基于MODIS NDVI的东北虎分布区植被变化趋势

Variation trends of the vegetations in distribution region of Amur tiger based on MODIS NDVI

基于2000—2010年MODISNDVI(分辨率250m)生长季均值数据,采用普通线性回归方法,分析了东北虎分布区——俄罗斯远东和中国东北东部地区植被的变化趋势及其与人类活动的关系.结果表明:研究期间,归一化植被指数(NDVI)显著下降像元面积占当前东北虎分布区面积的比例为9.6%,NDVI显著上升像元所占面积比例仅0.5%;NDVI显著下降像元散布于整个研究区,NDVI显著上升像元则集中在俄罗斯远东的北部中间区域;东北虎分布区内NDVI显著下降像元的面积比例稍高于其在整个研究区域的面积比例.当前东北虎分布区内土地覆盖类型的变化以渐变形式为主.NDVI显著下降的像元主要分布在海拔低、坡度缓以及距公路和铁路较近的区域;NDVI显著下降的像元先随着与居民点最近距离的增加而增多,而后持续下降,NDVI显著下降与人类活动密切相关.采取有效措施减少人类活动的干扰,可遏制该地区植被退化,进而为东北虎保护和维护该区域丰富的生物多样性提供可持续的基础.

By using the averaged 250 m MODIS NDVI data in growth seasons of 2000-2010 and the approach of ordinary linear regression,this paper analyzed the variation trends of the vegetations in the distribution region of Amur tiger （Panthera tigris altaica）,the Far East region of Russia and the eastern part of Northeast China,as well as the relationships between these variation trends and the anthropogenic activities.In 2000-2010,the areas with significantly decreased NDVI were sparsely distributed and accounted for 9.6% of the total,while the areas with significantly increased NDVI were mainly concentrated in the central part of northern Russia Far East Region and only accounted for 0.5% of the total.The percentage of the areas with significantly decreased NDVI in the distribution region of Amur tiger was slightly higher than that in the whole study region.The areas with significantly decreased NDVI were mainly distributed in the places of low elevation,gentle slope,and close to roads/railroads.The number of the pixels with significantly decreased NDVI increased with the increase of the nearest distance to residential locations first,and then decreased gradually.The significant decrease of the NDVI was closely related to the anthropogenic activities,and thus,to adopt effective measures to reduce human disturbances could control the vegetation degradation,and further,provide sustainable basis for the protection of Amur tiger and the conservation of the biodiversity in the studied region.