Wetland Plant, Soil And The Diversity Of Microbial Communities In Response To Changes In The Hydrological Processes In Poyang Lake

Plant, soil and microbia is a very important part of the wetland ecosystem. Water is the main mass medium for transferring armamentarium in the wetland.It plays a decisive role for the biological composition of wetland ecosystem.The change in hydrological processes not only directly affect the formation and development of wetland vegetation type but also is bound to affect the transformation and recycling of the wetland elements and the formation and distribution of microbial. In recent years,due to climate change,human activeties and other reasons,the hydrological processes in Poyang lake is different from the usual.2009is a normal year,2010is a wet year,but2011is a dry year.The article is based on the changes in the hydrological processes in the past three years,developing the study for the plants, soil and microbial of the dynamic response of the hydrological processes change,guiding the manggement in Poyang wetland,and providing the basis for their sustainable development.The main results are as follows:(1)The impact abort the hydrological processes for the distribution of Poyang Lake wetland vegetation has two aspects that they are respectively the water gradient and different water levels.Firstly,it is the change of the water gradient.The TWINSPAN clustering and DCA of riparian plant communities showed that:the84stands could be primarily divided into8communities types and they can be distinguish in the DCA and CCA ordination diagram.Soil moisture is the main environmental factors.Secondly, it is the change of the different water levels.The main species is from Carex.The changes in water level affects both plant species and community types,and Triarrhena lutarioriparia community is more sensitive to the change.It has a impact diversity index and primary productivity.The result of the Speices richness index is2011>2009>2010, the Shannon-Weiner index is2009>2011>2010,the evenness index is2009>2011>2010.The result of primary productivity is2011>2009>2010.(2)Through we are analysis the relations between the soil moisture and soil available N,we are able be find:soil available N undle water gradient is gradually increased and showed a wavelike,but the ratio between soil available N has two peak in the result. From time scale,the changes in hydrological processes has more effective soil available N,and the result ot the soil available N is2009>2010>2011.(3)Analysising the soil bacterial communities from Poyang Lake, we can be able to find the bacterial species of the lake is not very rich but the main species is not greatly different from the usual and the same species has some differences in the number.Form the diversity index,the three diversisy indices have a lesser extent.The main result of the Shannon-Weiner index is Water district>Bare area>Vegetation zone,and it is a same with the result of the species richness index.The result of evenness index has a lesser extentent.Secondly, the result of the RDA is that the total soil nitrogen has a most large impaction in all soil elements with the distribution of soil bacteria,and the second is soil organic carbon.Soil moisture content influences the distribution of soil bacterical communities with other environmental factors together.