中文摘要：

采用Q型聚类法和α-多样性指数（丰富度指数R、Shannon-Wiener多样性指数、Simpson指数和群落均匀度指数）,对2010—2014年盐池县农牧交错带不同土地利用方式〔人工封育、退耕还林（灌木）和林间草地（柠条灌木林）〕的植被特征和多样性进行分析。结果表明：1 2010—2014年,人工封育、退耕还林和林间草地的植被均以豆科和菊科为主,退耕还林（灌木）植物总体的生长状况较差;2 3种土地利用方式下草地植被多样性变化趋势一致,α-多样性指数（丰富度指数R、Shannon-Wiener指数和群落均匀度指数）均呈现＂M＂型变化趋势,而Simpson生态位优势度呈现＂W＂型变化趋势;3在干旱和半干旱地区,相较于退耕还林（灌木）和林间草地的土地利用方式,人工封育仍是恢复退化草地植被比较有效的措施之一。

英文摘要：

Analysis on the dynamic change of vegetation under different land use patterns can provide a reference for revegetation. In this study,the vegetation characteristics and the plant diversity under various land use patterns（ such as the artificial enclosure zones,zones of returning farmland to forest or shrubbery and grass plots in forest）in Yanchi County,Ningxia Hui Autonomous Region during the period of 2010- 2014 were analyzed by means of clustering analysis,Shannon-Wiener index,Simpson index,evenness index and richness index. Results are as follows： 1 During the period of 2010- 2014,the dominant species in three plots were compositae and leguminosae.The vegetation growth in the artificial enclosure zones,zones of returning farmland to forest or shrubbery and grass plots in forest was holistically poor; 2 The change trend of vegetation diversity in three plots were similar. During the period of 2010- 2014,the Shannon-Wiener index,evenness index and richness index were ＂M-shaped＂. On the contrary,the Simpson index was ＂W-shaped＂; 3 In arid and semiarid regions,artificial fencing is still one of the effective measures of regenerating the degenerated grassland vegetation compared with the measure of returning farmland to forest or shrubbery and grass plots in forest.