【摘要】 草原植被覆盖状况是研究草原生态环境状况、草原生产力和草原植被碳固持能力的重要指标.应用遥感与GIS技术,利用长时间系列遥感数据,采用最大值合成法,将每个像元曾经出现的最大NDVI值合成到一个图层,构建了相当于未退化最佳状态图层,将该图层与不同时期的平均状态或某一个具体年份的实际情况作对比分析,有效地揭示了植被覆盖状况与未退化最佳状态的差距以及变化规律,以此对不同区域的碳增汇潜力做出估测.呼伦贝尔草原的实例研究表明,20世纪八九十年代,呼伦贝尔草原与未退化最佳状态相近的未退化草原面积在91%以上,进入21世纪,草原退化程度明显提高,植被覆盖度降低15%-50%的中轻度退化草原面积增加到接近50%,同时还出现了一定比例的覆盖度降低50%以上的区域.这些区域可以通过草原保护与植被建设提高生产力和碳固持能力.更多还原

【Abstract】 Vegetation coverage of the grassland is an important index to study grassland environmental condition,grassland productivity and grassland carbon sequestration capacity.Maximum NDVI of each pixel once appeared in a long time series of remote sensing data were imported into a layer by a maximum value composite method.The composite grassland image was an ideal reference layer,can be regarded as the original grassland reached its high-point.Compared the difference between the actual layer and the ideal layer,carbon sequestration potential can be estimated by the difference of vegetation coverage.A case study of Hulunbeier grassland shows that areas of original grassland was above 91%in the 1980’and 1990’.Into the 21 st century,the degradation of grassland was aggravating.Vegetation coverage reduction within 15%-50% was taken as a lightly and moderately degraded grassland,and its area increased to nearly 50%.A certain amount of heavier degraded grassland emerged,whose vegetation coverage reduced more than 50%.These degraded areas have great potentialities to improve vegetation coverage and carbon sequestration capacity of grassland by grassland protection and vegetation construction.更多还原