Do Protected Areas Reduce Forest Fragmentation? A Microlandscapes Approach

Conservation policies influence both the amount of habitat loss and patterns of habitat fragmentation. This paper develops a “microlandscapes” approach that combines fragmentation measures with quasi-experimental evaluation methods in order to assess the effects of policy on habitat fragmentation. As an application, the paper estimates whether and to what extent wildlife sanctuaries and national parks in Thailand prevented forest loss and fragmentation. I find that both types of protected areas significantly increased forest cover, average forest patch size and maximum forest patch size. Comparisons between the two types indicate that wildlife sanctuaries were more effective than national parks in terms of protecting forest in the interior versus exterior areas of parks and preventing fragmentation conditional on the level of forest cover. The differences are consistent with predicted differences resulting from spatial patterns of enforcement that are uniform or core-focused in the wildlife sanctuaries versus boundary-focused or include agglomeration penalties in the national parks. Given the greater effectiveness of wildlife sanctuaries in preventing fragmentation and the suggestive link to enforcement types, these results reinforce existing theoretical work urging conservation managers to consider how the spatial distribution of enforcement may affect patterns of resource use.