgrass Prairie Relict.
Candidate ANSIs are sites that have been selected by MNR to become official ANSIs but for
which the review process has not yet been completed by MNR. According to the MNR, at the
time of writing, there are eight candidate (i.e., not yet designated) provincially significant life
science ANSIs and three candidate regionally significant life science ANSIs within the Lake
Simcoe Watershed. Candidate ANSIs will be added to the NHS for the Lake Simcoe Watershed
if and when they are designated as confirmed ANSIs by the MNR.
10.3
Life Science ANSIs in the Lake Simcoe Watershed
The Lake Simcoe Watershed has seven provincially significant life science ANSIs, comprising a
total of just over 2,000 ha (Table 10.1). This represents a very small proportion of the watershed
(approximately 0.6%).
88
Table 10.1 Provincially Significant Life Science ANSIs in the Lake Simcoe Watershed
ANSI
Area
Primary Features
(ha)
Allandale Lake
3.7 Oak-maple and hemlock-beech forest, 70 m above old
Algonquin Bluffs
Algonquin lake plain, best bluff complex in Site
District 6-8
DeGrassi Point
31 Relict prairie-parkland complex on a sandy, till slope
Prairie Relict
reworked by Lake Algonquin. This oak-pine savanna
has some 27 species with prairie affinities (i.e.,
Sorgastrum
nutans,
Andropogon
scoparius,
Desmodium canadense)
Derryville Bog
237 Situated on the Peterborough Drumlin field, this bog is
the largest, most diverse and least disturbed in
Ecodistrict 6-8, and may be one of the only in the
watershed that meets the strictest definition of a true
bog
Duclos Point
388 Illustrates a variety of different community types
Park Reserve &
associated with wetland habitat. Contains a lakefront,
Adjacent Lands
sandbar and associated backshore marsh complex,
unique to Lake Simcoe
Holland Landing
32 The prairie at Holland Landing is dominated by two
Prairie
prairie grasses, the Big and Little Bluestem
(Andropogon gerardii and A. scoparius). This is the
largest and most extensive prairie remnant in the
Simcoe Lowlands physiographic region
Holland Marsh
1,309 Extensive area and a historical remnant of one of the
largest marshes in southern Ontario. Two regionally
significant features: 1) breeding and migratory
waterfowl habitat and 2) contains a shrub fen, an
uncommon vegetation type
Rugby West
106 Rugby West offers the best example of relatively
undisturbed kame hills with upland semi-mature
woods in Ecodistrict 6-6
Total area
2,106.7
Source: OMNR (2005).
There are seven regionally significant life science ANSIs in the Lake Simcoe Watershed (Table
10.2). These regional ANSIs occupy a total area of 6,870 ha. Excluding the lake, this represents
2.62% of the watershed.
89
Table 10.2 Regionally Significant Life Science ANSIs in the Lake Simcoe Watershed
ANSI
Beaverton River
Swamp
Martin Farm South
McGinnis Point
Pefferlaw Brook
Swamp
Pottageville Swamp
North
Wilfred Bog
Zephyr Creek Swamp
Total area
Area Primary Features
(ha)
1,712 River-swamp complex along Beaverton River
valley with various swamp communities
120 Gentle to moderate rolling kame hills with
immature to semi-mature sugar maple-ash-beech
with sugar maple forest
281 Shoreline swamp on north shore of Lake Simcoe in
Barnstable Bay with two creek outlets.
1,177 River swamp and lake complex along a portion of
the Pefferlaw Brook and Mud Lake
214 This section of the swamp lies on glaciolacustrine
deposits overlain by organics
49 Mature, rich kettle-hole sphagnum-dominated
community. Now mostly extracted for peat.
3,317 River swamp complex
6,870
Source: OMNR (2005).
10.4
Policy Framework
The Provincial Policy Statement (PPS) addresses provincially significant ANSIs in Section 2.1,
Natural Heritage. Section 2.1.4 of the PPS (MMAH 2005) states that:
Development and site alteration shall not be permitted in significant areas of
natural and scientific interest unless it has been demonstrated that there will be
no negative impacts on the natural features or their ecological function.
This policy includes both provincially significant life science and earth science ANSIs. The PPS
defines Areas of Natural and Scientific Interest (ANSI) as:
…areas of land and water containing natural landscapes or features that have
been identified as having life science or earth science values related to protection,
scientific study or education.
Municipal official plans generally incorporate the provincially significant ANSIs within their
environmental protection policies. Occasionally, regionally significant ANSIs are also afforded
some policy protection.
90
10.5
Criteria
As with other components, ANSIs may well reside within more than one NHS criterion (for
example, the Derryville Bog ANSI is also designated a Provincially Significant Wetland).
The criteria for ANSIs have been based primarily on the existing provincial policy framework
but have extended beyond the PPS to include regionally significant ANSIs. This is discussed
further below.
Provincially Significant Life Science ANSIs
All confirmed provincially significant ANSIs will be included in the NHS as a Level 2 Natural
Heritage System component.
Regionally Significant Life Science ANSIs
Regionally significant ANSIs will be included in the NHS as Level 3 Natural Heritage System
components.
Candidate Life Science ANSIs
If and when a candidate life science ANSI is evaluated to a provincially or regionally significant
status the intention is that it be added to the NHS. The local MNR District Office can be
consulted for the latest information on the status of ANSIs.
The Lake Simcoe Watershed ANSI criteria are summarized in Table 10.3. Figure 10.1 depicts a
mapping example.
Table 10.3 Summary of ANSI Criteria for the Lake Simcoe Watershed
Feature
Provincially
Significant ANSIs
Regionally
Significant ANSIs
All confirmed provincially significant
ANSIs
All confirmed regionally significant ANSIs
91
Level
Level 2
Level 3
Attribute
Name
A2-P
A3-R
92
10.6
Literature Cited
Ontario Ministry of Municipal Affairs and Housing. 2005.
Provincial Policy Statement 2005. Ontario Ministry of Municipal Affairs and Housing.
Toronto. 37 pp.
Implementation Strategy: Areas of Natural and Scientific Interest. Ontario Ministry of
Natural Resources. 19 pp.
Natural Heritage Information Center. Natural Areas Report by Area List. Available
online: http://nhic.mnr.gov.on.ca/MNR/nhic/areas/areaslist.cfm.
93
11.0
11.1
Habitat for Fish
Background: What is Habitat for Fish?
Many wet areas provide habitat for fish such as lakes, rivers, streams, ponds, wetlands,
intermittent streams and at certain times of the year seasonally flooded areas (OMNR 1999).
The Provincial Policy Statement 2005 (MMAH 2005) defines fish habitat as:
…spawning grounds and nursery, rearing, food supply, and migration areas on
which fish depend directly or indirectly in order to carry out their life process.
This broad definition, which is also consistent with the federal Fisheries Act (FA), includes many
organisms (i.e., plants, insects, larvae, mollusks, arthropods and others) as part of the food
supply (LSEMS 2003). Fish habitat provides food and cover and conditions for successful
reproduction. Fish habitat also includes most of the tributaries within a watershed, as they are
directly or indirectly related to the life-cycle of a fish. Included are in-water structures, such as
logs and stumps, pools and riffle areas, riparian and aquatic vegetation, groundwater
recharge/discharge areas and areas of permanent, seasonal and ephemeral flow. Fish habitat
includes the watercourses that act as direct habitat and also as corridors allowing fish to move
from one area to another. Different fish species have different habitat requirements which can
vary with the life-stage, season and even the time of day (OMNR 1999).
The intent of the Natural Heritage System (NHS) is not to reflect or employ the legal definition
of “fish habitat” as defined by the FA. Any activity that may affect fish habitat must satisfy the
regulatory requirements of LSRCA and the federal Fisheries Act, whether or not the NHS
identifies the presence of habitat for fish.
The Natural Heritage System generally seeks to include those areas where direct fish habitat is
found, either permanently or seasonally. To avoid confusion with the requirements of the
Fisheries Act, the NHS for the Lake Simcoe Watershed will use the terminology “Habitat for
Fish”.
11.2
The Importance of Habitat for Fish
As stated in Ontario Ministry of Natural Resources’ Natural Heritage Reference Manual
(OMNR 1999), habitat for fish is important because:
Fish and their habitats are a vital component of natural ecosystems. Fish habitat
commonly occurs in many of the other natural heritage areas (e.g., wetlands,
valleylands, woodlands, ANSIs). It therefore contributes to the value of the other
areas and is influenced by the protection they are provided through the planning
process. Fish also provide important social and economic benefits. For example,
94
angling is an important leisure activity that contributes substantially to the tourism
industry. Fish depend on clean water, ground water discharge areas and other
elements of healthy aquatic ecosystems.
Habitat for fish is critical in maintaining fish populations and biodiversity. Nearly one-half of the
described vertebrate species of the world are “bony” fishes (Allan and Flecker 1993). Fish are
biologically diverse and exhibit many particular characteristics that place them at high value. For
instance, as organisms that are immersed in their surrounding environment, fish are exposed to
every contaminant that is carried in the water.
Fish are indicators of environmental change. If the health of aquatic ecosystems declines, fish
populations can soon suffer. Like the “miner’s canary”, fish populations provide early warning
signals of environmental degradation. Conversely, improvements in fisheries may indicate
progress with rehabilitation and inspire society to continue to manage for healthy aquatic
ecosystems (OMNR 2003).
Fish are important economically, supporting the sport fishing and tourist industries, as well as the
commercial fishery. Healthy fish communities are a source of pleasure to the many people who
watch fish (OMNR 2003). Fish can also sustain a way of life including that of aboriginal
communities, commercial fishing operations and communities whose livelihood is dependant
upon tourism.
11.3
Habitat for Fish in the Lake Simcoe Watershed
In addition to the Lake (72,300 ha), which is the dominant feature providing habitat for fish,
there are numerous creeks and rivers that flow into the lake, which are also an important
component of the habitat for fish within the Lake Simcoe Watershed. The Lake itself supports 49
fish species that together form a complex and diverse assemblage of warm water and coldwater
species, each with specific habitat requirements (LSEMS 2003).
Lake Simcoe’s Coldwater Fishery
The cold water fish species of Lake Simcoe have undergone a dramatic decline in abundance due
to eutrophication. Concerns over the declining cold water fishery began over 30 years ago, which
prompted the Ontario Ministry of the Environment (MOE) to investigate the situation in 1979.
Excessive amounts of phosphorus were identified as the leading source of pollution
compromising the water quality of Lake Simcoe and its cold water fishery (LSEMS 2001).
A reduction in phosphorus loading was, and still is, necessary to ensure that the cold water fish
of the lake prosper. The provincial government has enacted laws, policies and regulations that
direct municipalities, private landowners and developers to create ponds controlling urban
stormwater run-off. Direct urban runoff accounts for nearly 15% of the total phosphorus load
entering Lake Simcoe every year (Scott et al. 2005).
95
Municipalities within the watershed were also required to upgrade their sewage treatment plants
(STPs). In 1988 STPs contributed 12.5 tonnes of phosphorus to the total load. By 1995 every
STP in the watershed was using the best available technology for phosphorus reduction, and by
1997 their combined loads were reduced to 6.2 tonnes (LSEMS 2001). The average STP load in
2003/04 was down to 4.2 tonnes (Scott et al. 2005).
Populations of lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis)
have been sustained by annual stocking programs as indicated by angler catch surveys and fall
trap-netting results. Other coldwater species in the lake include: lake herring (Coregonus
artedii), rainbow smelt (Osmerus mordax), brook trout (Salvelinus fontinalis), mottled sculpin
(Cottus bairdi) and burbot (Lota lota) (LSEMS 2003). Lake Simcoe whitefish is listed as
“Threatened” by the MNR and the Committee on the Status of Endangered Wildlife in Canada
(COSEWIC).
Lake Simcoe’s Warmwater Fishery
Functional warm water habitat cannot exist without suitable water quality/quantity and a healthy
adjoining ecosystem. Any human activity that negatively affects water quality/quantity or the
terrestrial ecosystem will have an effect on the healthy of aquatic habitat. The management
issues that are common throughout the majority of urbanized and/or agricultural subwatersheds
are nutrient input, accumulation of sediment, altered stream flow patterns and channel
morphology, the lack of stream side vegetative cover, the presence of instream barriers and
obstructions limiting fish migration and to a lesser degree, water temperature (LSRCA 1998).
Today, Lake Simcoe supports a relatively stable population of warm water fish such as
largemouth bass (Micropterus salmoides), brown bullhead (Ameiurus nebulosus), pumpkinseed
(Lepomis gibbosus) and rock bass (Ambloplites rupestris). The effects of some rather well
known introduced exotic species such as the zebra mussel (Dreissena polymorpha), black
crappie (Pomoxis nigromaculatus), and round goby (Neogobius melanostomus) have not
necessarily been realized to date (LSEMS 2003).
Creek Systems within the Watershed
The Lake itself is to some extent the sum of all its tributaries. The tributaries themselves,
whether small headwaters creeks or the approximately 78 km of larger watercourses such as the
Beaver River; all contribute to the value of the fishery within the entire watershed.
Some of the supporting creeks and rivers are directly supporting the fishery of the Lake by
providing food, nursery habitat and refuge habitat. Others have their own self-sustaining warm or
cold water fisheries associated with them. These watersheds, many of which originate as
headwaters in the Oak Ridges Moraine and drain northwards to Lake Simcoe, contain extremely
diverse vegetation communities and land cover types, ranging from forest to grassland to urban
environments.
96
Management issues regarding the protection of groundwater recharge and discharge and water
quality, as well as flood storage, are key elements for the Authority’s guiding principles within
the fisheries management plans.
Economic Benefits
The most important industries directly associated with Lake Simcoe are recreation and tourism.
Lake-related recreational activities produce millions of dollars annually for the local and regional
economy. The lake also affords considerable social benefits by improving the quality of life and
enhancing the well-being of many watershed residents.
Lake Simcoe hosts more angling than any other inland lake in the province. In 2000, an
estimated 130,000 anglers visited Lake Simcoe (LSEMS 2003). Ice fishing is extremely popular
and accounts for most of the angling activity, with an estimated 2,000 to 4,000 ice-fishing huts
erected on Lake Simcoe each winter. During the ice-fishing season the most sought after species
are perch, lake whitefish and lake trout.
Ice fishing alone generates an estimated annual revenue of $112 million dollars. During the
winter of 2001, and for the first time in more than 50 years, the surface of Lake Simcoe did not
freeze over; the consequence of this was the worst economic year in the history of the ice-fishing
industry (LSEMS 2003).
It is not only the lake fishery itself that generates economic activity. Many anglers who use the
creeks and rivers also contribute directly and indirectly to the overall economic value that is
generated by fish within the Lake Simcoe Watershed.
11.4
Policy Framework
With respect to Natural Heritage planning, fish habitat is regulated by Section 2.1.5 of the
Provincial Policy Statement (PPS) 2005 (MMAH 2005), which states that:
development and site alteration shall not be permitted in fish habitat except in
accordance with provincial and federal requirements.
Although the PPS definition of “fish habitat” is consistent with the Fisheries Act it does not state
that all issues of fish habitat revert to the Fisheries Act. The federal Fisheries Act prohibits
anyone from carrying out a process that will cause harmful alteration, disruption, or destruction
of fish habitat (known as a “HADD”), unless approved by the Minister of Fisheries and Oceans.
The Fisheries Act typically applies at the implementation and permitting stages of a project and
therefore it is not a planning tool. Through the PPS, the MNR has the lead role for planning
matters in Ontario as they relate to the protection of fisheries resources and fish habitat.
97
11.5
Criteria
As with other components, habitat for fish may well reside in more than one of the criterion that
collectively make up the NHS. For example, a polygon recognized as habitat for fish may also be
a Significant Valleyland which typically contains a watercourse, or perhaps a Significant
Wetland.
