中文摘要：

选择三江平原沼泽湿地4个群落演替系列,采用样方法研究其β多样性的变化.结果表明：以水分条件最充分的群落为起点,随着水分梯度递减和水平距离的增大,各群落与起始群落的相似性系数呈减小趋势.不同演替系列内群落间物种更替速率从低地向高地呈现增大趋势.各系列的基本演替趋势是物种数逐渐增多,共有种逐渐减少,群落间β多样性增大.演替机制分析支持了“初始植物区系组成说”.在三江平原沼泽湿地中,小叶章的优势地位将进一步扩大.

英文摘要：

Four typical successional series in the marsh communities of Sanjiang Plain were selected to investigate the changes of their β diversity. The results indicated that from the ‘starting eommtlnity＇ to the‘ end community＇ , which had the most and the least moisture level in the series, respectively, the similarity coefficient between each community and ‘starting＇ community decreased with decreasing moisture gradient and increasing horizontal distance. The species turnover speed among the communities in each series had an increasing trend from lowland to upland. In the process of succession, the general trend was that the total number of plant species increased while the common species decreased, with the β diversity between communities increased gradually. The analysis of succession mechanism supported the ‘ initial floristics composition hypothesis’ , and the plant Calamagrostis angustifolia would intensify its dominance in the mash of Sanjiang Plain.