An Ecological Study Of Wetland Plants Of The Shuangqiao Stream Near The Lake Chaohu

Wetland system is one of the three largest ecosystems in the world. A great attention has been paid on the wetland studies in recent years by investigators from different fields. Shuangqiao stream is one of the main channels of pollutants into the lake Chaohu. The wetland of Shuangqiao stream lies near suburb of ChaoHu city .The wetland can remove the pollutants by adsorption, sedimentation, assimilation, and microbe decomposition of the soil or plants. It is important to study on the wetland plants' eco-characteristics and the soil physicochemical properties. Quantitative ecology is used to research the changes of the quantitative characteristics of the wetland plants in defferent seasons in a year. Soil specimens were analyzed too.The study focus on the floristic diversity, the interspecific association of plant communities, the association between plant communities and soil. The major results are summarized as follows:1. The plants composition and distribution in the wetlandThe results of DCA ordination and TWINSPAN analysis indicate that there are obvious relationships between the distribution pattern of plant associations and soil water content, soil texture. The plants composition and distribution is different in different seasons. The water level of the stream is the major factor.2. The species diversity variation in the wetlandThe diversity index, the evenness index and the richness index were used to analyze the plants communities' diversity of the wetland in different seasons. The results indicate that the plant diversity index in the low water level period was higher than that in the high water level period, but its evenness index didn't vary.3. The plants interspecies associations in the wetlandThe analysis of variance, x~2 and Jaccard are used together with a 2×2 association table in order to analyze the interspecies associations of the plants communities in the wetland. The results indicate that the community structure is instable in every season. Human activity is possibly the major factor.4. The fitting and assessment of species-area curves in the wetlandFour curves were chosen as the model of the species-area curves. Correlation index (CRI) was chosen to assess the fitness of the model. The classic models of every season are different. Minimum sampling areas were confirmed in different season.5. The physicochemical properties of the soil in the wetlandSoil contents such as C N P, pH were measured. The relativity of them was analyzed. The species richness marked a positive correlation with soil pH.