The Habitat for Fish layer for the NHS was developed by merging four LSRCA GIS layers that
together depict Lake Simcoe and all other waterbodies, including on-line and mapped offline
ponds, watercourses including rivers and creeks (but generally excluding ditches, swales and
depressions), as well as all identified Municipal (Agricultural) Drains. The Authority undertook
the classification of all known municipal drains in accordance with the guidelines of the
Fisheries Act on behalf of the Department of Fisheries and Oceans (LSRCA 2003). Drains and
constructed off-line ponds may occasionally be maintained (i.e., dredged).
This combination of data layers was found to best describe habitat for fish strictly for the
purposes of the NHS as a Level 3 feature. Under existing policies and regulations fish habitat has
for many years been subject to compensatory mechanisms when a HADD has been identified.
For this reason Level 3 was selected as the appropriate policy level for the NHS. The designation
in the NHS or the NHS map does not in any way replace the identification of direct or indirect
fish habitat by the LSCRA.
Mapped on-line ponds will be included in the natural heritage system as a Level 3 feature.
Mapped off-line ponds will be included in the NHS as a Level 3 feature, only if they are within
30 m of another designated natural heritage feature (Level 1, Level 2 and/or Level 3). The
rationale is that ponds located that close to existing features are likely to support other natural
heritage functions associated with adjacent natural areas. Only mapped ponds are included as the
mapping process generally avoided mapping “fire ponds” and very small pond areas.
The Lake Simcoe Watershed habitat for fish criteria are summarized in Table 11.1. Figure 11.1
depicts a mapping example.
Table 11.1 Summary of Habitat for Fish Criteria for the Lake Simcoe Watershed
Feature
Level
Attribute Name
Watercourses and Watercourses identified in the Habitat for
Fish layer
waterbodies
Online waterbodies (including Lake
Simcoe) in the Habitat for Fish layer
Mapped drains identified in the Habitat for
Drains
Fish layer
All on-line ponds
On-line ponds
Level 3
HF3-A
Level 3
HF3-B
Level 3
HF3-C
Level 3
HF3-B
Mapped off-line ponds within 30 m of
another designated (Level 1, Level 2 or
Level 3) NHS feature
Level 3
HF3-E
Off-line ponds
98
99
11.6
Literature Cited
Allan, J. D. and A. S. Flecker. 1993.
Biodiversity conservation in running waters. BioScience. 43: 32-43.
Lake Simcoe Region Conservation Authority Annual Report 2001. Available online:
http://www.lsrca.on.ca/AboutUs/AnnualReports/ar2001.html#lsems.
State of the Lake Simcoe Watershed.
Maskinonge River Remedial Strategy Final Report
<http://www.lsrca.on.ca/Studies/Maskinonge.html>.
1998.
Available online:
South Central Conservation Authorities Municipal Drain Classification Project, 2003
Final Report.
37 pp.
Why
is
the
fisheries
resource
http://www.mnr.gov.on.ca/fishing/import.html.
important?
Available
online:
Scott, L.D., Winter, J.G., Girard, R.E. 2005.
Annual Water Balances, Total Phosphorus Budgets and total Nitrogen Chloride Loads
Lake Simcoe (1998 – 2004). Lake Simcoe Environmental Management Strategy
implementation Phase III, Technical Report No. Imp. A.6.
100
12.0
12.1
Linkages
Overview
Linkages, often referred to as corridors, or landscape connectivity (meaning the connecting of
natural areas and the function that is provided by those connections) is a complex and often
contentious topic. Arguments regarding the utility of corridors continue in the literature (e.g.,
Hannon and Schmiegelow 2002; Whitfield 2001) and recent high-profile Ontario Municipal
Board hearings in southern Ontario have highlighted some of the opposing arguments.
There can be no doubt that connectivity at the landscape level is an important element in the
function of ecosystems and in the maintenance or enhancement of ecosystem services and
biodiversity. However, just as the science and public policy have progressed from the protection
of largely recreational parks, to “islands of green” (Hilts et al. 1986), to the core and natural
corridor approach defined by Riley and Mohr (1994), it will surely evolve and respond again to
an increasing understanding and appreciation of ecosystem function and response.
12.2
Key Assumptions
In developing the Lake Simcoe Watershed Natural Heritage System there are several key
assumptions that have been made regarding landscape connectivity. These are discussed in the
following paragraphs.
Connectivity can take many forms
Connectivity can and does occur among patches that are not physically connected by natural
habitat or that are only connected by the surrounding landscape matrix (e.g., agricultural lands).
These patches can still be considered to be connected and are sometimes referred to as “stepping
stones of habitat”.
Relatively isolated habitat patches may still be used by a wide range of species and their apparent
isolation may be less complete than a one-dimensional GIS-generated map might indicate. For
example, wide-ranging species (e.g., many mammals, raptors, and woodpeckers) that can use the
matrix will move among woodland patches, and many species of wildlife will use isolated
woodland patches even if the matrix is inhospitable (e.g., birds while on migration).
In the Lake Simcoe Watershed NHS such isolated habitat patches can be considered part of the
NHS.
101
The prescribed “System” does not have to be continuous
The approach taken for the development of some natural heritage systems can result in the
presentation of a continuous uninterrupted NHS designation on a map.
In reality, these systems are always fragmented by highways, roads and a variety of other linear
infrastructure (e.g., railways, hydro lines, pipeline easements, etc.) or alternate land uses. The
detailed ELC and land use mapping that is available to LSRCA has negated the need to
generalize these pathways and all “mappable” component breaks (such as roads, railways, hydro
corridors and pipelines) are being shown where the response of the vegetation is visible using
ELC. Therefore the NHS is not a continuous fabric, but is a series of polygons that can be
continuous, separated by a few metres in some cases and up to a few kilometres in others.
Existing and proposed connectivity are different
The development of the Lake Simcoe Watershed NHS was predicated on following the PPS as
closely as possible. The PPS speaks to functions and features that are present “on the ground”
such as woodlands, wetlands, the existing linkages among them, as well as the potential for
restoring natural heritage features.
However, this NHS does not explicitly address restoration opportunities for woodlands,
wetlands, ANSIs, habitat for fish or any other components. Rather, the existing patterns of
natural heritage features have been incorporated into the NHS. This is largely the same approach
that will be applied to the designation of linkages, although this component will differ with the
inclusion of “proximity linkage areas”, which are not to be confused with restoration areas.
12.3
Differing Perspectives on Connectivity
Given the approach taken by this study to build the NHS based on existing functions and
features, it is beyond the scope of the project to provide an extensive review of landscape
connectivity functions that could be restored in a fragmented, temperate zone landscape. Rather,
this topic, along with other approaches to restoration within the watershed, is addressed in
Chapter 15: Where Do We Go From Here?
However, as many approaches to the building of natural heritage systems appear to elevate the
relative importance of connectivity by including restored connectivity (and not other restored
components), it is worthwhile considering some of the arguments around this topic.
Riley and Mohr (1994) presented some arguments both for and against the role of corridors and
cited Noss and Harris (1986), who proposed a conservation strategy that considers the pattern of
existing high-quality nodes relative to actual and potential corridors. This was the general
approach taken by the authors of the Big Picture (McMurtry et al. 2002), which is one proposed
connected system for southern Ontario that incorporates a series of natural feature core areas
connected by proposed corridors 200 m in width.
102
A review of recent literature associated with various woodland habitat metrics was undertaken
for the second edition of “A Framework for Guiding Rehabilitation in Great Lakes Areas of
Concern” (Environment Canada 2004). The relative importance of the four Framework criteria
for woodland habitat (i.e., woodland cover, quality, patch size and connectivity) was assessed
based on that review and presented in the document “Area Sensitive Forest Birds in Urban
Areas” (Environment Canada, in prep.). Table 12.1 is an excerpt taken from that document, and
it provides a subjective assessment on the relative importance of the underlying criteria used in
forming the guidelines. Although the Environment Canada review was primarily concerned with
breeding area-sensitive forest birds, it does shed some light on the relative importance of
landscape connectivity.
It is possible that with the advent of new scientific methods more information on the use of
pathways of connectivity will be forthcoming. This will help resolve outstanding questions, as
many of the empirical data that support corridor theory are not based on examples from the
fragmented landscapes of the temperate zone.
Table 12.1 Key Woodland Habitat Criteria for Woodland Breeding Birds
(taken from EC 2007)
General
Category
Likely Relative
Importance
Comments
• Threshold may be around 30% for area-sensitive woodland birds,
Total Cover
Habitat
Quality
Very High
•
High
•
Less than 30%
cover: High
Patch Size
More than 30%
cover: Moderate
More than 70%
cover: None
•
•
•
Connectivity
Moderate
below which they decline and other habitat metrics start to play a
greater role (e.g., patch size, connectivity)
A general concept that incorporates a range of metrics such as:
community structure, shape, interior, age, composition, invasive
species, community heterogeneity
In fragmented landscapes with less than 30% woodland cover this
metric may play a greater role. Little guidance is available in the
literature on the upper level of patch size effect on area-sensitive
woodland birds, likely to be landscape/species dependant and in
the thousands of hectares
In landscapes with more than 30% woodland cover, patch size
appears to be less critical, but it is difficult to isolate the effect of
patch size from other key metrics
In landscapes with more than 70% woodland cover, patch size
may not be important
There are few empirical studies demonstrating the importance of
connectivity for woodland birds. It has been difficult to tease apart
the relative importance of woodland cover and connectivity;
ecological mechanisms and effects of fragmentation are poorly
understood. Connectivity is likely to be more important once
woodland cover is less than 30%, and less important over 70%
103
In the recent publication entitled Corridor Ecology (Hilty et al. 2006), which promotes the
importance of corridors, the authors state the following:
…it is not always clear that connecting wildlands through linear habitat features
across a disturbed landscape enhances species’ persistence within reserves. In
many cases it is premature to suggest methods for enhancing connectivity when
not enough is known about the requirements of focal species and whether
increased connectivity will result in boosting their persistence.
These words are particularly relevant considering that many ecologists consider that
introductions of non-native species are second only to direct habitat loss as causes of the decline
and extinctions of species across the planet. The role of corridors in facilitating the spread of
exotic species, whether they are insects, plants or pathogens (aquatic and terrestrial), needs to be
carefully considered.
Table 12.2 summarizes many of the major pros and cons of connecting the landscape, largely
taken from Hilty et al. (2006).
Table 12.2 Corridor Pros and Cons
Potential Benefits
Potential Negative Effects
Provision, maintenance or enhancement of
habitat
Potential for increased populations (i.e.,
within the corridor)
Conduits for dispersal among patches
Rescuing populations or increasing genetic
diversity
Increased resilience to environmental
change
Support for productive populations
Increased predation, parasitism or disease
risks in edge-dominated corridors
Competition from exotic species within
edge-dominated corridors
Disturbance from adjacent matrix
Sex and age filtering of target species
Invasions of exotic species from matrix or
from connected patches
Invasions of deleterious native species (i.e.,
predators,
disease,
parasites
and
competitors)
Increase species’ persistence in patches
Demographic effects (e.g., dispersal sinks,
exposure to human depredations)
Help dispersers avoid predation or human- Social impacts (e.g., inhibition of
caused death
movements by territorial residents)
Facilitate range shifts in response to Economic impacts (e.g., costs of
broader changes (e.g., climate change)
acquisition and maintenance)
Help retain healthy functioning ecosystems Impacts on the adjacent matrix
(e.g., when riparian, or by allowing
predators to move among patches)
Diversion of conservation dollars and
efforts from other aspects of the NHS
104
The careful and considered reconnecting of the natural landscape is a laudable goal that should
be addressed in the context of other restoration objectives. The future development of a
connectivity strategy for the Lake Simcoe Watershed needs to consider landscape features and
attributes such as natural cover and the composition of surrounding matrix (i.e., to what are we
connecting), matching habitat for target species, corridor opportunities and constraints, as well as
a balanced view of potential ecological and non-ecological effects, both positive and negative.
12.4
Policy Framework
The Provincial Policy Statement (MMAH 2005) addresses linkages and landscape connectivity
in Section 2.1.2 as follows:
The diversity and connectivity of natural features in an area, and the long-term
ecological function and biodiversity of natural heritage systems, should be
maintained, restored or, where possible, improved, recognizing linkages between
and among natural heritage features and areas, surface water features and
ground water features.
The Provincial Policy Statement (PPS) defines “natural heritage system” as follows:
…a system made up of natural heritage features and areas, linked by natural
corridors which are necessary to maintain biological and geological diversity,
natural functions, viable populations of indigenous species and ecosystems. These
systems can include lands that have been restored and areas with the potential to
be restored to a natural state.
The PPS acknowledges that the connectivity of natural features should be maintained, or where
possible restored. It also recognizes that lands with potential for restoration to a natural state can
be included within natural heritage systems, but does not state this as a requirement.
The potential restoration of landscape features is not only recognized by the PPS for the purposes
of connectivity; it is applied to all natural heritage features and areas. In the development of the
Lake Simcoe Watershed NHS, up to this point, restoration potential has not been explicitly
addressed for any features (i.e., wetlands, woodland, valleylands, habitat for fish, etc.); except
perhaps tangentially for woodlands through the Big Woods Policy Areas (see Section 7.8
Significant Woodlands).
12.5
Criteria
The criteria applied for the identification of linkages in the NHS recognize that most existing
natural connectivity has been incorporated into other components, such as wetlands, habitat for
fish or valleylands. This has led to the development of two types of linkages in the Lake Simcoe
Watershed NHS.
105
The first of these two is stream linkages, which are existing linkages that connect two features
along either side of a watercourse. The second linkage type, proximity linkage areas, identify
linkage between two designated features that are within close proximity to one another (i.e., 60
m or less). This linkage differs from almost all other NHS components in that the exact location,
size or shape of the linkage itself is not prescribed. This is because in order to identify the most
appropriate linkage between two components, site specific field work is required. The criteria for
these two linkage types are described below.
Stream Linkages
Steam linkages connect designated Level 1, Level 2 or Level 3 NHS features (or their continuous
Level 4 - supporting features) along watercourses that are recognized as Habitat for Fish in the
NHS. The linkage consists of a minimum 30 m area applied to either side of the Habitat for Fish
feature.
Stream linkages are intended to cross breaks, such as roads, where the watercourse passes
beneath. This is consistent with the LSRCA’s regulated area and is also consistent with the area
that is often determined to be indirect fish habitat. This results in the designation of portions of
roads as Stream Linkage areas whenever a watercourse passes beneath them. While these areas
are clearly not of value from a NHS perspective it does highlight the importance of the area for
other planning exercises such as municipal Environmental Assessments for road upgrades.
A corridor ranging in width from 50 m to 100 m is generally supportable when its primary
function is to facilitate movement, rather than the provision of habitat patches. These Level 3
stream linkages will be over 60 m in width, which can facilitate movement for common
generalist species and provide habitat for up to 90% of riparian plant species (Spackman et al.
1995).
The stream linkage area will be treated as a Level 3 feature.
Proximity Linkage Areas
Although the approach taken in this NHS recognizes only existing pathways of connectivity
(rather than “potential” corridors), in the absence of a restoration opportunities analysis, there is
a need to “connect” NHS components that are in very close proximity.
There can be no doubt that there is biotic exchange and support (the so-called “contagion effect”)
between features that are only a few metres apart. How far apart this function extends is variable
and is at the heart of connectivity discussions. This NHS has taken a conservative approach;
where Level 1, Level 2 or Level 3 NHS features or their contiguous Level 4 - supporting features
(e.g., cultural thickets that are contiguous with Level 1 or 2 woodlands; see Section 7.8
Woodlands) are located within 60 m of each other, a symbol is used to indicate that a proximity
linkage area exists in that general location. The proximity linkage area, when determined through
further study (see below), will be a minimum of 60 m wide or the width of the feature
106
(whichever is less). An example is illustrated in Figure 12.1. The linkage area will be treated as a
Level 3 flag.
