Ecology Study On Estuarine Wetland Vegetation In The Northern Shore Of Chaohu Lake

It is well known that estuarine wetland is an important part of the wetland system such as lake. Taking 2008 as the base year, in this paper, the estuarine wetlands of Tongyang River and Shiwuli River in the northern shore of Chaohu Lake were selected as targets to study the composition of vegetation, plant association, relationship between species, species diversity and correlation between plants and environment conditions, etc. The conclusions were drawn and summarized as follows:(1) In 2008 April, August and November, a total of 60 quadrats were respectively set in the estuarine wetland of Tongyang River. The numbers of plant species corresponding to above three months were finally obtained namely 20, 13 and 11, respectively. As for them, Gramineae, Compositae and Tadeshina were the major compositions. In addition, the numbers of plant associations corresponding to above three months were also determined namely 12, 9 and 9, respectively.In 2008 April, August and November, a total of 50, 42 and 53 quadrats were respectively set in the estuarine wetland of Shiwuli River to investigate the numbers of plant species and plant associations. Finally, it was obtained that, corresponding to above three months, the numbers of plant species were respectively 22, 16 and 14, and the numbers of plant associations were 10, 8 and 11, respectively. Thereinto, Gramineae and Compositae were the main compositions. TWINSPAN classification and DCA sorting showed that the style of plant distribution patterns was closely correlated both to soil type and soil moisture.(2) The quantitative analysis on the relationship of wetland plant species was performed using 2×2 contingency table, by means of theχ2 test and Ochiai's index. The results showed that the degrees of inter-positive (or negative) correlations between the most dominant species were weak and the relationships between species were loose for the two estuaries in different periods. And thus it enables to fully share the community resources.(3) The wetland plant species diversities of the two estuaries in different periods were analyzed by means of such three methods as richness index, species diversity index and evenness index. The results showed that the richness index, evenness index and species diversity indexs for wetland vegetation of the two estuaries in different periods almost presented the similar change trendency.