Impact of Anthropogenic Threats on Species Diversity: A Case Study of the Sub-Himalayan Tropical Dry Deciduous Forests of Pakistan

Abstract

Effective forest conservation and management needs to consider ecological factors and the susceptibility of different tree species to anthropogenic activity. Dry deciduous forests in the tropics have been undervalued because of their low timber production compared to temperate and boreal forests. In order to quantify the current significance of Pakistan’s tropical dry deciduous forests in relation to ecological variables and anthropogenic threats, a broad phytosociological survey was conducted. In the study area, a total of 140 species of woody plants belonging to 52 families were identified. The cluster analysis depicts the distribution of nine plant communities in five clusters, in which Dodonaea viscosa-Acacia modesta-Dulbergia sissoo community was the most dominant community, showing cosmopolitan distribution in the study area. The results are further authenticated by DCA and CCA analyses, which indicate that altitude, precipitation, and temperature are the most important factors influencing the distribution and composition of tropical dry deciduous forests along the Himalayan foothills. In the study area, an annual fuelwood consumption of 270.38 tons was recorded. It was discovered that high-altitude forests were subject to extensive tree harvesting, overgrazing, browsing, and high fuelwood consumption. In addition, these forests have a low regeneration rate from 4.5 to 4.8 seedlings/quadrat, due to extensive human activities. Remarkable differences in the anthropogenic pressure and disturbances were found in the protected and unprotected forests. Based on our findings, we recommend that: (i) Immediate management intervention and an in-situ conservation strategy must be implemented in areas exposed to high levels of anthropogenic threats. (ii) Unsustainable grazing and fuelwood collection must be managed, and high-threat areas must be immediately prohibited. (iii) The local populace must be made aware of the grave consequences of anthropogenic disturbances, and a collaborative management strategy must be implemented.