Savannas in Belize: Results from Darwin Initiative Project 17

Transcription

Savannas in Belize:
Results from Darwin Initiative Project
17-022 and the implications for
savanna conservation
Savannas in Belize: Results from Darwin project 17-022
Savannas in Belize:
Results of Darwin Initiative Project 17-022
and implications for savanna conservation
Report assembled by Belize Tropical Forest
Studies (BTFS) for Darwin Project Partners
June 2012
Contributing authors: Sam Bridgewater, Iain Cameron, Peter Furley, Zoe
Goodwin, Elma Kay, German Lopez, Jan Meerman, Dimitrios Michelakis,
Duncan Moss and Neil Stuart.
Table of Contents
1
Introduction .................................................................................................................................... 4
1.1
2
Status Overview ............................................................................................................................... 6
2.1
3
Project Overview...................................................................................................................... 5
Conservation Status of Pine Savannas in Belize ........................................................................ 6
Products produced under the project ............................................................................................ 16
3.1
Project website launched and periodically updated;............................................................... 16
3.2
Plant diversity surveys and vegetation habitat surveys conducted in lowland savanna areas; . 17
3.2.1
Selected Results ............................................................................................................. 20
3.3
Development of the Belize savanna plant database ................................................................ 36
3.4
Photographic field guide to savanna plants developed and field tested .................................. 38
3.5
Integration of the Savanna Map into the Belize Ecosystems Map; .......................................... 39
3.6
Soil-vegetation relationships in the Belizean savannas ........................................................... 45
4
The Way Forward .......................................................................................................................... 57
5
References..................................................................................................................................... 61
6
Appendix 1: Agenda Science Meeting Wednesday April 13th, 2011 ............................................... 63
7
Appendix 2: Soil Analysis Methodology .......................................................................................... 65
8
Summary Table of Soils Fieldwork 2010-2012 ................................................................................ 67
Executive Summary
We report the results of a 3-year project of the UK government’s Darwin Initiative for the conservation
of biodiversity, involving partners from leading scientific institutions in the UK and Belize. From 2009 to
2012 information was collected about the plants and soils of the lowland savannas and a new national
mapping of the remaining savanna areas was produced as part of a new National Ecosystems Map and
published in 2012. In April 2011, a meeting was held at the Tropical Education Center at Belize Zoo, to
which leading national and international savanna experts were invited to present and to review the
state of knowledge about the biodiversity of Belize’s lowland savannas. This report documents the main
outputs from the Darwin Project that were presented at the Expert Meeting in April 2011 and
summarises the discussions that arose from the review of these outputs. We believe this report
provides the most current and comprehensive assessment of the present state of the lowland savanna
ecosystem in Belize and indicates how this can inform the future conservation and management of
remaining savanna areas in Belize.
1 Project Overview
In 2009 the “Savanna Ecosystem Assessment: Belize”, was initiated with the purpose of increasing
available data and enhancing the capacity of local institutions to undertake taxonomic research and
mapping required to identify priority areas for conservation within savannas. Commonly referred to as
the Darwin Savanna project, as it was funded by the UK Darwin Initiative, the project brought together a
consortium of partners from the UK and Belize including The University of Edinburgh (UoE), The Royal
Botanic Garden Edinburgh (RBGE), The University of Belize (UB), The Belize Forestry Department (FD),
Belize Botanical Gardens (BBG), Programme for Belize (PfB) and Belize Tropical Forest Studies (BTFS).
The specific aims of the Darwin Savanna project were to:
•
Provide improved and more current savanna vegetation mapping for Belize to support
conservation and management;
•
Conduct baseline taxonomic research and botanical survey of savanna areas;
•
Enhance the capacity of local institutions to collect and interpret these data for conservation
management.
The savannas of Belize occupy almost 10% of the land area, furnishing distinctive landscapes of
ecological and economic value. They are the most northerly example of lowland savannas in the
Americas. Whereas upland savannas of Central America have been the subject of numerous studies of
plant diversity, the lowland savannas had received little attention until this project. Lowland savannas in
Belize are threatened by a combination of human pressures and by climate change. The project results
presented in this report show that these savannas and associated wetlands are diverse ecosystems
providing important habitats for plants and wildlife, crucial drainage functions and other services.
The Darwin Savanna project aimed to resolve the problem of the insufficient baseline information as of
2009 upon which to develop a national conservation strategy for savannas. Specifically:
•
There was no comprehensive checklist of savanna species. Botanical information about plant
distributions was very partial. Many savanna areas, particularly in the south, were unexplored
botanically and little was known about patterns of endemism, so there was little basis for
making informed conservation decisions based on plant biodiversity in savanna areas.
•
Previous national maps of savannas were not truly representative of the different diversity of
savanna types present in the country and lacked the the detail required to allow savanna areas
of particular landscape /other value to be identified.
2 Conservation Status of Pine Savannas in Belize
Based on previous analysis by Meerman (2005) and Cameron et al (2011), between 22- 27% of the
remaining lowland pine savannas lie within some type of protected area in Belize. However, as Walker
et al (2009) have reported, the actual degree of protection varies greatly between the different
protected areas in Belize dependent on their type of designation and their management effectiveness.
This is nevertheless a considerably greater national area under protection than for many other savanna
areas in the world. The estimate of 448 km2 classified by Cameron et al from SPOT satellite imagery
from 2008-10, which is mapped in figures 1 (a) and (b) includes 12 km2 of forest areas found within what
are broadly savanna areas – for example narrow gallery forests associated with watercourses traversing
savanna areas. It also includes 3 km2 of wetlands that occur as patches within savanna areas.
Subtracting these areas yields an estimate of 433 km2 of savanna areas under protection, which is similar
to the figure of 436 km2 calculated by Meerman in 2005. Care should be taken in making direct
comparisons however, as the boundaries of some protected areas may have changed between 2005 and
2011; some new protected areas such as HWATCHY and the Jaguar Corridor were being proposed at the
time of the Savanna Science Meeting in 2011 but are not included in table 1; also, the boundaries and
area of the Mango Creek (4) Forest Reserve were found to be different in the 2011 protected areas
mapping compared to their previous extents depicted on mapping before 2010.
Table 1. Conservation status as assessed by Meerman (2005) and Cameron et al (2011)
Figures 1 (a) and (b) and table 2 break down the total area of 448 square km of protected savanna
according to the different protected areas found in Belize. Inspection of table 2 shows that the large
tracts of savanna under protection in the south of Belize are found in three forest reserves - Deep River,
Swasey-Bladen and Mango Creek 4 (although the boundaries of this reserve appear to have changed
recently) and in the Paynes’ Creek National Park. In the North of Belize, the largest protected areas of
savanna are in the privately managed Rio Bravo Conservation & Management Area and the Crooked
Tree Wildlife Sanctuary. In central Belize, savanna is protected in smaller amounts in several privately
managed areas such as the quite recently created Peccary Hills National Park and the smaller Runaway
Creek Nature Preserve, the Monkey Bay Wildlife Sanctuary and within the Belize Zoo and Tropical
Education Center (although the latter is not designated formally as a protected area) while some
savanna still remains within the Grants Works forest reserve north of Dangriga.
