科尔沁沙地人工固沙群落草本植物种群生态位特征

运用Levins生态位宽度和Pianka生态位重叠公式，计测分析了科尔沁沙地流动沙丘以及山竹子Hedysarum fruticosum、柠条锦鸡儿Caragana korshinskii、黄柳Salix gordejevii和小叶锦鸡儿C. microphylla人工固沙群落内草本植物种群的生态位宽度和生态位重叠。研究结果表明：在不同的生境条件下物种的生态位宽度存在差异，沙蓬Agriophyllum squarrosum在流动沙丘上的生态位宽度最大，狗尾草Setaria viridis、毛马唐Digitaria ciliaris分别在山竹子群落和黄柳群落中的生态位宽度最大，烛台虫实Corispermum candelabrum在柠条锦鸡儿群落和小叶锦鸡儿群落中占据着最宽的生态位。各群落中生态位宽的物种对生态位重叠值较大，但有些较窄的生态位物种对之间也出现较大的生态位重叠，这种现象从另外的角度表明各群落内环境资源存在一定的空间异质性。不同固沙群落中相同物种的生态位宽度和生态位重叠的差异在一定程度上反映了各群落内不同的区域环境特征。

Niche characteristic of herbages in artificial sand-fixing communities in Horqin sandy land

By using Levins index of niche breadth and Pianka index of niche overlap,the niche characteristics of herbaceous species on mobile sand dune and in different artificial sand-fixing communities were studied.The results showed that the niche breadth of species varied in different habitats,Agriophyllum squarrosum,Setaria viridis and Digitaria ciliaris had the widest niche breadth on mobile sand dune and in Hedysarum fruticosum community and Salix gordejevii community respectively,while the niche breadth of Cor...