i

Selecting priority areas in the Scotland District for reforestation under the Sustainable Land

Management Project of the NCC/OAS KAREEM J. SABIR AND ROBIN MAHON

CERMES Technical Report No 34

Centre for Resource Management and Environmental Studies (CERMES) University of the West Indies, Faculty of Pure and Applied Sciences,

Cave Hill Campus, Barbados

2010

ii

ABSTRACT

Selecting priority areas in the Scotland District for reforestation under the Sustainable Land Management Project of the NCC/OAS

Kareem Jamal Sabir and Robin Mahon

Land degradation by deforestation and unsound agricultural practices in Small Island Developing States (SIDS) has been a major issue in achieving sustainability. Since large scale reforestation of lands is hardly possible in SIDS, it is useful to look at land rehabilitation and sustainable land management at a watershed scale and pursue smaller scale reforestation in strategic locations

The National Conservation Commission (NCC) and the Organization of American States (OAS) have commenced a Sustainable Land Management (SLM) project in Barbados to combat land degradation and promote sustainable land management practices in the Scotland District. To assist in achieving this overall goal, the current project was aimed at selecting priority areas in the Scotland District for reforestation. A watershed approach was taken here, using a Geographic Information System (GIS) with various maps and orthoimagery to select sites in a watershed where reforestation can benefit sustainable land management by reducing erosion, conserve biodiversity and benefit communities directly.

The Walkers River watershed was chosen. The land use and land cover were mapped in broad categories by aerial photograph interpretation. These maps were overlaid on landslide and erosion hazard maps to select sites with potential for reforestation. The riparian vegetation in the stream channels was also mapped and this riparian zone was included in selection as a strategic area where reforestation efforts can occur.

Four sites in the catchment were selected as having potential for reforestation and recommendations of planting strategies were presented for three of these sites at Swanns, north of Turners Hall Wood and a site near Belle Hill. The riparian vegetation mapping elucidated a high percentage of vegetation cover (98.7%) around stream channels, a high proportion of which is forest vegetation (78.4%). Wild clammy cherry (Cordia obliqua), river tamarind (Leucaena leucocephela) and poison tree (Sapium hippomane) were the most common trees in the riparian zone. Two sites south of Bawdens and north of Turners Hall Wood were suggested for the establishment of a forest buffer around the riparian zone for further protection from erosion and land slippage.

KEY WORDS: reforestation, sustainable land management, watershed, Scotland District

ii

ACKNOWLEDGEMENTS

Special thanks must go to Ryan Braithwaite of the National Conservation Commission for giving me the idea and opportunity to conduct this research and for his initial guidance.

Great appreciation should also go to all the other staff and colleagues at CERMES especially Neetha Selliah and Dr. Nurse for their support. My classmates have helped me out both technically and logistically throughout as well, also we helped each other maintain sanity. Monique Welch in particular assisted with GIS aspects.

Glen Marshall and Michelle Wilson of the Soil Conservation Commission have provided tremendous support and information that was of great help to me. Claus Eckleman of FAO sub-regional office provided literature on valuable forestry and watersheds which CERMES library also benefited from. Jason Holder from the Land Tax and Valuation Department provided assistance with determining land ownership in the study area. Ronnie Braithwaite of the BADMC and George Bailey of the Ministry of Agriculture and Rural Development library should also receive thanks.

iii

CONTENTS

1 INTRODUCTION................................................................................................................. 1 1.1 THE SUSTAINABLE LAND MANAGEMENT PROJECT .......................................................... 1 1.2 BACKGROUND .................................................................................................................. 1

1.2.1 Erosion and Land Degradation .................................................................................. 1 1.2.2 Watershed management .............................................................................................. 2 1.2.3 Riparian Forests ......................................................................................................... 3 1.2.4 Trees outside forests ................................................................................................... 5

1.3 RATIONALE OF THE STUDY ............................................................................................... 6 1.4 OBJECTIVES ..................................................................................................................... 7

2 METHODOLOGY ............................................................................................................... 9 2.1 CATCHMENT LAND USE MAPPING .................................................................................... 9 2.2 REFORESTATION POTENTIAL AREAS WITHIN CATCHMENT ................................................ 9 2.3 REFORESTATION POTENTIAL IN THE WATERSHED BUFFER .............................................. 10

3 WATERSHED ASSESSMENT ......................................................................................... 11 3.1 WATERSHED DESCRIPTION ............................................................................................ 11 3.2 POTENTIAL REFORESTATION AREAS ............................................................................... 14

3.2.1 Planning approach.................................................................................................... 14 3.3 BAWDENS/SEDGE POND CROPLAND ............................................................................... 24

4 WATER COURSE ASSESSMENT .................................................................................. 28 4.1 CHARACTERIZATION OF STREAM CHANNELS .................................................................. 28 4.2 POTENTIAL SITES FOR ESTABLISHMENT/ENHANCEMENT OF RIPARIAN VEGETATION ....... 34 4.3 POTENTIAL SITES FOR BUFFER ESTABLISHMENT ............................................................. 34

5 DISCUSSION ...................................................................................................................... 36

6 CONCLUSION ................................................................................................................... 39

7 REFERENCES .................................................................................................................... 40

8 APPENDICES ..................................................................................................................... 43

8.1 APPENDIX 1 VEGETATION CATEGORIES USED FROM (CARRINGTON ET AL 2003) ............ 43 8.2 APPENDIX 2 RAW FIELD DATA ....................................................................................... 44

Citation:

Sabir, K.J. and R. Mahon. 2010. Selecting priority areas in the Scotland District for reforestation under the Sustainable Land Management Project of the NCC/OAS. CERMES Technical Report No 34. 44pp.

1

1 INTRODUCTION

1.1 The Sustainable Land Management Project The current project was undertaken in collaboration with of the National Conservation Commission (NCC) of Barbados who have commenced a Sustainable Land Management (SLM) project funded and guided by the Organisation of American States (OAS) and the Caribbean Environmental Health Institute (CEHI). Entitled ‘Preventing Land Degradation in Small Island Ecosystems in the Caribbean through Sustainable Land Management’ the main objectives of the project are, among others: adressing the problem of land degradation, especially deforestation and the consequent loss of ecosystem goods and services and biodiversity; and to improve land management practices as well as policies and institutional arrangements concerning mitigating land degradation (OAS Department of Sustainable Development 2007, CEHI n.d.).

The current study was done to select priority sites for reforestation in the study area of the SLM project (Scotland District). A watershed approach was taken to perform the site selection, using GIS as the main site selection tool. The outputs were intentioned to assist the SLM project in Barbados.

1.2 Background 1.2.1 Erosion and Land Degradation

Barbados signed the United Nations Convention to Combat Desertification and Drought (UNCCD) in May, 1997 and the convention came into force in August 1997 (Ministry of

Physical Development and Environment 2002). Desertification is defined as “Land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities” (UNCCD 2008). In Barbados, land degradation is of greatest concern in the Scotland District which is found in the Northeast of the island and makes up 1/7th the total land area (Figure 1.1). Unlike the remainder of the island, the Scotland District has had its coral cap removed by erosion, exposing the older and more vulnerable mixture of oceanic and volcanic ash geological substrates. The area is also hilly and exposed to the Northeast Trade Winds, making for heavy rainfall and accelerated erosion. These factors are combined with forest clearing, unsound agricultural practices and housing development, creating a significant problem for Barbados in its fight against land degradation and land slippage

The direct impacts of severe land erosion and land slippage are damage to properties after slippage events and loss of agricultural productivity through top soil loss. Indirectly, as a result of the extensive drainage network of Barbados, sediments are transported to the near-shore marine environment, this being exacerbated by the

Figure 1.1: The Scotland District

2

anthropogenic factors mentioned above. In addition, harmful pesticides, herbicides and fertilizers also reach the near-shore environment, affecting water quality and marine ecosystems (and the associated negative consequences).

In May 1997 Barbados became party to the United Nations Convention to Combat Desertification in order to improve the capacity to address these problems, as well as to collaborate with other countries to share technical assistance and experiences (Ministry of Physical Development and Environment 2002).

The Soil Conservation Unit (SCU) of the Ministry of Agriculture and Rural Development (MARD) is the main agency responsible for mitigating and managing the threats of excessive soil erosion and land slippage in the Scotland District. Since its establishment in 1957 its main focus has been reforestation and ad hoc tree planting to reduce soil erosion in problem areas of the Scotland District. It then became an autonomous unit and embraced several other departments such as hydrology and engineering and took on several remedial tasks in the area, under the authority of the Soil Conservation Act (1959).

Three major agroforestry projects have been undertaken by the Soil Conservation Unit since then (Ministry of Agriculture 2002) to promote rural development and a more diverse and environmentally sound agriculture. The first project (1982-1986) was funded by the Government of Barbados and the European Development Fund. It was executed in Back River Valley to improve the protection of that watershed and rehabilitate agricultural land. The slopes in the area were planted with forest and fruit trees to stabilize the land and provide the hotel market with fruit produce while exporting surplus to Europe. The outcome was over 400 acres of land planted and soil erosion reduced. The unit also gained some key infrastructure for plant propagation. The Scotland District Conservation Project (1983-87) which involved agronomic research in Greenland and Turners Hall to determine the most suitable species for agroforestry. It ran in conjunction with the European Development Fund project and served to establish another agroforestry system in the area. The latest of the three projects (2002) involved erosion mitigation works similar to the previous two in Morgan Lewis, St. Andrew after a trend of receding vegetation on the slopes in the area. Most recently, the SCU has conducted reforestation on 4.84 ha of land in 2008. In Morgan Lewis a total of 650 seedlings were planted on 0.56 ha while vetiver grass and 69 fiddlewood (Citharexylum spinosum) saplings were plant on the banks of a watercourse (0.08 ha) in Bruce Vale, St. Andrew (Lucas 2008).

Coastal reforestation has also been undertaken by the Coastal Zone Management Unit (CZMU) in the past. In 1999, The Coastal Revegetation and Dune Stabilization Project was implemented. The project involved planting 370 plants (including casuarinas, sea grapes, seaside almond, and seaside mahoe) and erecting 75m of sand fences in the Barclays Park area to revive the dune systems, which have been impacted by a combination of natural and anthropogenic factors (GoB 1999).

1.2.2 Watershed management

An FAO report on sustainable development in Small Island Developing States (SIDS) aptly underpins the need for watershed management considering the close proximity of highlands and coastal environment. The report emphasises the importance of maintaining vegetation cover and embracing engineering innovations in land management to reduce land degradation and facilitate soil production. In this way agricultural production can be made more sustainable (FAO 1994).

