Mapping the Forest Type and Land Cover of Puerto Rico, a Component of the Caribbean Biodiversity Hotspot

摘要

The Caribbean is one of the world's centers of biodiversity and endemism. As in similar regions, many of its islands have complex topography, climate and soils, and ecological zones change over small areas. A segmented, supervised classification approach using Landsat TM imagery enabled us to develop the most detailed island-wide map of Puerto Rico's extremely complex natural vegetation cover. Many Caribbean forest formations that are not spectrally distinct had distributions approximately separable using climatic zone, geology, elevation, and rainfall. Classification accuracy of 26 land cover and woody vegetation classes was 71 % overall and 83 % after combining forest successional stages within image mapping zones. In 1991-92, Puerto Rico had about 364,000 ha of closed forest, which covered 41.6 % of the main island. Unlike previous island-wide mapping, this map better identifies the spatial distributions of forest formations where certain groups of endemic species occur. Approximately 5 % of Puerto Rico's forest area is under protection, but the reserve system grossly underrepresents lowland moist, seasonal evergreen forests.