Identifying conservation-priority areas in the tropics: a land-use change modeling approach

Most quantitative methods for identifying conservation-priority areas requi re more detailed knowledge about the extent and distribution of biodiversit y than is currently available. Accelerated and irreversible losses of biodi versity call for the development of alternative methods to identify priorit y sites for biodiversity inventory and protection. We focused on the state of Arunachal Pradesh, a biodiversity-rich region in northeast India. We use d a geographic information system and spatially explicit modeling to examin e the correlation of land-cover and land-use patterns with biogeophysical c haracteristics and to project future patterns of land-use change. In 1988, 70% of Arunachal Pradesh was covered by forest. We project that 50% of the state's 1988 forest will be lost by 2021, based on anticipated growth of th e human population and resulting resource use. Of the total simulated defor estation, 76% occurs in areas that have no legal state protection. We devel oped a map of threats to biodiversity that divides areas that were forested in 1988 into four categories: (1) susceptible to future deforestation and currently unprotected; (2) susceptible to future deforestation but currentl y within the protected-area network; (3) not susceptible to future deforest ation and protected; and (4) neither susceptible to future deforestation no r currently protected. We make the following recommendations based on our a nalyses. Areas in category I should be a high priority for biodiversity inv entory and conservation action. Areas in category 2 should have rigid enfor cement of protection. Areas in category 3 are locations of relatively low p riority for enforcement. Areas in category 4 that have a high conservation potential are politically the easiest to include in the protected-area netw ork and should be protected before they become targets of future land-use c hange. Reserve forests-forests managed by the state forest department for a variety of purposes, including selective logging for timber harvesting-are predominantly located in areas susceptible to land-use change and are prim e candidates for upgrading of protection status.