3

Watershed management does not seem to be in the forefront of environmental management in Barbados when various natural resource management plans are perused, however it is a key component of the SCU’s mandate with respect to reducing land slippage in watercourses by engineering and forestry interventions. A combination of gabion weirs and watercourse vegetation is a common feature of watershed management by the SCU (Figure 1.1). These increase land stability which has a direct benefit to agricultural productivity and to the structural integrity of physical infrastructure in the vacinity such as roads and buildings. Additionally sedimentation of streams and eventually coastal water will be reduced. Runoff water from crop lands and other non-point sources of pollution have a significant negative impact on coastal water quality. Sediments from the streams and rivers smother the benthic environment of shallow coastal waters. Nitrates and phosphates in suspension and adsorbed to soils can result in algal blooms and eutrophic conditions. Fertilizers and other chemicals along with eutrophication result in decreases in biodiversity and ecosystem complexity and productivity. The socioeconomic impacts include threats to public health, coastal tourism, fisheries declines and an overal effect on livelihoods in the coastal realm (National Research Council 2000).

Figure 1.1: Gabion weirs are constructed around some watercourses to reduce the likelihood of landslides during heavy rainfall. In the foreground, maintenance is being conducted on a gabion structure in Greenland while in the background dense vegetation in the watercourse surrounds older (not visible) retaining structures.

1.2.3 Riparian Forests

The ecosystem functions of forests with respect to land stabilization and water quality and quantity are well known. The services of riparian vegetation in particular will be highlighted here. There are several definitions of riparian vegetation in the literatures. Riparian areas are lands adjacent to water bodies ranging from creeks and rivers to lakes and wetlands (Oklahoma

4

Corporate Extension Service 1998). Thus riparian forests represent unique assemblages of trees and shrubs that form the interface between aquatic and terrestrial environments.

Osborne and Kovacic (1993) presented a detailed literature review of the function of vegetated buffer strips (VBSs) in the United States. The establishment of these is a recognized management practice suitable for mitigating the negative impacts of agricultural practices on aquatic water quality. Numerous documented instances were reported of significant reductions in sediment loading, and nitrate concentration after establishment of riparian buffer strips of various sizes and composition (Osborne and Kovacic 1993). In this way riparian vegetation has a dual service of interest to the Scotland District; reducing soil erosion and improving water quality.

Riparian vegetation acts as a physical barrier to runoff water from upland areas. Its presence dissipates the energy of overland flow water and prevents concentration of water flow during heavy rains. Leaf litter in riparian forests protects soil directly while tree roots bind the soil of the stream bank, thus reducing erosion from stream flow as well as surface and subsurface flow from upland areas. Studies of 100 years of aerial photography of the Sacramento River in California reveal that floodplains in agriculture are 80-150% more erodible than forested floodplains (CWRP 2006).

Riparian buffers help reduce the impact of non-point sources of pollution on watersheds. Pesticides, herbicides and fertilisers bind to soil particles and are transported in surface and subsurface runoff from agricultural lands. Riparian vegetation act as a sink for nitrogen and phosporus by root uptake. In this way, the productivity of riparian forests can be taken advantage of in agroforestry or limited timber harvest. The biophysical conditions in riparian areas also often create conducive environments for denitrifying bacteria to convert dissolved nitrigon to gaseous nitrogen (OCES 1998). The ability of riparian forests to reduce pollution in watercourses has been so recognized that in Shei Pa National Park, Taiwan intense research is used to determine the appropriate buffer width based on the forest’s ability to be an effective barrier to 50 studied chemical contaminants. Slope, soil characteristics and processes necessary for degradation of these contaminants are all taken into account to determine adequate buffer widths (CWRP 2006). It is worth noting however that although forests can function in this way to reduce erosion and stream sedimentation, it has to be appreciated that extreme high rainfall events will more often than not overcome any forestaion or engineering works (Calder, Hofer and Warren 2007).

In addition to ecosystem services of land rehabilitation and water quality, riparian vegetation also serve the funtion of enhancing biodiveristy, especially regarding birds (Natta, Sinsin and Maesen 2002). Riparian forests also act as corridors for the movement of wildlife between forest fragments. The National Park Development Plan maps areas with potential as forest linkages, including the riparian vegetation in the Walkers River watershed (GoB 1999). In this way, riparian vegetation in the Walkers catchment has the potential to serve as forest corridors for critical seed dispersers such as birds, bats and monkeys, and thus facilitate the growth and regeneration of forests in the Scotland District.

5

1.2.4 Trees outside forests

Off-forest tree resources (Unasylva 2000/1), trees outside forests (Kleinn 2000/1) and ‘working trees’ (USDA National Agroforestry Center 2008) are all terms to refer to trees integrated into land use and land management systems for a variety of ecosystem and socioeconomic services. Trees in the landscape outside what is defined as forest are equally important in providing ecosystem services regarding land management and water quality. Indeed, strategic incorporation of trees in the landscape is probably more feasible to achieve than largescale reforestation in the context of the Scotland District. It is important to appreciate the landscape level and longterm approach to management. Some of the uses of trees outside forest will be described here.

Trees are commonly employed in agriculture systems. The International Council for Research in Agroforestry (ICRAF) provides perhaps the most widely accepted definition of agroforestry (Nair 1990):

‘Agroforestry is a collective name for land-use systems and technologies where woody perennials are deliberately used on the same land-management units as agricultural crops and/or animals, in some form of spatial arrangement or temporal sequence. In agroforestry systems there are both ecological and economical interactions between the different components.’

Most agroforestry practices can be classified into three broad categories of agrisilvicultural (crops and trees), silvopastoral (trees and pasture/livestock) and agrosilvopastoral (trees, crops and livestock). They can then be further subdivided according to a variety of spatial and temporal arrangements (Nair 1990). These systems may also be classified temporally with some systems having the different components existing together permanently and others being fallow systems with rotations of varying time scales (Beets 1989).

Spatial arrangements include random mixes, windbreaks, shelterbelts and alley-cropping among others. Random mixture systems have no particular pattern for trees and shrubs in the crop unit. In most cases the trees have been in the landscape before crop production and they are ususally high value trees like fruit trees or nitrogen fixing trees, or they may be used for shade and foliage in silvopastoral systems. The random mixture system is most widely used in the Caribbean with forest trees, coconut, citrus and Albizia lebbeck (nitrogen-fixing legume) most commonly integrated with bananas, root and vegetable crops or livestock (Gumbs 1994).

Alley cropping takes the form of bands of trees and shrubs in the crop landscape with root and vegetable crops grown between the trees. Fruit trees may be use in this system to diversify the crop production as well as stabilize the soil. Leucaena leucocephela is also quite commonly used throughout the tropics in these systems for soil stability, fertilisation and animal fodder (Beets 1989, Kleinn 2000/1, Young 1997, and Nair 1990). An example of alley cropping for soil management comes from the Philippines. The leguminous nitrogen fixing tree Gliricidium sepium is planted at regular intervals in fields. It is fast growing and its root system helps stabilize the soil on hillside farm systems. It also improves fertility by fixing nitrogen in the soil. Foliage is pruned from the trees and spread on the ground as mulch to reduce erosion by rainfall while black pepper vines climb on the trunks of the trees. Between the Gliricidium there may also be banana plants in production (Young 1997). Contour planting is also a form of alley cropping and involves planting trees or tree/grass combinations along the contours of slopes to stabilise the slope-side. This reduces the movement of soil particles downhill during rainfall,

6

eventually creating natural terraces. Crops are then grown in the alleys (Gumbs 1994). This system may also use either trees for soil fertility of food production.

With respect to watershed management various agroforestry systems mentioned above are inevitably linked to reducing runoff from agricultural land. The role of trees in riparian zones and alley cropping has been described earlier. Windbreaks and shelterbelts bordering agricultural fields provide the function of maintaining the soil in the crop unit by reducing windspeed and soil sheet-flow. Waterbreak systems are rows of trees (alley cropping) planted perpendicular to the direction of water flow in the catchment or cropland. This helps prevent channelization of water downhill thus reducing rill and gully erosion. It also reduces the impact of flood damage (USDA National Agroforestry center 2008).

1.3 Rationale of the study Establishment of stream-side vegetation buffers have been widely accepted in the United States as a management practice under the Conservation Reserve Program, even to the point where numerous scientific reviews of riparian buffer effectiveness are being conducted and documented (Osborne and Kovacic 1993; Oklahoma Corporate Extension Service 1998). Countries in South America have also embarked in riparian forest restoration in major watersheds to combat the land degradation and depletion of water quality that resulted from unregulated agriculture, logging and livestock development in major riparian areas and flood plains (World Bank 2005). Its global importance is exemplified by FAO Unasylva’s 2007/4 issue entitled ‘Forests and Water’ showcasing knowledge and experience worldwide of the use of riparian forests and catchment forests in watershed management.

A broad review of OECS Natural Resource Management Unit documents on watershed management policy development have shown a general lack of specific plans to restore riparian vegetation or implement development control policies specific to preserving riverbank forests (OECS NRMU 1999). Key findings of the OECS Regional Policy Dialogue on Watershed Management in Small Island States were summarized in OECS NRMU (2002). The problems of land degradation and water pollution and their causes were consistent among the OECS representatives at the workshop, but among the solutions the need for vegetation buffers in watershed protection was not prominent in terms of specific research and policy development.

The obvious need for agriculture and rural development makes broadscale reforestation in the Scotland District unfeasible, thus leaving strategic placement of trees in the landscape as the only viable option for forestry-based soil stabilisation and erosion control. Therefore, the purpose of this study is to attempt to bring into the spotlight the restoration of riparian forests as a tool to assist in both land rehabilitation and watershed protection in the Scotland District. The employment of this kind of approach to reforestation can hopefully be repeated for other watersheds around Barbados and the region, to realise not only the benefits of increased forest cover and the corresponding ecosystem services to land management, but also to provide marketable fruit crops and to a limited extent wood products. An equally important benefit of this watershed approach is the potential reduction of sediment and nutrient loading of streams and subsequent near-shore coastal waters that is common in the rainy season.

7

1.4 Objectives The overall goal of the SLM project is to develop a forestry management plan to assist in management of areas with high frequency of erosion in Barbados and to provide a means of rehabilitating degraded rural lands. The intention is also to identify high priority areas for reforestation, of which two have already been identified. The project also seeks to draft implementation and management plans for the two selected areas.