Figure 1(a) Savanna areas and Protected Areas in Northern Belize
Figure 1(b) Savanna areas and Protected Areas in Southern Belize
Protected Area
Bladen
Burdon Canal
Community
Baboon Sanctuary
Crooked Tree
Deep River
Gales Point
Gragra Lagoon
Grants Works
Manatee
Mango Creek (1)
Mango Creek (4)
Monkey Bay
Monkey Caye
Payne's Creek
Peccary Hills
Rio Bravo C&MA
Runaway Creek
Swasey-Bladen
Grand Total
Total
Area of
PA
404.11
21.26
52.52
Dense
Tree
Savanna
0.81
0.31
3.06
0.04
0.45
0.24
129.9
272.31
36.81
5.34
31.99
365.75
43.71
77.18
8.58
6.7
140.53
43.48
1048.97
23.23
59.8
2808.38
12.85
29.90
0.22
0.48
3.10
0.11
1.09
10.77
17.01
20.53
0.64
1.01
7.40
69.25
0.27
0.10
5.40
15.56
1.57
28.22
0.48
1.20
46.57
14.15
44.89
0.93
25.24
263.56
0.09
4.10
2.80
30.86
2.02
23.41
160.60
Table 2: Areas
Forest
Inclusion
0.55
1.61
2.75
0.02
1.64
12.52
Open
Savanna
Seasonally
Waterlogged
Savanna
4.63
Wetland
Inclusion
Savanna
area
0.11
0.09
0.81
0.70
3.60
0.72
0.21
0.32
4.02
8.64
0.09
0.61
0.61
0.00
0.24
3.02
of lowland savanna within each protected area (Km2)
(savanna areas based on Darwin savanna map 2010)
26.08
102.25
0.81
0.10
7.13
27.66
18.58
49.29
0.48
1.29
52.38
17.56
83.13
2.97
50.53
448.34
% of PA
that is
savanna
0.20
3.31
6.85
20.08
37.55
2.19
1.86
22.29
7.56
42.51
63.86
5.58
19.20
37.27
40.39
7.92
12.78
84.50
Management
effectiveness
National ranking 1
(best) -65 (poorest)
Protected Area
Type of protected
area (IUCN)
Organisation
Managing
Community Baboon Sanctuary
Private Reserve (IV)
Women's
Conservation Group
1985
38 - Moderate
Crooked Tree
Wildlife Sanctuary (IV)
1984
15 - Moderate
Deep River
Forest Reserve (VI)
Belize Audubon
Society
GOB Forest Dept.
1949
28 - Moderate
Grants Works
Forest Reserve (VI)
GOB Forest Dept.
1989
64 - Poor
Manatee
Forest Reserve (VI)
GOB Forest Dept.
1959
43 - Moderate
Mango Creek (1)
Forest Reserve (VI)
GOB Forest Dept.
1989
40 - Moderate
Mango Creek (4)
GOB Forest Dept.
GOB Forest Dept.
1989
41 - Moderate
Monkey Bay Wildlife Sanctuary
MBWS
1987
29 - Moderate
Monkey Caye
Forest Reserve (VI)
GOB Forest Dept.
1996
63 - Poor
Payne's Creek
National Park (II)
TIDE
1994
9 - Very Good
Peccary Hills
National Park (II)
Gracie Rock Reserve for
Adventure/Ecotourism
2007
25 - Moderate
Rio Bravo
Programme for Belize
1988
5 – very Good
Runaway Creek
Foundation for Wildlife
Conservation/ Birds
without Borders
1998
46 - Fair
Swasey-Bladen
Forest Reserve (IV)
GOB Forest Dept.
1989
36 - Moderate
Created
Table 3: Characteristics of Protected Areas with over 5% savanna land over
(ranking of all PAs mean effectiveness scores from Walker & Walker, 2009)
One area of consensus from the delegates attending the savanna science meeting was that the sociopolitical situation in Belize does not currently favour the creation of large new protected areas, and that
it would be better to focus on strengthening the effectiveness of savanna areas that are actually under
conservation. Table 3 indicates the management effectiveness of each of the protected areas
containing savanna. The ranking is based on a comprehensive assessment of 65 protected areas in
Belize according to an assessment framework including a variety of indicators developed by Young
(2005) for the National Protected Areas System Plan and used subsequently to report to APAMO on the
effectiveness of Protected Areas in 2009 (Walker & Walker, 2009).
An interpretation of table 3 is that privately managed areas are more effectively managed than
government forest reserves. Some of the privately managed protected areas such as Payne’s Creek,
RBCMA and Crooked Tree WS are managed very effectively and so the level of protection can be
considered to be very good for these savanna areas. Some of the smaller private reserves such as
Peccary Hills, Monkey Bay and Runaway Creek and the Community managed Baboon Sanctuary at
Bermudian Landing (which borders savanna areas) received moderate scores, whilst the forest reserves
received the lowest scores. Deep River forest reserve was noteworthy for being ranked higher than
some private reserves, whilst only Grants Works was assessed to be very poorly managed.
Using this information, one could identify a number of protected areas that are presently in the
moderate category, where efforts could be made to strengthen their management effectiveness and in
turn improve the level of protection for the savannas they manage. Among private protected areas,
priorities could be Peccary Hills, Monkey Bay and Runaway Creek, whilst among the forest reserves it
could be argued that Deep River, Swaysey Bladen and Mango Creek (1) would be the priorities.
Looking beyond the areas that are presently designated as protected areas, there may be management
options if privately owned lands were to become zoned according to ‘appropriate/not appropriate’ land
uses. This is part of the vision of the new Land Use Policy and Planning Framework, once this becomes
implemented. As an example, many savanna areas have been considered in the past as generally not
suitable for most forms of agriculture, other than very limited areas in the south where banana and rice
are grown. The poorly drained and infertile soils of many savanna areas have been mostly evaluated as
suitable for pine, pasture or aquaculture. Some of the better drained areas are suitable for housing and
infrastructure such as roads.
A more specific zoning of savanna areas could be developed, based on land cover, soils and drainage
which would make clearer the opportunities and limitations for private landowners. In the most
unfavourable areas for other use, conservation can be indicated. Many of the most frequently
inundated savannas have relatively high conservation value in terms of the habitats they create for birds
and mammals. This is evident for the savannas bordering the Crooked Tree WS, fringing the New River
Lagoon within the RBCMA and at Payne’s Creek.
2.1 Threats to the Pine Savannas
The above section advances two strategies for the identification of priority areas requiring conservation
– the strengthening of management effectiveness of some existing protected areas that contain savanna
areas and the zoning of savanna land within a national framework so that private land owners may
voluntarily consider managing savanna areas for conservation . To identify areas requiring protection
or enhanced protection, one also needs to consider the threats to different savanna areas, as well as
their intrinsic qualities such as their relative biodiversity and general suitability/unsuitability for other
purposes.
Estimated area
of savanna
converted to
Land use
other uses (ha)
Agriculture/Pasture 10844
Aquaculture
4884
Logging
373
Aggregates
782
Urban
3129
Figure 2 Estimated area of lowland savanna converted to other uses.
By comparing the Darwin Savanna Ecosystem Map 2010 against archived Landsat imagery dating from
1980, topographic mapping from 1993 and by inspection of recent high resolution imagery we estimate
that from an original total area of 168,000 ha, approximately 20,000 ha has been converted to other
uses, i.e. roughly 12% of the once existing lowland savanna has already been lost to development. Figure
3 shows that the largest conversions of savanna lands have been to agriculture (pasture mainly) and to
aquaculture (mainky shrimp farming), together making up almost 80% of the total areal loss of savanna.