When proximity linkages occur along the Lake Simcoe shoreline and an “inland” feature such as
a riparian system, wetland or a forest, the intent remains the same: to recognize functional
connectivity between the lake and terrestrial systems. This could be related to wide range of flora
and fauna and ecological functions.
In situations where development and site alteration is proposed and a proximity linkage area
occurs, the width, location and configuration of the linkage is to be addressed as part of an
Environmental Impact Study (EIS) (see Appendix 4). Where more than one linkage opportunity
exists between the same two features on the same parcel of land the EIS shall determine the most
appropriate location, which does not necessarily need be at the closest proximity between the
two features, but rather where functionality can be maximized. Hedgerows can be incorporated
into proximity linkage areas during the EIS process.
Oak Ridges Moraine Linkages
The Oak Ridges Moraine Conservation Plan (ORMCP) requires the application of the
connectivity technical guideline in areas designated as “Countryside” (OMNR 2004). This can
only be addressed at the site level and therefore ORM linkage areas are not shown as a GIS layer
in this NHS.
Table 12.3 provides a summary of the Lake Simcoe Watershed NHS Linkage criteria.
Table 12.3 Summary of Linkage Criteria for the Lake Simcoe Watershed
Feature
Level
Linkage:
stream
linkage
Minimum 30 m on either side of designated Habitat
for Fish when located between two designated
Level 1, Level 2 or Level 3 components (or their
continuous Level 4 – supporting features)
At a minimum, the smaller of: 60 m or the width of
the feature, where Level 1, Level 2 or Level 3
components (or their continuous Level 4 –
supporting features) are located within 60 m of each
other, subject to an EIS where appropriate
All requirements of the ORMCP and draft technical
guidelines
Level 3
Attribute
Name
LS3
Level 3
LP3
Linkage:
Proximity
linkage
Oak Ridges
Moraine
107
Requires sitespecific
investigations
108
12.6
Literature Cited
Area Sensitive Forest Birds in Urban Areas. Minister of Public Works and Government
Services Canada.
Hannon, S.J. and F.K.A. Schmiegelow. 2002.
Corridors may not improve the conservation value of small reserves for most boreal
birds. Ecological Applications 12: 1457-1468.
Hilty, J. A., W.Z. Lidicker Jr., A. M. Merenlender. 2006.
Corridor Ecology. Island Press. Washington, D. C.
McMurtry M., Riley, P. Sorrill and T. Sorrill. 2002.
Summary of Methodology for Big Picture, 2002. Available online:
<http://nhic.mnr.gov.on.ca/MNR/nhic/projects/bp/bigpict_2002_main.cfm >.
37 pp.
Oak Ridges Moraine Technical Paper. Supporting Connectivity Within the Oak Ridges
Moraine T. P. 3. February 2004 Draft.
Noss, R.F. and L.D. Harris. 1986.
Nodes, networks and MUMS: Preserving biodiversity at all scales. Environmental
Mangement 10: 299-309.
Riley, J.L. and P. Mohr. 1994.
The natural heritage of southern Ontario’s settled landscapes. A review of conservation
Resources, Southern Region, Aurora, Science and Technology Transfer, Technical
Report, TR-001. 78 pp.
Spackman, S.C., C. Hughes and W. Jeffrey. 1995.
Assessment of minimum stream corridor width for biological conservation: Species
richness and distribution along mid-order streams in Vermont, U.S.A. Biological
Conservation 71:325-332.
109
Whitfield, J. 2001.
Urban wildlife may not use green corridors. Nature News Service/Macmillan Magazines
Ltd., 2001.
110
13.0
Suggested Policy Templates
The policies presented here are meant to represent a framework of suggestions; they are not
meant to be either prescriptive or comprehensive. Neither are they meant to be adopted
wholesale without adaptation for local circumstances and conditions. They are offered to further
the interests of good planning in the context of the Provincial Policy Statement and in
recognition of natural heritage features and functions that may be important to the residents of
the Official Plan (OP) area, and to the long-term sustainability of ecological functions and
services provided by important natural areas within the watershed.
There are two policy frameworks presented in this section. The first (presented in Section 13.1)
has been designed for consideration by the LSRCA. The second (presented Section 13.2) is for
use by municipalities (i.e., Regions, Counties, Cities, Towns and Townships) or other planning
authorities that may seek to adopt the Natural Heritage System or a version of it, in order to meet
the natural heritage policy requirements of the Provincial Policy Statement or to further their
ambitions of sustainability and good planning.
A template for a “Terms of Reference for Environmental Impact Studies” is also provided as
Appendix 4. In the following policy sections the term “EIS” is meant to encompass all
environmental evaluations, environmental impact studies, natural heritage evaluations,
environmental assessments or similar undertakings.
13.1
Lake Simcoe Region Conservation Authority Suggested Policies
1.0
Preamble
The suggested policies outlined below are meant to assist the Authority in implementing its
program to conserve, restore, develop and manage the natural resources in its watershed. As the
Natural Heritage System is based on the premise of the Provincial Policy Statement, the
implementation will be through the LSRCA planning program. It will also provide direction in
addressing natural heritage issues during the development of subwatershed plans, fisheries
management plans, and the Authority’s Land Acquisition Program and in implementing its
Section 28 Regulation.
The mission of the LSRCA is:
To provide leadership in the protection and restoration of the environmental
health and quality of Lake Simcoe and its watershed with our community,
municipal and other government partners.
In working towards achieving this mission, the LSRCA has developed a Natural Heritage System
(NHS) to identify the natural heritage features and functions that contribute to the environmental
health and quality of Lake Simcoe and its watershed. The policies of the NHS are designed to
protect the existing system, and to ensure no net loss of the system. The NHS strives to achieve
111
a balance between development pressures on the watershed and the natural heritage features and
functions required to achieve and then sustain a functional ecosystem and a healthy lake.
The NHS is based upon the principles of the Provincial Policy Statement.
2.0
Objectives
2.1
To identify and protect the natural heritage features of the Lake Simcoe Watershed by
identifying a NHS;
2.2
To support biodiversity and ecological functions and to maximize the conservation of
native flora and fauna in the Lake Simcoe Watershed;
2.3
To protect the natural heritage system by encouraging planning authorities to adopt the
Natural Heritage System and appropriate policies in their Official Plans;
2.4
To assist member municipalities in directing development in a manner that will provide a
sustainable ecosystem for the residents of the Lake Simcoe Watershed.
3.0
General Policies
3.1
The Authority supports and encourages an ecosystem approach to land use planning that
considers natural heritage features, functions and attributes and how they interact in the
landscape as expressed by the NHS.
3.2
The Natural Heritage System shall be protected and enhanced.
3.3
The NHS consists of four levels of protection. These are: Levels 1 through 3 and Level 4
- supporting. Level 1 features should be retained on the landscape. Level 2 features
should be retained, though some flexibility is envisaged provided no negative impact has
been identified. Both of these levels are considered to be provincially significant. Level 3
features are considered watershed significant, are generally to be retained, and no net
negative impacts are contemplated, but replacement is intended. Level 4 - supporting
features are not necessarily development constraints and replacement is encouraged.
3.4
The Authority shall encourage planning authorities to adopt the NHS and incorporate
appropriate policies in their Official Plans to protect and enhance the system.
3.5
The precise limits of the NHS shall be further refined based on the criteria described
through subwatershed plans or through development applications. Municipalities and the
Province will be encouraged to use these criteria to refine the System.
3.6
Designation of lands as NHS does not imply intent of the planning authority or other
public agency to purchase such lands, nor does it imply their use as publicly accessible
112
open space. Such land will not be accepted as part of the park dedication required by the
Planning Act but conveyance of these areas to a public authority will be encouraged as
part of the development process and may be considered for acquisition by CAs,
municipalities, and other conservation organizations.
3.7
The Authority will pursue and encourage a range of land stewardship initiatives within
the NHS, including conservation easements and rehabilitation/restoration.
3.8
The Authority will undertake to assist the planning authority with the technical expertise
and assistance required to deal with matters relating to the NHS as identified by the
Authority.
3.9
The Authority will maintain and update data and mapping related to the NHS, as
required.
3.10
Interested individuals and groups will be encouraged to use the Authority's procedures in
identifying additional components of the NHS and are encouraged to share their
information with the Authority and the planning authority (and where appropriate, the
MNR) for consideration.
3.11
Removal, damage or modification of natural features within the NHS, through natural or
other causes, will not necessarily result in their deletion from the NHS and all policies
will continue to apply as though the feature had not been altered.
3.12
Within the Oak Ridges Moraine Plan Area the Oak Ridges Moraine Conservation Plan
requirements shall apply.
3.13
Within the Greenbelt Plan Area the Greenbelt Plan requirements shall apply. Until the
Province releases guidelines for the identification of Key Natural Heritage Features
(KNHF) within the Natural Heritage System of the Greenbelt, this plan can be used to
identify KNHFs.
3.14
Within sub-area assessment areas of the Growth Plan, this NHS can be used as a tool to
identify natural heritage features.
3.15
Nothing in these policies is meant to prevent an existing legal use of lands within the
NHS.
3.16
The policy requirements of the NHS do not apply to the following:
a)
b)
Normal farming practices in areas which are currently farmed (as of
January 1, 2006). This includes land that has been left fallow as part of
regular crop rotation. Peat extraction is not classified as a normal farming
practice.
Development proposals which have been approved pursuant to the
Planning Act or Environmental Assessment Act, where impacts from the
113
c)
proposed development on the NHS have been previously assessed and
approved.
Municipal proposals which have been approved pursuant to the Municipal
Environmental Assessment Class EA where impacts from proposed
developments on the NHS have been previously assessed and approved.
4.0
Watershed Development Policies - Natural Heritage System
4.1
The Authority encourages the planning authority to designate the NHS as Environmental
Protection Areas.
4.2
The boundaries of the NHS may be refined through an EIS prepared to the satisfaction of
the Authority and as outlined in Appendix 4.
4.3
Once a formal development proposal or application has been made, the boundaries of
features within the NHS will be staked in the field and approved by the planning
authority in consultation with the Conservation Authority, and in the case of PSWs, or
Endangered and Threatened species the MNR, and subsequently surveyed.
4.4
The approved and surveyed boundaries of features and the resulting limits of the NHS
will be shown in environmental reports. NHS Level determinations (i.e., Level 1, 2 3 or
4 supporting) will be shown on draft plans of subdivision or other application documents.
4.5
All development or site alteration applications will generally require an Environmental
Impact Study (EIS) (see Appendix 4). When the NHS is further than 120 m from the
proposed development or site alteration, the requirement for an EIS may be waived at the
discretion of the planning authority in conjunction with the Authority.
4.6
An EIS is required for all development or site alteration proposals or applications which
are located inside or within 120 m of any Level 1, Level 2, or Level 3 NHS features.
Removal and potential replacement of Level 4 - supporting features should be addressed
through an EIS.
4.7
The EIS must be prepared by a qualified professional in the environmental sciences,
completed to the satisfaction of the planning authority in conjunction with the Authority.
4.8
Once an EIS is triggered, the study must address all elements of the NHS, its functions
and features within and adjacent to the subject property, as outlined in the EIS Terms of
Reference, and will be required to determine appropriate critical functions zones and
protection zones (i.e., buffers).
4.9
It is mandatory that the applicant and/or its consultant meet with the Authority in
consultation with the planning authority to determine the specific scope and terms of
reference of the EIS prior to the commencement of these studies to ensure that the work
114
needed to complete the study is clearly identified at the outset. This will facilitate a more
streamlined and timely review process.
4.10
Where the applicant has not undertaken pre-submission consultation, the EIS will be used
by LSRCA to determine the appropriate Terms of Reference in order to assure that
appropriate requirements are met.
4.11
Where an EIS has indicated that the development would have a negative effect (or net
negative effect after replacement has been applied where appropriate) on the NHS or the
environmental functions, attributes or linkages for which the lands were identified, the
application will not be supported by the Authority.
5.0
Level 1 Features
5.1
imperative to the health and the function of the watershed and of Lake Simcoe. These
features are to be retained on the landscape. Level 1 features consist of the following*:
Component
Wetlands
Feature
• Provincially Significant Wetlands
Woodlands
• Woodland Patches ≥ 25 ha
Wildlife
Habitat
• Significant Habitat of Endangered and Threatened Species
*Plus ORMCP features as determined by the draft ORMCP technical guidelines and Greenbelt features
in accordance with guidelines when available
5.2
The significant habitat of Endangered and Threatened species, as approved by MNR, are
considered to be Level 1 features.
5.3
The Authority shall not support development or site alteration in Level 1 features.
5.4
Development or site alteration shall not be permitted adjacent to a Level 1 feature unless
it has been demonstrated through an approved EIS that there will be no negative impacts
on the natural features or their ecological functions.
5.5
When confirming the limits of Provincially Significant Wetlands, all contiguous wetlands
will generally be included within the PSW limits, subject to approval by MNR.
5.6
Where development is permitted through other legislation (e.g., Environmental
Assessment Act, etc.), replacement for the loss of the feature (or portions of) is
115
encouraged and shall be determined in consultation with and to the satisfaction of the
Authority.
6.0
Level 2 Features
6.1
Level 2 features are considered to be provincially significant components of the Natural
landscape. Level 2 features areas are subject to limited flexibility within the planning
process where no negative impact (consistent with the definitions of the PPS) can be
demonstrated. These features consist of the following*:
Component
Wetlands
Feature
• Unevaluated wetlands ≥ 10 ha
• Unevaluated wetlands contiguous with PSWs
Woodlands
•
•
•
•
•
•
Valleylands
Wildlife Habitat
ANSIs
Woodland patches ≥ 10 and < 25 ha
Significant valleylands as identified in the NHS mapping
Core winter deer yards (Stratum 1)
Colonial waterbird nesting sites
Rare vegetation communities (alvars, prairies, fens and bogs)
Confirmed Provincial Life Science ANSIs as determined by
the MNR
*Plus ORMCP features as determined by the draft ORMCP technical guidelines
6.2
The Authority shall discourage development or site alteration in Level 2 features.
6.3
Development or site alteration would not be accepted by the Authority unless it has been
demonstrated through an approved EIS that there will be no negative impacts on the
natural features or their ecological functions consistent with the definitions of the PPS.
6.4
Mitigation for impacts on the natural features or their ecological functions that are
permitted by the PPS may include replacement approaches, at the discretion of the
planning authority in conjunction with the Authority. These could include enhancement
or restoration on or off site.
6.5
Replacement shall be determined in consultation with and to the satisfaction of the
Authority. To the extent possible, replacement shall occur within the same subwatershed.
7.0
Level 3 Features
7.1
Level 3 features are considered to be significant within the watershed. It is the overall
intent that these features should be retained on the landscape. However, flexibility is
116
contemplated in the way in which these features are addressed when a land use change or
other development is considered. Level 3 features consist of the following:
Component
Wetlands
•
•
•
Woodlands
•
•
ANSIs
Habitat for Fish
Linkages
Feature
Evaluated non-Provincially Significant Wetlands (Non-PSW)
and designated Locally Significant Wetlands (LSW)
Unevaluated wetlands contiguous to evaluated Non-PSWs and
designated LSWs
Unevaluated wetlands ≥ 0.5 ha that overlap with, or fall
within, 30 m of any identified Level 1 or other Level 2 NHS
features
Socially Significant Woodlands ≥ 4 ha to < 10ha (only in
designated Urban Areas)
The entirety of any woodland ≥ 0.5 and < 10 ha that overlaps
or is located within 30 m of any other identified NHS Level 1
Level 2 or Level 3 feature
• Confirmed Regional Life Science ANSIs as determined by the
MNR
• Watercourses and waterbodies, drains, online ponds, mapped
offline ponds within 30 m of another NHS feature
• Stream linkages between Level 1, Level 2 features and/or
Level 3 features (or their continuous Level 4 - supporting
features)
• Proximity linkages between Level 1, Level 2 and/or Level 3
features (or their continuous Level 4 - supporting features)
7.2
An EIS is required to demonstrate that there are no net negative impacts on the Natural
Heritage System. Mitigation for the loss of a natural heritage feature, or an identified
impact, is recommended through replacement. Approaches to address replacement could
include creation, enhancement or restoration on or off site.