Following are the main goals of the current proposed project, intended to support the SLM project by identifying additional priority sites for reforestation. This will be done using a watershed approach, with the idea of establishing a riparian forest buffer along the watershed selected to assist in, among others, soil stability and erosion reduction. To achieve this, the project will:

− Characterize the land use of an entire catchment for an analysis of how land use practices affect land degradation;

− Take a planning approach to identify areas within the catchment with reforestation potential;

− Assess and characterize the land use and vegetation types adjacent to the stream channels of the watershed to identify the areas not already forested or naturally reforesting;

− Select from non-forested areas the most feasible locations for reforestation as well as suitable reforestation strategies;

− Identify the challenges faced and benefits for the selected sites.

8

Figure 1.2: Key landmarks in the Walkers River Watershed study area

9

2 METHODOLOGY

2.1 Catchment Land use mapping The Walkers River catchment was chosen by subject judgement, based mostly on selecting a watershed of intermediate size; not being unmanageably large and not too small. The complexity of land use in this catchment also influenced the decision. The mixture of agriculture, forest, tree plantations, mining quarries and residential areas were a good combination to study the feasibility of forestry-based soil stabilization and other sustainable land management practices (Figure 1.2).

Land-use in the Walkers catchment was assessed by aerial photograph interpretation. Ortho-images licensed by Digital Globe were imported into ArcMap of the ESRI ArcView suite. The boundaries of the catchment were inserted from the watershed mapping data of the Gully Ecosystem Management Study outputs (EPG, PDA, SEMS 2004). The aerial images were analysed visually at around 1:10000 scale and the editing tool was used to make simplified cartographic illustration of land-use in the area. In conjunction to the computer mapping, site visits were conducted to assist in ground-truthing and confirming land-use categories.

The purpose of the land use mapping is to assist with site selection and not to give detailed description and statistics of land use and land cover. Detailed land cover for Barbados was published recently (Helmer et al 2008). It was decided best not to use the output land cover map from Helmer et al (2008) because such detail was not needed and the resolution of the source image used in that study was coarser than the source imagery used in the current study. Thus it was thought best to create a general land cover map using the Digital Globe source imagery. Broad categories of land-use were used and defined as follows:

− Agriculture: land currently in active cultivation;

− Grassland: natural rangeland, livestock pasture land and agricultural land not in recent cultivation, lands recovering from fires;

− Water bodies: ponds and water courses;

− Built infrastructure: These represent buildings in the area. Polygons were drawn around individual buildings and also groups of houses, merely to give an indication of where settlement occurred;

− Forest/tree cover: Forests, tree crops, scattered trees and shrub land.

2.2 Reforestation potential areas within catchment A planning approach was taken to begin the selection of potential sites for reforestation. Two maps from Scott Wilson’s ‘Scotland District: Soil Conservation/Development Study Final Report’ prepared for the MARD (2000) were used for initial site selection. These land capability and planning guidance maps (for landslide and erosion susceptibility) were produced to assist the SCU in making recommendations on development land use changes and new developments in the Scotland District (Marshall pers. comm. 2008). These maps have categorised three zones in the Scotland District based on erosion and landslide risk; category three being the zone of highest constraint in terms of development control where ‘residential and infrastructural development should be prevented...’ (Scott Wilson 2000).

10

This study focused on category 3 areas of erosion and land slide hazards and GIS layers representing this category were extracted from the maps using the GIS edit tool. These layers were used to determine the areas in category 3 not already in forest or residential land use by overlaying them on the land use map produced. These areas not already in forest or residential land use were identified as potential reforestation sites. Field visits to these sites were conducted to provide a description of the area including the present vegetation type, floristic information and soil conditions. Options for revegetation were developed along with the overall feasibility of maintaining trees at the sites.

Specific attention was given to the Barbados Agricultural Development and Management Corporation (BADMC) Land for the Landless Program in Bawdens, St. Andrew. There were several reasons for this. Part of the land lies within category 3 of the erosion and landslide land capability maps by Scott Wilson, it also lies adjacent to one of the Walkers River stream channels in the north of the catchment area, and it offers the opportunity to assess the feasibility of agroforestry systems in this type of land tenure agriculture operation. General information about the Land for the Landless Program and the Integrated Rural Development Project were obtained from the BADMC. Information included, inter alia, the amount of land in total, sizes of leased plots, lease arrangement, aspects of crops production and incentives for tree planting. This information was then used to help identify strengths, weaknesses, opportunities and threats of an agroforestry system in the area, and recommendations were made using specific species combinations and tree orientations. Recommendations of potential agroforestry systems were supported by schematic diagrams (not drawn to scale) using Adobe Photoshop CS3.

2.3 Reforestation potential in the watershed buffer For ease of assessment the Walkers River watershed has been divided into sections based on the location of the stream channels. The main sections of the stream in the valley have been designated ‘main channel 1, 2 and 3’ while the branches coming from higher ground have been designated names based on where they originate (Figure 2.1).

11

Figure 2.1: Subdivision of the Walkers River to make data collection and analysis more manageable.

Field assessments were done in the stream channels to gather information on vegetation types, size of the channel, dominant species, adjacent land use and evidence of erosion and slippage. The assessments helped elucidate areas within the watershed that could have benefited the most from revegetation. Vegetation types were classified in three stages. Primarily by observing the aerial photographs used in the study and Google Earth images. Further verification was done by visual observation in the field from various vantage points within the area. Finally further detailed field visits were done in some areas to identify vegetation types and record other characteristics of the stream channels. The data were collected using rapid assessment field sheets (Appendix 2), while using a GPS unit and topographical maps to assist with navigation. Data were collected at various points along the stream channels and gullies when riparian vegetation type changed and other times when there were observations worthy of recording. The entire watershed was not assessed on the ground because of limited access in some places. Vegetation classification was based on that used in the Biodiversity Conservation Subcomponent of the Gully Ecosystem Management Study (Carrington et al 2003). The broad categories used here are described in Appendix 1.

3 WATERSHED ASSESSMENT

3.1 Watershed Description The Walkers River catchment is situated in the Northeast of the island in St. Andrew. According to the delineations made by the Gully Ecosystem Management Study, it covers approximately 1029 ha and contains several important features such as a portion of the sand dune system and its sand-mining operations, the Long Pond estuarine ecosystem, the ‘National Park Villages’ of Belleplaine and Walkers (GoB 1999), Turner’s Hall Forest, and the BADMC’s Land for the Landless Programme in Bawdens and Sedge Pond.

A total of 22.34 km of combined permanent and intermittent streams was estimated based on GIS calculations using the stream channels shapefile (EPG, PDA, SEMS 2004). The stream

12

channel originates from the higher lands in Bawdens and Greenland in the north, Swanns in the west and Turners Hall in the south. Each of these branches drains into one stream in the low lying central area of the catchment where it meanders through Walkers and Belleplaine to the coast. The river flows into Long Pond estuary and flood plain. The Bruce Vale watershed to the immediate south also drains into Long Pond.

It is worth noting that much of the land in the catchment is terraced or otherwise engineered to reduce its steepness and vulnerability to land slippage. About 27% of the catchment has indeed been stabilised in various ways by the SCU (Ministry of Agriculture 2002). Some of the reforestation efforts have already been highlighted in the introduction. Gabion wells, weirs and boxes were observed in abundance throughout the catchment. Terracing in the Bawdens and Sedge Pond area has made these areas more amenable to agriculture and general development. Terracing is also very pronounced in the Swanns and Turners hall areas, from viewing aerial photography.

13

Figure 3.1: Land use/ land cover map of the Walkers catchment in St. Andrew based on visual interpretation of DigitalGlobe copyrighted satellite imagery.

The majority of settlement exists in the eastern side of the watershed where the land is less rugged. Open spaces are concentrated in Swanns, Turners Hall area in the southwest of the

14

catchment where a portion of one of the national forest candidate sites (Turners Hall Woods) is situated. This area is steep and hilly, with some parts exceeding 200m above sea level. The area is also known for its susceptibility to land slippage, evidence of which is seen from the numerous cracks and undulations in the roads at Swanns and Turners Hall. Regarding agricultural land use, the BADMC has large land holdings in the Bawdens and Sedge Pond area, portions of which are leased to landless farmers. This occurs in the northwest of the catchment, also in hilly erosion-prone lands (Figure 3.1). The large expanse of grassland in the valley near Walkers is privately owned land with remnants of past agricultural production. These areas are not regarded to be at great risk of slippage and erosion (Scott Wilson 2000).

3.2 Potential reforestation areas 3.2.1 Planning approach

Landslide hazard category 3 lands in the catchment make up approximately 216.15 hectares, most of which already has forest or fruit tree cover (Figure 3.2). Five potential areas have been identified because of their current vegetation cover and their potential to improve land stability as a result of reforestation. All of them are classified as grassland from imagery interpretation (Error! Reference source not found.) but will be described in more detail later. Two agricultural sites also fall within category 3. These two sites at Bawdens and Sedge Pond have been given special attention in the following section (3.1.2). Table 3.1: Some summary information on sites selected. Size was calculated in the GIS and actual land cover/use was described based on field observations. Sites 4 and 5 were given the same name based on proximity and similarity, later combined and described as one site.

Site Size (ha) Interpreted land cover Actual land cover/use 1. Sedge Pond 4.12 grassland burnt forest re-establishing 2. Swanns 9.98 grassland livestock pasture 3. North of Turners Hall 6.11 grassland grassland 4. Near Belle Hill 2.51 grassland grassland/inactive

agriculture 5. Near Belle Hill 4.98 grassland grassland/inactive

agriculture

15

Figure 3.2: Category 3 of land capability and planning guidance map for landslides were overlaid on catchment land use to identify 5 non-forested sites in category 3 as potential reforestation sites (grassland areas numbered in red).

16

Site 1: Sedge Pond

Site 1 is an area recovering from fires and thus mapped as grassland according to the broad land cover categories used here. The area is just uphill (northwest) of the Sedge Pond agricultural area leased by BADMC. The area is classified as ‘deciduous, evergreen coastal and mixed forest or shrubland’ according to (Helmer et al 2008). Field visits confirmed that site 1 is indeed a patch of Leucaena forest that had suffered from fire. The soil types in the area consist of soils derived from sandstones and Scotland clays (Vernon and Carroll 1965).

