The Impact Of Land Use Change On The Habitat Of Asian Elephants In Nangun River Basin

The conservation of Asian elephant population and habitat in China is the priority of biodiversity conservation in Southwest China.However,under the influence of large-scale expansion of thermal cultivation and engineering construction,land use change has led to the loss and serious fragmentation of Asian elephant habitat,frequent human-elephant conflicts in the region,and ecological and economic poverty,which have directly threatened the regional sustainable development and ecological civilization construction.Therefore,to explore the spatial-temporal process of land use change and reveal its influence mechanism on the suitable habitat of Asian elephants is the premise and basis for the protection and restoration of Asian elephant habitat,and of great significance for the protection of cross-border biodiversity and the maintenance of ecological security in border areas.In this paper,the Nangun River Basin,the remaining cross-border watershed of Asian elephants along the China-Myanmar border,was taken as a case study.Landsat TM images in 1988 and Landsat OLI images in 2018 were classified using random forest classification method,which fused spectral,texture and topographic factors and other multivariate information,and the changes of land use in the watershed in the past 30 years were detected by the method of post-classification and contrast change detection.Based on the classification map of land use remote sensing and combined with the data of the occurrence point of Asian elephant species,the habitat suitability of Asian elephant in 1988 and 2018 was evaluated by means of valuation accumulative multiplication and ENFA model,and the habitat pattern and landscape index differentiation rule of Asian elephant suitability were analyzed.The LandTrendr time-series change detection algorithm was used to diagnose the interannual forest disturbance process and its intensity in Nangun River Basin from 1988 to 2018,as well as the impact of forest disturbance change on Asian elephant habitat.The results show that:(1)From 1988 to 2018,the land use change in Nangun River Basin was mainly manifested as the conversion of forest into other land use types,among which the most obvious deforestation was caused by the expansion of rubber plantation,and the forest disturbance intensity in Myanmar was significantly higher than that in China.(2)Land use change and forest disturbance in Nangun River Basin lead to the loss of partial habitat of Asian elephants,and at the same time,inter-habitat connectivity was also reduced.(3)The process of habitat loss of Asian elephants in Nangun River Basin is characterized by gradual infiltration from the edge to the interior and finally a steady state.(4)It is an important way to realize the conservation of Asian elephant population and reduce the conflict between human and elephant in Nangun River Basin by restraining the expansion of hot cultivation dominated by rubber plantation,constructing the China-Myanmar cross-border ecological corridor,expanding the existing protected area and establishing the Asian elephant cross-border protected area,so as to improve the connectivity of suitable habitat for Asian elephant.