7.3
Development or site alteration would not be accepted by the Authority unless it has been
demonstrated through an approved EIS that there will be no net negative impacts on the
natural features or their ecological functions.
7.4
Mitigation for net negative impacts on the natural features or their ecological functions
may include replacement approaches, at the discretion of the planning authority in
conjunction with the Authority. These could include enhancement or restoration on or off
site.
7.5
Authority. To the extent possible, replacement shall occur within the same subwatershed.
117
7.6
The precise location and configuration of proximity linkage areas is to be determined
through an EIS.
7.7
Development or site alteration shall not be permitted within Habitat for Fish except in
8.0
Level 4 – Supporting Features
8.1
Level 4 - supporting features are considered to be supporting Level 1, 2 and 3 NHS
features. Retention of these features is encouraged, however, they are not necessarily a
constraint to land use change. These features consist of:
Component
Wetlands
Woodlands
Wildlife Habitat
Feature
• Unevaluated wetland units that are ≥ 0.5 and
< 10 ha
• Cultural thickets continuous with NHS Level
1, Level 2 and/or Level 3 woodlands and/or
wetlands
• Woodland patches ≥ 2 and < 10 ha that are
not otherwise a NHS woodland feature
• ELC grassland communities as follows
(subject to the supporting text):
o CUM and CUT ≥15 ha
o CUT and CUM ≥ 10 ha when
by
other
NHS
surrounded
components
o Contiguous CUT/CUM communities
≥ 20 ha
8.2
Development or site alteration shall avoid Level 4 - supporting features where reasonable
and possible.
8.3
If it is not reasonable or possible to avoid the removal of part or all of a Level 4 supporting feature, replacement is encouraged, and is at the discretion of the planning
authority, in conjunction with the Authority, through the EIS process.
9.0
Big Woods Policy Areas
9.1
The Big Woods Policy Areas are those areas where there is a high percentage of
woodland cover and large woodland patches. These areas are considered most likely at
the landscape scale to represent high ecological function, diversity, connectivity and
are priority natural areas within the Lake Simcoe Watershed.
118
9.2
The Authority shall generally identify these areas in the NHS for restoration and
stewardship within its Stewardship and Land Acquisition Programs.
9.3
The Authority encourages the planning authority to recognize the ecological importance
of these areas and to incorporate these areas into their Official Plans and
restoration/stewardship programs.
9.4
In addition to addressing other policies of this Plan, development applications within or
overlapping with Big Woods Policy Areas shall strive to ensure no net loss of woodland
cover within the Big Woods Policy Areas.
9.5
All other applicable NHS policies of this NHS still apply to Big Woods Policy Areas.
The underlying designated NHS Level (i.e., Level 1, 2 or 3) applies.
13.2
Suggested Implementation Policies for Official Plans
1.0
Preamble
The purpose of these policies is to provide guidance to all of those involved in land use planning
in the Lake Simcoe Watershed. As the Official Plan is the primary document guiding the growth
and management of resources by the municipality, the following policies are provided as a
means of implementing the Natural Heritage System. The Natural Heritage System includes of
features listed within the Provincial Policy Statement. These features are: Wetlands, Habitat of
Endangered and Threatened Species, Habitat for Fish, Woodlands, Valleylands, Wildlife Habitat,
Areas of Natural and Scientific Interest, and Linkages.
These natural areas are important in ensuring sustainable ecological health and the quality of life
of residents of the Official Plan (OP) area. They also serve to create distinct boundaries
separating Urban Areas and Agricultural Lands.
2.0
Objectives
2.1
To identify and protect the natural heritage features by designating a Natural Heritage
System (NHS) as an essential structural component of the OP area;
2.2
To support biodiversity and ecological function and to maximize the conservation of
native flora and fauna in the OP area;
2.3
To provide opportunities for controlled access and recreational activities where these do
not significantly affect negatively natural heritage resources; and
2.4
To ensure that proposed changes in land use have minimal negative impacts on the NHS.
119
3.0
General Policies
3.1
To protect and where possible enhance the Natural Heritage System.
3.2
To coordinate planning and management initiatives with adjacent municipalities,
particularly for those features that are ecologically and physically linked.
3.3
The boundaries and limits of the Natural Heritage System shall be confirmed based on
application of the criteria that define the elements of the NHS, through the preparation of
an Environmental Impact Study or by periodic refinements by the planning authority and
conservation authorities. Minor changes or adjustments will not require an amendment to
this Plan. However, the addition or deletion of an NHS feature may require an
amendment to the OP.
3.4
There are four Levels of protection assigned to features within the NHS. These are Level
1, Level 2, Level 3 and Level 4 - supporting.
3.5
Nothing in these policies is meant to prevent an existing legal use of lands within the
NHS.
3.6
To direct major land use changes away from the Natural Heritage System. Where this is
not possible, it is the intention to protect the Natural Heritage System by using such
techniques as:
Justifiable increases in density;
Appropriate reductions and/or modifications in public realm elements
(e.g., reduction in road allowance) through revised development standards;
Reconfiguration of public uses;
Shared facilities;
Other financial arrangements, which may include replacement; and/or
Sharing the equity in protecting the Natural Heritage System through
comprehensive developer agreements and comprehensive public/private
agreements.
3.7
Designation of lands as NHS does not imply intent of this planning authority or any other
agency to purchase those designated lands or to promote their use by the public.
3.8
Removal of all or portions of a NHS feature does not necessarily result in their
deletion from the NHS.
3.9
The planning authority will cooperate with the conservation authorities and
Ministries of the Province of Ontario in establishing, maintaining and improving a
data base on the Natural Heritage System.
120
3.10
The planning authority will pursue and encourage a wide variety of land stewardship
options, including: easements, trusts, tax incentives and right-of-way approaches to
preserving, enhancing and accessing features.
3.11
The planning authority will explore and develop land securement strategies to implement
the Natural Heritage System and support Conservation Authority and land trust
organizations where possible with the securement of lands containing NHS features.
3.12
Within the Oak Ridges Moraine Planning Area, outside of Urban Areas, Towns and
Villages shown on Schedule X, the Natural Heritage System shall be comprised of the
Oak Ridges Moraine Conservation Plan (ORMCP) Natural Core Area and Natural
Linkage Area designations and subject to the applicable policies of the ORMCP.
3.13
Within Urban Areas and Towns and Villages, the Natural Heritage System shown on
Schedule X may be further refined through municipal Official Plans and zoning by-laws
without amendment to this plan. The Policy provisions of this Plan or local Official Plans
or secondary plans, whichever are the more restrictive, shall prevail.
3.14
Within the Greenbelt Plan area the Greenbelt Plan requirements shall apply. Until the
Province releases guidelines for the identification of Key Natural Heritage Features
(KNHF) within the Natural Heritage System of the Greenbelt, the NHS can be used to
identify KNHFs. It can also be used to identify features outside of the Natural Heritage
System.
3.15
Within sub-area assessment areas of the Growth Plan, this NHS can be used as a tool to
identify natural heritage features.
4.0
Natural Heritage System
4.1
The planning authority will designate and zone the NHS as Environmental Protection
once the boundaries have been refined through an official plan or zoning by-law
amendment based on an approved EIS and any other time the opportunity arises.
4.2
The boundaries of the features within the NHS will be staked in the field and approved by
the planning authority in consultation with the Conservation Authority, and in the case of
PSWs and the Significant Habitat of Endangered and Threatened Species the MNR, and
subsequently surveyed.
4.3
The approved and surveyed boundaries of features and the resulting limits of the Natural
Heritage System, as determined through studies, will be shown on a map in EIS reports.
NHS Level determinations (i.e., Level 1, 2, 3 or 4 supporting) will be shown on draft
plans of subdivision or other application documents.
4.4
For development and site alteration applications, an EIS will generally be required for all
applications. When the NHS is further than 120 m from the proposed development and
121
site alteration, the requirement for an EIS can be waived at the discretion of the planning
authority, in conjunction with the Conservation Authority.
4.5
An EIS will be required for all such applications which are located inside or within 120 m
of any Level 1, Level 2, or Level 3 NHS feature. Removal and potential replacement of
Level 4 - supporting features should be addressed through an EIS.
4.6
The EIS must be prepared by a qualified professional in the environmental sciences,
completed to the satisfaction of the planning authority in conjunction with the Authority.
4.7
Once an EIS is triggered, the study must address all elements of the NHS, functions and
features within and adjacent to the subject property (not just the feature that triggered the
study) as outlined in the EIS Terms of Reference and will be required to determine
appropriate critical functions zones and protection zones (i.e., buffers).
4.8
It is mandatory that the applicant and/or its consultant meet with the Authority in
consultation with the planning authority to determine the specific scope and terms of
reference of the EIS prior to the commencement of these studies to ensure that the work
needed to complete the study is clearly identified at the outset. This will facilitate a more
streamlined and timely review process.
4.9
The terms of reference for the EIS must be confirmed in writing with the Conservation
Authority in conjunction with the planning authority, and will in most circumstances
include addressing Endangered and Threatened species.
4.10
That where an EIS has indicated that the development would have a net negative impact
(after replacement has been applied if appropriate) on the NHS or the environmental
functions, attributes or linkages for which the lands were identified, the application will
not be supported or approved by the planning authority.
4.11
EIS guidelines are to be followed (Appendix 4), subject to policy 4.4.
5.0
Level 1 Features
5.1
imperative to the health and the function of the watershed and of Lake Simcoe. These
features are to be retained on the landscape. Level 1 features consist of the following*:
122
Component
Wetlands
Woodlands
Wildlife
Habitat
Feature
• Provincially Significant Wetlands
• Woodland Patches ≥ 25 ha
• Significant Habitat of Endangered and Threatened Species
*Plus ORMCP features as determined by the draft ORMCP technical guidelines and Greenbelt features
in accordance with Greenbelt guidelines when available
5.2
Development and site alteration is not permitted within Level 1 features.
5.3
Development or site alteration is not permitted adjacent to a Level 1 feature unless it has
been demonstrated through an approved EIS that there will be no negative impacts on the
natural features or their ecological functions.
5.3
The Significant Habitat of Endangered and Threatened species, as approved by the MNR,
is to be considered a Level 1 feature.
5.4
When confirming the limits of Provincially Significant Wetlands, all contiguous wetlands
will generally be included within the PSW limits, subject to approval by MNR.
6.0
Level 2 Features
6.1
Level 2 features are considered to be provincially significant components of the Natural
landscape. Level 2 features areas are subject to limited flexibility within the planning
process where no negative impact can be demonstrated. These features consist of the
following*:
Component
Wetlands
Feature
• Unevaluated wetlands ≥ 10 ha
• Unevaluated wetlands contiguous with PSWs
Woodlands
•
•
•
•
•
Valleylands
Wildlife
Habitat
ANSIs
Significant valleylands as identified in the NHS mapping
Core winter deer yards
Rare vegetation communities (alvars, prairies, fens and
bogs)
• Confirmed Provincial Life Science ANSIs as determined
by the MNR
*Plus ORMCP features as determined by the draft ORMCP technical guidelines
123
6.2
The planning authority shall discourage development or site alteration in Level 2
features.
6.3
Development or site alteration would not be accepted by the planning authority unless it
has been demonstrated through an approved EIS that there will be no negative impacts on
the natural features or their ecological functions consistent with the definitions of the
PPS.
6.4
Mitigation for impacts on the natural features or their ecological functions that are
permitted by the PPS may include replacement approaches, at the discretion of the
planning authority (in conjunction with the Conservation Authority). These could include
enhancement or restoration on or off site.
6.5
planning authority. To the extent possible, replacement shall occur within the same
subwatershed.
6.6
through an EIS.
7.0
Level 3 Features
7.1
Level 3 features are considered to be significant at the watershed level. It is the overall
intent that these features should be retained on the landscape. However, flexibility is
contemplated in the way in which these features are addressed when a land use change or
other development is considered. Level 3 features consist of the following:
Component
Wetlands
•
•
•
Woodlands
•
•
ANSIs
Feature
Evaluated non-Provincially Significant Wetlands (Non-PSW)
and designated Locally Significant Wetlands (LSW)
Unevaluated wetlands contiguous to evaluated Non-PSWs and
designated LSWs
Unevaluated wetlands ≥ 0.5 ha that overlap with, or fall
within, 30 m of any identified Level 1, Level 2 and/or Level 3
NHS features
Socially Significant Woodlands ≥ 4 ha to < 10ha (only in
designated Urban Areas)
The entirety of any woodland ≥ 0.5 and < 10 ha that overlaps
or is located within 30 m of any other identified NHS Level 1
Level 2 and/or Level 3 feature
• Confirmed Regional Life Science ANSIs as determined by the
MNR
124
Component
Habitat for Fish
Linkages
Feature
• Watercourses and waterbodies, drains, online ponds, mapped
offline ponds within 30 m of another NHS feature
• Stream linkages between Level 1, Level 2 features and/or
Level 3 features (or their continuous Level 4 - supporting
features)
• Proximity linkages between Level 1, Level 2 and/or Level 3
features (or their continuous Level 4 - supporting features)
7.2
An EIS is required to demonstrate that there are no net negative impacts on the Natural
Heritage System. Where impacts can not be avoided, further mitigation for the loss of a
natural heritage feature, or an identified impact, is recommended through replacement.
Approaches to address replacement could include creation, enhancement or restoration on
or off site.
7.3
Development or site alteration would not be accepted by the planning authority unless it
has been demonstrated through an approved EIS that there will be no net negative
impacts on the natural features or their ecological functions.
7.4
Mitigation for negative impacts on the natural features or their ecological functions may
include replacement approaches, at the discretion of the planning authority in conjunction
with the Conservation Authority. These could include enhancement or restoration on or
off site.
7.5
planning authority in conjunction with the Conservation Authority. To the extent
possible, replacement shall occur within the same subwatershed.
7.6
through an EIS.
7.7
Development or site alteration shall not be permitted within Habitat for Fish except in
8.0
Level 4 – Supporting Features
8.1
Level 4 - supporting features are considered to be supporting Level 1, 2 and 3 NHS
features. Retention of these features is encouraged, however, they are not necessarily a
constraint to land use change. These features consist of:
125
Component
Wetlands
Woodlands
Wildlife Habitat
Feature
• Unevaluated wetland units that are ≥ 0.5 and
< 10 ha
• Cultural thickets continuous with NHS Level
1, Level 2 and/or Level 3 woodlands and/or
wetlands
• Woodland patches ≥ 2 and < 10 ha that are
not otherwise a NHS woodland feature
• ELC grassland communities as follows
(subject to the supporting text):
o CUM and CUT ≥15 ha
o CUT and CUM ≥ 10 ha when
surrounded
by
other
NHS
components
o Contiguous CUT/CUM communities
≥ 20 ha
8.2
Development or site alteration shall avoid Level 4 - supporting features where reasonable
and possible.