This site will not be recommended as a potential reforestation site for the main reason that it is already observed to be actively regaining its forest cover. Compared to its denuded appearance in the 2005 aerial photographs it now has many scattered Leucaena and Albizia trees and it is not anticipated to require any intervention in reforesting. The fecundity of these species and abundance in surrounding areas will allow for rapid natural regeneration of the forest.

Site 2: Pasture land at Swanns

This site is an open sour-grass pasture (Bothriochloa pertusa (L.) A. Camus) with no tree cover except a small thicket in the centre of the pasture (Figure 3.4). Soils here are thin raw soils derived from Scotland Clays (Vernon and Carroll 1965). There is approximately a 6o slope on the wind-swept hillside with maximum elevation around 135 m. There is significant evidence of erosion from runoff. Though generally ground-cover by grass was good, there are pronounced gullies forming in the hillside. In these gullies, taller grasses dominate (vetiver grass perhaps) in some sections while carpet daisy (Wedelia trilobata) in others; testament to the increased levels of moisture. Where these two were not present there was evidence of small slippages in the rills and these were generally wider and steeper. Guava saplings (Psidium guajavum) were observed in the gullies as well. The small thicket in the centre of the pasture comprised common native and naturalised forest species like clammy cherry (Cordia dentata), Acacia sp., Capparis cynophallophora and Casuarina equisitifolia. The current land-use appears to be open grassland; formerly active agriculture but now used for grazing cattle with no signs of private ownership or exclusive access. The land is part of the BADMC’s land holding in the area.

Considering the conditions and land use at this site, a scenario can be created where this land becomes unsustainable. If livestock development continues, as is planned for some areas in the Walkers watershed (Ministry of Agriculture 2002), then increasing stocking densities of cattle for example on this already vulnerable pasture land will likely result in overgrazing and subsequently making the pasture increasingly more vulnerable to erosion and slippage. The soil will become more exposed, drier and easily removed by rainfall. The already evident rill erosion will continue and create gullies thus reduce the amount of usable land. In turn, livestock production will suffer if the grassland productivity is reduced. Even in its current state, erosion will probably greatly reduce the quality of the land by dividing the land with growing gullies and removing the richer top soil.

To help avoid the above scenario and foster more sustainable use of the land a silvo-pastoral system is recommended here (Figure 3.3). Gliricidia sepium is a Neotropical legume cultivated throughout the Americas. It can thrive in a wide variety of soil and rainfall conditions, also quickly recovering from perennial fires (Suttie unknown). Propagation requires little effort. Cuttings of mature branches (>7cm diameter) are simply stuck in the ground and new growth generates after rainfall, thus the common name ‘quick stick’. Gliricidia is widely used in the Americas in crop and livestock systems (Beets 1989). Along with the usual services of trees

17

such as soil stability and soil-water regulation, it provides other benefits to livestock production such as shade, protein fodder and soil fertility. Combellas et. al. (1996) documented 1.5x increases in live weight of cattle supplemented with Gliricida for 2hr/day compared to cattle fed on grass alone. Similar increases were observed when cattle were given a daily artificial protein supplement. The nitrogen-fixing capability of the trees would help maintain soil fertility and facilitate grass production. In this way, more cattle can be grazed on these lands to maximise livestock production.

Figure 3.3: Integrating nitrogen fixing trees into the landscape at site 2 establishing a silvo-pastoral system.

The trees can be planted in rows along the contours, perpendicular to the direction of runoff flow. It is recommended that the rows of trees be segmented and sufficiently wide apart to allow unrestricted movement of animals in the pasture (Figure 3.4). Rows of trees can be pruned or lopped in a rotational scheme to provide fodder for the cattle. Cutting for forage is recommended at 6-12 week intervals for humid tropics. Plant spacing can be variable but empirical evidence showed that as plant spacing decreased, individual tree yield decreased but yield per unit area increased, as did leaf:wood ratio (Suttie, unknown). This would be acceptable in this case since the trees are grown for their leaves. Note however that planting along the contours and regular trimming of leaves for fodder will reduce the function of the trees as shade providers. East-facing rows would be more suitable for maximising shade, but would be inefficient in reducing runoff flow because of the orientation of contours.

18

Figure 3.4: Aerial view of site 2 at Swanns. Green lines represent a suitable orientation of Gliricidia trees to achieve soil stability, obstruct runoff and reduce the rate of rill and gully erosion.

A system such as this is anticipated to meet the objectives of the SLM project; soil conservation and rural development. In a system like this, should the land be returned to crop cultivation, alley cropping can be practiced where cash-crops are cultivated between the rows, thus still reaping the benefits of soil stability and fertility. The main constraints of this system however would be issues of access, use rights and land tenure. It was suggested by locals that the area is open for anyone to graze their livestock. The usual conflicts that arise from open-access resources are likely to occur, compromising the sustainability of the system.

Site 3: North of Turner’s Hall Woods

Site 3 is a grassland just north (downhill) of Turner’s Hall Wood, adjacent to the stream channel (Figure 3.2). There is a high percentage of ground cover by sour grass and carpet daisy (in moister places), with scattered trees; mostly Acacia, Ziziphus mauritiania (dunks) and clammy cherry species. The shrub black sage (Cordia curassavica) is the most abundant shrub. The area is also characterized as pasture land by Helmer et al (2008) with nearby vegetation classified as ‘drought deciduous open woodland’ and ‘mixed and woody agriculture’ (Helmer et al 2008). On the aerial photographs there is evidence of terracing along the contours, but not so pronounced on the ground. The area has an approximate 11o slope, with some moist depressions and also some evidence of slippage. Gully erosion was observed along the stream bank; deep, vertical escarpments extended into the field at right angles to the watercourse. The soil is compact, hard and light-coloured. Like site 2 it is derived from Scotland clays (Vernon and Carroll 1965). The

19

use of this open grassland appears to be for livestock grazing. There was evidence of grazing (dung, hoof prints, water containers) but no animals were seen at the times of site visits. There does not seem to be a high density of grazing here (Figure 3.5).

Figure 3.5: Looking south at a portion of the open pasture in the landslide susceptible area of site 3 with forest in the background.

Strips of forest can be established along the contours and alternate with open pasture. The rationale for this is to stabilize the hillside, establish forest linkages and still maintain the area’s use for livestock grazing. This option involves establishing strips of forest alternating with grassland along the already existing contour terraces. Each strip can be around 50-60m width (consistent with the terrace width) stretching around 600m parallel to the stream channel. The result would be the establishment of around 6 hectares or 0.06 km2 of forest in the area (Figure 3.6). Though the width of the strips may be adjustable it is important to orient the strips in such a way that the strip closest to the watercourse is forested and likewise the area closest to the access trail from the road remains grassland. In this way, the pasture land will still have the same accessibility to livestock farmers and also important from an ecological aspect, the riparian buffer zone can be extended.

20

Figure 3.6: Recommended reforestation scheme at site 3 aimed at reducing land slippage while still accommodating livestock farmers.

21

Forestry species should be planted here. Species of economic value such as mahogany can be grown along with other faster growing, nitrogen-fixing forest trees. Since Acacia and Leucaena were present at the site it is anticipated that they will establish on their own.

In this reforestation option, there are two main ecological advantages. The first is the growth of the forest in the area. The Turners Hall Woods just south of the site would have the potential to be extended and secondary forest linkages established to facilitate increases in biodiversity and movement of seed dispersers like monkeys, birds and bats. It should be noted that this section of stream bank is designated as a Natural Heritage conservation area and proposed for preservation as important forest linkages (GoB 1999). The other benefit to be derived is the widening of the riparian zone, thus increasing the stability of the stream banks and increasing the area’s resilience against erosion and slippage. Sediment loads in runoff water would reduce as a result. From a socio-economic perspective the area can still be used for livestock farming and even support an increase in the density of grazing further to enhance community development. The presence of leguminous nitrogen-fixing vines (Rhynchosia minima) associated with the grass and the proposed forest strips containing nitrogen-fixing trees would indicate that soil fertility would be sufficient for a higher density of livestock.

The main constraints will be the difficulties in establishing the forested strips in the area. The exposed hillside, grazing animals, competitive grass and seasonal fires would pose some challenges to establishing the trees. The Philippines provides an example of various methods of assisting the establishment of forest from grasslands. One such method involves using wooden paddles to trample or flatten the grass around young trees. It was recognised that the tall grasses were competing with the trees for resources but cutting the grass would only stimulate rapid new-growth and exacerbate the problem. Thus, trampling the grass was done until trees were sufficient mature and independent (Ganz and Durst 2003). Preventing damage from livestock and removing lianas and vines would be useful in accelerating the establishment of the forest strips. Lianas and vines add to the complexity and diversity of mature forests but can hinder the development of emerging forest.

Sites 4 & 5: Near Belle Hill

Sites 4 and 5 have been integrated into one site because of their proximity. Like site 3 the landscape is dominated by grassland with scattered trees. Again, clammy cherry, Acacia and Leucaena are the dominant trees, all of small size. The base of the hill show signs of previous agriculture and has a slope of approximately 11.3o. The hill slopes have fewer trees, are wind-swept and mostly covered with grass. There are however signs of rill erosion and less abundant signs of slippage in the slope face (Figure 3.7). The hillside also shows signs of recent wildfires thus accounting for limited ground-cover in some places. Watercourses dissect the hills resulting in clammy cherry thicket and Leucaena scrub in the lower end of the watercourses and a more forested appearance at the summit with mango and white willow trees (Capparis indica) more common. Some of the watercourses have deep, near vertical walls. The soils in this area are those derived from Scotland Sandstone and clay colluviums. There is also a thin band of course-textured alluvial soils at the base of the hill (Vernon and Carroll 1965). Significant erosion was observed on the exposed trails up the hillside.

22

Figure 3.7: Site 4 near Belle Hill just south of Walkers main road and north of St. Simons. Note forested depressions (wooded watercourses) result in forest fragments in the grassland.

The main rationale for forestation at this site would be to stabilize the hillside and to re-establish native forest in this area. Forestation on these hills will help connect the forest fragment in the area (Figure 3.7). In pursuing a forestation effort here, there could be a forested corridor established linking Turners Hall Woods (National Forest Candidate) and the coastal forest/clammy-cherry scrub at Long Pond. An existing corridor takes the form of the forest in the ‘Belleplaine branch’ of the watercourse (Figure 3.8). Forest linkages are vital for the movement of animals which in turn can facilitate seed dispersal of plant species, benefiting biodiversity and ecosystem functioning as a whole.

