Expanding protected areas can benefit mammalian and ecosystemic biodiversity

Protected areas have had undeniable positive effects in preserving biodiversity around the world for more than one century. Recent studies assessed the limits of these positive effects especially in the face of global environmental crises. During the last few years, some public interest has increased towards the policy target of having 30% of lands protected by 2030 which has attracted some concerns about its rationality. This study presents a detailed analysis of land use and mammal diversities around the protected areas of eleven countries in Southeast Asia. Currently, the 1634 terrestrial protected areas cover 595164.1 km², equivalent to 13.3% of the emerged lands in Southeast Asia. Among countries, this value varied from 6% to 40%. The analyses reported identified 603374.2 km² of land around these PAs. Nearly 56% of the analysed lands were covered by forest with a probability of occurrence decreasing with increasing distance from the border of the protected areas. Larger protected areas had significantly more forest and less urban areas or agricultural lands. The number of species of mammals and an index of mammalian trophic diversity also decreased with increasing distance to the protected area border in interaction with the type of land cover. All analyses revealed important differences among countries which could hardly be related to their sizes or levels of development. These results suggest that extending existing protected areas is a feasible and effective strategy to increase overall protected areas in Southeast Asia.