8.3
If it is not reasonable or possible to avoid the removal of part or all of a Level 4 supporting feature, replacement is encouraged, and is at the discretion of the planning
authority, in conjunction with the Conservation Authority, through the EIS process.
9.0
Big Woods Policy Areas
9.1
The Big Woods Policy Areas (BWPAs) are those areas in the Lake Simcoe Watershed
where there is a high percentage of woodland cover and large woodland patches. These
areas are considered most likely at the landscape scale to represent high ecological
function, diversity, connectivity and are also priority natural areas within the
municipality.
9.2
The planning authority recognizes the importance of the BWPAs and will preferentially
direct reforestation opportunities towards these areas whenever possible.
9.3
In addition to addressing other policies of this Plan, development applications within or
overlapping with BWPAs shall ensure no net loss of woodland cover within BWPAs.
9.4
The planning authority will seek opportunities to reduce the impact of linear
infrastructure, including roads, through BWPAs.
9.5
All other applicable NHS policies of this NHS apply to Big Woods Policy Areas. The
underlying designated NHS Levels apply.
126
14.0
Mapping Interpretation
The mapping product for this Natural Heritage System was developed using a GIS-based
platform. This map is to be used as an information tool; the text is intended to provide the
overarching definition for the NHS. The map is subject to ongoing refinements and updating as
LSRCA improves the ELC database and integrates the mapping with improving aerial
photography and other information sources. The intent of the Authority is that the map
eventually be accessible online.
As the NHS study was undertaken on a landscape scale (i.e., 350,000 ha), inevitably some
mapping irregularities occur. In addition, the GIS queries that are run occasionally produce
unintended results. These will be eliminated over time. However, in addition to the priority of the
text over the mapping (in a similar fashion to the Authority’s regulation), the reader’s attention is
drawn to these commonly occurring anomalies:
•
The symbol for proximity linkages (a red “P”) sometimes occurs in clusters. This is
because two features often approach to within 60 m of each other at multiple points,
which causes several proximity linkage opportunities to be generated side by side. Only
one “P” is intended.
•
On occasion stream linkages are generated in areas where one or both of the two NHS
features that are supposed to be being connected are actually absent. This is a GIS query
error and should be disregarded.
•
Where a Habitat for Fish feature (and if appropriate, an associated Stream Linkage) is
shown but such a feature is determined (in conjunction with the Authority) not to exist,
the updated information is intended to take precedence.
•
The land use layer used in the NHS mapping was examined for accuracy. However,
where discrepancies arise the municipal data set shall prevail.
•
Some areas that are subject to pending Ontario Municipal Board hearings and/or
decisions, regarding land use planning have been excluded from the system mapping.
It is intended that through consultation with municipal partners and greater scrutiny of the
mapping that changes may be made to the mapping to reflect known existing conditions, such as
draft plan approved subdivisions. Furthermore, instances may arise where the ELC mapping
may be amended based on more detailed, site-specific information.
127
15.0
Where Do We Go From Here?
The NHS primarily represents an understanding of the natural heritage system that is in place in
the watershed today. This project was primarily concerned with the “maintenance” aspect of the
PPS, rather than identifying opportunities for restoration or enhancement.
In many areas of the watershed, the NHS is highly fragmented and many subwatersheds are close
to or below certain thresholds that indicate the potential loss or impairment of some functions
and attributes. They could benefit substantially from efforts to improve the quality and quantity,
and therefore the function, of the system.
Landscape level restoration and enhancement is contemplated by the PPS and approaches to
landscape restoration have been suggested by others. There is an opportunity and an imperative
to develop an approach, suitable for this watershed, to address restoration, enhancement and
securement initiatives building on the existing natural heritage framework as described by Phase
1 of the NHS.
In particular, once planning authorities have established the components of their NHS, the
careful and considered reconnection of core natural areas, such as those within Big Woods
Policy Areas, could be a priority. Analysis undertaken during the process of developing this NHS
will provide a solid foundation upon which to build connectivity in the landscape.
Based on the experiences of the project team, the following recommendations are offered for
consideration by LSEMS and the LSRCA:
1. The development of Phase 2: Restoration, Enhancement and Securement strategy that
includes the expansion of linkages and integrates stewardship initiatives;
2. The NHS be used to further refine land acquisition and securement strategies and priority
areas in the watershed;
3. The Conservation Authority maintain and upgrade the ELC on a regular basis;
4. Efforts be established to improve knowledge of Species at Risk in the watershed;
5. The Authority prepare “watershed rare” lists for all faunal groups; and
6. The NHS be used as a basis for targeted wetland evaluations under the OWES.
128
16.0
Conclusions
The report provides the criteria and rationale for the identification of the components of a
Natural Heritage System based on the Provincial Policy Statement. The intent of this project is to
provide interactive mapping that can be used by a range of users in addition to the Conservation
Authority, such as planning authorities and the public.
The development of criteria for each of the components used a combination of existing practices
(in both ecological and planning contexts), recommended approaches by credible sources, and
examination of the pertinent literature.
The NHS was developed on the basis of existing conditions and generally avoided the realms of
restoration and enhancement. However, these aspects will be addressed in the second phase of
the project in which strategies for restoration and enhancement will be developed. This strategy
will also incorporate components of the LSRCA Land Acquisition Strategy as well as its
numerous stewardship activities. This will ensure that these programs are effectively
contributing to the NHS for the Lake Simcoe Watershed.
As part of the gathering of background data, the Ecological Classification System and Land Use
mapping that underpins the NHS was examined to ensure accuracy.
The criteria for the components of the Natural Heritage System have been input to ArcGIS and
processed to develop the resulting ‘system’. The mapping is based on an ArcGIS platform, which
enables users to delineate the location of the NHS, and to determine the individual features (i.e.,
woodlands, wetlands or other features) that comprise the system. The user can click anywhere
on the system and an attribute table will be displayed, indicating the components that are
contained within the system in that location and its respective level (Figure 16.1). To view and
use the mapping, software that supports shape files, such as ArcExplorer, ArcView, ArcGIS, and
Manifold, is required.
Overall, and excluding the lake itself, 105,000 ha have been identified as part of the Natural
Heritage System (Figure 16.2). This is approximately 40% of the total land mass within the
watershed, although this total includes valleylands, within which a variety of land uses occur.
provincially significant Level 1 and Level 2 components comprise about 32.7% of the land mass,
and watershed significant Level 3 components comprise about 4% and Level 4 - supporting
components comprise approximately 3.4%.
The following table (Table 16.1) indicates the distribution of the NHS by the subwatershed areas
used in this report.
129
Table 16.1 The Natural Heritage System by Subwatershed Areas
Maskinonge
River
Barrie Creeks
Hewitt’s Creek
West Holland
East Holland
Innisfil Creeks
Lover’s Creek
Beaver River
White’s Creek
Ramara Creeks
Talbot River
Georgina
Creeks
Uxbridge Brook
Oro South
Creeks
Oro North
Creeks
Pefferlaw Brook
Black River
Hawkestone
Creek
Islands in Lake
Simcoe
combined
Total
Area of
Subwatershed
(ha)
Percent of
Subwatershed
in NHS
7,179
18.7
10.7
2.8
2.6
Level 4 supporting
2.6
3781
1,751
35,410
23,910
10,757
5,995
32,724
10,520
14,350
7,056
4,946
19.3
22.3
30.5
33.1
33.3
34.0
36.0
38.4
41.6
42.3
42.3
7.1
10.5
21.6
24.2
17.4
21.8
17.0
19.3
28.9
21.5
28.2
4.2
3.1
2.2
2.5
5.6
5.2
10.7
8.2
2.6
6.5
3.0
6.1
6.9
3.8
3.6
6.0
3.4
5.3
6.7
5.8
7.0
3.2
1.9
1.8
2.9
2.8
4.3
3.6
3.0
4.2
4.3
7.3
7.9
17,495
5,769
44.5
44.5
31.0
25.6
8.7
9.2
2.2
5.6
2.6
4.1
8,344
45.2
31.8
3.1
5.3
5.0
28,482
37,536
3,971
49.6
52.0
54.4
35.7
37.5
40.7
8.4
8.8
5.3
2.5
3.0
4.1
3.0
2.7
4.3
1,912
87.1
63.1
7.4
1.8
14.8
261,887
40.2%
26.4%
6.3%
4.1%
3.4%
130
Percent of Subwatershed by Component Level
Level 1
Level 2
Level 3
131
132
Acknowledging that many of the components are overlapping (e.g., wetlands can also be
woodlands and both can be in valleylands) the NHS breakdown is presented in Table 16.2.
Table 16.2 Area of the Natural Heritage System Components
NHS Component
Area in
including the Lake (ha)
Wetlands
36,673
Woodlands
76,104
Valleylands
20,036
Wildlife Habitat
12,501
ANSIs
10,383
Habitat for Fish
74,203
Linkages (Stream)*
3,546
*624 Proximity Linkage points have also been identified
In addition to providing an important tool for the LSRCA, as the NHS closely follows the
general framework of the Provincial Policy Statement, it is also well-positioned for inclusion
within municipal Official Plans that seek to meet the policy requirements of the province.
The identification and description of the Natural Heritage System provides a tool to:
•
Protect natural heritage resources and move towards the sustainability of
ecosystem services;
•
Examine change over time;
•
Refine existing municipal natural heritage systems;
•
Guide the scope of environmental studies and assess the impacts of proposed land
use change;
•
Guide future ecological planning initiatives (e.g., wetland evaluations);
•
Help identify priority communities/subwatersheds/planning jurisdictions for
restoration or enhancement opportunities;
•
Identify high value restoration or enhancement areas (i.e., those locations where
the greatest ecological benefit can be realized for the least amount of dollars); and
•
Identify land acquisition targets for conservation organizations.
133
There have been several landscape planning initiatives that have been initiated (e.g., MNR’s
“Natural Spaces”) or completed (e.g., MNR’s “The Big Picture”, various municipal woodland
studies). However, most have not been incorporated into critical planning documents. One
objective of this study was to provide a NHS that could be supported and adopted by planning
authorities.
During the review process for this document several reviewers requested further guidance on the
principles of Replacement. The authors of this document believe that this subject requires
considerable review of practices elsewhere in North America and current restoration science. In
general, younger and less structurally diverse communities (such as some marshes, grasslands
and thickets) are relatively easy to replicate and with the appropriate application of the current
state of restoration science, there can be considerable certainty regarding the success of their
replication. Other systems, such as forested communities, take longer to establish (i.e., more than
a human lifetime) and there is increased uncertainty regarding the final outcome. A third group
may not be easily re-established (e.g., treed swamps, fens and bogs) and uncertainty is high.
Wetlands are often replaced at ratios of three (replaced) to one (removed). However, to
maximize success, replacement strategies need to consider a wide range of possibilities that
include: variable ratio-based replacement, targeted restoration or enhancement, banking of
replacement commitments, cash alternatives and other joint ventures.
It is the belief of the authors of this report that it reflects both the most recent science and a
pragmatic approach, which should enable a wide range of stakeholders to lend support to this
initiative. In the future, it is hoped that new scientific research, watershed data, updates and
revisions can further improve the NHS.
In many developed countries formerly common and widespread flora and fauna species are in
decline; in the end, this project will have been successful when a functional and sustainable
Natural Heritage System appears as a Schedule within municipal Official Plans, and is used as
part of the daily business of the Lake Simcoe Region Conservation Authority.
The Conservation Authority intends to adopt the NHS as a tool for plan review, providing
advice to its municipal partners and members of the public, as well as furthering and fostering
partnerships and land stewardship, and contributing to protection and research initiatives
across the watershed.
It is recommended that the planning authorities within the Lake Simcoe Watershed use the
NHS as a basis to identify sustainable natural heritage systems within their jurisdictions and
to amend and adopt the supporting implementation policies and to embed these within their
respective official plans.
134
17.0
Additional Cited Literature
Ducks Unlimited Canada. 2006.
Leading ag economist weighs in on sustaining landscapes. Ducks Unlimited Canada
Conservator 27: 12.
Environment Canada. 2005.
Beyond Islands of Green: A Primer for Using Conservation Science to Select and Design
Community-based Nature Reserves. Environment Canada, Downsview, Ontario. 80 pp.
Federation of Ontario Naturalists. 2006.
Available Online:
http/::www.ontarionature.org:pdf:urban_forest.pdf.
Foley, J.A., R. DeFries, G.P. Asner, C. Barford, G. Bonan, S.R. Carpenter, F.S. Chapin,
M.T. Coe, G.C. Daily, H.K. Gibbs, J.H. Helkowski, T. Holloway, E.A. Howard, C.J. Kucharik,
C. Monfreda, J.A. Patz, C. Prentice, N. Ramankutty, P.K. Snyder. 2005.
Global consequences of land use. Science 309: 570-574.
Gabor, T.S., A.K. North, L.C.M. Ross, H.R. Murkin, J.S. Anderson, and M.A. Turner.
2001.
Beyond the Pipe - The Importance of Wetlands & Upland Conservation Practices in
Watershed Management: Functions & Values for Water Quality & Quantity. Ducks
Unlimited Canada. 43 pp.
Hilts, S., M. Kirk. and R. Reid. 1986.
Islands of Green. Natural Heritage Protection in Ontario. Ontario Heritage Foundation.
Toronto. 200 pp.
Lake Simcoe Environmental Management Strategy. 2006
Available online: http://www.lsems.info/index.html.
Available online: http://www.lsrca.on.ca/AboutUs/index.html.
Margules, C.R. and R. L. Pressey. 2000.
Systematic Conservation Planning. Nature 405: 243-253.
37 pp.
Ministry of Municipal Housing and Affairs, 2005.
Greenbelt Plan 2005. ISBN:0-7794-7642-5. Queen’s Printer for Ontario. Toronto. 57 pp.
135
Ministry of Municipal Housing and Affairs, 2002.
Oak Ridges Moraine Conservation Plan 2002. Ministry of Municipal Housing and
Affairs. Queen’s Printer for Ontario. Toronto. 73 pp.
Ministry of Public Infrastructure Renewal. 2006.
Places to Grow: Growth Plan for the Greater Golden Horseshoe. 48 pp.
Natural Heritage Reference Manual for Policy 2.3 of the Provincial Policy Statement. 127
pp.
Protecting Natural Areas Through Land Trusts. Available online:
http://www.mnr.gov.on.ca/MNR/Csb/news/2006/may11bg_06.html.
Pierce, S.M., R.M. Cowling, A.T. Knight, A.T. Lombard, M. Rouget and T. Wolf. 2005.
Systematic conservation planning products for land-use planning: Interpretation for
implementation. Biological Conservation 125: 441–458.
Polasky, S. 2006.
You can’t always get what you want: Conservation planning with feedback effects.
PNAS 103: 5245-5246.
Redford, K.H. and B.D. Richter. 1999.
Conservation of biodiversity in a world of use. Conservation Biology 13: 1246-1256.
Riley, J.L. and P. Mohr. 1994.
The natural heritage of southern Ontario's settled landscapes. A review of conservation
Resources, Southern Region Aurora, Science and Technology Transfer, Technical Report
TR-001. 78 pp.
136
APPENDICES
137
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138
Appendix 1
Ecological Land Classification Methodology
1.0
Introduction
The Ecological Land Classification (ELC) (Lee et al. 1998) map layer is a primary building
block of the Lake Simcoe Watershed Natural Heritage System. This data layer is more accurately
described as the Natural Heritage and Land Use Map as it consists of two principal land
classification data components: natural heritage and land use. The LSRCA initiated the mapping
program in 2000 to map the entire LSRCA jurisdiction of the Lake Simcoe Watershed in order to
achieve a mapping product with complete coverage.