Another important function that vegetation cover can serve here is to reduce the speed and force of runoff downhill since there are remnants of agriculture at the base of the hill. Cultivation of these lands in the future will benefit from a forested, stable hillside. Again, native forest trees should be planted here. Mahogany would be of high value, while other trees like white cedars (Tabebuia spp.) and willows (Capparis spp.) can be used as well.

23

Figure 3.8: Possible forest corridor from Turners Hall to Long Pond if site 4 is subject to forestation by native forestry species.

24

3.3 Bawdens/Sedge Pond cropland The Bawdens/Sedge Pond area used in the Land for the Landless Programme of the BADMC (no. 8 & 9 in Figure 1.2) is not recommended as a priority site for the NCC SLM reforestation project. However, given its location in an area vulnerable to land slippage and erosion it presents an opportunity to explore options of incorporating trees into this landscape, i.e. sustainable land management practices. Some agroforestry options will be described here, as well as the benefits and challenges considering the physical environment and the land tenure system. Some specific information was provided by Mr. Ronnie Braithwaite, Agricultural Services manager of the BADMC, in an informal telephone interview.

Based on the 2004 annual report there are 1565.55 acres of land in the BADMC land bank, 75% of which is arable land, the remainder being for pasture and livestock. In 2004 875.64 acres were distributed to 124 farmers. In Bawdens 341.35 acres is leased and managed by the St. Andrew Small Farmers Cooperative Society Limited (BADMC 2005) for which some summary statistics are presented below (Table 3.2).

The land holdings in the Scotland District have generally been regarded as difficult grounds for cultivation because of terrain, clay content in the soil, erosion and heavy rainfall. It has become a constraint to the BADMC according to the report since small farmers are

reluctant to lease the land in Greenland, Bawdens and Sedge Pond for just these reasons. The St. Andrew Small Farmers Cooperative Society Limited expressed difficulty in production during 2004 because of excessive rainfall and flooding (BADMC 2005). This provides the rationale for these areas to have additional focus for exploring the potential of agroforestry in light of the difficult environmental conditions.

Recommendation 1: Agrosilviculture

It will be difficult to recommend an agroforestry system that benefits all the landless farmers leasing the land. Though some farmers have undertaken agroforestry in Bawdens as well as Greenland in the past (Braithwaite pers. Comm.) it would be ideal to develop a system for the entire area to improve soil conservation and sustainability; a system that would be permanent and still allow landless farmers to lease land and cultivate annual and perennial crops.

In this way the main priority should be to maintain the riparian vegetation that dissects the cropland. The waterway is already protected by wild cane (Gynerium sagittum) and scrub consisting of Leucaena and clammy cherry among others. A small stretch of it is lined with bananas, presumably from one farmer’s crop system. Creating a more permanent riparian buffer system along the edge of the waterway is the main objective. The BADMC or the St. Andrew Small Farmers Cooperative Society Limited can establish a buffer around the waterway where permanent tree crops or shrubs can be cultivated (Figure 3.9). The species used should have some agricultural value and the benefits accrued in various ways. The income can either go to the BADMC, the farmer’s cooperative leasing the area, or the individual farmer that is leasing

Table 3.2: Estimated root crop/vegetable production for Bawdens Land for the Landless Programme. Figures are estimated of the 2004 season extracted from Land for the Landless Programme 2004 Annual Report (BADMC 2005) Parameter Estimated measurement Total available land area 138.14 Hectares in production 11.5 Produce yield (kg) 76158 Per hectare yield (kg/hectare)

6622.4

25

land abutting the buffer. The last option would be best since the farmer would then have an incentive to maintain the buffer because he would be getting direct benefits.

Figure 3.9: Suggested waterway buffer zone for the Bawdens agricultural area to protect the watercourse from erosion.

As mentioned in the introduction, dimensions of riparian buffer zones are variable and sometimes determined by conditions such as slope, adjacent land use buffer vegetation type. The constituents of the buffer may also be flexible. What is important however is the presence of low perennial grass to slow down water flow and shrubs or trees to stabilize subsurface soil.

Another option would be to mandate establishment of a shelterbelt on the downhill boundary of each land plot. Upon application, farmers can be informed that for the sake of reducing erosion from runoff each plot of land must be lined with a perennial shrub, tree crop or perennial grass that would act as a barrier to downhill surface runoff. The applicants can be informed by the BADMC of various species options that can be quickly established and provide some economic benefit. Mr. Braithwaite suggested that farmers would normally be willing to undertake agroforestry because they know that it would be of benefit to them during their 5-10 year minimum lease period. However, the Bawdens landscape is still noticeably devoid of trees, possibly because farmers are not well informed of the benefits and implementation options, and also because they is not enough incentive to digress from the traditional system of maximising space with cash-crops. Pigeon peas (Cajanus cajan, syn. C. indicus), guava or carambola (Averrhoa carambola) are but a few examples of perennials that can be planted in a 5m strip on the downhill boundary of the cropland to stabilise soil and bring economic benefits. A single row of trees such as mangoes, jamoon or citrus would perform a similar function.

The constraints of a system like this would be that this protective buffer would be established on land that is currently leased. Also as mentioned above, farmers would be reluctant to reduce the amount of land used for cash-crops. The effects of runoff will not be prevented during heavy downpours and extreme weather events. This fact must be appreciated and accepted.

26

Recommendation 2: Agroforestry with aquaculture

It is appreciated that this system is not entirely focused on reforestation but the value of its contribution to sustainable land management should make it of interest to the SLM project. There is great potential to improve the efficiency of use of on-farm water resources in the Bawdens area as well as to integrate trees into the farm system. Small-scale integration of irrigation and aquaculture is common in other developing countries in attempts to maximise productivity on the farm system (CTA 1999). The SCU conducted the engineering works to create retention dams in Bawdens to provide the landless farmers in the BADMC programme with easy access to water for irrigation. The farmers use this pond for their irrigations systems and pay for the water through a metered system.

Since the overall goal of these recommendations is to improve the sustainability of the area’s land and the community’s livelihoods, one can go beyond agroforestry in Bawdens to consider the potential for aquaculture in the retention ponds. The situation is similar to the most common examples of agro-pisciculture in sub-Saharan Africa where fish are grown in high numbers in the pond, the water used for irrigation is therefore high in nutrients, crop waste from the fields can be put back into the pond to increase plankton productivity (the main food source of the fish), and likewise sediment build-up from the pond is dredged to fertilise the fields (CTA 1999). This is a model for a typical crop field with adjacent irrigation pond. Even without aquaculture the dredge from the pond can still be applied to field as a form of fertiliser.

Agroforestry can be employed in the same way as above (recommendation 1) but with further tree planting around the pond. Trees around the pond will provide shade on the pond and improve the microclimate around the edge of the pond to benefit fish growth. Leaf litter from over-hanging trees will also contribute to the nutrient cycling, primary productivity and thus fish productivity. In this way, there is a full circle use and reuse of water and nutrient resources. There is also less need to apply chemical fertilisers using this system.

Specific components/composition of this system:

Considering the extra nutrient input that irrigation would provide to the fields if aquaculture is integrated, trees for the purpose of nitrogen fixation can be substituted with trees/plants for diversifying produce and soil stability. Therefore, leguminous trees and shrubs like Leucaena and Albizia can be replaced by fruit crops such as bananas (Musa sp.), citrus, or jamoon (Eugenia jamblana) Banana plants would be ideal in this case because of their quick growth, market value, and ability to cover ground with foliage to reduce erosion. Bananas can be incorporated into an alley cropping system with the existing root/vegetable crops. The green mulch from the rows of bananas can reduce the speed of surface water and help prevent channelization in the fields. However, the soil stability function of bananas is not great because of their shallow roots. Trees for shelterbelts and windbreaks will be the same as above. A few trees can be planted around the pond. Fruits may be difficult to harvest from the pond’s edge but remain an option. A fast growing legume like Gliricidia sepium can be used. It has a large crown to provide shade for the pond. Its falling leaf litter will provide extra ‘green fertilizer’ to boost plankton and detritus for fish food, and Gliridia foliage has also been used in green mulch to reduce erosion by rain (Nair 1990). A system like this can be a reasonably closed and self sustaining regarding nutrient cycling (Figure 3.10).

27

Figure 3.10: Aquaculture system integrated with agroforestry for more efficient on-farm resource use resulting in more sustainable land management; a model for Bawdens, St. Andrew.

Tilapia (Oreochromis spp.) is commonly used in inland aquaculture in the Americas and is growing in commercial importance. They have high marketing potential, grow up to 1kg, and their rearing can be done from natural feeding since they thrive on detritous, plankton and bacterial biofilms (Coche 1998). In this way, fish can be reared in the pond with minimal cost impact from supplemental feeds and fish can be harvested for food.

A summary of benefits and challenges is provided below (Table 3.3). Of these, the most important foreseeable benefit is the contribution of the system to development and increased resilience of the surrounding rural communities, and the increase in production and crop diversity of the landscape. The main challenge would be integrating trees and aquaculture into the BADMC tenure system. For instance, who would have ownership and management of the pond? The possibility lies in leasing the pond just as the land parcels are leased, or perhaps leaving it open access as is currently the case to avoid use conflict. Also, agroforestry development now may not benefit the landless farmers currently leasing the plots and so they would have to be given appropriate incentives to be supportive of this change. Table 3.3: Projected challenges and benefits agro-pisciculture in Bawdens, St. Andrew to the community and the environment.

Benefits Challenges Diversification of production Tenure and ownership issues Increased resilience of the community as a result of this diversity

Lack of research and experience in local aquaculture

Potentially increased production per unit area Irrigation-aquaculture integration may compromise food quality if not done properly

Maximise use of water resources Fluctuating water levels in the dry season Reduce the use of field fertilizer Contamination of fish stock from crop chemicals Reduced soil erosion Reduced space for root/vegetable crop production Fingerlings for ‘seeding’ the fish stock may not be easily

accessible

28

4 WATER COURSE ASSESSMENT

4.1 Characterization of stream channels The stream channels were estimated to be 22.34 km in length, with 17.88 km (76.75%) classified as intermittent streams and 5.42 km (23.25%) permanent streams. The permanent streams were restricted to the lower elevations around Walkers and Belleplaine villages while the intermittent streams were most common in the higher elevations such as Turners Hall and Rock Hall (Figure 4.1).

