Anthropogenic impacts and global climate change are one of the most critical issues on the conservation of forest ecosystems not only in developing countries 1 but also in developed countries 2. The rapid population growth in developing countries has increased the demands in forest exploitation in the tropics 1.
Many people have migrated from urban areas to establish new villages in tropical forests, because of rapid population increase in cities for the last several decades 3,4. Tropical forests have been heavily exploited by those immigrants. Urban immigrants, unlike indigenous people, have no traditional knowledge or skill on the sustainable use of natural forests, causing severe damage to forest ecosystems 5,6. The rapid
expansion of these existing communities into protected areas is expected to cause severe anthropogenic degeneration and fragmentation of natural forests, further deteriorating the forest structure and biodiversity of important natural tropical forests 4,7,8. Such anthropogenic impacts result in the degradation of ecological services received from forest ecosystems.