2.0
Methodology
A grid was created for each subwatershed and hard copy sheets of aerial photographs were
printed. Additional layers such as evaluated wetlands (from MNR), 5 m contours, watercourses,
and Areas of Natural and Scientific Interest (ANSIs) were superimposed onto the photographic
base. The landscape was then delineated on the hard-copy sheets using on-screen information
for assistance. In addition to the layers on the hard-copy sheets, other sources of information
included: soils, parcel fabric, and watershed boundaries. The minimum polygon size for a natural
heritage feature was generally 0.5 ha, however some smaller units (generally wetlands) were
included where it was thought to be appropriate.
Natural Heritage
Each natural heritage feature identified was assigned a unique code, specific to that watershed.
Each code referred to a unique natural heritage record, comprised of an ELC code to Community
Series (i.e., deciduous forest, mixed swamp, cultural meadow, etc.), which also included the
other standard ELC community information: System (terrestrial, wetland, aquatic); Site (open
water, surface deposits, etc.); Substrate (organic, mineral); Topography (rolling upland,
tableland, bottomland, etc.); History (cultural, natural); Cover (treed, shrub, open); Form
(submerged, deciduous, mixed, etc.); and Community (swamp, fen, forest, etc.). The natural
heritage records were entered into an Access 97 database, created specifically for this mapping.
Land Use
Land use was identified concurrently with the delineation and identification of the natural
heritage features. The land use codes were based on the codes used by the Credit Valley
Conservation Authority in its mapping. Land uses include: intensive agriculture (i.e., row crop,
sod farm, etc.); non-intensive agriculture (hay, pasture); urban; rural development; estate
residential; manicured open space; institutional; rail; and roads. Each unique land use code was
also entered into the Access database.
139
Mapping
Upon completion of hard copy delineation of polygons, sheets were heads-up digitized at a scale
of 1:4000 using ArcView 3.2 (and more recently ArcGIS 9.1). Following the digitization of the
polygons, points were added to each polygon that contained the natural heritage record code.
The mapping was then processed such that each polygon contained a unique code. The mapping
was then linked to the Access database containing the detailed record information. The resulting
data layer enables the user to click on any polygon and read the information for that polygon.
Timing and Photographic Resources
The mapping was generally undertaken on a subwatershed basis, commencing with the 1999
colour orthophotography. The Region of York and the Township of Innisfil were originally
mapped using 1999 50 cm colour orthogonally-rectified aerial photography (orthophotography).
The original mapping for the Region of Durham was done using 2000 20 cm black and white
photography. The City of Barrie was mapped using 2001 10 cm black and white orthophotography. OroMedonte, Orillia and Ramara were mapped using 2002 20 cm colour orthophotography. York,
Durham, Innisfil and Barrie were updated using 2002 20 cm colour orthophotography.
Staff
Three GIS staff were involved in the mapping process led by Darren Campbell, GIS Coordinator.
There were four natural heritage interpreters involved in the mapping procedure led by Kim
Baker, Senior Natural Heritage Biologist.
3.0
Other Information
Wetlands
The mapping contains three categories of wetlands: Ministry of Natural Resources (MNR)
evaluated wetlands (Natural Resources and Values Information System - NRVIS), Oak Ridges
Moraine wetlands (NRVIS), and interpreted wetlands. The MNR evaluated wetlands were
integrated into the mapping as “Evaluated Wetlands”, as they existed in NRVIS; no edits were
made to these polygons, except where obvious change had occurred (e.g., residential
development). The ELC mapping is updated on an on-going basis to reflect recent MNR
wetland evaluation updates. The wetland community information contained within the wetland
evaluations was used to assist in applying the ELC protocol.
The Oak Ridges Moraine wetlands (those that were not evaluated wetlands) were originally
identified and mapped by the MNR. These wetlands are included in the mapping as mapped by
the MNR as “ORM wetlands” where they are greater than 0.4 ha.
The third category of wetland was “Interpreted”. These were wetland units that were identified
through interpretation of aerial photography and/or field checking. These wetlands may include
areas adjacent to evaluated wetlands that had been missed during the evaluation, or may be in
areas that have not been evaluated at the time of the ELC mapping.
140
Breaks in Polygons
Polygons generally begin and end based on either a change in vegetation community (e.g., FOD
to FOC) or a change in topography (e.g., tableland to valleyslope). Anthropogenic features such
as hydro transmission lines and pipelines were mapped according to their vegetative
characteristics within ELC; usually as cultural meadow or cultural thicket. These linear features
are therefore often visible in the vegetation mapping as a result of the linear vegetation
community and do therefore represent breaks in other features such as forest. This approach,
while conservative is also ecologically defensible. In general, all municipal road rights-of-way
constitute a break in the vegetation. Roads were also delineated as polygons. Unopened road
allowances were not mapped out as roads, but were strictly mapped based on their ELC
vegetation communities.
Single family dwellings and their associated manicured areas, including driveways, were
identified as rural development or estate residential, depending on the size and setting of the lot.
Built up areas such as towns and cities were identified as urban. Trails were generally included
within the vegetation community, unless they represented a change in vegetation community.
Railways were delineated as “Railway” as a land use. Old railway lines that have been
converted to trails are identified as “Manicured Open Space” (this category was also used for
parks). Watercourses that were digitizable at 1:4,000 for a reasonable length were identified as
“Open Water” and were delineated from the adjacent vegetation communities.
Other Features
Known Christmas tree farms and orchards were mapped as “Intensive Agriculture”. All
hedgerows that were continuous with another natural heritage feature were mapped as Cultural
Woodlands (CUW) and noted as 'Hedgerow' in the attribute table. Isolated hedgerows (i.e.,
those not connected to another feature) were generally not mapped. However, some isolated
hedgerows that were deemed to be 'substantial' (i.e., several trees wide or were dominant on the
landscape) may have been mapped. All mapped hedgerows are identifiable in the attribute table.
The ELC definition of “savanna” was not used, as no examples of this community type were
interpreted or are thought to occur as natural communities within the watershed.
Field Checking
Field checking was undertaken intermittently throughout the watershed, mostly by roadside
reconnaissance by the Natural Heritage Biologist and Natural Heritage Technician. In addition,
a blind field test of ELC data was undertaken as part of the NHS development and is reported in
Appendix 2.
141
ELC Codes
The following table provides the ELC codes used in this document.
ELC Community Code
AL
BOO
BOS
CUM
CUP
CUT
CUW
FEO
FES
FOC
FOD
FOM
MAM
MAS
OAO
SAF
SAM
SAS
SWC
SWD
SWM
SWT
TP
4.0
ELC Community
Alvar
Open bog
Shrub bog
Cultural meadow
Cultural plantation
Cultural thicket
Cultural woodland
Open fen
Shrub fen
Coniferous forest
Deciduous forest
Mixed forest
Meadow marsh
Shallow marsh
Open aquatic
Floating-leaved shallow aquatic
Mixed shallow aquatic
Submerged shallow aquatic
Coniferous swamp
Deciduous swamp
Mixed swamp
Swamp thicket
Tall grass prairie
Cited Literature
Lee, H.T., W.D. Bakowsky, J. Riley, J. Bowles, M. Puddister, P. Uhlig and S. McMurray. 1998.
Ecological Land Classification for Southern Ontario: First Approximation and its
Application. Ontario Ministry of Natural Resources, Southcentral Science Section, Science
Development and Transfer Branch. SCSS Field Guide FG-02.
142
Appendix 2
Blind Field Checking of LSRCA
Ecological Land Classification Data
1.0
Introduction
The Ecological Land Classification (ELC) and land use layer forms the basis of the Lake
Simcoe Watershed Natural Heritage System. The goal of ELC is to establish a uniform
and consistent method for identifying, describing, naming, mapping and organizing
landscape patterns and vegetation communities (Lee et al. 1998).
The vegetation communities in the Lake Simcoe Watershed were classified to the
Community Series level of the ELC System. This involved delineating the natural
heritage features into polygons based on similar broad level vegetation communities. The
Community Series level is determined by the type of vegetation or plant form that
characterizes the community (Lee et al. 1998). The polygons were identified based on the
community's cover (open, shrub or treed), and whether the tree or shrub form is
deciduous, coniferous or mixed or whether the plant form is herbaceous or graminoid.
LSRCA began the classification process in 2000 and is continuously updating it to reflect
recent orthophotography. The Regional Municipality of York and the Town of Innisfil
were originally mapped using 1999 colour orthogonally-rectified aerial photography
(orthos). The Regional Municipality of Durham and the City of Barrie were mapped
using the 2000 black-and-white orthos. Oro-Medonte, Orillia and Ramara were classified
using 2002 colour orthos. York, Durham, Innisfil and Barrie were all updated using 2002
colour orthos.
Three LSRCA GIS staff were involved in the mapping process. This was coordinated by
Darren Campbell, the GIS Coordinator at the Authority. The ELC classification work was
undertaken by three natural heritage interpreters, and was overseen and reviewed by Kim
Baker, Senior Natural Heritage Biologist. For details on the ELC protocols see Appendix
1.
2.0
Methods
A blind protocol was used in order to ensure accurate, unbiased results. A GIS technician
from the LSRCA generated a random sample of 69 ELC polygons with unique site
identification numbers. Provided by the LSRCA were close-up images of the polygons on
2002 air photo maps, an overview map in order to locate the polygons, as well as an
attribute table with the polygon information. Four field technicians went into the field to
locate the polygons and assign to each an ELC designation. The field exercises were
undertaken in the late summer and fall of 2006. Following the completion of field
checking for the polygons the field check designations were compared to the attribute
143
table designations. The attribute table was not shown to the field technicians prior to the
completion of fieldwork.
Following the field check comparison to the attribute table, each polygon was placed into
one of six categories. The categories are as follows: correct call, correct call with minor
mapping issue, minor error, moderate error, major error – LSRCA, and major error –
MNR. These six categories are part of two larger groups: correct call and incorrect call.
Determination of acceptable accuracy was based on the latter two groups.
3.0
Results
Table 1 presents the comparison of the field check including the site identifier, the ELC
code, the field check code, species information, notes and analysis. The analysis column
presents whether the polygon was properly evaluated in comparison to the field and the
notes column provides information on the error type.
144
Table 1. Results of the Field Tests
Site ID
ELC
Code
W1749
SWC
Field
Check
Code
FOD
W1454
CUM
MAM
B895
SWT
CUM
OS270
FOD
SWM
P2172
FOC
SWC
B1162
MAM
W2423
OS698
Species Information
Notes
Populus trembuloides, Populus, Fraxinus sp.,
Betula papyrifera, Equisetum sp., Rhamnus
cathartica, Upland Solidago spp.,
Toxicodendron radicans
Typha, Phalaris, Solidago sp., some shrubs
but less than 25%
Mapping error, whole thing looks like
FOD, or FOM
CUT
Acer negundo, Rhamnus cathartica
FOM
SWM
Canopy: Thuja occidentalis (~ 50%), Betula
papyrifera (~ 35%). Ground- Fraxinus sp.
Organic soil, depth unknown.
SWD
FOD
Acer saccharum, Fraxinus Americana,
Betula papyrifera, Ulmus americana
Presumed non-natural region. Very
moist but not 50% wetlands veg. Unit
mismapped, 50% meadow (probably
MAM) and 50% part of wooded unit.
Looks wet as it is beside a river, hard
to interpret from photo
Soil was very dark black and very wet
even at the top of the hill. Photo
indicates topography that would lead to
dry rather than wet soils
All species were upland species.
Groundcover was minimal.
Analysis
Major Error
MNR mapping error to
evaluated wetland
Major Error
Riparian wetland mapped
as cultural upland
Daucus carota
Next to SWT. Overmapped, included a Major Error
MAS.
Acer saccharinum, Fraxinus pennsylvanica, ~ 30% Pinus sp., wet, vernal pooling
Major Error
Populus tremuloides, Pinus strobus, Onoclea
sensibilis, Equisetum sp., Typha sp.
With Rhamnus cathartica, Populus
Deep organics >60cm. Couldn't view
Moderate Error
balsamifera, Thuja occidentalis (dominant)
the understory from aerial photo
145
Riparian, degree of wetness hard to
interpret.
Moderate Error
Includes portion from
woodland, some could
have been mapped as
MAM
Moderate Error
Called upland when was
wetland, but could be
difficult call
Moderate Error
Called wetland when was
Site ID
ELC
Code
Field
Check
Code
Species Information
E2471
CUT
CUT/
MAS
Solidago sp., Thuja occidentalis
407
FOC
FOC/
SWC
Thuja occidentalis
Notes
Analysis
upland. Air photo indicates
drainage area, could be a
difficult call
Mapped too general – are two MAS in Moderate Error
this polygon.
Difficult to see on aerial, combined Moderate Error
SWC/FOC polygon
Difficult to map
polygon
2744
FOC
SWC
Thuja occidentalis, Acer saccharum
P2254
CUW
SWT
Thuja occidentalis, Salix sp.
P5729
FOD
FOD,
SWM,
SWD
1831
FOM
SWM
I852
FOD
SWD
I418
CUW
SWD
Ulmus americana, Acer rubrum, Acer
Xfreemanii, Onoclea sensibilis, Thuja
occidentalis, Populus tremuloides, Rhamnus
cathartica
Picea glauca, Betula papyrifera, Ulmus
americana,
Acer
rubrum,
Populus
tremuloides
Fraxinus sp., Populus tremuloides, Acer
saccharum, Thuja occidentalis, moss,
Crateagus sp., Cornus stolonifera, Ulmus
americana, Geranium robertianum
Ulmus americana, Populus tremuloides, Acer
rubrum, Betula alleghaniensis, Thuja
146
wet
Swamp on a slope; old shoreline? Moderate Error
Some upper sections were FOC
High
slopes
made
interpretation of swamp
difficult
Overmapped
Moderate Error
Undermapped
Moderate Error
10 yrs ago could have been SWD
Moderate Error
An unusual Sugar Maple, Black Ash Moderate Error
swamp. Vernal pooling, complex
microtopography
Clay component in soil. Area being
filled with compost. Severely
Moderate Error
Site ID
ELC
Code
Field
Check
Code
Species Information
Notes
encroached. % cover close to 60. Dry
swamp
Typha sp., Phragmites sp., Phalaris Undermapped. Was ag., but has
arundinacea, Salix sp., Cornus stolonifera
regenerated to wetland.
Analysis
occidentalis, ferns, mosses
L214
CUM
MAS
&
SWT
T271
FOC
CUP/
CUW
Acer saccharum, Picea sp., Abies balsamea
(CUP)
FOM
SWM
Populus tremuloides, Thuja occidentalis,
Fraxinus pennsylvanica, Larix laricina,
Abies balsamea
Thuja occidentalis co-dominant with
Fraxinus nigra > Picea spp., Betula, Carex
lacustris, Equisetum sp., Osmunda
cinnamomea, moss, dead trees
Pinus sylvestris
Aerial is deceiving
ON198
ON795
SWC
SWM
P5618
CUW
CUP
ON795
SWC
SWM
P937
CUW
CUP
B5298
CUW
FOC
B358
MAS
MAS
350
MAS
MAS
Thuja occidentalis (co-dominant), Fraxinus
nigra (co-dominant) > Picea spp., Betula,
Carex lacustris, Equisetum sp., Osmunda
cinnamomea, moss, dead trees
Pinus sp. and Picea sp.
Mapping error, combined two types
Moderate Error
Moderate Error
Overestimated % cover
and overmapped a CUP
Moderate Error
Difficult to discern soil
moisture
Minor Error
Underestimated deciduous
component
Minor Error
Minor Error
Underestimated deciduous
component
Mapping error
Minor Error
Thuja occidentalis >> Tilia americana, Moist not wet, no understorey, soils Minor Error
Populus sp., Ulmus americana, Malus sp., were siC
Difficult to interpret, could
Rhamnus cathartica
be
mostly
hedgerow,
inconclusive rules
Typha sp.