The stream channels had high vegetation cover, only 1.25% of the entire length having been classified as having no vegetation cover. Eight vegetation types were identified; three of which were a result of the transition of vegetation types from the coast inland as described later. Closed forest vegetation was the most common vegetation type (Figure 4.2, Figure 4.3), making up 78.4% of the riparian vegetation in the watershed. Scrub and marshy grassland types made up an additional 15.8% combined (3.09 km). These two types were similar and sometimes difficult to differentiate, especially on the aerial photographs. In this case, they both were found in moist, disturbed areas of the watershed (MC3 and BWL) mainly at permanent streams where residential development and agriculture had their influence. The grass Gynerium sagittum (wild cane) was common in both types, but ‘scrub’ was more abundant in small (<5m) clammy cherries and wild tamarinds.

29

Figure 4.1: Intermittent and permanent streams in the Walkers watershed classified according to topographical maps (1:5000) and field observations.

Figure 4.2: Composition of riparian vegetation types and the total length they occupied in the stream channel. Determined after aerial photograph interpretations and field confirmation, calculated in the GIS

30

Upon overlaying the category 3 landslide and erosion susceptibility areas over the riparian vegetation data, the following information was extracted. A total of 4.629 km (20.6%) of the stream channels are within category 3 landslide areas. Most of the riparian vegetation in these susceptible areas is however made up of closed forest (75.7%) and scrub (14.5%). None of the stream channels in the landslide risk area were denuded at the time of data collection (Table 4.1). Table 4.1: Composition of riparian vegetation in category 3 erosion and landslide risk areas, determined by overlaying Scott Wilson's land capability maps on the stream channels shapefile in the GIS.

percent cover Vegetation type category 3 erosion category 3

landslide Bamboo forest 0.7 4.4 Closed forest 73.8 75.7 Marshy grassland 1.4 5.4 None 1.7 0.0 Scrub 22.4 14.5

Similarly, category 3 erosion risk areas contained 10.332 km (46.2%) of stream channels with 74% covered by closed forest and 22.3% covered by scrub. A small portion of the stream channels were denuded (1.7%) in Bawdens and Belleplaine villages (Table 4.1).

31

Figure 4.3: Riparian vegetation types in the Walkers watershed and their adjacent land use/land cover.

32

Regarding the species that comprised the riparian vegetation in the watershed, clammy cherry (Cordia obliqua) was most abundant and widespread. This species formed most of the canopy in forested areas, and as mentioned above was also common in scrub habitat type. River tamarind (L. leucocephela) was also quite common in all the vegetation types but less dominant in terms of numbers. In closed forest and scrub, poison tree (S. hippomane) was a common feature in riparian vegetation in and near inland forested areas; forming an open emergent canopy above the lower clammy cherry canopy. This feature was less common near the coast however.

‘Main channel 1’ offered the most variability in vegetation type. From the mouth of the river at Long Pond, vegetation changed from beach strand to marshy grassland with scattered coconut trees to dune vegetation dominated by wind-swept fat pork (Chrysobalanus icaco). All of these vegetation types were found on flat or gently sloping stream banks, with still water and few signs of erosion. Further inland the vegetation became open forest; first dominated by clammy cherry and manchineel, then opening into a stand of mile trees (Casuarina equisitifolia). The stream caused severe erosion in the dunes, resulting in steep escarpments. Forest opened into a small grassland used for cattle grazing before returning to forest of little undergrowth with mostly shallow intermittent streams. This forest section runs adjacent to the Belleplaine village up until Walkers village.

The ‘Belleplaine branch’ originates from around 70 m above sea level, again with forest dominated by clammy cherry, with Acacia more abundant here than other sections of the watershed, suggesting drier conditions. Private pasture/livestock land, small-scale agriculture and cactus scrub are the adjacent land on the steep slope in the upper portion of the branch. The gully then enters Belleplaine and loses its vegetation as it goes through the village. As it meets up with main channel 1 it regains its forest cover with an association typical of the coastal conditions. Seaside mahoe (Thespesia populnea) is most abundant here. It is also worth noting that poison tree is not a prominent feature in the channels near the coast.

The ‘Walkers branch’ of the stream channels is different from the others in that though its surrounding land uses are grassland/pasture and residential, there is a buffer present around the riparian vegetation and even at the bridge there are few signs of disturbance compared to other bridges in the watershed. There is as much as 100 m wide buffer in some places (using GIS measure tool on orthoimages); for example around the bridge and near to this branch’s intersection with MC1. The buffer consists mainly of scrub river tamarind and clammy cherry. The species encountered along a 10m stretch are presented below:

− Poison tree (Sapium hippomane)

− Fiddle wood (Citharexylum spinosum)

− Clammy cherry (Cordia dentata)

− River tamarind (Leucaena leucocephela)

− Scratch wiss (Cissus verticillata)

− white wood (Tabebuia pallida)

− black sage (Cordia curasavica)

− wild cucumber (Coccinea grandis)

− bread & cheese (Pithecellobium unguis-cati)

33

MC2 is similar to MC1 in species composition, minus the abundance of coastal plants. It lies in the lower elevation of the catchment. The closed forest is again dominated by clammy cherry, Leucaena and fiddle wood to a lesser extent. There is little undergrowth in these forests, but like the other branches, there are signs of disturbance near the roads and bridges where there is less penetrable vegetation because of bushy undergrowth. There is a more constant water flow here than in higher elevation branches of the river. The water is surprisingly clear as well, just like in MC3. The Greenland branch originates from just south of Greenland shale quarry and flows south into MC2. Again closed-canopy clammy cherry forests persist with little undergrowth. The stream channel here is less pronounced and temporary, being less than a metre deep.

Wild cane (Gynerium sagittum) and clammy cherry formed an association interpreted here as marshy grassland, though poison tree still emerged but not as frequently as other branches such as Turners Hall and Swanns branches. This vegetation was dense and mostly impenetrable on the stream banks. The wild cane-clammy cherry association occurred in the moister portions of the watershed, mostly along main channel 3 and the Bawdens branch.

MC3 is characterised by a gentle running stream through both active and inactive agricultural land. There is a similar situation with the Bawdens branch. The bridge in the Bawdens branch was a recent site of vegetation clearing, presumably a result of routine clearing and maintenance (Figure 4.4).

Figure 4.4: View from bridge of vegetation clearing in Bawdens: exposed water-course in foreground and remaining dense wild cane-clammy cherry association in background.

The Turners Hall branch originates from national forest candidate site Turners Hall Woods. Though the area is classified here as closed forest, the riparian zone is not easily distinguishable. Based on field observations there were no specific associations around the stream, but there is less understory vegetation in the stream channel compared to the rest of the forest. Rocky stream

34

beds are common with some permanent streams. The stream channel emerges from the forest and goes north through grassland vegetation. The riparian vegetation here remains closed forest but with different species than in the forest. Clammy cherries and Leucaena make up the majority of the canopy, but with poison tree forming a distinct emergent canopy. Grasses and shrubs were still restricted to the periphery of the riparian vegetation, only seen in the channel where disturbance was evident. There was no permanent water in this section of the stream channel, though silty deposits were the most common bottom type. The stream channel is wide (~10 m) and shallow (~4 m). Though shallow, the gully sides are mostly steep, with signs of slippage in places, and also signs of much higher water levels at times. Severe rilling was observed in the adjacent grassland, resulting in trenches protruding perpendicularly from the gully.

The Swanns and Rock Hall branches are similar to Turners Hall branch; originating from forests of higher elevation, having similar floristics and stream channel characteristics. Some parts of the Swanns branch channel were relatively deep (10 m) with Cecropia shreberiana and poison tree dominating.

4.2 Potential sites for establishment/enhancement of riparian vegetation Regarding the grassland area in MC1 there was evidence of possible tree planting on the stream banks there. Besides small Acacia and seagrape trees, there were a few manchineel trees of similar height and regular spacing, suggesting that there could have been some tree-planting there. There does not seem to be a great threat from erosion here in any case.

To have permanent vegetation in 100% of the stream channels and gullies may present a challenge merely because some of the drainage areas go through residential areas, as with the case with denuded sections of Bawdens and Belleplaine branches. Shallow watercourses that meet bridges and other built drainage infrastructure will require regular maintenance which includes vegetation clearing. In the Bawdens case, while the drain/bridge is now less obstructed, the watercourse is completely exposed to erosion (Figure 4.4). In a case like this, only one high rainfall event would be needed to increase the width and depth of the watercourse by stream bank erosion, thus reducing the amount of usable land adjacent; in this case cropland and residential space. The challenge lies in finding suitable planting material that makes the watercourse less ‘bushy’ and easier to maintain without completed denudation. A balance needs to be found where the stream banks can be permanently vegetated so that when maintenance is done in the watercourse only the obstructive vegetation directly in the stream bed need to be removed. This is the main challenge.

The quality of water and the amount of garbage to be seen in Figure 4.4 may hinder the growth of perennial food crops. A combination of perennial crops and small trees a feasible option and a combination of tree crops with gabions would be ideal as well. On the other hand, ornamentals can be used to help improve aesthetics in the village areas. Native landscaping is key here however, to avoid invasion of the natural riparian vegetation by alien species.

4.3 Potential sites for buffer establishment There are two sites with potential for establishing a permanent riparian buffer. The first is between Bawdens road and ‘MC3’. The other site is along the Turners Hall branch.

The first site is classified here as grassland, also classified in Helmer et al (2008) as pasture, hay or inactive agriculture. Field visits confirm these classifications. Bawdens village and BADMC

35

agriculture lie to the north (Figure 4.5) and the agroforestry coconut grove to the north-west. There is a relatively gentle gradient (~5.7o based on topographical map). There are instances of moist depressions in the grassland, also an irrigation pond to the west of the site (Figure 4.5). Land valuation maps show the area to be part of the BADMC land holdings, thus being owned by the crown. It should also be noted that part of the area has been mapped as first priority forestation land in the forestry component of the draft Agricultural Development Plan for the Scotland District (Ministry of Agriculture 2002). All these factors make this site feasible for establishing forested buffer for the northern bank of MC3.

Figure 4.5: Potential site for riparian buffer establishment on the northern side main channel 3.

As mentioned earlier, the Turners Hall branch of Walkers river dissects a large area of grassland; the western side of which has already been suggested as having reforestation potential (site 3). The recommendations made at site 3 provide a forested buffer, but only on the western side of the watercourse. The grassland on the eastern side appears equally vulnerable to erosion and slippage and therefore should have a forest buffer also. This side has similar conditions to site 3 described earlier but is recently recovering from fire; meaning much shorter grass and less ground cover, also fewer trees. The land is terraced and does not have a steep gradient but the

36

areas closest to the watercourse show signs of slippage and erosion (Error! Reference source not found.).