Aquaculture in particular has dramatically increased in scale from the first experimental pond in 1980, to
generating revenues of BZ$ 84.28 million by 2004. Some of these areas are particularly concentrated
in certain parts of the country, with for example, most of the conversion of savanna to pasture taking
place in the northern and western districts of Orange Walk and Cayo, whilst most shrimp farms have
been constructed on southern savannas in Stann Creek and Toledo. Attempts to convert savanna to
smallholder agriculture have occurred in many Districts; larger scale citrus plantations were attempted
unsuccessfully in Orange Walk District (on savanna areas which are now mostly within the RBCMA and
the new Yalbac PA) whilst one sees papaya, banana and limited rice growing in wetter, low lying areas
close to water courses in some savannas of the Southern Plains. Savanna areas are often favoured
sites for infrastructure; the two largest airstrips in Belize (Philip Goldson and the as yet unfinished
airport near Placencia) are both on savanna tracts, whilst all the main highways preferentially pass
through savanna areas. The new capital city Belmopan was built in savanna and later new towns such
as Mahogany Heights have also been sited on savanna land. Recently, there have also been proposals
to locate other municipal facilities including Belize’s national waste dump on savanna, although some
have pointed out the possible negative effects on groundwater unless mitigation is in place.
Lowland savannas are in themselves a potentially significant economic resource. For example, the FD
seeks to harvest pine, palms and other plant resources and to promote ecotourism in a sustainable
manner that protects biodiversity hotspots within savanna areas, but presently lacks the taxonomic or
geographic information needed to ensure that harvesting does not inadvertently affect areas of high
conservation value.
One approach that is now widely used to establish the value of conserving or protecting an ecosystem,
especially where some of the value is not easily expressed in monetary terms, is to assess the services
that an ecosystem provides. This is often expressed by outlining and where possible also quantifying
the provisioning, supporting, regulating services provided by the ecosystem. This approach can be
applied to savanna areas, so that appropriate and sustainable use is made of savanna areas and the
biodiversity of these areas is not degraded.
2.2 Value of the Pine Savannas –
One approach for recognizing areas of savanna with particular value for conservation would be to
tabulate environmental services provided by specific Pine Savannas. Such environmental services
include:
• Economic opportunities/livelihoods
• Firewood
• Watershed protection, flood mitigation
• Amenities
• Biodiversity areas
• Ecotourism
• Carbon
• Aesthetics
• Climate control
• Hunting
• Timber
• Education/appreciation
• Medicinal plants
2.2.1 Animal biodiversity
– although originally thought to be barriers for many large mammals, The value of Pine Savannas as
biological corridor is under review (Jan; can you give some detail/links? on this to Key Biological Areas?).
New research (ref Bart please?)has revealed that at least some species will use a Pine Savanna matrix
when moving between forests. Some evidence from Bart and the Panthera project please?
2.2.2 Plant Biodiversity
Savannas were also thought to be species poor, yet this project has found more than 950 plant species
in the lowland savanna, or approximately 28% of the nation’s flora as recognised by Balick et al. (2000).
380 of these are savanna specialists. Of the 41 vascular plant species reported by Balick et al. (2000) as
endemic to Belize 18 (44%) are recorded in the lowland savanna. Whilst some savanna plants are
widespread, others (including some endemics) show localized distributions.
With 75% of savanna areas not under protection, this means that many of the endemic, endangered or
threatened species are vulnerable to having more of their habitat lost, as areas of savanna are
converted to other uses. (Zoe, can we identify certain plant distributions in section 3 that are mainly in
unprotected areas? E.g. Ageratum radicans, Melastelma stenomeres, Syngonanthus spp (all outside) ,
Turnera difusa only in North and except for one record in RBCMA, rest of the known findings are in areas
with no protection from development.
maybe also Passiflora urbaniana, altho its more widespread?)
Also, some restricted plants have only been found in one PA – e.g. Turnera curassavica only found in
Payne’s Creek to date.
2.2.3 Economic forestry
Jan:- some commentary about FD revenue from logging concessions on the southern plains please?
(Oswaldo?)
2.3 The conservation and management of Pine savannas
At present, only two NGOs managing protected areas (Programme for Belize for Rio Bravo and TIDE for
Paynes Creek) have large areas of savanna lands under their management. and this raises some
concerns about, -> Jan pls continue argument?
PfB have had a savanna management plan as part of their RBCMA management plan since 2005; in this
the primary function of the savannas was to provide ’buffer zone’ to protect the core broadleaf forest
from pressures outside the reserve boundary (including agriculture, hunting, increased fire etc) . In
recent years, the value of savanna as habitat for endangered birds has been recognized (e.g. yellow
head Parrot) and built into the Savanna Management Plan. A third aspect of savanna management has
been the assessment of fire frequency and controlled burning regimes, with both PfB and TIDE collecting
empirical data from ground surveys to refine guidance from <??US ref> as part of meso-american fire
prevention in savanna areas.
One concern to the long term conservation of savanna areas is that there is no clear view or policy from
the Forest Department within the Ministry of Natural Resources regarding savannas. Jan please list the
areas of savanna under different PA’s and what policies do apply – and how these may hinder savanna
conservation – eg burning to show signs of active management. etc
Crooked Tree is an area with a variety of savanna and wetland cover types and a conservation presence
(Community Based). This is a spectacular area, biologically and scenically. Expand? This raises the
question whether there should be more community involvement in the management of Pine Savannas.
Summarise discussion from the meeting?
Runaway Creek?
Private protected areas? Western highway Corridor?
3 Outputs from the Darwin project
3.1 Project website(s)
The project website (http://www.eeo.ed.ac.uk/sea-belize) is still maintained as it contains an archive of
material produced by the project such as educational materials about savanna plants and habitats and
reports that will remain a valuable resource in future. The website has links to the new Savanna
Ecosystem Map and to the online savanna plant database, now maintained by the University of Oxford.
(http://dps.plants.ox.ac.uk/bol/seabelize)
Figure 1. Project Website (main screen)
Figure 2. Brahms savanna plant database (main screen)
3.2 Plant diversity and vegetation habitat surveys in lowland
savannas;
Rapid botanical surveys were conducted at seventy lowland savanna sites by botanists Zoë Goodwin and
German Lopez in two field seasons from April – June and from October – December 2010. As figure 6
shows, the sites for the botanical surveys were selected to cover a wide range of savanna areas across
the country, including some sites within protected areas but also many sites in areas that are not
currently protected.
At each site within an area of approximately 25 x 25 m a full vegetation description and species list was
compiled, with known species recorded and unknown or unusual species collected. This focused species
list was augmented with wide patrolling around the core area. 600 plant specimen collections and
around 2,000 species observations were made across the seventy survey sites (with a mean of 36 taxa
recorded at each site).
In total 975 species have been collected in Pine Savanna (Landscape Level), but of these, only 380 are
"true" Pine Savanna Species. Also of the 975 landscape level species, 121 species have to be qualified
as wetland species.
The Pine Savanna is rich in endemic plant species, of the 41 country endemics, 17 are Pine Savanna
specialists. Some of these are widespread, others very restricted. Unfortunately, even with the sampling
effort achieved so far, true areas of high diversity/endemism cannot be identified. Although some
endemics are found within protected areas, many have been also found in areas with no protection.
Summarising the results of section 3.2.2 which follows:- summarise geographical distributions by
plants found mostly in protected/not, plants localized to just one or two PAs…
Zoe, can we identify certain plant distributions in section 3 that are mainly in unprotected areas? E.g.
Ageratum radicans, Melastelma stenomeres, Syngonanthus spp (all outside) , Turnera difusa only in
North and except for one record in RBCMA, rest of the known findings are in areas with no protection
from development. maybe also Passiflora urbaniana, altho its more widespread?)
Also, some restricted plants have only been found in one PA – e.g. Turnera curassavica only found in
Payne’s Creek to date.
ADo we need all these maps? Is it just bulk if we don’t interpret them?
Figure 3. Number of botanical records (left) and observed species richness (right).
Note that the species richness effectively depends upon the collecting effort.
Figure 4. Locations of the botanical collecting sites.
