Leeward Islands moist forests
Basse Terre, the western portion of Guadalupe, is mosly covered by moist forest. NASA
The Leeward Islands moist forests are an ecoregion within the Caribbean Basin; because the size of these islands is limited, this ecoregion assumes a disproportionate value of endemism for its areal extent. The forests of this ecoregion, including the forested cores and their peripheral edges, have historically provided the downslope communities with a wide variety of useful goods and services such as building materials, fuelwood, natural medicines, wild fruits, and a habitat for game species and other wildlife. By far however, the most important service provided by the forests is as a reliable source of domestic water for each component island. Except for the more remote, inaccessible areas characterized by high relief, many of the forests on different islands in this ecoregion suffer from similar human-related pressures, i.e. agricultural encroachment, hunting, and limited enforcement of wildlife and environmental legislation. Increased communication, networking and effort of conservation on a regional basis are needed to ensure that these rich forests and their wildlife are maintained and protected.
Location and General Description
This ecoregion is found in various proportions on the Caribbean’s Leeward Islands and is characterized by rugged, volcanic mountains covered in moist tropical forest. Specifically, this ecoregion covers approximately 85% of Basse Terre of Guadeloupe, the central, mountainous portions of Montserrat, St. Kitts and Nevis, small southern portions of Antigua, and western portions of the U.S. and British Virgin Islands.
Technically, the Leeward Islands are found north of the Windward Islands extending to just east of the Virgin Islands between latitudes 15° 45' N to 18° 35' N and longitudes 61° 45' W to 63° 20' W. This ecoregion is delineated farther east to include the US and British Virgin Islands. All of the Leeward Islands lie within the tradewinds belt resulting in a subtropical climate. Islands with sufficient relief receive adequate rainfall, but those with a more subduedtopographytend to be dry to semi-arid. The main hurricane track passes through these islands.
Nevis Peak, St. Kitts and Nevis. Source: Robert Young The Leeward Islands exhibit two geologically distinct belts. The island of Guadeloupe marks the southern end of the two belts and embodies characteristics of both. Guadeloupe consists of two distinct parts. The eastern half of Guadeloupe is called Grande Terre and is composed entirely of limestone overlying older andesitic and dacitic volcanics. Basse Terre, the western half, is dominated by Soufriere, a 1467 metre (m) high active volcano. The inner belt or arc of islands is volcanic in origin and tends to have higher, more rugged topography. These include Montserrat, Nevis, St. Christopher, St. Eustatius, and Saba. Andesitic flows, pyroclastic units, and volcanoclastics of recent to Eocene age dominate this belt. These volcanics are interbedded with Pliocene and Pleistocene limestones on some islands, notably on St. Eustatius, St. Christopher, and Montserrat. Formiferal or oolitic limestone underlies the remaining islands in the outer belt or arc of islands including Guadeloupe's offshore islands of Marie Galante and Desirade, Antigua, Barbuda, St. Barthelemy, St Martin, and Anguilla.
The Caribbean is an important biological region due to its rich vegetation and the large number of endemic plants. The West Indies have about 200 endemic genera; the largest Wallenia has 30 species while 6 other genera have 10 or more. The larger genera (Bontia, Spathelia, Lagetta and Catesbaea) are more or less widely distributed over the archipelago. The moist forests of this ecoregion are primarily an association of Miconia and Clusia spp. Where relatively undisturbed, gommier (Dacroydes excelsa) is the principal species, with an understory of regenerating gommier and palms. Other forests characteristics over 600 m include numerous palms (often the mountain cabbage palm, Euterpe globosa) which can form over 60 percent of the total crop. Beard noted a surprising lack of well-developed rain forest in some of these Leeward Islands. This he attributed to periodic stand damage from passing hurricanes that cause breakage and subsequent forking of larger specimen trees. The resulting uneven forest canopy allows additional light to penetrate and encourages growth in adventitious or second growth species that may not be part of the climax forest type. The effect of storms is undoubtedly an impact that continually molds the forest cover and maintains much of the forest in a pre-climax condition.
Biodiversity Features
The Leeward Islands are similar to other Caribbean islands in having a relatively high degree of island-endemism. The amount of diversity and number of island endemics in the Lesser Antilles is related to island size, diversity of habitat, and distance from the mainland or another island. Thus, larger islands from Guadeloupe and south into the Windward islands have relatively high diversity and a higher degree of endemic flora and fauna.
Bats are the most common mammal to this ecoregion. Ten species are reported from Guadeloupe of which Eptesicus guadeloupensis and Sturnira thomasi are island-endemics. Guadeloupe is also home to the endemic Guadeloupe Racoon (Procyon minor) that resides in rainforest above 300 m and mangrove areas. Mammalian introductions have occurred periodically in this region and include species such as agouti (Dasyprocta agouti), fallow deer (Dama dama) to provide game, the indian mongoose (Herpestes auropunctatus) and the inadvertent importation of rats (Rattus rattus, R. norvegicus). There are no remaining endemic rodents in the Lesser Antilles.