The benefit of establishing a forested buffer would be to reduce the expansion of the watercourse into the grassland which is valuable land for agriculture or livestock development. Soil slumps at the edge of the watercourse like the one shown in Error! Reference source not found. are testament to the instability of the land here. These gullies will grow and reduce the amount of usable land. The buffer should consist of native forest trees with a zone of shrub and grasses eventually being established further away from the watercourse. The composition of the buffer is more critical than the width. The trees will offer improved soil stability while grasses and shrubs will reduce the flow of surface water. Native species can be substituted with fruit trees if agriculture is returned to the area. Buffers with fruit trees can be wider (>30 m) than those with native forestry species since they will also bring direct economic benefit. As mentioned in the introduction there is some flexibility in determining the buffer size.

5 DISCUSSION The various options presented here are all in one way or another aiming towards the general goal of sustainable land management; combating land degradation while simultaneously benefiting biodiversity, community development and community resilience. There will be no attempt to choose a single best option because the aim is also to see practices of sustainable land management established in the watershed as a whole, thus no particular option in a particular location will be ranked more important than the others. The ideal would be to implement all these options and replicate similar strategies throughout the Scotland District. The frequent thunder storms and resulting floods throughout the 2008 rainy season along with the uncertainty regarding weather patterns that climate change brings would hopefully provide the impetus for

Figure 4.6: This site would benefit from a forested buffer. Signs of slippage adjacent to the watercourse are seen in the foreground. Scattered trees and recovering grassland in the background.

37

promoting and implementing sustainable land management in SIDS for the sake of land conservation, biodiversity, resilience and food security.

There will be challenges that will bring into question the feasibility of sustainable land management practices such as riparian buffers. Conflicting land use will be the most prevalent problem. In urban watersheds and rural residential developments it will be difficult to establish riparian vegetation buffers. It should however be appreciated that other approaches to implementing practices of sustainable land management and other means of site selections for reforestation can be employed at small scales rather than a single broad-spectrum approach.

One can also appreciate that the nature of the stream channels (generally unstable, some with deep vertical sides) effectively prevents residential and agricultural land uses from encroaching the riparian vegetation, thus accounting for the high percentage of vegetation cover and furthermore abundant mature vegetation. In this way maintaining riparian vegetation is not foreseen to be a great challenge. The real challenge comes in trying to establish an additional buffer around the stream channels to offer further stability and reduce erosion. This would involve a combination of taking up usable land in residential areas and reducing the amount of land available for conventional agriculture. The most feasible option would be that of an agroforestry composition where farmers and residents will reap some direct economic benefit from the buffer in addition to its ecosystem functions.

Based on the simplified land-use mapping and general field observations, the Walkers catchment is in some ways an opposite scenario to ideal sustainable land use. Regarding agriculture, the Scotland District has been suggested as the area to focus on for livestock development (Ministry of Agriculture (2002), Ministry of Physical Development and Environment (2002)) since pasture lands would be less susceptible to erosion than exposed agricultural fields. In the Walkers catchment, private lands around the Walkers village are predominantly fallow or used for livestock production. Though this would be in keeping the development plan for the Scotland District, it is conflicting with the land-use in more erosion-prone lands in the catchment area such as Bawdens and Sedge Pond. Completely exposed agriculture is widely practiced in Bawdens and Sedge Pond and the small farmers leasing the land have expressed that they have experienced great difficulty in doing this. The ideal situation would be the opposite. It would be to promote livestock and agroforestry in these most vulnerable areas and encourage ‘back-yard’ farming in the flatter lands around Walkers village. In this way, ground cover is maximised in the higher lands of the catchment while still facilitating agricultural production and community development, then more intensive agriculture can be practised by small land holders in the valley where the impacts on the watershed and land quality would be less. Environmental sustainability, community development and resilience, and national food security could be increased if this scenario can be realised.

Realising the above ideal would require a fundamental shift in thinking; a more self-sustaining attitude from Barbadians in light of the state of the global economy, and a more positive perception towards agroforestry and the importance of trees in general in land management. It is critical that both these trains of thought are promoted until they are established. The first ideology alone would result in simply more diverse agriculture but the same unsound agricultural practices, or even becoming more efficient in agriculture in the Scotland District in a way that excludes biodiversity and ecosystem services of watersheds. Adoption of only the latter ideology of incorporating trees into the crop landscape and other open spaces would benefit the environment of the Scotland District but would not facilitate the extent of economic growth and

38

development that the government has in mind. These two ideas have to be reconciled and a balance found in maintaining biodiversity and ecosystem services while still maximizing agricultural productivity and other economic development within the context of sustainability.

Certain institutional arrangements and governance mechanisms are already in place to achieve sustainable land management in the Scotland District. The SCU acts as the District’s steward; promoting and facilitating soil conservation, forestry, biodiversity, sustainable agriculture and community development. The capacity of the SCU to service the entire Scotland District is limited however, thus emphasizing the need for co-management involving communities and NGOs. Further promotion of SLM practices would also be needed through public awareness and training done by these community groups and NGOs to assist in bringing about the changes in the communities such as solid waste disposal in villages or better farming practices. Sound farming practices need to be impressed upon not only established farmers and farmers groups in an official training setting but to the many small back yard farmers that aerial photographs of the catchment show to be quite common. The cumulative effect of these small farms has as significant an impact on watersheds and soil quality as large farms.

Above all, what is needed is a move to introduce policies and legislation to ensure that sustainable land management practices are implemented. Policies to protect watersheds, forests and ensure environmentally-sound agriculture are need as well for this shift to occur. Examples of such legislation and polices would be a mandatory riparian buffer between watercourses and active agriculture, or further, a mandatory native hedge-row around all agricultural plots. These would protect watersheds, reduce soil erosion from field runoff and increase crop-land biodiversity (in terms of natural pest control and resilience).

There were some limitations faced during the study. From a conceptual side it was difficult to define the riparian zone since it was so variable in the literature. This carried over to the practical aspect. It was not always possible to distinguish the riparian zone, especially when the adjacent land cover is forest. Also, vegetation types were left to interpretation, with some difficulty in placing vegetation types into simplified categories.

From a technical point of view, the various sources of maps, both paper and digital, created a source of error when maps are digitized, projected and geo-referenced. For instance, the stream channels shapefile did not always follow the watercourse on the aerial photographs. However this was not a great constraint because it did not hinder characterizing and mapping of the vegetation around the stream channels and the adjacent land use. More importantly though, overlaying the Barbados map, land capabilities map and other shapefiles proved difficult in terms of locating the exact sites in some cases. Most of the sites had physical landmarks making them easy to find in the field but sites 4 and 5 for instance appeared in the GIS slightly further north than they should have, thus having to verify their locations based on topography and other indicators using topographical paper maps in the field. For these reasons no coordinates of site boundaries or precise acreage was presented in the study. Their locations were illustrated as graphically as possible since the coordinate systems of all these maps were not always consistent.

Regarding opportunities for further research, empirical evidence of the benefits of trees in improving crop conditions and stabilizing stream banks would be ideal. Research into the effects of agroforestry on agricultural productivity and soil quality versus conventional agriculture is needed, especially research focused on Scotland District agriculture. It would be useful to

39

undertake a more quantitative study of the role of riparian vegetation in reducing sedimentation of waterways and increasing stream bank stability. A follow-up study of the economic importance of gullies and other riparian vegetation would also be interesting. The economic valuation could be focused on property values and coastal water quality since vegetation cover would help check the growth of gullies and reduce sediment, nutrients and debris reaching the coast, thus benefiting coastal tourism.

A study of the perception of rural communities towards riparian vegetation would answer some questions that arose throughout the study. Gullies and watercourse dissecting communities reduces the amount of usable land on their properties, but some can provide a suitable microclimate for fruit production and other agriculture. The riparian vegetation near the Bawdens community was denuded during the time of the study. Was it seen as useless, unsightly or unsafe? Are the benefits of riparian vegetation and trees outside forests understood or appreciated? How are gullies and watercourses used by residents? Answers to these questions would highlight the opportunities for rural land management including gully and watershed management. Community education about watersheds and sustainable land management or even community management of forests and watersheds would require findings regarding the knowledge, attitudes and perceptions of rural communities regarding forests, trees and watersheds.

It is appreciated that the SLM project was focused on rural development and combating desertification in the Scotland district. However, apart from studies of watersheds and tree use to reduce erosion and maintain soil quality, it is also critical for the SLM project or future endeavours to focus some effort in the area of sustainable land management in an urban sense. That is, a Caribbean-specific approach to greening cities, not only in a resource use sense, but from the perspective of physical planning and space-use. With urban sprawl occurring rapidly in Barbados in places such as Warrens and plans of massive development for rural areas like in St. Lucy, studies into tree-use and watershed management in urban settings would be useful as proactive measures in preventing soil loss and reducing flood risk in cities. Studies should involve developing urban areas without completely removing vegetation and sealing the land with concrete, thus decreasing the natural resilience of the system. The same should apply for watersheds; establishing buffer zones, maintaining vegetation and only employing canal construction where necessary would also reduce the risk of flood damage and allow the watershed and riparian vegetation to perform its useful functions.

6 CONCLUSION To conclude, the objectives of the study were as follows:

− Characterize the land use of an entire catchment for an analysis of how land use practices affect land degradation;

− Take a planning approach to identify areas within the catchment with reforestation potential;

− Assess and characterize the land use and vegetation types adjacent to the stream channels of the watershed to identify the areas not already forested or naturally reforesting;

− Select from non-forested areas the most feasible locations for reforestation as well as suitable reforestation strategies;

40

− Identify the challenges faced and benefits for the selected sites.

With the use of a GIS and taking a planning approach, four sites in the Walkers River catchment were selected as having potential for reforestation with various planting options, to accrue maximum benefits to the environment and local communities. Agroforestry options were highlighted in erosion prone areas as a means of sustainable land management and diversifying agriculture. The stream channels came under additional focus, characterising the riparian vegetation in the watershed. Subsequently, two sites were identified with potential for establishing an additional riparian buffer.

