西南三省1986-2018年森林覆盖时空动态及驱动过程分析OA

Forest ecosystems are a critical foundation for ecological security and carbon cycling in southwest China.A comprehensive understanding of the spatiotemporal dynamics and driving mechanisms of forest cover is essential for promoting regional forest sustainability.Based on Landsat data from 1986 to 2018,combined with land-use transition matrices and spatial hotspot analysis,this study systematically investigates the spatiotemporal patterns and drivers of forest cover across three provinces in southwest China.The results indicate that,1)between 1986 and 2018,the region experienced a cumulative forest cover loss of 17 673.81 km2,following an inverted U-shaped trend with a peak during 1996‒2004(approximately 7 900.13 km2).Forest loss was dominated by small and fragmented patches,with 95.9％smaller than 0.01 km2,and shifted toward lower elevations and gentler slopes.2)During 1996-2004,Yunnan Province experienced the largest forest loss(3 685 km2),followed by Guangxi(3 297 km2)and Guizhou Province(918 km2).Forest loss exhibited significant spatial clustering,with hotspots shifting from Yunnan to Guangxi.3)Approximately 99％of old-growth forest loss occurred outside protected areas,where the loss rate was significantly higher than within protected areas.The implementation of the Natural Forest Protection Program markedly reduced old-growth forest loss in the region.4)Land-use change analysis revealed that about 80％of forest loss areas underwent subsequent regeneration,while the remainder was primarily converted to shrubland and built-up land.Forest loss areas in Guizhou and Guangxi showed higher conversion rates to built-up land,reflecting urbanization-driven impacts,whereas Yunnan was characterized by conversion to shrubland.These findings provide a scientific basis for forest monitoring,old-growth forest conservation,and ecological restoration in southwest China.