Existing protected areas in Costa Rica were compared with Holdridge Life Zones to assess their coverage of biodiversity. The analysis revealed that only nine of the 23 life zones or transitional life zones were adequately represented according to our area criterion of > 10,000 ha. These zones plus three with between 5000 and 10,000 ha protected, account for 98% of the total area protected in the country. The 11 remaining life zones contained only 2% of Costa Pica's protected area, which leads us to conclude that a significant portion of the country's biodiversity is at risk. The addition of about 400,000 ha to the park system by expanding 12 existing protected areas and establishing one new 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 among the protected areas. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.
