镇江内江湿地植物群落演替动态研究

DYNAMICS IN THE SUCCESSION OF VEGETATION COMMUNITIES IN INNER-RIVER WETLAND IN ZHENJIANG

采用“空间代替时间”方法,于镇江内江湿地选择4类典型样地,分别代表群落演替的4个不同时间段,从物种组成、多样性及生活型等方面研究湿地植被的演替规律,从而探索受损群落的修复途径。结果表明:不同演替阶段植物群落的物种组成、多样性指数和生活型变化明显。物种丰富度指数和多样性指数随演替呈上升趋势,且演替中后期最高,均匀度随演替递增,而优势度递减;在生活型上,多年生草本的重要值随演替先降后升,其物种数逐渐上升并在后期维持相对稳定,并在各演替阶段处于主导地位。而一、二年生草本植物的重要值和物种数均为先升后降;在科属总数上,科属数随演替逐渐增加,其中,禾本科植物始终处于优势种地位。

By using the spatial series to replace temporal courses, the authors selected four typical sampling sites representing different successive stages in inner-river wetland in Zhenjiang City, and then investigated the laws of vegetation community, e. g. , species composition, species diversity and life-form in order to establish restoration approaches for degraded vegetation communities. The species diversity, species composition and life-form along different successive stages differed from each other significantly. In general, there was an increasing trend in species richness and species diversity along different successive stages, with the highest richness and diversity observed in the mid-last successive stages; the evenness degree increased continuously, while ecological dominance declined progressively along with succession. For life- form composition, along with succession process, the importance value of perennial herbaceous plants declined firstly and then increased, while the species number of perennial herbaceous plants increased gradually and became relatively steady in later successive stages, and perennial herbaceous plants were dominant in all successive stages. As to annual-biennial herbaceous plants, the importance value and species number increased firstly and then declined. The total number of family and genera increased gradually as succession proceeded, and Gramineae were dominant species at all time.