Ecological Risk Assessment Riparian Zone and Access Road

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Ecological Risk Assessment Riparian Zone and Access Road
Ecological Risk Assessment
Riparian Zone and Access Road
Jericho Research Forest
Jericho, VT
Kristin Elsmore, Luke Emerson-Mason, Meredith Curling,
Jason Weiner, Pearson McCracken
Background
In a Riparian zone is where two environments meet.
There we find some of the most productive and biologically
diverse environments on the planet.
Riparian zones are often subject to high degrees of
vulnerability in a landscape due to a variety of anthropogenic
and natural stressors.
Our risk assessment focused on a
riparian zone located in the Jericho
Research Forest.
Background Continued
UVM acquired the land in Jericho in 1940
which had previously been agriculture
land.
At this point the process of reforestation
began with the intention to bring back the
natural environment of northern Vermont.
Today our focus stream has a large buffer
except for where an old logging road is in
close proximity.
Our intention was to provide an
understanding of the potential risks to the
stream in regards to the nearby road, as
well as those involved with the future
restoration project
Problem
The stream is being
disrupted from a
constructed road that’s
producing runoff,
erosion, sediment
deposition in the stream.
Key Objectives
• Obtain information regarding potential
management alternatives and relevant data
available on the site from risk managers and any
other stakeholders by March 1, 2006.
• Develop best management practices based on
our analysis of the situation by April 12, 2006
• Complete the construction of conceptual models,
potential risk model, and summarization of
assessment results (for the finalized assessment
report that will be presented to managers and
stakeholders) by April 18, 2006
Findings
Soil Types
• Adams and Windsor
Loamy Sands
• Moderately – Highly
Erodible
• 12-30% Slope
Erosion
• Erosion from unpaved
roads causes
Sedimentation
• Gravel Roads yield 99%
more sediment quantity
in runoff than paved
roads
• Erosion from logging
roads can be 220%
greater than erosion
from undisturbed sites
Altered Hydrology
• “When a road bed is raised above the
surrounding land surface, it will alter
surface sheet flow patterns, restricting the
amount of water reaching downstream
areas” – Noss 2000
• Sedimentation
Lane’s Diagram
Current Efforts
• A new logging road has been constructed
farther than the recommended 70 ft from
the stream
• Old road unused but unforested – at some
points comes within 20 feet of stream
GIS Analysis
•Watershed Approach?
•No Mapped Watershed, No
Mapped Stream Data available.
Approach
• Use of Bare Earth LIDAR Data.
• ArcMap 9.1 Hydrology Tools, used to Map
out streams and Watershed.
• Quality control with Comparison of Output
and Vermont Hydrography Dataset.
• Analysis in ArcMap
Data Outputs
• Watershed boundaries for Stream of
Interest as well as neighboring stream.
Outputs Cont.
• Why is it important to map out watershed?
• Provides holistic approach to
understanding what is influencing the
stream.
• Can decide what areas may be of greater
importance to focus on.
• Used in Further and possible Future
analysis.
Outputs Cont.
• Slope Layer generated.
Output Cont.
• Slope Over 12%
Outputs cont.
• Slope information: Important especially
with respect to measuring erosion.
Greater Slope= Greater erosion potential
• High Slopes usually said to be 12% or
greater.
• Slope important for compliance with
Vermont Logging road Best Management
Practices.
Conceptual Model
Concept Model (cont.)
• Current Capabilities
– As it stands right
now the concept
model is only a
visual representation
of how we believe
the variables in and
around the logging
road interact.
• Possible
Capabilities
– With considerable
modifications the
conceptual model
could be helpful in
determining the
trends of the area
and could also be
linked with GIS maps
for data and testing
purposes.
Recommendations
• Use of maps and contributed data layers
to pinpoint areas of concern.
• Including high slope areas, especially
those close to the streams, and highly
incised areas.
• Use of over all slope data to assure bmp
for logging road in place.
• GPS old and new logging road for future
analysis.
Our Recommendations
• Urge managers to consider re-forestation of
the road as soon as possible
• Re-forestation efforts should focus on
mirroring conditions of the surrounding forest
through the use of local root stock
• Look to published reports on similar
restoration efforts in and around VT for
additional ideas, particularly those matching
budgetary constraints
Our Recommendations Cont.
• To ensure management strategies are
working, water quality monitoring should
occur during key periods and continue
until re-forestation is well underway
• Monitoring should focus on incision of
stream banks, deposition of sediments,
stream bank erosion, turbidity, and flow
rates, particularly in critical areas indicated
on GIS maps.
Department of Forests, Parks, and
Recreation Recommendations
• The handbook for Acceptable Management
Practices for Maintaining Water Quality on
Logging Jobs in VT recommends that areas
of exposed soil within 25 ft of streams be
seeded and mulched with 20 lbs/acre of rye
grass, and 60 lbs/acre of hay.
• The handbook also recommends that the
riparian buffer on a 12-20% slope between
roads and streams equal 70 ft
Conclusions
• If left unmanaged the existing logging road may
potentially lead to adverse effects on the adjacent
aquatic system.
• Simply re-seeding the road would only be a “quick fix”
and may be challenging due to soil compaction
• Parameters that are of particular interest for monitoring
purposes include incision of stream banks, deposition of
sediments, stream bank erosion, turbidity, and flow rates.
• With the new logging road located far enough away to
provide an adequate buffer to the stream, restoration of
the old logging road should significantly reduce the risks
posed.
Thank You
Jesse Mohr
Kristen Simard
Breck Bowden
Deb Perry
David Brynn

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