Assessment of forest health status using a forest fragmentation approach: a study in Patharia Hills Reserve Forest, northeast India

Diverse anthropogenic pressure has led to land use change in the form of decline of vegetation and fragmented habitats. With rising anthropogenic threats, many species are restricted to fragmented and degraded habitats and declining biodiversity. The aim of the study was to understand the forest health status in Patharia Hills Reserve Forest (RF) using land use land cover (LULC) trajectories along with forest cover and fragmentation approach. Landsat TM and OLI images for three particular days of each of the year 1988, 1997 and 2016 were used to assess spatio-temporal variation in forest cover. Fragmentation model was used to examine the patterns of forest fragmentation in the Patharia Hills RF during the study period. The results indicated an overall increase in forest cover (10.52%) along with rise in human settlements and agriculture, while decrease in grasslands between 1988 and 2016. However, the fragmentation analysis revealed that the health of the RF has been deteriorating. Increasing edge effects with declining core areas were the prime indicators of disturbances on the forest. The eastern border of the RF is under tremendous influence of anthropogenic activities and most of the land use land cover change was observed in that side. Human settlements, agriculture, and developmental activities were main contributors to forest fragmentation at that side of the RF, while better protection at the international border area was the major factor to increase forested areas at the western part of the RF. Forest fragmentation has a large impact on biodiversity and increase risks for survival for many species, especially primate and the migratory elephant would suffer more in the study area. Fragmentation habitats would lead to increasing Human–Elephant Conflict (HEC). To control the habitat fragmentation, proper management strategies should be prepared which include afforestation in the perforated areas, reduce anthropogenic pressures, and demarcate the RF for its better protection.