Small mapping errors on both ends
OK
Typha sp. >> Aster puniceus, Impatiens
capensis
147
Groundwater discharge
OK
Site ID
ELC
Code
Field
Check
Code
CUP
Species Information
P910
CUP
W626
L449
CUP
CUM
I916
FOD
CUP
CUM
/CUT
FOD
I987
FOD
FOD
I819
SWD
SWD
HA356
FOM
FOM
Picea sp., Pinus strobus (>40%), Acer
saccharum (>40%), Ulmus americana (one),
Rhus sp., Solidago, Picea pungens, Acer
saccharum, Understory: Populus tremuloides
B2018
FOD
FOD
178
FOM
FOM,
FOD
Populus balsamifera (dominant), dead Ulmus
americana (few), Fraxinus nigra (few),
Populus tremuloides (few), Picea glauca,
Thuja occidentalis, Rhamnus cathartica,
Understory: Rhamnus cathartica, Thuja
occidentalis, Fraxinus sambucifolia, Cornus
stolonifera
FOM: Acer saccharum > Tsuga canadensis
30% to East.
FOD: Acer saccharum > Prunus serotina >
Betula sp., Understory 25% Tsuga
Canadensis
Notes
Pinus strobus P. resinosa, Picea glauca
Pinus strobus, Picea sp.
Solidago sp., grasses, Cercium sp.
Acer saccharum, Populus sp., Betula
papyrifera Understory: Acer saccharum
Groundcover: Equisetum sp., Trillium
grandiflorum,
Understory: Fagus grandifolia, Ground
cover: Convallarina montana, Carex sp.,
Canopy: Populus, Betula papyrifera, Acer
saccharum
> 60% deciduous cover
148
Analysis
OK
Watercourse runs through, good call
Successional change, very minor
mapping error
OK
OK
OK
OK
May be slightly over split from
surrounding units
The 2002 air photo shows differences
from current. CUP in the adjacent
polygon (as indicated on photo), also
development (single family dwellings)
in the subject polygon
Transitional. Upland but close to
wetland. Could easily be called SWD
OK
Mapping call
OK
OK
OK
Site ID
ELC
Code
B1211
CUW
Field
Check
Code
CUT
B95
CUM
U5190
Species Information
Notes
Analysis
All grazed, % tree cover, height of veg.
mistaken
NAG
Thuja sp., Rhamnus cathartica, Ulmus
Americana (dead and sapling line)
Pasture
OK
Minor mapping issue
OK
Could be agricultural
change
FOD
FOD
Acer saccharum, Tsuga canadensis (one)
Polygon over mapped to include valley
features, 80% correct
OK
Minor mapping issue
502
SWC
SWM
Tsuga canadensis, Thuja occidentalis, Picea
glauca > Populus tremuloides, Betula
papyrifera
Groundwater seepage, % deciduous
underestimated
OK
Small error in % conifer
1440
CUP
CUP
Pinus sylvestris
Over-mapped (too small)
OK
Minor mapping issue
892
CUM
CUT
Thuja occidentalis, Rhamnus cathartica
Open, 30% shrubs, would have been
CUM five years ago
W1484
FOM
FOD
Populus tremuloides, Pinus sp., Fraxinus sp.,
Equisetum sp. (lots), Toxicodendron
radicans, Asclepias tuberose
Disturbed, natural regeneration
W575
CUW
FOD
Populus; Understory: Pinus strobus,
Solidago sp., Equisetum sp., Rhus typhina
Natural regeneration small mapping
error, upland sandy soils
E1689
SWD
SWC
Thuja occidentalis
Combined with small MAS
OK
Minor mapping issue,
succession
OK
Negligible error in %
conifer % which may have
been removed for hedging
OK
Minor mapping issue,
succession
OK
Minor mapping issue
149
Site ID
ELC
Code
Field
Check
Code
FOD
Species Information
Notes
W353
FOD
W9203
FOD
FOM/
FOD
W241
CUM
CUM
Solidago sp., with Cornus stolonifera and Very transitional with CUW, CUM and OK
Malus sp. (<25%)
CUT in one polygon
6050
FOC
FOC
P2315
MAS
SWT
Pinus resinosa, Pinus strobus,
americana, Fagus grandifolia
Salix sp.
Acer saccharum, Fagus grandifolia, Tsuga Aerial looks like FOD, close to FOM
canadensis
Acer saccharum, Fagus grandifolia, Tsuga
canadensis
Analysis
OK
OK
Ulmus Extensive path throughout, but has OK
>60% cover
Most likely was MAS five years ago. OK
Hydro corridor
Minor mapping
succession
OK
U2229
CUM
CUM
B321
FOM
FOM
171
CUP
CUP
Pinus strobus, Picea glauca,
saccharum, Fagus grandifolia
Pinus resinosa
U1193
CUP
CUP
Pinus strobus
R408
SWD
SWD
L249
FOD
FOD
Lots of Vincetoxicum rossicum, Equisetum
sp., Fraxinus nigra, Ulmus americana,
Populus tremuloides, Thuja occidentalis,
moss, Onoclea sensibilis, dominant Aster sp.
Acer saccharum, Prunus serotina
Somewhat overmapped; included some OK
FOD, are man-made berms. siS soils
on slopes, organics in depression,
wetter
No wetland near stream
OK
ON414
FOM
FOM
Rhus typhina, Pinus strobus, Picea glauca,
Betula papyrifera, Acer saccharum
OK
Acer
OK
OK
OK
150
issue,
Site ID
ELC
Code
BC277
CUW
Field
Check
Code
CUW
1175
SWC
SWC
W1064
CUM
CUM
Solidago sp.
E2411
SWT
SWT
Salix sp.
W416
CUM
CUM
Solidago sp.
I114
CUT
CUT
Malus sp., Cornus stolonifera, grasses
R488
CUM
R237
SWT
CUM
MAM
SWT
TA148
SWT
SWT
L7
CUM
OS723
FOD
CUM/
CUT
FOD
CUM: Solidago sp., Rubus, Urtica dioica,
MAM: Phalaris >> Salix sp.
Salix sp., Cornus stolonifera, Eupatoria
maculatum, Euthamia graminifolia, Phalaris
arundinacea, Phragmites australis
Alnus incana, Saccharum freemanii, Cornus
stolonifera
Cornus stolonifera, Pinus sp., Rhus typhina
OS736
FOM
ON276
CUT
CUW/
FOM
CUM
Species Information
Notes
Thuja occidentalis, Picea glauca, Acer Very close to being a FOD/FOM
negundo, Populus tremuloides, Tilia
americana
Thuja occidentalis, Ledum groenlandicum, Groundwater discharge
Pinus strobus, Athyrium sp., Larix laricina,
Abies balimea, Ulmus americana
Some Malus sp., Juniperus virginiana,
but less than 25% will become CUT in
next few years
In the middle of Holland Marsh, could
be SWD
Analysis
OK
OK
OK
OK
OK
Cattle paths, mapped farm in.
OK
OK
OK
A little over-mapped
OK
Small % difference in tree cover.
Included CUW in polygon with CUM.
Could be bigger polygon.
OK
Minor mapping issues
OK
Pinus strobus, Thuja occidentalis, Fraxinus Backyards mown. Could connect to
americanum
URB polygon.
Cornus stolonifera, Salix sp., asters, SWT in pockets; the majority is CUM
Asclepias syriaca
OK
OK
Acer sp., Solidago sp., Alliaria petiolata
151
The data in Table 1 have been assigned to various categories and summarized in Table 2.
Table 2. Summary of Results
Call Type
Definition
Correct
Correct in type and area
32
Correct
with minor mapping
issues
Minor Error
Essentially correct, some nonsignificant issues with call or
mapping
Essentially correct,
underestimating deciduous or
coniferous component
Wetland versus upland or
community mapping problems;
due to difficult to interpret
conditions
Wetland versus upland, or
community mapping; should
have been correctly called
Wetland versus upland, or
community mapping; should
have been correctly called
13
Moderate Error
Major Error – LSRCA
Major Error – OMNR
evaluated wetland
layer
Number
%
5
Comments
95% Based on information levels available to the
interpreter, these categories are generally
considered to be a correct call.
Woodland cover and land use categories
generally correct.
15
3
1
152
5% These categories are considered to be an
incorrect call that could affect watershedwide data.
Lake Simcoe Watershed Natural Heritage System – Final Draft
4.0
Discussion
It is recognized that the sample size of the test is insufficient to properly test the ELC data set
and provide statistically valid accuracy, given that some 34,767 polygons have been interpreted
over the multi-year program. However, the test is a useful qualitative exercise that can form the
beginning of a more robust quality control program and increase the accuracy of mapping in the
future.
Overall, 95% of the Ecological Land Classification units that were field checked were correct.
generally the mapping, which integrates both land use and land cover (i.e., there is no “white
space”) is remarkably accurate. Gross errors that are typically common to landscape-level remote
sensing techniques were almost absent. For example, the identification of intensive agricultural
lands, infrastructure and residential/industrial/commercial land uses was usually correct. The
lines created by the digitizing methods were generally precise (e.g., roadside edges were in the
correct locations) and “bleed” into adjacent polygons very limited in extent.
Some of the errors that were observed in ELC designations appear to be related to the\
experience of interpreters (e.g., the designation of a cultural meadow along a stream, that should
clearly have been designated as wetland), and therefore it is likely that those types of errors have
gradually declined over the five years of the program. Some units had been altered due to
changes in agricultural practices or successional processes.
Two of the major errors resulted from upland being mapped as wetland and of these one was
sourced from an Ontario Ministry of Natural Resources wetland evaluation map. As discussed
above, these data were taken as they were provided, and by rule they were not re-interpreted,
even if a mapping error was visible to the technician.
Under-mapping of wetlands occurred in 12 of the test plots while over-mapping of wetlands only
represented only two of the test plots. This is not surprising, as wetland calls can be difficult
even for experienced evaluators when standing in the field. Most of the errors were in these
upland versus wetland calls (particularly in treed units) and in the relative proportions of
deciduous versus coniferous trees. Both of these are known to be potential pitfalls of aerial
photograph interpretation. However, these types of errors are unlikely to substantially affect the
development of the natural heritage system and the net result is that wetlands are likely to be
somewhat under-represented by the ELC mapping.
The aerial photographs used were of various ages and types, and the classification program
extended over several years. These two practical realities are bound to introduce some level of
variability in the final product. In addition, a seven year period (from the first 1999 photos)
induces some potentially significant shifts in communities (e.g., from CUM to CUT to CUW, or
shifts from and to alternative land uses.
In general, all of the ELC mapping correctly identified cultural meadows, treed units and cultural
thicket/cultural woodlands. This means for example that forest cover data for the watershed are
likely to be accurate.
153
It is also notable that the blind test did not include land use polygons. If it had, the percentage of
correct calls would likely increase.
4.1
Recommendations
The ELC and land use mapping program has become an important planning tool for the
Authority and an integral part of the Natural Heritage System. It also provides a powerful tool
for measuring future changes in landscape composition. Ongoing improvement and upgrading
should be undertaken. The following recommendations are offered in this regard.
1. At least one subwatershed area should be upgraded annually, to the highest level of
photography available at that time. Efforts should be made to have only watershedexperienced and ELC-qualified interpreters undertake the work.
2. An annual blind quality control program of at least 50 polygons, stratified to reflect the
results of the initial batch, should be tested by ELC-qualified staff (and preferably not
those who did the original interpretation).
3. To provide greater definition, greater accuracy and to allow more detailed ecological
analysis, the Authority should consider moving the ELC towards Ecosite determination.
154
Appendix 3
Technical Methodology for Determining Significant Valleylands
The following is a technical description of how significant valleylands were determined for the
purposes of the Lake Simcoe Watershed NHS.
1.0
Off the Oak Ridges Moraine
1.1
Large Valleys
Scale 1: 60,000 - 75,000
To determine the location of large significant valleys and their respective shapes the following
layers were used:
•
•
•
Swp_shd_50m2 (hillshade file);
Raster file of slope classification (≥8%) Classified breaks occur <8%, 8-9.99%,
10-14.99%, and ≥15%; and
Point layer of Stable Top of Slope which is derived from a script which calculated
average slope and bank height and then queried to select points which are ≥ 5m and ≥ 8%
average slope.
155
Scale 1:40,000
Digitizing the top of valley when the slope is clearly defined by the above mentioned layers.
An additional layer from the Authority’s Regulation data (i.e.“SlopeErosion”) was used to verify
that the valley is appropriately located. As the “Slope Erosion” criterion was much broader than
valleyland criterion, the valleylands should be situated in most cases within the “Slope Erosion”
polygons.
Scale 1:20,000
Digitizing top of valley when slope is not clearly defined by the layers mentioned above.
An additional layer has been used to render these areas more clearly defined.
•
Raster file of slope classification (>=7%) Classified breaks occur <7%, 7-9.99%,
10-14.99%, and >=15%.
As these areas are sometimes ill-defined, the portion of polygon serves more as a link to provide
a continuous valley. See examples below.
156
1.2
Smaller Valleys
These valleys are not connected to the large significant valleys yet nevertheless they appear as
relatively obvious features on their particular watercourse
Scale 1: 5,000
Valleys were digitized using the following criteria:
•
•
•
Polygons must be greater than 50m x 25m;
Valleys must be two sided; and
Slope must be >= 8% with a rise >= 5m.
157
2.0
On the Oak Ridges Moraine
Scale 1: 5,000
Valleys were digitized using similar criteria to the small significant valleys above. The only
difference in criteria being:
•
Slope must be ≥15% with a rise ≥ 5m, which is consistent with the Oak Ridges Moraine
Conservation Plan (ORMCP).
This captured most of the ORMCP Significant Valleylands. However, as with all ORMCP
components, site specific investigations and the appropriate guidelines must be applied at the site
specific level to ensure conformity with the requirements of the ORMCP.
158
Appendix 4
Terms of Reference: Environmental Impact Study
The following are the general Terms of Reference for an Environmental Impact Study (EIS) to
determine the potential impacts on the Natural Heritage System (NHS) from development and
site alteration proposals. The actual Terms of Reference for any particular application will be
determined by the planning authority in conjunction with the Conservation Authority.
1.0
Objectives
The objectives of the Terms of Reference are as follows:
1.1
To provide an outline to applicants and their consultants of the expectations of the
Authority for an EIS, subject to a Terms of Reference meeting with the Authority.
1.2
To ensure that the required work and/or studies are known and agreed to prior to the
commencement of work, to facilitate a cost-effective, stream-lined and timely review
process.
2.0
General Policies
2.1
It is mandatory that the applicant and/or their consultant meet with the Authority to
determine and agree upon the Terms of Reference of the EIS prior to the commencement
of any work. Failure to hold this meeting and/or to reach agreement on the scope of the
study prior to commencement of the EIS may result in refusal on the part of the Authority
to review or approve the EIS.
2.2
The EIS must be undertaken by a qualified professional in environmental or related
sciences to the satisfaction of the Authority.
2.3
A visit to the site may be required by the Authority prior to, during, or upon receipt of the
EIS.
2.4
The staking of regulated areas (i.e., wetlands, top of bank, etc.) and NHS features (i.e.,
woodlands, etc.) by the Authority may be required. Staking will generally occur between
the end of May and the end of October. Any staking that occurs outside of this time may
require a confirmatory visit between May and October.
159
3.0
Terms of Reference
3.1
Existing Conditions
3.1.1
The existing conditions of the subject property must be clearly described and clearly
mapped on aerial photographs.
3.1.2
The description must include the zoning and all designations of all Official Plans on and
adjacent to the subject property. This includes any land use designations from
other
municipal planning documents, such as Secondary Plans.