3.2.1 Results for selected species
Figure 5 Ageratum radicans - Endemic
Figure 6. Curatela Americana - Characteristic
Figure 7 Dalechampia schippii - Endemic
Figure 8. Hypericum pratense - Endemic
Figure 9 Hypericum terra-firmae - South and Central
Figure 10 Melastelma stenomeres - Endemic
Figure 11. Paepalanthus gentlei - Endemic
Figure 12 Passiflora urbaniana - Endemic
Figure 13 Syngonanthus bartletii - Endemic
Figure 14. Syngonanthus hondurensis - Restricted
Figure 15. Syngonanthus lundellianus - Restricted
Figure 16 Tibouchina aspera - Restricted
Figure 17 Turnera aromatic - Characteristic
Figure 18 Turnera curassavica - Restricted
Figure 19. Turnera difusa - North Only
Zamia prasina - Characteristic
Figure 20. Zamia prasina - Characteristic
3.3 Belize savanna plant databases
In 2009, collection data for approximately 4000 savanna specimens was collated and imported into a
database from three herbaria: Missouri Botanical Garden (MO) 2872, RBGE (E) 707 and the Natural
History Museum, London (BM) 406. Since then, additional specimen information has been added to the
Belize savanna plants database to give a total of 5,409 specimens for 4,640 botanical records. The
specimens in the database are now derived from records from nine institutions. For seven institutions
(GH, MO, NY, E, K, US & MICH) the data was derived from online resources (most of the data from E &
MO was obtained in year 1); the data from BM and BRH is from specimens seen.
A copy of the savanna plant database was published online in March 2010, hosted by the Department of
Plant Sciences, University of Oxford on the BRAHMS website (http://www.ox.ac.uk/bol/seabelize/).
Whilst the Brahms database is suitable for specialist users, a more general purpose interface, suitable
for a wider audience and allowing the plant collections to be browsed using a mapping interface, was
also developed ( http://xweb.geos.ed.ac.uk/~belize/)
Figure 21. Searching the Brahms database of all savanna plant records in Belize
http://dps.plants.ox.ac.uk/bol/seabelize/Search/Index
Figure 22. Example of results from a Brahms database query
Figure 23. Web mapping tool allows geographical query and reporting of records.
http://xweb.geos.ed.ac.uk/~belize/
3.4 Photographic field guides to savanna plants
Several photographic guides to the common savanna plants have been developed throughout year 2.
The photoguides have already proved to be a useful teaching aid for both undergraduates students and
for protected area wardens, allowing non-specialists to perform field identifications of common species.
Positive feedback from field-testing such during the field course in November 2010 encouraged the
supplementary development of a more technical field guide that includes leaves and other
distinguishing characters, in addition to existing flower-based guides. A positive response was also
received to the Photoguide to Endemic or Rare Savanna Species that was field-tested this year by several
protected area management organisations. Laminated copies of the Casual User and Endemic Plant
photoguides were provided this year to attendees of the Introduction to the Vascular Plants of the
Belizean Savanna and the Botanical Resources for Conservation and Taxonomy courses.
These photoguides proved extremely useful for training in plant identification during the Introduction to
the Vascular Plants of the Belizean Savanna course. They were also commended by staff and students of
the University of Belize BSc Natural Resource Management programme who used the photoguides this
year during their field course held in the upland savannas of Mountain Pine Ridge.
The photoguides are published on http://www.geos.ed.ac.uk/research/eeo/sea-belize/education.html.
Figure 24: Example of photoguides available
3.5 Integration of the Darwin Savanna Map into the Belize
Ecosystems Map 2012;
UoE have combined the new mapping with a variety of other geographical data sets including elevation
and drainage, the locations of roads and settlements, agricultural and aquaculture developments and
data on land ownership in order to determine which of the remaining areas of savanna are not presently
within protected areas and which may be at greater risk of degradation and conversion. The first stage
has been to calculate the proportion of the remaining savanna areas that are within protected areas.
In the Darwin savanna map (2011) the relationship of Pine Savannas with their surrounding and
integrated landscape is schematized as shown in Figure 27:
Figure 27. Savanna classes in the Darwin savanna map (2011)
BTFS agreed to further validate the mapping, to use it in formulating the National Land Use Policy for
the Government of Belize (http://www.landusepolicy.bz ) and to assimilate it into the National
Ecosystems Map of Belize in 2012.
Figure 28. 2004/2010 Ecosystems map classification detail
Figure 29. 2011 Savanna Map detail of same area
Figure 30: 2004 ecosystems map overlain on 2011 savanna map,
showing some discrepancies
Figure 31: Resolution of discrepancies
Figure 32. Resulting 2011 Ecosystems Map
The new Belize Ecosystems Map (2012) data are accessible through:
http://www.eeo.ed.ac.uk/sea-belize/savanna_map.html and http://www.biodiversity.bz
Figure 33: Comparison of savanna areas from the Cameron et al (2010) image classification and savanna
areas mapped in the 2011 Ecosystems Map.
<insert table> refer to table 1.
Savanna mapping should now be considered finished for the present time. The new statistics and
mapping present a realistic baseline data for the extent of remaining savannas in Belize as of 2011
against which further changes can be monitored using remote sensing.
There is little requirement for more detailed national mapping of savannas, although individual PAs may
want to create their own higher resolution maps. Given the national remit, it has not been possible to
validate the map in all localities. Therefore, it will be important will be that PA managers test the
mapping and verify it for their local areas, reporting back changes or errors for future modifications.
The national mapping allows areas of savanna within/outside present protection to be examined in
relation to animal and plant biodiversity, and level of threat to these different areas to be examined.
Monitoring land use change in the savanna areas is the next important task, so that the conversion of
savanna areas can be monitored and assessed. The map can be used as a baseline for monitoring this
change. Depending on the baseline date selected, the amount and rate of savanna loss calculated
varies. For example, by comparing the Savanna Ecosystem Map 2010 against archived Landsat imagery
dating from 1980 and topographic mapping Cameron et al (2011) estimated that from an original total
area of 168,000 ha, approximately 20,000 ha has been converted to other uses, i.e. roughly 12% of
lowland savanna has already been changed into pasture, aquaculture or for other types of development.
Comparing the area mapped as savanna on the new 2011 Ecosystems Map with figures from the 2005
(table 1)…
3.6 Soil-vegetation relationships in the Belizean savannas
3.6.1 Preface
The soil investigations outlined here were not part of the original Darwin core programme but, following
the early reconnaissance, it became apparent that better knowledge of the soil properties could
contribute towards greater a understanding of the nature and characteristics of the savanna vegetation.
Soil properties such as fertility and drainage are among the factors that most limit the capability of
savanna lands for agriculture. Understanding the variation in soil properties is therefore vital for
reaching informed decisions about the potential for, or the constraints upon using savanna areas for
different purposes.
An award from the Carnegie Trust made it possible to complement the botanical surveys.
The principal aims of the soil survey component of the project were:
•
To describe and assess the nature of soil properties underlying savanna vegetation
•
To examine the soil-plant relationships of the dominant plant associations
3.6.2 Introduction
At a world scale, the extent of savanna in Belize is tiny, but the vegetation is characteristic of significant
stretches of the country and possesses a number of special features that deserve greater recognition.
The savannas in Belize represent the northernmost outliers of the neotropical lowland formation
although the upland savannas in the Maya Mountains are continued northwards into Guatemala and
Mexico along the highland axis of the cordilleras.
Throughout these areas, a typical sequence of savanna subtypes is evident , from open grassland to
savanna woodland. All of these subtypes are represented in Belize.
