现代黄河三角洲植物群落数量分类研究

采用TWINSPAN和DCA排序方法对现代黄河三角洲植物群落进行了数量分类。TWINSPAN将研究区植被分为碱蓬群落、柽柳群落和草本群落3大类，包括12个群落类型。采用3类物种多样性指数，计算了各群落的物种丰富度、均匀度和多样性。结果表明，从碱蓬群落、柽柳群落到草本群落过渡，多样性指数和丰富度指数逐渐增加。均匀度指数在碱蓬群落和柽柳群落波动较大，而在草本群落波动较小。DCA排序结果表明，决定现代黄河三角洲植物分布类型的环境因子主要是土壤盐分和水文状况。在土壤含盐量较高区域，植物群落物种组成单一，群落结构简单；在土壤含盐量较低区域，组成群落的植物物种丰富，群落结构复杂。 

Quantitative classification of plant communities in the modern Yellow River Delta

Plant communities in the modern Yellow River Delta are studied by the methods of TWINSPAN(Two-Way Indication Species Analysis) and DCA(Detrended Correspondence Analysis) in this paper.TWINSPAN classification results show that the vegetation in the study area is divided into three large groups of communities dominated by the species Suaeda salsa,Tamarix chinensis and herbage,which includes 12 community types.Three species diversity indices are used to study the changes in species richness,evenness and diversity in different communities. Diversity and richness indices increase gradually from the communities S.salsa and T.chinensis to herbage,but species evennesses fluctuate greatly in the communities S.salsa and T.chinensis.However evenness fluctuation is little in herbaceous community.Results of ordination by DCA reflect that the plant community distribution patterns are affected by environmental factors such as soil salt content and hydrological situation.In the area with high soil salt content,species composition is single and community structure is simple.In the area with low soil salt content,species composition increases and community structure is complex.