Savannas in Belize: Results from Darwin Initiative Project and the implications for savanna conservation

Transcription

1 Savannas in Belize: Results from Darwin Initiative Project and the implications for savanna conservation

2 Savannas in Belize: Results of Darwin Initiative Project 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.

3 Table of Contents 1 Introduction Project Overview Status Overview Conservation Status of Pine Savannas in Belize Products produced under the project Project website launched and periodically updated; Plant diversity surveys and vegetation habitat surveys conducted in lowland savanna areas; Selected Results Development of the Belize savanna plant database Photographic field guide to savanna plants developed and field tested Integration of the Savanna Map into the Belize Ecosystems Map; Soil-vegetation relationships in the Belizean savannas The Way Forward References Appendix 1: Agenda Science Meeting Wednesday April 13th, Appendix 2: Soil Analysis Methodology Summary Table of Soils Fieldwork

4 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 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.

5 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.

6 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 km 2 classified by Cameron et al from SPOT satellite imagery from , which is mapped in figures 1 (a) and (b) includes 12 km 2 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 km 2 of wetlands that occur as patches within savanna areas. Subtracting these areas yields an estimate of 433 km 2 of savanna areas under protection, which is similar to the figure of 436 km 2 calculated by Meerman in 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 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.

7 Figure 1(a) Savanna areas and Protected Areas in Northern Belize

8 Figure 1(b) Savanna areas and Protected Areas in Southern Belize

9 Protected Area Total Area of PA Dense Tree Savanna Forest Inclusion Open Savanna Seasonally Waterlogged Savanna Wetland Inclusion Savanna area % of PA that is savanna 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 Table 2: Areas of lowland savanna within each protected area (Km 2 ) (savanna areas based on Darwin savanna map 2010)

10 Protected Area Type of protected area (IUCN) Organisation Managing Community Baboon Sanctuary Private Reserve (IV) Women's Conservation Group Crooked Tree Wildlife Sanctuary (IV) Belize Audubon Society Created Management effectiveness National ranking 1 (best) -65 (poorest) Moderate Moderate Deep River Forest Reserve (VI) GOB Forest Dept Moderate Grants Works Forest Reserve (VI) GOB Forest Dept Poor Manatee Forest Reserve (VI) GOB Forest Dept Moderate Mango Creek (1) Forest Reserve (VI) GOB Forest Dept Moderate Mango Creek (4) GOB Forest Dept. GOB Forest Dept Moderate Monkey Bay Wildlife Sanctuary Private Reserve (IV) MBWS Moderate Monkey Caye Forest Reserve (VI) GOB Forest Dept Poor Payne's Creek National Park (II) TIDE Very Good Peccary Hills National Park (II) Gracie Rock Reserve for Adventure/Ecotourism Moderate Rio Bravo Private Reserve (IV) Programme for Belize very Good Foundation for Wildlife Runaway Creek Private Reserve (IV) Conservation/ Birds without Borders Fair Swasey-Bladen Forest Reserve (IV) GOB Forest Dept Moderate Table 3: Characteristics of Protected Areas with over 5% savanna land over (ranking of all PAs mean effectiveness scores from Walker & Walker, 2009)

11 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.

12 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 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$ million by 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

13 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 Biodiversity areas Carbon Climate control Timber Medicinal plants Amenities Ecotourism Aesthetics Hunting Education/appreciation

14 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? 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 Economic forestry Jan:- some commentary about FD revenue from logging concessions on the southern plains please? (Oswaldo?)

15 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?

16 3 Outputs from the Darwin project 3.1 Project website(s) The project website ( 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. ( Figure 1. Project Website (main screen) Figure 2. Brahms savanna plant database (main screen)

17 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 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 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?

18 Figure 3. Number of botanical records (left) and observed species richness (right). Note that the species richness effectively depends upon the collecting effort.

