三峡库区消涨带植物群落的数量分析

运用双向指示种分析法(TWINSPAN)和除趋势对应分析法(DCA)对三峡库区消涨带植物群落进行了数量分类和排序分析。TWINSPAN将122个样方分成19类，可归为4个植被型，分类结果反映了植物群落与环境梯度间的关系，并在DCA分布图上得到较好的验证。DCA分布图的对角线基本反映了水淹时间长短和土壤湿度高低，表明水淹时间和土壤湿度是该区域植物群落组成和空间分布的主要限制性影响因子。对消涨带不同部位植物群落的物种组成和分布规律的分析为筛选耐水淹物种、进行三峡水库消涨带的植被恢复提供了物种参考。

Quantitative Analysis of Plant Communities in Water-level-fluctuation Zone within Three Gorges Reservoir Area of Changjiang River

Based on field survey for plant community by quadrates, both quantitative and ordination analyses of plant communities in water-level-fluctuation zone within Three Gorges Reservoir Area of Changjiang River were performed using TWINSPAN (Two Way Indicator Species Analysis) and DCA (Detrended Correspondence Analysis) methods. One hundred and twenty-two quadrates collected from the study area were classified into nineteen types by TWINSPAN, and four vegetation types were identified. The result revealed a relationship between the plant communities and environmental gradients, which is also confirmed in the chart of DCA. Diagonal line of the two-dimensional ordination diagram of DCA indicated that soil water content is highly correlated to submersed duration in the areas, suggesting that the major factors restricting distribution and composition of plant communities are submersed duration and edaphic humidity. Analysis of the composition and distribution of those communities provides a baseline data for selecting plants for reconstructing water-level-fluctuation of Three Gorges Reservoir in the future.