Assessing representativeness of protected natural areas in Costa Rica for conserving biodiversity: a preliminary gap analysis.

摘要

Existing protected areas in Costa Rica (national parks, forest reserves, wetlands, biological refuges) were compared with Holdridge life zones to assess their coverage of biodiversity. The Holdridge life zone system uses gradients of temperature andprecipitation relative to evapotranspiration and altitude to form a theoretical framework for plant communities or associations; it divides Costa Rica into 23 different zones, and is used in this study as an indicator of biodiversity distribution. The analysis revealed that only nine of the 23 life zones or transitional life zones were adequately represented according to our area criterion of >10thin000 ha. These zones plus three with between 5000 and 10thin000 ha protected, account for 98% of the total area protected in the country. The 11 remaining life zones contained only 2% of Costa Rica's protected area, which leads us to conclude that a significant portion of the country's biodiversity is at risk. The study identified a range of under-protectedhabitats centred on two regions: Pacific slope habitats between 500 and 1500 m altitude, and northwest seasonally dry habitats. The addition of about 400thin000 ha to the national park system by expanding 12 existing protected areas and establishing onenew one would increase the number of adequately protected life zones from the present nine zones to 19. In addition, we propose the establishment of a network of linkage zones, to be developed over the long term, to provide ecological connectivity amongthe protected areas.