The main foreseen benefits of the suggested sites were to reduce the rate of land degradation by improving soil stability and stream bank stability as was the case with riparian buffer at suggested sites. Community development interests and biodiversity conservation being enshrined in the principles of sustainable land management were also greatly considered during site selection and reforestation recommendations. The main challenges foreseen were common to any reforestation effort; harsh environments, seedling survivorship, competition and land tenure issues.

7 REFERENCES BADMC. 2005. Land for the Landless Programme Annual Report 2004. BADMC Programme

Management.

Beets, W.C. 1989. Agroforestry in ACP Countries. Netherlands: Technical Centre for Agricultural and Rural Cooperation.

Calder, I., T. Hofer, and S. Vermont and P. Warren. 2007. Towards a new understanding of forests and water. Unasylva. Forests and Water Vol.58 No.229: 3-11.

Carrington, C.M. S., J. Horrocks, and and R. Mahon. 2003. Gully Ecosystem Management Study: Report on the biodiversity conservation subcomponent. Bridgetown: The Government of Barbados, Ministry of Physical Development and Environment.

CEHI. Sustainable land Management (SLM) Project. http://www.cehi.org.lc/slmindex_files/Page367.htm (accessed June 18, 2008).

Coche, A. G. 1998. Simple methods for aquaculture management for freshwater fish culture, fish stocks, and farm management. Food and Agriculture Organization of the United Nations, Rome.

CTA. 1999. Sustainable Agro-pisciculturesystems in sub-Saharan Africa. Summary Report of a CTA study visit. CTA, Malawi.

CWRP. 2006. Riparian Setbacks: Technical information for Decision-makers. Ohio: Chagrin River Watershed Partners, Inc.

EPG, PDA, SEMS. 2004. Gully Ecosystem Management Study: Report on the Broad-Scale Survey and Development of the GIS Database. The Government of Barbados, Ministry of Housing, Lands and the Environment 59 pp.

Helmer, E. H, T. A. Kennaway, D. H. Pedreros, M. L. Clark, H. Marcano-Vega, L. L. Tieszen, T. R. Ruzycki, S. R. Schill, and C. M. S. Carrington. 2008. Land Cover and Forest Formation Distributions for St. Kitts, Nevis, St. Eustatius, Grenada and Barbados from

41

Decision Tree Classification of Cloud-Cleared Satellite Imagery. Caribbean Journal of Science, Vol. 44, No. 2: 175-198.

FAO. 1994. The role of agriculture, forestry and fisheries in the sustainable development of small island developing states. Food And Agriculture Organization Of The United Nations, Rome.

Ganz, David, and P. Durst. 2003. Assisted Natural Regeneration: An Overview. Advancing Assisted Natural Regeration (ANR) in Asia and the Pacific. Editors Durst, Ganz, Mckenzie Dugan, 1-5. FAO Regional Office for Asia and the Pacific, Bangkok.

GoB. 1999. Demonstration Projects Final Report for: Coastal Revegetation and Dune Stabilisation Project. Peoples Dynamics Associates.

GoB. 1999. The National Park Development Plan. Guidelines for Management and Operations of the Barbados National Park and Other Heritage Conservation Areas. Government of Barbados, Bridgetown.

Gumbs, F. A. 1994. Farmers and Soil Conservation in the Caribbean. Commonwealth Secretariat, London.

Combellas, J., L. Ríos, P. Colombo, R. Alvarez and L. Gabaldón. 1996. Influence of Gliricidia sepium restricted grazing on live weight gain of growing cattle in star grass pastures. Livestock Research for Rural Development Volume 8, Number 4.

Kleinn, C. 2000. On large-area inventory and assessment of trees outside forests. Unasylva vol.51 200, 1: 3-11.

Lucas, C. H. 2008. Annual Report of Soil Conservation unit for the period April 2007-March 2008. Bridgetown: Government of Barbados. Ministry of Agriculture and Rural Development.

Ministry of Agriculture. 2002. Draft-Agricultural Development Plan for the Scotland District. Forestry. Ministry of Agriculture.

Ministry of Physical Development and Environment. 2002. Barbados National Action Programme to Combat Desertification and Land Degradation, and to Mitigate Against the effects of Desertification, Land Degradation and Drought. Working Draft. Bridgetown: Moores and Associates.

Nair, P.K.R. 1990. The Prospects for Agroforestry in the Tropics. World bank Technical Paper Number 131: 94 pp.

National Research Council. 2000. Clean Coastal Waters: Understanding the Effects of Nutrient Pollution. National Academy Press, Washington, DC.

Natta, A.K., B. Sinsin, and L. van der Maesen. 2002. Riparian forests, a unique but endangered ecosystem in Benin. Bot. Jahrb. Syst. 124: 55-69.

OAS Department of Sustainable Development. Department of Sustainable Development. Sustainable Land Management. 17 June 2007. http://www.oas.org/dsd/Caribbean/Sustainable%20Land%20Management.htm (accessed June 18, 2008).

OCES. 1998. Riparian Area Management Handbook. Oklohoma: Oklohoma State University.

42

OECS NRMU. 2002. Proceedings of the Regional Policy Dialogue on Watershed Management in Small Island States. Castries, St. Lucia: OECS Natural Resources Management Unit.

OECS NRMU. 1999. Watershed managment in the OECS: Dominica. St. Kitts and Nevis, St. Vincent and the Grenadines. A summary report of three pilot projects. Castries, St. Lucia: OECS Natural Resource Management Unit.

Oklahoma Corporate Extension Service. 1998. Riparian Area Management Handbook. Oklahoma: Oklahoma State University 110pp.

Osborne, Lewis, and David Kovacic. 1993. Riparian vegetated buffer strips in water-quality restoration and stream management. Freshwater Biology 29: 243-258.

Scott Wilson Group plc. 2000. Scotland District: Soil Conservation/Development Study. Barbados Final Report. Prepared for the Ministry of Agriculture and Rural Development. Scott Wilson KirkPatrick & Co. Ltd, England.

Suttie, J. M. Grassland Species. Gliricidia sepium (Jacq.). unknown. http://www.fao.org/ag/AGP/AGPC/doc/Gbase/data/pf000156.htm (accessed August 6, 2008).

Unasylva. 2000/1. World of Forestry. Unasylva Vol.51 200, p63-66.

UNCCD. Cobatting Desertification. A Glossary. 28 June 2008. http://www.unccd.int/knowledge/glossary.php (accessed July 2, 2008).

USDA National Agroforestry Center. Working Trees for Agriculture. New England: USDA, 2008.

USDA National Agroforestry center. Working Trees for Water Quality. New England: USDA, 2008.

Vernon, D. M, and K. C. Carroll. 1965. Soils & Land-Use Surveys. No. 18 Barbados. St. Augustine: Soil and Land Use Section of the Regional Research Centre, Imperial College of Tropical Agriculture. University of the West Indies.

World Bank. 2005. Ecosystem Restoration of Riparian Forests in Sao Paolo Project. Project Appraisal Document Report No: 32151-BR. The World Bank.

Young, A. 1997. Agroforestry for Soil Management. 2nd Edition. CAB International.

43

8 APPENDICES

8.1 Appendix 1 Vegetation categories used from (Carrington et al 2003)

Forest: Vegetation dominated by trees more than 5m high, with a distinct canopy − Closed forest: Tree cover predominating; >60% − Open forest: Tree cover approximately 25-60% − Scattered trees: <25% − Thicket: Dense, impenetrable woodland of small trees and shrubs

Scrub: Vegetation dominated by shrubs, usually less than 5m tall − Continuous scrub: an area mainly in scrub − Scattered scrub: patches of scrub, amounting to less than half the area − Cactus thorn scrub: Scrub dominated by thorny plants including cactus

Grassland: Herbaceous vegetation dominated by grasses − Grassland: a dry community dominated by grass − Marshy grassland: a wet community without standing water dominated by grasses and

sedges Species key for raw data table Leuleu- Leucaena leucocephela Riccom- Ricinus communis Corobl- Cordia obliqua Cocnuc- Cocos nucifera Cocuvi- Cocoloba uvifera Casequ- Casuarina equisitifolia Hipman- Hippomane mancinella Acasp. – Acacia sp. Pitung- Pithecellobium unguis-cati Thepop- Thespesia populnea Corcur- Cordia curasavica Citspi- Citharexylum spinosum Saphip- Sapium hippomane Manind- Mangifera indica Miclae- Miconia laevigata Ludsp.- Ludwigia sp.

44

8.2 Appendix 2 Raw field data

section x y elev depth width Bot-type Veg-type Dom-Tree Dom-Shrub Adjacent landuse comments BWL 0219849 1465843 142 mud thicket Leuleu inactive agriculture BWL 0219887 1465844 130 mud bush Riccom inactive agriculture BWL 0220156 1465807 117 mud thicket Corobl water body BWL 0220228 1465649 4 10 stagnant water none residential BWL 0220282 1465598 20 water thicket Leuleu residential MS1 0223176 1466426 -4 40 water none beach

MS1 0223012 1466389 -3 34 water marshy grassland Cocnuc Morcit marshland

MS1 0222921 1466441 8 water dune veg. Cocnuc Cocuvi coastal dune MS1 0222866 1466483 28 8 water open forest Corobl Cocuvi coastal dune MS1 0222795 1466482 4 10 water open forest Casequ Cocuvi coastal dune MS1 0222757 1466410 5 water grassland Hipman AcaSp. grassland MS1 0222742 1466317 4 water open forest Corobl Pitung mixed forest MS1 0222079 1466223 2 4 water open forest Corobl residential small farming BPL 0222034 1466186 5 10 water open forest Thepop Corcur residential

BPL 0221827 1465953 1 1 mud none residential bridge by school

BPL 0221657 1465450 218 26 mud open forest Corobl Citspi pasture/residential sheep grazing MS1 0221601 1466230 79 70 mud open forest Corobl Leuleu inactive agriculture MS1 0221134 1466129 59 6 15 concrete/water thicket Leuleu Corobl residential bridge THL 0220366 1465090 149 4 10 mud open forest Saphip Corobl pasture WL 0221216 1465748 59 8 10 mud open forest Manind Corobl pasture WL 0221300 1465874 mud thicket Leuleu Corcur pasture SL 1 4 water open forest Saphip Miclae scrub SL 0219568 1463750 1 3 mud open forest Saphip Pitung scrub/fruit crops SL 0219568 1464407 10 20 water open forest Saphip Ludsp. forest/scrub

MS3 0219559 1465142 1 2 water marshy grassland Leuleu Corden grassland/agriculture