From a global point of view, savanna soils have a characteristic range of physical, chemical and biological
properties. Whilst many of these properties are cosmopolitan, the neotropical savannas are in general
more highly weathered and leached as a result of greater precipitation compared to those of Africa and
Australasia. (Table 1):
Table 2 World Savanna Soils Compared
Footnote: Belize has similar soil properties but the lowland savannas have a greater proportion of poorly drained soils.
The names in brackets refer to USDA Soil Taxonomy.
Figure 33. Structural variation in savanna (after Furley 1999)
3.6.3 Savanna soils of Belize
The soils underpinning savanna vegetation vary according to location but, for simplicity, can be divided
into two main groups related to altitude. Over the Maya Mountains, the soil cover is extremely old,
reflecting long periods of intense weathering, whereas over the lowland savannas the soils are younger
occurring over different parent materials in different environments resulting in heterogeneous soil
properties and diversified resource potential:
Upland savanna soils: These generally occur around 1000m asl; the climatic regime is cooler with
greater exposure to storms and weathering; the rainfall is orographic and the inland locations avoid
most coastal influences. The landscape is extremely old, consisting of deeply weathered, highly leached,
acidic soils with end-product low activity clay minerals (kaolinite and iron oxides), derived from granitic
and metamorphic parent materials; the soils are mostly very infertile (low cation availability) with low
levels of organic matter and associated nutrients (such as available P); characterised by stone lines and
erosion surfaces. The steep relief determines that runoff is rapid and the soils are freely drained. There
is a distinct catena effect with savanna woodland and grassland over the convex upper slopes and
damper plant associations or gallery forest in the valleys. The incidence of fire adds to the pressure on
fire-susceptible species and can result in a cyclical pattern from savanna woodland to virtual grassland
(Furley 1974/76; Hicks et al., 2010)
Lowland savanna soils: These environments are closer to sea level and coastal influences (saline spray
and marine influences on ground water); there is a marked seasonality with wetting and drying (flooding
and desiccation); the landscape is relatively flat and poorly drained and comprises younger parent
materials (largely siliceous palaeo-alluvium derived from the Maya Mountains and/or palaeo-coastal
deposits). King et al., refs. Most of the soils are coarse textured but with fine fractions washed to
depressions and to the subsurface where they may impede drainage. The soils are acidic with low
nutrient reserves and the entire area is susceptible to fire s and storms. Many of the inland savanna
areas occur over older Pliocene deposits (Figure 2), which have older, deeper and sandier parent
materials which can carry a dense pine cover where freely drained.
Figure 25 E-W section across the northern plains showing the locations of the
principal savannas
Figure 35.Sampling Sites for linked soil and botanical surveys
3.6.4 Methodology
The project extended over two short field seasons. The first survey in April 2010 concentrated on the
inland savannas of northern Belize, whilst the second in April 2011covered all the coastal savannas from
Sarteneja to Deep River. The analyses have been completed for the first samples; the second batch of
samples is currently being processed. Sites were chosen to give as broad a representation as possible of
the sub types of savanna vegetation. In most cases these followed the sites and numbering outlined in
the botanical surveys. In total 23 profiles were examined covering all the vegetation subtypes with the
exception of freshwater hyperseasonal grasslands. Profiles were taken to approximately rooting depth
except where ground water prevented further inspection. Samples were taken from the principal
horizons for later analysis in the UK.
The locations of field sites and links with the botanical surveys are illustrated in Figure 3 (map) and
summarised in Appendix 2. The soil profile descriptions are collated in Appendix 3.
The methods of soil analysis are summarised below:-
3.6.5 Results
The provisional (unchecked) results for sites 1-9 are given in Appendix 3.
3.6.6 Interpretation and discussion
The results so far are consistent with the pattern of properties for the neotropics, comparing the Belize
samples with an 800 site set of figures for the Brazilian savannas :-
Table 3. Belize Soil Data Compared with Brazilian Savanna Data
Savanna Surface Horizons
•
Median
Belize (2010)
Interpretation
pH (H2O)
5.0 [4.3 – 6.2]
5.3
High Acidity (<5)
Ca (cmol/Kg)
0.25 [0.04 – 6.81]
0.51
Below lower limit
recommended for agriculture
Mg (cmol/Kg)
0.09 [0.00 – 2.02]
0.02
Low
K (cmol/Kg)
0.08 [0.02 – 0.61]
0.28
Low
Effective CEC (cmol/Kg)
1.1 [0.35 – 8.10]
0.3
Indicative of highly
weathered soils
Organic Matter (%)
2.2 [0.7 – 6.0]
3.9
Contributes little to the
effective CEC values
P (Mg/ml)
0.4 [0.1 – 16.5]
0.5
Low –unsuited to cultivation
Clay (%)
33.5 [4.5 – 72.4]
7.6
Surface low; subsurface high
Note: Many of the Ex.K figures are unusually high giving high CEC results. These have been removed from
the averages and are being further checked. The figures quoted are from the earlier Programme for Belize
samples (Furley et al., 2001).
Most sites are acidic, with pH (H20) values ranging from 5.3 to 5.7 with the higher values often
associated with the influence of ground water or perched water table. The pH(CaCl2) levels were
approximately a pH unit lower. Cation exchange capacity and exchangeable cation figures are
consistently low supporting the view of poor soil fertility, with Ex. Ca averaging 0.51 cmol/kg; Ex.Mg
averaging 0.04 cmol/kg and Ex K 0.55cmol/kg (the K figures will need to be checked). The organic
matter, as described in the field and evidenced in the C and N figures (averaging 1.7% and 0.07%
respectively), is mostly concentrated in the top 10cm of the soil profile and varies with the degree of
vegetation cover and, as far as can be ascertained, with the incidence of fire. One distinctive feature of
the soils is the subsoil level of fine inorganic material, particularly the clay fraction. Most of the subsoils
in the flatter parts of the lowland savanna are markedly clay-rich, sufficient to impede drainage and
affect rooting depth (an average of 7.6% at the surface rising to 20.3% and often very much higher in the
subsurface horizons).
Dense pine (savanna woodland) usually occurs over freely drained soils with deep profiles in coarse
textured materials, frequently very sandy at the surface; oak woodlands appear to cope with at least
temporary flooding and, where the subsurface is impermeable, seem to have a root adaptation that
allows for greater surface spread. At site D3 for example, a single prostrate oak was found to spread
over the surface with a c.5m radius, with a few vary large roots (≥5cm lying above the more
permanently wet subsoil. Palmetto groves are nearly always associated with water but isolated trees
appear to have ingenious ways of coping with both seasonal flooding and intense desiccation (Furley
2008 ; Milne 1997). The most fertile surface soils seem to be associated with dense mixed savanna
woodland, although this is likely to be a result of vegetation affecting soil properties rather than the
reverse. Open grasslands and sedge-grasslands cover areas which are unfavourable to tree growth (as
in the seasonally flooded freshwater grasslands) or have been heavily disturbed (as illustrated in some
of the coastal saline grasslands and degraded savannas of the interior). The sub-type edges are
extremely dynamic and the tree-grass ratios may change relatively rapidly with changes in
environmental controls. Each of these sub-types has been influenced by the incidence of fire and the
current vegetation is therefore not necessarily synchronous with the character of the underlying soil.
Some of the preliminary ideas concerning the processes involved are summarised diagrammatically
overleaf:-
Figure 36. Hypothetical model showing the processes influencing the development
of savanna sub-types
3.6.7 Savanna soil surveys; Summary
Several distinguishing features characterize the lowland savanna soils:•
Many of the soils are strongly affected by seasonal or semi-permanent flooding or poor
drainage. This results from the low gradients preventing runoff, and/or the presence of argillic
subsurface horizons. The level land surface and proximity to the water table results in shallow
damp depressions which may be seasonally filled with water.
