Land use/land cover change and its impacts on protected areas in Mengla County, Xishuangbanna, Southwest China.

Land use/land cover change (LUCC) in tropical areas threatens biodiversity and protected area integrity and then affects global ecosystem functions and services. In this study, the spatiotemporal patterns and processes of LUCC in Mengla County, Xishuangbanna, which is located on the northern edge of tropical Asia, were examined using a modified post-classification change detection technique based on random forest classifiers and Landsat images acquired at a 5-year time interval (e.g., 1994, 1999, 2004, 2009, and 2014) from 1994 to 2014, with a special focus on protected areas and their surroundings. The overall accuracies of land use/land cover classification reached 90.13-97.90%, with kappa coefficients of 0.84-0.96. Massive but decelerating conversion from forests to artificial plantations has occurred in recent decades. From 1994 to 2014, the area of plantations increased by 1833.85 km2, whereas that of forests decreased by 1942.67 km2. The expanded areas of artificial plantations decreased from 158.41 km2 per year in 1994-1999 to 59.70 km2 per year in 2009-2014. More considerable transformation from forests to artificial plantations occurred in lowland areas with elevations below 1000 m and at the edges of National Nature Reserves, which observed a forest loss rate of greater than 40% between 1994 and 2014. This poses serious challenges for sustaining both protected areas and surrounding human communities and to solve the increasingly escalating human-elephant conflicts. The complex food, biodiversity, and land use nexus in this region remain to be untangled in future study.