3.1.3
Land use designations from any other applicable planning documents (i.e., Oak Ridges
Moraine Conservation Plan, Greenbelt Plan) must be clearly described and the limits
identified in the mapping.
3.1.4
The EIS shall identify the components of the Natural Heritage System and their
respective Levels. The boundaries of the NHS shall be staked in the field by the
proponent and approved by the Authority and the planning authority. The staked and
surveyed boundaries shall be provided on a figure in the report.
3.1.5
All designated environmental features (i.e., the NHS or natural features identified in the
OPs) must be identified in the mapping and described in the report. These features
include provincial or regional Areas of Natural and Scientific Interest (ANSIs),
Provincially Significant Wetlands (PSWs), etc.
3.1.6
The vegetation communities must be identified using the Ecological Land Classification
(ELC) system to vegetation type. The communities must be identified in the mapping,
using the appropriate ELC codes, as well as described in the text. A three-season survey
may be required.
3.1.7
As a component of the ELC, a plant list must be included as an appendix. The list must
include an analysis for the presence of federal, provincial, regional and/or watershed rare,
threatened or endangered species. This should include information from the MNR district
office and NHIC.
3.1.8
The EIS may require a breeding bird survey. The need for such a survey will be
determined as part of the initial Terms of Reference/scoping meeting. The survey must be
conducted during the breeding bird season at an appropriate time of day in appropriate
weather conditions and by a qualified professional. A minimum of two surveys are
required and they must follow generally accepted scientific protocols, not necessarily
atlassing methods.
3.1.9
A list of the breeding birds is required as an appendix. The list must include an analysis
for the presence of federal or provincial rare, threatened or endangered species.
Watershed rarity status shall be determined in conjunction with the Conservation
Authority.
160
3.1.10 The EIS may require a breeding amphibian/reptile survey. The survey must be conducted
during the breeding amphibian season and by a qualified professional. For calling
amphibians a minimum of three surveys are required. These surveys must span the full
amphibian breeding season to ensure that the peak periods of activity for early and late
breeding species are accounted for. For non-calling amphibians, appropriate methodology
must be used.
3.1.11 A list of the breeding amphibians is required as an appendix. The list must include an
analysis for the presence of federal, provincial, threatened or endangered species.
Watershed rarity status shall be determined in conjunction with the Conservation
Authority.
3.1.12 If any watercourses or waterbodies identified in the NHS as habitat for fish are present, a
fisheries assessment shall be provided. Existing data regarding fish species shall be
obtained from LSRCA and/or the MNR. Where necessary, fish will be sampled through
electrofishing and/or netting during the appropriate season, under a collection permit
issued by the Ministry of Natural Resources. The assessment shall include a description
of watercourses or other fish habitat on and/or adjacent to the property.
3.1.13 All incidental wildlife observed shall be reported on and listed in an appendix. The list
must include an analysis for the presence of federal or provincial rare, threatened or
endangered species. Watershed rarity status shall be determined in conjunction with the
conservation authority.
3.1.14 A functional assessment of the subject property describing the ecology of the natural
heritage features and functions should be provided. This shall include a consideration of
the hydrological requirements of natural heritage features, particularly wetlands.
3.1.15 Where the NHS has identified a stream linkage or potential proximity linkage on or
adjacent to the property, the EIS must identify the location, width and proposed
vegetation composition of the linkage. Once the limits of the linkage have been
determined to the satisfaction of the planning authority and the Conservation Authority,
these shall be staked in the field and subsequently surveyed.
3.1.16 Mapping (at a minimum) shall consist of the following:
a)
All mapping must have a title, figure number, north arrow, legend and scale or
scale bar.
b)
A site location map that provides the regional or watershed context of the
subject property.
c)
The extent of the Natural Heritage System and its components must be clearly
demarcated on an orthophoto base.
161
d)
The locations of all watercourses and waterbodies and an indication of their flow
and thermal regimes.
e)
Vegetation communities must be delineated and identified using ELC.
f)
The location of any rare, threatened or endangered species and/or
populations shall be identified.
g)
The location of any important wildlife features (i.e., hibernacula, den, stick nest,
etc.) shall be identified.
3.2
Assessment of Impacts
3.2.1
The potential impacts to the features and functions of the Natural Heritage System
shall be identified and discussed.
3.2.2
An assessment of the potential impact on wildlife at a local, watershed and
provincial (if applicable) level shall be provided.
3.2.3
In the case of Level 1 and Level 2 features, the EIS must demonstrate that there is no
development or site alteration within the feature or negative impacts. The EIS must
determine appropriate buffers from Level 1 and Level 2 features through the
identification of critical function and protection zones
3.2.4
In the case of Level 3 features, the EIS must demonstrate no net negative impacts on the
natural features or ecological functions, which may involve the identification of buffers
from Level 3 features and other mitigation measures.
3.2.5
A description of the natural features proposed for removal shall be provided. The
quantity of removal shall also be included.
3.2.6
An assessment of the potential impact on the Natural Heritage System, including any
Linkages areas that have been identified.
3.3
Recommendations and Mitigation Measures
3.3.1
Avoidance of any NHS feature, regardless of its assigned Level, is the preferred approach
to mitigation. In the case of Level 1 features, avoidance is required.
3.3.2
Determine adequate buffers through the identification of the critical function and
protection zones of the NHS.
162
3.3.3
Where avoidance of a feature is not feasible or possible, mitigation
approaches/techniques must be provided. These may include edge management plans,
buffer plantings, fencing, etc.
3.3.4
In cases where a Linkage area has been identified on a property, the EIS must
demonstrate how it will be integrated into the proposed development plan.
3.3.4
Recommendations for Best Management Practices during construction should be
provided. This may include silt fencing, tree protection, fencing, identification of timing
or seasonal constraints to construction or restoration, etc.
3.3.5
Mitigation for negative impacts on the natural features or their ecological functions (or to
achieve no net negative impact) may include, at the discretion of the planning authority in
conjunction with the Authority, approaches to replace lost areas or functions.
3.3.6
If acceptable, replacement shall, to the extent possible, occur within the same
subwatershed as the proposed development or site alteration.
3.3.7
The appropriate amount of replacement will be determined through discussions with the
Authority and the planning authority and will be agreed to by all parties in writing.
3.3.8
If monitoring is required, the details of a monitoring program must be agreed to in
writing by the Authority, planning authority and other parties.
3.4
Conclusions
The EIS must demonstrate the following:
3.4.1
No development or site alteration within NHS Level 1 features.
3.4.2
No negative impacts to NHS Level 2 features.
3.4.3
No net negative impacts to NHS Level 3 features.
3.4.4
How NHS Level 4 - supporting features have been addressed.
3.4.5
Conformity with the policies and requirements of the Official Plan(s).
3.4.6
Conformity with the policies and requirements of other applicable planning documents
(i.e., ORMCP, Greenbelt Plan, etc).
3.4.7
Conformity with the requirements of the LSRCA’s Watershed Development Policies.
163
164
Appendix 5
Acronyms
Acronym
Definition
ANSI
BWPA
CWS
DFO
E&T
EIS
ELC
GIS
LSEMS
LSRCA
LSW
MMAH
MNR
MOE
MPIR
NHIC
NHRM
NHS
Non-PSW
OMAF
OP
ORM
ORMCP
OWES
PL
PPS
PSW
RRCA
SL
SWH
SWHTG
Areas of Natural and Scientific Interest
Big Woods Policy Area
Canadian Wildlife Services
Department of Fisheries and Oceans
Endangered and Threatened
Environmental Impact Assessment
Ecological Land Classification
Geographic Information Systems
Lake Simcoe Environmental Management Strategy
Lake Simcoe Region Conservation Authority
Locally Significant Wetland
Ministry of Municipal Affairs and Housing
Ontario Ministry of Natural Resources
Ministry of the Environment
Ministry of Public Infrastructure Renewal
Natural Heritage Information Centre
Natural Heritage Reference Manual
Natural Heritage System
Non-Provincially Significant evaluated wetland
Ontario Ministry of Agriculture and Food
Official Plan
Oak Ridges Moraine
Oak Ridges Moraine Conservation Plan
Ontario Wetlands Evaluation System
Proximity Linkage
Provincial Policy Statement
Provincially Significant Wetland
Raison Region Conservation Authority
Stream Linkage
Significant Wildlife Habitat Technical Guide
165
166
Appendix 6
Summary of NHS Components and their Policy Levels
Level of
Significance
Provincially
Significant
Policy
Level
Level 1
Provincially
Significant
Level 2
Watershed
Significant
Level 3
Feature Description
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Supporting
Level 4
Provincially Significant Wetlands (PSWs)
Woodland Patches ≥ 25 ha
Significant Habitat of Endangered and Threatened Species
All non-evaluated wetlands ≥ 10 ha
Any wetland contiguous with evaluated non-PSWs where the total area
≥ 10 ha
Unevaluated wetlands contiguous with PSWs
Significant valleylands
Core Winter Deer Yards (Stratum 1)
Rare vegetation communities (alvars, tallgrass prairies, fens and bogs)
Confirmed Provincial Life Science ANSIs
Evaluated non-PSWs and designated Locally Significant Wetlands
Watercourses, waterbodies, drains, online ponds and mapped offline
ponds within 30 m of another NHS feature (Habitat for Fish)
Confirmed Regional Life Science ANSIs
Woodlands ≥ 0.5 and < 10 ha that overlap or are within 30 m or less of
any other identified Level 1, 2 or 3 feature
Unevaluated wetlands ≥ 0.5 ha that overlap or fall within 30 m or less
of any identified Level 1, 2 or 3 NHS feature
Woodlands ≥ 4 ha and < 10 ha in urban areas
Stream Linkages minimum 30 m from creek between Level 1, Level 2
and/or Level 3 features (or their continuous Level 4 - supporting
features)
Proximity Linkages between Level 1, Level 2 and/or Level 3 features
(or their continuous Level 4 - supporting features)
• Unevaluated wetland units ≥ 0.5 and < 10 ha
• Cultural thickets (CUTs) that are continuous with NHS Level 1, Level
2 and/or Level 3 woodlands and/or wetlands
• Woodland patches ≥ 2 and < 10 ha
• Grassland communities as follows: CUM and CUT ≥ 15 ha; CUT and
CUM ≥ 10 ha when surrounded by other NHS components; and
contiguous CUT/CUM ≥ 20 ha
Note: within the Oak Ridges Moraine area the draft ORMCP technical guidelines apply and
within the Greenbelt, the Greenbelt technical guidelines shall apply.
167
168
Appendix 7
Glossary
Apparent valleyland: a depressional feature associated with a river or stream (regardless
of whether it contain a watercourse) and with valley walls of at least 3 metres in height.
Area of Natural and Scientific Interest (ANSI): areas of land and water containing
natural landscapes or features that have been identified by the MNR as having life
science or earth science values related to protection, scientific study or education.
Big Woods: a colloquial phrase indicating the concept of identifying expansive
productive habitats or ecosystems (i.e., thousands of hectares), usually but not always
applied to woodlands. In the NHS, referring to areas of known woodland aggregations
overlain with areas of contiguous patches >500 ha, that represent areas of enhanced
ecological function.
Biodiversity: the variability among organisms from all sources including terrestrial,
marine and other aquatic ecosystems and the ecological complexes of which they are
part; this includes diversity within species, between species and of ecosystems (OMNR
1999).
Exurban: areas outside of the urban area where there are single family dwellings or
subdivisions, often within natural areas, not usually serviced by municipalities.
Ecological Land Classification (ELC): the southern Ontario classification of lands from
an ecological perspective; an approach that attempts to identify ecologically similar areas.
Ecodistrict: is an area defined by the MNR that has a distinct combination of landforms,
soils, waters, plants and animals.
Fish habitat: spawning grounds and nursery, rearing, food supply, and migration areas
on which fish depend directly or indirectly in order to carry out their life process (as
defined in the PPS 2005).
Habitat for Fish: those areas in the NHS where direct fish habitat is expected to be
found, either permanently or seasonally.
Lake Simcoe Watershed: all lands within the Lake Simcoe Region Conservation
Authority jurisdictional boundary, including the islands and the Lake itself, as well as the
City of Orillia within the physical watershed boundaries. The total area of the watershed
(including the Lake) is 334,139 hectares (Figure 1.1).
169
Negative impacts: degradation that threatens the health and integrity of the natural
features or ecological functions for which an area is identified due to single, multiple or
successive development or site alteration activities (PPS definition).
Net Negative impacts: degradation that threatens the habitat and integrity of the natural
features or ecological functions for which an area is identified due to single, multiple or
successive development or site alteration activities that persists after consideration of
mitigation, including where appropriate, replacement.
Normal farming practices: a farming practice that: a) is consistent with the Nutrient
Management Act, 2002; b) is conducted in a manner consistent with proper and
acceptable customs and standards as established and followed by similar agricultural
operations under similar circumstances; or c) makes use of innovative technology in a
manner consistent with proper advanced farm management practices. Peat extraction is
not considered a normal farming practice.
Proximity linkage: the smaller of: 60 m or the width of the feature, where Level 1 or
Level 2 or Level 3 components (or their continuous Level 4 – supporting features) are
located within 60 m of each other. This feature is represented by a symbol on the
mapping product.
Replacement: a mitigative strategy that allows for the provision of habitats or areas to be
restored in exchange for the loss of an existing feature or area. Replacement may be at
various ratios.
Stream linkage: minimum 30 m on either side of designated Habitat for Fish when
located between two designated Level 1, Level 2 or Level 3 components (or their
continuous Level 4 - supporting features). Stream Linkages are existing features and are
treated as Level 3 policy features.
Urban area: an urban area in this NHS is an area defined by the respective municipality
in their official plan mapping as “urban”.
Wetlands: there are two wetland definitions within the Lake Simcoe Watershed NHS.
They are as follows:
Unevaluated wetlands: unevaluated wetlands in the watershed are identified
using the following ELC codes: FEO, FES, BOO, BOS, BOT, MAM, MAS, SAS,
SAM, SAF, SWT, SWD, SWM and SWC.
Evaluated wetlands: evaluated wetlands in the watershed have been evaluated
using the Ontario Wetland Evaluation System.
170
Wetlands as defined in the ORMCP: those wetlands as defined in the Oak
Ridges Moraine Technical Paper MNR T.P.-1.
Significant Wetlands as defined in the PPS 2005: an area identified as
provincially significant by the Ministry of Natural resources using evaluation
procedures established by the province, as amended from time to time.
Woodlands: all treed communities, whether upland or wetland. The ELC communities
that were considered to represent woodlands are: FOD, FOM, FOC, SWD, SWM, SWC,
CUP and CUW.
Significant Woodland as defined in the ORMCP: those woodlands as defined
in the Oak Ridges Moraine Technical Paper MNRT.P.-7.
Significant Woodland as defined in the PPS 2005: an area which is ecologically
important in terms of features such as species composition, age of trees and stand
history; functionally important due to its contribution to the broader landscape
because of its location, size or due to the amount of forest cover in the planning
area; or economically important due to site quality, species, composition, or past
management history.
Woodland cover: the amount of woodland in a certain area, usually expressed as a
percentage of that area.
Woodland patch: the total area of a contiguous patch of wooded habitat as mapped by
the LSRCA ELC mapping project.
Valleyland: a natural area that occurs in a valley or other landform depression that has
water flowing through or standing for some period of the year.
Wildlife habitat: areas where plants, animals and other organisms live and find adequate
amounts of food, water, shelter and space needed to sustain their population. Specific
wildlife habitats of concern may include areas where species concentrate at a vulnerable
point in their annual life cycle; and areas which are important to migratory or nonmigratory species (as defined in the PPS 2005).
171

Natural Heritage System for the Lake Simcoe Watershed

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