•
Soil textures vary from gravel and fine sand to heavy clay, although most surface horizons are
coarse textured.
•
The inland savannas over the northern plains tend to be higher with greater relief and
consequently drainage is better. The deeper soils on siliceous alluvium are more intensively
leached and more typical of other neotropical savanna conditions. These sites are often
associated with slightly older (possibly Pliocene) sands and gravels supposedly derived from
ancient outwash from the Maya Mountains (see Figure 3 – cross section across the north). In
some southern parts of the country, similar conditions at a smaller scale are found closer to the
shoreline. The marginally higher topography and greater slope generates a micro-catena effect
and significantly influences plant distribution.
•
The soils are consistently acidic with low nutrient resources. Organic levels are frequently
higher than typical savanna soils and this may result from the impeded drainage and anaerobic
conditions and therefore less decomposition. Conversely this may be offset by the frequency of
fires. The locally heterogeneous environments result in considerable spatial variation in soil
properties at a micro-scale
•
A provisional model of soil-plant association relations and dynamic processes has been
developed and will be tested further against the second field season results and compared with
the national soils surveys
•
The soil data provides valuable information for land suitability assessment and potential
conservation strategies. At present it would appear that the savannas are too difficult to
manage for subsistence agriculture other than extensive ranching, except where there are
reliable water supplies.
3.7 Savanna Fauna
109, 200 specimens in Berds database in total for belize
Is this because savanna fauna are undercollected? The total number of fauna observations provided by
BERDS for the lowland savanna and MPR are 2833. The total number of fauna observations within just
the lowland savanna are 1188. Lowland savanna are relatively undercollected , representing only 1% of
the total collections from all ecosystems.
Figure 37: of the small number of records for the savanna, most are avian species.
Source: BERDS, 2012.
Figure 38: Geographical distribution of BERDS fauna records within savanna areas.
Implications of the findings for savanna conservation and management in Belize:
forward?
the way
The project has produced a significant amount of primary scientific data that can be separated into:
• Plant diversity surveys;
• Savanna Map integrated into Belize Ecosystems Map;
• Soil Survey data;
Additionally, at the Meeting on April 13th 2011, our partners tabled important further data. For example
BTFS provided information concerning the fauna of savanna areas.
In the final session of the Expert meeting, the above information was considered together to form
various recommendations and advice concerning the lowland savanna ecosystem to be communicated
to the government of Belize, to NGOs and to others involved in the management or development of
savanna areas. These discussions are summarized around the following points:Is savanna in Belize adequately protected?
What are the main threats to savanna?
Although pressure for shrimp farming seems to be diminishing due to economic lack of competitiveness,
In the light of pressures for roads, housing (summarise other big threats ?)
What elements of savanna is it most important to conserve?
Should we conserve a/c to ecosystem services not just biodiversity? Although endangered spp like
Yellow head Parrots help? Services such as flood storage, pine carbon storage, local value of palmetto
and popta seeds etc?
Which areas of savanna in Belize have particular importance for conservation?
Existing protected areas
Value/importance
RBCMA
Paynes Creek
Areas not presently under protection
Value/importance
South of Crooked Tree
Lemonal-San felipe
Suggest a series of callouts
indicating the areas we are
identifying
How should we foster conservation of savanna areas?
Considered unlikely to have savanna on Crown Lands declared nationally for protection in their own
right, except in relation to other initiatives eg mile 34 jaguar corridor project, …any others?
Private land owners/ part of other projects/ community initiatives/pointing out their unsuitability for
other uses/pointing out their critical sustaining functions/land in trust-mechanisms/ zoning in land use
policy.
4.1 Next steps for savanna management and policy
National level mechanisms for conserving savannas
How to take these results forward – routes into government NGOs etc? Elma’s decision making
pathways?
•
Forest Act
•
National Protected Areas System Act
•
National Land use Policy
•
?Sustainable Land Use management policy? (elma?)
•
Convention on Biological Diversity
•
Etc etc? jan?
While these studies have not (as yet) resulted in added protection for the savanna's, the foundation has
been laid for a better understanding and therefore better decision taking. The integration of the Belize
Ecosystems Map into the Belize Land Use Policy Mapping Tool is a first concrete step towards this. ..
Local level mechanisms
Assimilation of finding into savanna management Plans (PfB and TIDE)
4.2 Next steps for data
Although the project has gathered significant new primary data, it has also revealed areas where more
data would further assist conservation zoning and monitoring efforts. The mapping of savanna
nationally has been completed to a high specification and the challenge is mainly now to maintain the
currency of the Ecosystems Map 2012 in the coming years by receiving corrections and updates.
Botanically, in spite of the wealth of data gathered, there are difficulties in using this to identify
"hotspots" or areas of savanna with unusually high biodiversity, because the species richness per site
was shown to be strongly correlated with the sampling effort (See figure 5). In simple terms, more
variety was found in areas where more survey effort was expended. This is normal for botanical surveys
and should encourage ongoing sampling efforts within savannas, especially in different seasons to
search specifically for certain plants. The photoguides and other resources created to aid the
identification of certain rare or less common species will assist NGOs and organisations such as the ERI
(which has a national remit for botanical surveying and monitoring) with this task.
While the soil survey was added to the project at a later stage and funded through a different source;
this very valuable addition opens the way for a truly better understanding of the ecology and floristic
composition of the Belize Savannas. One of the next steps forward would therefore be to study the
relationships between the sampled soils and the species composition at these sites. Ultimately an
improved understanding of the relationships between savanna soils and vegetation cover could inform
the next revision of the ecosystem map.
4 References
Balick, M.J., Nee, M.H. & Atha, D.E. 2000 Checklist of the Vascular Plants of Belize. Memoirs of the New
York Botanical Garden 85: 1–246.
Bridgewater, S., Ibáñez A, Ratter J. A. & Furley, P. 2002. Vegetation Classification and floristics of the
savannas and associated wetlands of the Rio Bravo Conservation and Management Area, Belize.
Edinburgh Journal of Botany 59 (3): 421-442.
Cameron, I. D., Stuart, N. & Goodwin, A. Z. 2011. Savanna Ecosystems Map of Belize 2011: Technical
Report, Darwin Initiative Project 17022, University of Edinburgh, Edinburgh.
http://www.eeo.ed.ac.uk/sea-belize/data/sav_eco_2011/sea-belize_sav-eco-map-2011_techreport.pdf
Furley,P.A. 1999 The nature and diversity of neotropical savanna vegetation with particular reference to
the Brazilian cerrado. Global Ecology and Biogeography 8, 223-241.
Furley P A 1974,1976 'Soil-slope-plant relationships in the northern Maya Mountains, Belize: 1, The
sequence over metamorphic sandstones and shales', Journal of Biogeography, 1,3:171.86 2. The
sequence over phyllites and granite', Journal of Biogeography, 1:263-79 3. Variations in the
nature and distribution of soil properties', Journal of Biogeography, 3;303-19.
Furley P.A. and Ratter, J.A. 1989 Further observations on the nature of the savanna vegetation and soils
in Belize. Biogeographical Monographs No 3, 1-22.
Furley, P.A. 2008. Significance and biomass of the palmetto palm (Acoelorraphe wrightii (Griseb. &
H.Wendl.) ex Becc. In Belizean lowland savannas. Report to the Carnegie Trust 14pp.
Edinburgh.
Furley, P. A.,Bridgewater, S., Ibanez-Garcia, A., Minty, C.,Murray, M., Ratter, J. A., Stuart, N and Vasquez,
M. 2001. Savannas of the Rio Bravo Conservation Area: Vegetation and soil –plant community
relationships. In Furley, P. A. and Young, R.. (eds) Ecological and environmental research in
Belize. Vol.1 Vegetation and Plant-Soil Studies. Journal of Belizean Affairs Vol. 3.No.2, 56-96.
