Spatial-temporal Changes of Vegetation Cover in Mongolian Plateau during 1982—2006

Abstract

The spatial and temporal changes of vegetation cover in Mongolian plateau were analyzed by employing the time-series of HANTS-smoothed GIMMS NDVI from 1982 to 2006.The results indicated that the annual increasing trend of vegetation cover in Mongolian Plateau was 0.0004 ·a-1,and the increasing trend in Mongolia(0.0005·a-1) was more significant than that in Inner Mongolia(0.0003·a-1),while the multi-year mean NDVI in Inner Mongolia is 0.0433 higher than in Mongolia;For the different vegetation types,besides the change trend of NDVI in forest and Gobi-desert was relatively stable,grassland,farmland and shrub experienced significant increasing trends;At spatial scale,regions with increased vegetation cover were distributed in south of Mongolian Plateau,i.e the farming-pastoral ecotone of Inner Mongolia,and central,western and northern mountains and its surrounded big-lake basins in Mongolia,while regions with decline in vegetation cover were concentrated on central arid area in Mongolian Plateau and Hulunbeier regions.At temporal scale,area with increasing trend in vegetation cover was larger than area with decreasing trend for four different study period in Mongolian Plateau,and the sort of area with increasing trend was 1980s1990s2000s.