19 Figure 4. Locations of the botanical collecting sites.

20 3.2.1 Results for selected species Figure 5 Ageratum radicans - Endemic

21 Figure 6. Curatela Americana - Characteristic

22 Figure 7 Dalechampia schippii - Endemic

23 Figure 8. Hypericum pratense - Endemic

24 Figure 9 Hypericum terra-firmae - South and Central

25 Figure 10 Melastelma stenomeres - Endemic

26 Figure 11. Paepalanthus gentlei - Endemic

27 Figure 12 Passiflora urbaniana - Endemic

28 Figure 13 Syngonanthus bartletii - Endemic

29 Figure 14. Syngonanthus hondurensis - Restricted

30 Figure 15. Syngonanthus lundellianus - Restricted

31 Figure 16 Tibouchina aspera - Restricted

32 Figure 17 Turnera aromatic - Characteristic

33 Figure 18 Turnera curassavica - Restricted

34 Figure 19. Turnera difusa - North Only

35 Zamia prasina - Characteristic Figure 20. Zamia prasina - Characteristic

36 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 ( 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 ( Figure 21. Searching the Brahms database of all savanna plant records in Belize

37 Figure 22. Example of results from a Brahms database query Figure 23. Web mapping tool allows geographical query and reporting of records.

38 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 Figure 24: Example of photoguides available

39 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 ( ) and to assimilate it into the National Ecosystems Map of Belize in 2012.

40 Figure /2010 Ecosystems map classification detail Figure Savanna Map detail of same area

41 Figure 30: 2004 ecosystems map overlain on 2011 savanna map, showing some discrepancies Figure 31: Resolution of discrepancies

42 Figure 32. Resulting 2011 Ecosystems Map The new Belize Ecosystems Map (2012) data are accessible through: and

43 Figure 33: Comparison of savanna areas from the Cameron et al (2010) image classification and savanna areas mapped in the 2011 Ecosystems Map.

44 <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)

45 3.6 Soil-vegetation relationships in the Belizean savannas 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 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):

46 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)

47 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

48 Figure 35.Sampling Sites for linked soil and botanical surveys

49 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: Results The provisional (unchecked) results for sites 1-9 are given in Appendix 3.

50 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 [ ] 5.3 High Acidity (<5) Ca (cmol/kg) 0.25 [ ] 0.51 Below lower limit recommended for agriculture Mg (cmol/kg) 0.09 [ ] 0.02 Low K (cmol/kg) 0.08 [ ] 0.28 Low Effective CEC (cmol/kg) 1.1 [ ] 0.3 Indicative of highly weathered soils Organic Matter (%) 2.2 [ ] 3.9 Contributes little to the effective CEC values P (Mg/ml) 0.4 [ ] 0.5 Low unsuited to cultivation Clay (%) 33.5 [ ] 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 (H 2 0) 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(cacl 2 ) 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

51 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:-

52 Figure 36. Hypothetical model showing the processes influencing the development of savanna sub-types

53 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.

54 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 The total number of fauna observations within just the lowland savanna are Lowland savanna are relatively undercollected, representing only 1% of the total collections from all ecosystems.

55 Figure 37: of the small number of records for the savanna, most are avian species. Source: BERDS, 2012.

56 Figure 38: Geographical distribution of BERDS fauna records within savanna areas.

57 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 13 th 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?

58 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

59 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.

60 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.

61 4 References Balick, M.J., Nee, M.H. & Atha, D.E Checklist of the Vascular Plants of Belize. Memoirs of the New York Botanical Garden 85: Bridgewater, S., Ibáñez A, Ratter J. A. & Furley, P 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): Cameron, I. D., Stuart, N. & Goodwin, A. Z Savanna Ecosystems Map of Belize 2011: Technical Report, Darwin Initiative Project 17022, University of Edinburgh, Edinburgh. Furley,P.A The nature and diversity of neotropical savanna vegetation with particular reference to the Brazilian cerrado. Global Ecology and Biogeography 8, 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: The sequence over phyllites and granite', Journal of Biogeography, 1: Variations in the nature and distribution of soil properties', Journal of Biogeography, 3; Furley P.A. and Ratter, J.A Further observations on the nature of the savanna vegetation and soils in Belize. Biogeographical Monographs No 3, Furley, P.A 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 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, 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??)