Goodwin, Z.A., Harris, D.J., Bridgewater, S.G.M., Lopez, G.N., Haston, E., Cameron, I.D., Michelakis, D.,
Ratter, J.A., Furley, P.A., Kay, E., Whitefoord, C., Solomon, J. & Stuart, N. (2011) A checklist of the
vascular plants of the lowland savannas and associated wetlands of Belize, Central America.
Phytotaxa (accepted –vol/pages??)
Hicks, J.,Goodwin, Z.A.,Bridgewater, S.G.M., Harris, D.J. and Furley, P.A. 2011. A floristic description of
the San Pastor savanna and preliminary checklist of the savannas of Belize, Central America.
Edinburgh Journal of Botany 68(2),273-296.
King, B., Baillie,I.,Grimble,J.,Pratt,J.,Wright,A.C.S & Zisman,S. 1992 Land Resource assessment of
Northern Belize. Natural Resources Institute, ODA. Chatham, Kent
King, R.B.,Pratt,J.H., and WarnerM.P & Zisman S. 1993 Agricultural development prospects in Belize,
Bulletin No 48, Natural Resources Institute, ODA. Chatham, Kent.
Lenthall.J., Bridgewater,S.,Furley,P.A. 1999. A phytogeographic analysis of the woody elements of New
World savannas. Edinburgh Journal of Botany 56 (2), 293-305
Meerman, J. C. 2005. NPASP – Protected Areas System Assessment & Analysis: Gap Analysis, Protected
Areas Systems Plan Office, Belize.
http://biological-diversity.info/Downloads/NPAPSP/gap_analysis.pdf
Milne, Rhoderick,F 1997 A biogeographical and ecological study of Acoelorraphe wrightii, Belize,
unpublished thesis, BSc Geography, University of Edinburgh
5 Appendix 1: Agenda Science Meeting Wednesday April
13th, 2011
Facilitator: Jan Meerman
Location: Belize Zoo and Tropical Education Center.
8.30 AM
Registration
9.00 AM
Welcome – Jan Meerman
9.05 AM
Introduction of participants, individual expectations of this meeting
9.15 AM
Quick overview of the Darwin Savanna conservation project – Neil Stuart
9.25 AM
2010 Mapping of the Lowland Savannas of Belize. Methodology and outputs – Duncan
Moss, Neil Stuart
9.45 AM
Botany and Biodiversity of the Lowland Savannas of Belize – Zoe Godwin
10.00 AM
Fauna of the Lowland Savannas of Belize – Jan Meerman
10.15 AM
Soils of the Lowland Savannas of Belize – Peter Furley
10.30 AM
Synthesis of findings from the Darwin project– Sam Bridgewater. Linking soils,
geography and vegetation: An Ecological Integration.
10. 45 AM
Break
11.00 AM
Integration of the 2010 Savanna Map into the Belize Ecosystems Map.
Current status and follow up needs – Jan Meerman
12.15 AM
Break for Lunch
1.00 PM
Group working session: Status and future of Belize’s Lowland Savannas, threats,
conservation priorities, data needs, future activities
Introductory presentation: Protected areas with substantial savanna coverage and which savanna areas
are still within the national lands portfolio? Can we deduct focal areas? Followed by group discussions
and analysis
3.00 PM
Conclusions and delegation of future activities
3.30 PM
Closing
Present:
David Tzul (BWB)
Dimitrios Michelakis (UoFE)
Duncan Moss (UofE)
Elma Kay (ERI/UB)
Elmer Requena TIDE
German Lopez (ERI/UB)
Jan Meerman (BERDS)
Jon Pixler (BBG)
Judy DuPlooys (BBG)
Maarten Hofman (YCT)
Mario Muschamp TIDE
Neil Stuart (UofE)
Omar Figueroa (ERI/UB)
Percival Cho
Peter Furley (UofE)
Raina Lamb (APAMO)
Ramon Pacheco PfB
Rudi Aquil (BBG)
Sam Bridgewater (UofE)
Steven Brewer (BFREE)
Zoe Goodwin (RBGE)
6 Appendix 2: Soil Analysis Methodology
Soil Analysis: Soil samples were analysed for water content, pH, phosphate content, carbon and
nitrogen content, exchangeable cations (Ca.,K.,Mg.) cation exchange capacity and particle size.
Preparation of soil for analysis
The soil samples were air-dried and then passed through a 2 mm sieve. If soil contained
aggregates larger than 2 mm these were crushed with a pestle and mortar prior to sieving. Stone
content was determined to be negligible.
Analysis of water content
2 g of soil (± 3 d.p.) was oven dried at 105ºC for 24 hours, re-weighed, then transferred to a
furnace at 550ºC for 16 hours. Soil samples were re-weighed and the water loss (the difference in
sample weight between oven and furnace drying) was calculated.
Analysis of pH
A 10 g sample of the 2 mm sieved air-dried soil was placed in a 100 ml pyrex beaker with 25 ml
de-ionised water, the mixture was then stirred vigorously with a glass rod before being left to
stand for ten minutes. Then the mixture was stirred again before a pH reading was taken. 2 ml of
0.125M CaCl2 was added to the mixture, followed by more stirring, before a second pH reading
was taken. This procedure was repeated for all soil samples. The pH probes were recalibrated
with standard solutions of known pH after every six readings.
Analysis of carbon and nitrogen content
Sample particle size was reduced to powder. 12 g samples of powdered soil were placed in
screw-top bottles, sealed with electrical tape and placed in a mill for a 20 minute cycle. Samples
where then analysed for carbon and nitrogen content using an automated Dumas procedure on a
Carbo Erba NA 1500 analyser (Erba Science UK).
Soil samples, approximately 15-30 mg, were placed in a combustion column maintained at
955°C. The sample was flash combusted in a temporarily enriched atmosphere of oxygen. The
combustion products were carried by a carrier gas (helium) past an oxidation catalyst of
chromium oxide, and then past silvered cobalt oxide which ensures complete combustion inside
the combustion column. The combustion products were then passed through a reduction reactor
to remove excess oxygen and reduce N oxides to N2. The resulting gases were then passed
through magnesium perchlorate to remove water, and transferred to a thermal conductivity
detector. The detector generates an electrical signal proportional to the concentration of N or C
present (Clarity chromatography software (DataApex Ltd., Czech Republic)). The results were
given in percentages (Sollins et al., 1999).
Analysis of phosphate content
2.5 g samples of air dried soil were added to 20 ml of distilled water, the mixture were shaken
(92 rpm, 20 minutes) and then centrifuged (500 rpm, ten minutes) at 20ºC. The resulting
supernatant was then collected in screw-top bottles and analysed for phosphate.
The procedure for the determination of phosphate levels is based on the reaction of ammonium
heptamolybdate and potassium antimony (III) oxide tartrate in an acidic medium with diluted
solutions of phosphate to form an antimony-phosphomolybdate complex. This complex is
reduced to an intensely blue-coloured complex by L(+) ascorbic acid. The complex is measured
at 880 nm.18
Individual exchangeable cations and cation exchange capacity
2.5 g of air dried soil was weighed out and added to a filter funnel that had been plugged with
cotton wool. The soil was then washed with 33 ml of 1M potassium chloride three times and then
twice with 20 ml of ethanol and the resulting fluid discarded. The clean soil was then washed
three times with 1M ammonium acetate and the liquid product was collected in a bottle and made
up to 100 ml using more 1M ammonium acetate. A 2.5 ml sample of this was then mixed with
10% lanthanum and absorbance measured against at set of known standards using a Unicam
AAS Flame M5.
