Abstract: Alpine meadow on the Qinghai-Tibet Plateau occupies an important position on the national ecological environment protection strategy,but in recent decades,climate change and anthropogenic factors have led to patchy degradation in large areas of alpine meadow. In order to investigate the spatial differentiation of alpine meadow patchiness and the distribution pattern among patch types (bare patches,short term revegetated patches and long term revegetated patches) as well as the influence of their topographic factors,this study obtained the patch distribution and topographic factor data at four typical study areas locating in Henan and Maduo counties,Qinghai Province,through 3S (RS,GIS,GNSS) technology,and used landscape ecological indices to explore the spatial distribution differences of each patch. The results showed that vegetation cover in the study areas showed a trend of increasing and then decreased with elevation;the degree of fragmentation of the patchy landscape showed a trend of decreasing and then increased. The patch types with higher degree of fragmentation at different elevations were long-term revegetated patches and healthy meadow patches. The topographic factors affected the distribution of patches to different degrees,and the longer-term revegetated patches and healthy meadow patches were mainly distributed in gentle areas on sunny slope. This study elucidated the spatial distribution differences of patchy degradation in alpine meadow and the influence of topographic factors on alpine meadow on the Qinghai-Tibet Plateau.

Key words: Patchiness, Fractional vegetation cover, Landscape Pattern, Topographic Factors, Spatial Variability

摘要： 青藏高原高寒草甸在国家生态环境保护战略中占据重要位置，近几十年来，气候变化和人为因素导致大面积高寒草甸发生斑块化退化。为探究高寒草甸斑块化空间分异性及各斑块类型间（裸地斑块、短期恢复斑块和长期恢复斑块）的分布规律以及其地形因子的影响，本研究通过3S （RS，GIS，GNSS）技术获取位于青海省河南县和玛多县4个典型研究区的斑块类型分布及地形因子数据，利用景观生态指数探究不同斑块的空间分布差异。结果表明，研究区植被覆盖度随着海拔升高呈现先增加后减小的趋势，斑块景观的破碎化程度呈现先减小后增大的趋势。不同海拔地区斑块化程度最高的斑块类型都是长期恢复斑块。地形因子显著影响着不同斑块的分布，长期恢复斑块和健康草甸主要分布在阳坡平缓区域。

关键词: 斑块化, 植被覆盖度, 景观格局, 地形因子, 空间差异