The forests of this ecoregion are important for a number of regional and island endemic avian and herpetological species. Due to the small size of these forests, continued pressure from human population growth, [[agricultural] expansion], and a significant growth in tourism will factor significantly in how well suitable habitat is preserved.
Current Status
Conservation measures in this forest ecoregion vary significantly from island to island. On smaller St. Kitts and Nevis there are no wildlife sanctuaries, protected wildlife areas, wildlife officers or resource management programs for wildlife. Likewise, in Montserrat, there is no substantive legislation for establishing and managing natural areas for either the conservation of fauna and flora, or the declaration of terrestrial or marine parks. Nor is there any governmental organization with responsibilities for wildlife conservation, although the draft Forestry and Wildlife Ordinance makes provision for a Forestry and Wildlife Division to be responsible for management and wildlife. In contrast, Guadeloupe has several established protected areas, i.e., Basse Terre Nature Park, Guadeloupe National Park, Beaujendre, and Pitons du Nord. In 1986 Basse-Terre still had untouched rain forest and lower montane rain forest. In 1977 it was estimated that woods and forests occupied 70,000 hectares (ha). Guadeloupe, as an Overseas Department of France, has the same legislation as France that applies to the establishment of national parks and reserves. The Direction de la Protection de la Nature is responsible for regulating hunting, conducting research on fauna and flora and administering parks and preserves.
Large western portions of each of the US Virgin Islands are encompassed by this forest ecoregion. Nineteen percent (6,623 ha) of the total land area is considered a protected area. The protected areas include the Virgin Islands Biosphere Reserve which has produced a significant number of scientific studies regarding the local flora and fauna. At present, terrestrial parks in the British Virgin Islands (BVI) cover 2.1% of the land area. The BVI park system plan sought to define a system of parks and protected areas that would incorporate the existing parks into a larger system of comprehensive ecological units, in order to preserve the most important areas of natural and cultural heritage. Twelve additional parks were proposed, but none of these has yet been declared. This is partly due to the approach adopted in the BVI of preparing management plans and strengthening institutions in advance of park declaration.
Types and Severity of Threats
Threats to this ecoregion are similar for most of the Leeward Islands. Margetson identified three major conservation problems in Montserrat that can be applied to other similar forests in this ecoregion. They include the need to conserve resources: low financial and technical input in resource use; deforestation and over-exploitation of fish resources; and conflict between individual and national needs and conservation needs. An additional concern is the lack of a coordinated government policy on conservation.
Specific threats to the flora and fauna include [[agricultural] development], land alteration associated with mining, loss of trees to charcoal burning, infrastructure to accommodate population increases and tourism, and introduced animals and plants. The small land mass of the smaller Leeward Islands means that any future systems of parks and protected areas will consist of small, probably isolated ‘islands’ of more or less ‘natural’ habitat surrounded by a matrix of more intensive land uses. If maintained largely as ‘native’ vegetation, such reserves could include sufficient area to protect smaller species of wildlife that may require that particular type of habitat, but this is matter of individual species characteristics.
Justification of Ecoregion Delineation
The moist forests of the Leeward Islands were classified by conglomerating the following moist terrestrial life zones for each individual island, designated by the CCA Preliminary Data Atlases: moist forest, rain forest, and cloud forest. Small islands with minimal moist forest coverage (ie Saba) were lumped with the dominant vegetation cover to maintain the broad scale classification scheme.
References
- For a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion.
- Beard, J. 1949. The natural vegetation of the Windward and Leeward Islands. Oxford: Clarendon Press.
- Butler, P. 1991. Making a move on Montserrat. Philadelphia: Rare Centre.
- Caribbean Conservation Association (CCA). 1991. St. Kitts and Nevis: Environmental Profile. St. Michael, Barbados.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Virgin Gorda, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Anegada, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Saint Barthélemy, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Saint Martin, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Saba, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Anguilla, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: St. Eustasius, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Montserrat, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Tortola, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: St. Kitts, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Barbuda, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Nevis, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Guadeloupe, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Caribbean Conservation Association. 1980. Survey of conservation priorities in the Lesser Antilles: Antigua, Preliminary Data Atlas. Eastern Caribbean Natural Area Management Program, Caribbean Conservation Association, the University of Michigan and the United Nations.
- Lacereda, L.D. 1994. Conservation and sustainable utilization of mangrove forests in Latin America and Africa regions. Part 1, Latin America. Mangrove Ecosystems Technical Reports. Vol. 2. International Society for Mangrove Ecosystems. International Tropical Timber Organization.
- Rand McNally. 1988. World atlas of nations. New York: Rand McNally. ISBN: 0528833154
- Donovan, S. K., and T. A. Jackson. 1994. Caribbean geology: an introduction: Kingston Proceedings from a workshop of the IUCN/SSC Rodent Specialist Group, #4. p. 11-19.
| Disclaimer: This article contains information that was originally published by the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content. |
