古尔班通古特沙漠南缘不同立地条件植物多样性和优势种群生态位特征研究

Plant Species Diversity and Dominance Population Niche Characteristics at Different Sites in Southern Gurbantunggut Desert

以古尔班通古特沙漠南缘不同立地条件植物群落为研究对象,分析了该区不同立地条件植物群落的种类组成、优势种群及优势种群的生态位特征。结果表明:①不同立地条件的植物群落均为灌木-草本模式,优势种群为梭梭、白梭梭、白皮沙拐枣、羽毛针禾、骆驼刺、琵琶柴、狭果鹤虱、沙蓬、倒披针叶虫实;②由于不同立地条件环境因子差异,造成其植物群落的α多样性指数存在差异;③Whittacker指数与Cody指数显示不同立地条件植物群落β多样性随环境变化可分为两个梯度,第一梯度为垄顶、迎风坡与背风坡上部,第二梯度为平坦荒地、丘间平地与背风坡中、下部;④生态位宽度大的物种间生态位重叠大。在古尔班通古特沙漠南缘进行受损群落植被恢复与重建时,可在适宜的立地条件种植梭梭与羽毛针禾。

Based on field surveying data in spring over southern Gurbantunggut Desert,Richness index,Shannon-Wiener index,Simpson index,Pielon index,Whittaker index,Cody index,niche breadth and niche overlap value were used to analyze the plant species diversity and dominance population niche characteristics.Results showed that：（1） Plant communities at different sites in southern Gurbantunggut Desert all were shrub-herb mode and the dominance species were Haloxylon ammodendron,Haloxylon persicum,Calligonum leucocladum,Stipagrostis pennata,Alhagi sparsifolia,Reaumuria soongorica,Lappula semiglabra,Agriophyllum squarrosum and Corispermum lehmannianum.（2） The α-diversity indices at different sites were different because of different environments.（3） Whittaker index and Cody index data showed that β-diversity index at different sites can be divided into two gradients.The first gradient was at top of dune,windward slope and upside of leeward slope,and the second gradient was at the other sites.（4） The dominance populations with high niche breadth had high niche overlap value.When we restore the vegetation in southern Gurbantunggut Desert,appropriate Haloxylon ammodendron planting density is needed,and other plant,e.g.Stipagrostis pennata,can be planted to increase species diversity.