Mechanical analysis
100g of air dried sample was treated with 20% hydrogen peroxide to oxidise organic matter.
After end-over-end shaking, the sample was then dispersed into a 1000ml cylinder and made up
to the mark with distilled water. The dispersed solution was then passed through sieves to extract
the coarser fractions and the clay was obtained by weight from oven dried residue.
7 Summary Table of Soils Fieldwork 2010-2012
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
D1 A1
17 51
49N
Trail to
Booth River
Dense oak
dominated
savanna
3
W
Well drained
towards Booth
River
34
D1 A2
88 47
08W
woodland
Booth River
D1 B
D1 C
D2 A1
130468
Trail to
Booth River
Open oakdominated
savanna
D2 A2
1975913
(closer to
San Felipe)
woodland
345856
North of
Belize Goal
Low oak
colony within
3
W
Ditto
35
2
SW
Wet at surface
and very wet
in subsurface;
WT at 37cm;
radial
prostrate oak
36
D2 B1
D2 B2
D3 A1
colony; much
oak generation
above
palmetto
gallery
D3 A2
D3 B1
D3 ?B2
1937140
open
grassland
much oak
generation
above
palmetto
gallery
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
D4 A1i
17 31
25N
North of
Belize Goal
Oak clump c
30x20m
0 to 1
SW
75m from D3;
36
discrete clump;
very wet below
surface;WT at
30cm filling
D4 A1ii
88 27
07W
0 to 1
S
Open
character of
savanna
woodland fire? Slope
wash from
?limestone hill
to S -heavy
textures
within
grassland
D4 B1
D4 B2
D5 A1
18 01
16N
N end of
old
Northern
Oak
dominated
savanna
D5 A2
88 31
26W
Highway
woodland
D5 B1
D5 B2
heavy textures
37
D6 A1
17 54
15.7N
Old
Northern
Highway
Low woody
savanna
woodland
(CuratellaByrsonima)
D6A2
88 20
8.2W
1.5km N of
Maribu
Lodge
Byrsonima
D6 B1
D6 B2
0.5
NW
Lies to N of
low hill ridge;
alluvial
flooding from
nearby
lagoon?
32
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
D7 A
17 31
25N
North of
Belize Goal
Open
grassland
0 to 1
SW
Not sampled
systematically;
intermediate
site between
D3 and D4;
burnt grass
over
impermeable
B; surface
water in places
36
D7 B
30m D4
D8 A1
?
D8 A2
D8 B1
impermeable
heavy textured
substrate
300m W of
Coffin
Creek, East
gate to
Yalbec Gate
PfB
Dense pine
savanna
East Gate to woodland
Yalbec gate
PfB
1
NE
Densest pine
(seen from
road) on PfB;
unusually tall
palmetto
clumps
Very well
drained
na
D8 B2
D8 C
D9 A1
17 30
49.3N
300m E of
Coffin
Creek
Dense Oakpine mixedf
savanna
1.5
SW
Very well
drained
na
D9 A2
88 42
57.3W
PfB
woodland
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
D10 A1
18 20
21.7N
100m from
lagoon
saline(?)
grassland
1
SE
Lagoonal
alluvium over
38
D10 C1
88 07
25.7W
Wild Tracks
D11 A1
18 18
59.3N
Shipstern
Lagoon
saline(?)
grassland
1
SE
Lagoonal
alluvium over
limestone
42
D11 A2
88 09
D9 A3
D9 B1
D9 II? B2
D9 II? B3
D10 C2/R
Silted solution
39.7W
hollow
D11 A3
D11 Bg
D12 A1
17 45
15.6N
Crooked
Tree
open
savanna with
pine and
some oak
and palmetto
D12 A2
88 35
54.5W
Lemonal
track
palmetto
D13 A1
17 46
37.9N
Crooked
Tree
savanna
woodland
D13 A2
88 34
48.3W
1/2m W of
second
causeway
oak
dominated
2
W
level plain
below shallow
convex ridge
31
<1
na
level well
drained site;
broad
interfluvial
plain
9C
D12 A3
D12 Bg
D13 A3
D13 Bg
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
D14 A1
16
3222.6N
Deepr River
FR (N)
medium
0-1
dense pine
with dense
understory
and
discontinuous
grass cover
D14 A2
88 42
52.0W
Nr Bladen
River bdy
and
discontinuous
grass cover
D15 A1
16 31
37.0N
Deep river
FR (N)
open sedgegrassland
with
scattered
D15 A2
88 42
29.8W
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
E
long footslope
and coastal
plain below
karstic hills;
c.1km from
Bladen R to W
17 to 18
na
long footslope
and coastal
plain
D14 A3g
D14 Bg
D15 B1g
D15 B2g
palmetto
clumps
<1
evidence of
surface water
flow
12
nearest
D16 A1
16 23
15.9N
Paynes
Creek
open sedge
grassland
with
D16 A2
88 36
24.7W
c 8km NW
of station
very large
clumps of
palmetto
D17 A1
16 24
37.0N
Deep River
FR (S)
mixed dense
savanna
woodland
<1
D17 A2
88 37
49.4W
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
16 30
19.0N
Off
Southern
Highway;
road
open
tussocky
grassland and
sedges;
D18A2/B1 88 28
30.6W
to shrimp
farm
scattered
pine,oak &
<1
na
dry coastal
plain with
evidence of
surface water
flow
24
nearest
na
well drained
through out
profile
25
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
1-2
N
upper slope of
catena with
overall slope
3-4ºN
D16 B1
D16 B2g
D16 B3g
D17
A3/B1
D18 A1
gentle convexlinear; signs of
26
surface water
flow
low shrubs
D18 Bg
D19 A1
16 30
37.3N
Off
Southern
Highway;
road
dense pine
savanna
woodland;
continuous
grass cover &
numerous
shrubs
D19
B1/2g
88 28
27.2W
to shrimp
farm
grass cover &
numerous
shrubs
D20 A1
16 32
04.4N
Behind
Savanna
Forest
dense (thin
bole) pine;
thick grass
D20 A2
88 27
29.7W
Station
cover with
frequent
shrubs
16 37
27.7N
E of
medium
Georgetown dense pine
with open
grass
3 to 5
N
lower slope of
catenafootslope step
3
dry valley
downslope base c 100m.
D19 B2g
3 to 5
SE
middway
down long
linear slope;
well drained
53
1 to 2
N
Level plain
leading down
to a small
gallery
68
D20 B1
D20 B2g
D21 A1
D21 A2
88 27
16.1W
track
leading
towards the
coast
with mixed
arboreal
patches
Sample
No
Grid
reference
UTM/latlong
Location
Type of
vegetation
Slope(°)
Aspect
Site and
drainage
Botanical
Survey
No.
D22 A1
17 08
57.3N
Coastal
Highway N
of Gales
oak
dominated
clump with
pine and
numerous
shrubs
<1
na
level [plain
dipping E
through
grassland and
palmetto
clumps
28
nearest
D22 A2
88 19
31.6W
Point
turning ;
100m from
road
numerous
shrubs
D21 B1
D21 B2g
D22
B1h/Fe
D22 B1Fe
D22 B2
D22 B3
D23 A1
Matamore
Pine ridge
D23 A2
D23 B
D23 C
17 15
32.5N
Coastal
Highway
Oak thicket
with pine and
88 25
24.9W
off trail to E
Bocotra
Pine Ridge?
palmetto
shrub
1 to 2
E
Gently upward
sloping plain
to E
over grassland
(topsoils
washed off?)
30

Savannas in Belize: Results from Darwin Initiative Project 17

Transcription

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