保护植物野生大豆群落不同物种间的生态关系分析

野生大豆(Glycine soja)为我国二级濒危保护植物.通过野外调查和室内实验,利用TWINSPAN分类、DCA间接排序和CCA直接排序的数量分析方法,定量研究了野生大豆群落分布与环境之间的关系.结果表明,TWINSPAN分类将106个样方分为4个群丛组,分别代表水库撂荒地、湿河床、较湿石质河床和较干土质河床4种不同的生境类型,不同的群从组在DCA排序轴上的位置基本反映出其分布与环境梯度的关系;进一步的DCA间接排序和CCA直接排序分析显示,土壤含水量和土壤养分是决定各个不同野生大豆群丛组分布的关键因子;最后通过建立野生大豆3个种群特征与DCA排序第一轴的回归关系分析,确定了盖度和重要值在反映野生大豆种群优势度上要优于高度.图4表1参19

Ecological Relationships Among Species in Communities of A Protected Plant Glycine so]a in Beijing, China

Glycine soja is a protected plant under grade two in China and it only distributes in East Asia. The germplasm of G. soja is abundant in China. Because of the human impacts on its natural ecosystem, it is now under the threat of extinction and is listed as an endangered species. Spatial patterns of G. soja communities were analyzed in the region of Beijing using multivariate analyses. TWINSPAN classification and DCA ordination results were consistent in general. TWINSPAN classification detected four distinct assemblages related to different habitat characters. The distribution of association groups in ordination space reflected the relationship between vegetation and environmental gradient, and soil moisture was strongly correlated with DCA axes for the distribution of plant species. Coverage and importance value were better than plant height in representing the population characters of G. soja. Fig 4, Tab 1, Ref 19