The Study On Soil Nature At Riparian Zone Of Qinhuai River And Taihu Lake

Riparian zones are the important transitional regions for exchange of substance, energy, and information between aquatic ecosystem and upland ecosystem, and as a kind of aquatic-terrestrial eco-tone. The banks of rivers or lakes covered with concrete in the city damage the plant communities. It leads to destroy the ecological function of the riverbank connected water ecosystem with terrestrial ecosystem. There are numerous examples of natural forces that cause shifts in the composition of riparian vegetation including climate, geology, wind, floods, gravity, and disease. The restoration of degradation of riparian plant communities is one of complex and challenging issue. However, studies on basic theories and methods of degraded riparian ecological rehabilitation in China are very poor. In this paper, we summarized and discussed the studies on the definition, structure, functions of riparian zones, and on ecological restoration of the damaged riparian in China and abroad. Moreover, the aspects of riparian research in the future are proposed.The research region is located in the Qinhuai River,Wuzhong and Wujiang area in Suzhou city of the Taihu Lake. In this pilot study,the distribution of plants has been investigated and the soil was sampled . Then the contents of microbial biomass,organic mater,total nitrogen, total phosphorus,Fe and Mn were measured,which is supposed to expose the distribution specialty of the soil nutrition in riparian ecosystem.The results were summarized as follows:(1) The means of microbial biomass in Lishui zone were (21.32 ,47.69,33.66) mgCO2-C/100gdm, respectively,from the open water to the land.The same parameters in Moling zone were (50.23,25.37,48.02) mgCO2-C/100gdm,while the parameters in Sanchahe zone were (17.14,23.02) mgCO2-C/100gdm.The results shows that the high concentrations of Microbial biomass are mostly in eulittoral zone.(2) The means of pH in Lishui zone were(5.37,5.18,4.79), respectively,from the open water to the land.The same parameters in Moling zone were (6.8,5.95,6.26),while the parameters in Sanchahe zone were (7.12,6.81).The results shows that the distribution of pH takes on a gradually increase trend along the gradiant from the upriver to the downriver.(3) The means of organic mater in Lishui zone were(2.536,1.84,4.192)%, respectively,from the open water to the land.The same parameters in Moling zone were (1.145,1.844,1.701)%,while the parameters in Sanchahe zone were (4.416,2.877)%.The results shows that the distribution of organic mater takes on a gradually decrease trend then a increase trend along the gradiant from the upriver to the downriver.(4) The means of TN in Lishui zone were(0.524,0.556,0.600)%, respectively,from the open water to the land.The same parameters in Moling zone were (0.471,0.485,0.520)%,while the parameters in Sanchahe zone were (0.703,0.574)%. The results shows that the distribution of TN takes on a gradually increase trend along the gradiant from the open water to the land.The means of TP in Lishui zone were(0.156,0.22,0.123)mg/g, respectively,from the open water to the land.The same parameters in Moling zone were (0.246,0.245,0.302)mg/g,while the parameters in Sanchahe zone were (0.952,0.695)mg/g.The results shows that the distribution of TP takes on a gradually increase trend along the gradiant from the upriver to downriver.(5) The means of Fe in Lishui zone were(18.853,19.222,18.753)mg/g, respectively,from the open water to the land.The same parameters in Moling zone were (18.063,19.405,21.19)mg/g,while the parameters in Sanchahe zone were (22.653,22.455)mg/g.The results shows that the distribution of Fe takes on a gradually increase trend along the gradiant from the upriver to downriver. The means of Mn in Lishui zone were(0.531,0.584,0.477)mg/g, respectively,from the open water to the land.The same parameters in Moling zone were (0.603,0.568,0.683)mg/g,while the parameters in Sanchahe zone were (0.556,0.572)mg/g.The results shows that the high concentrations of Mn are mostly in eulittoral river zone.(6) The means of microbial biomass,organic mater,total nitrogen,total phosphorus,Fe and Mn in Taihu Lake riparian zone were (9.31 ,6.27,5.20) mgCO2-C/100gdm, (1.842,3.512,1,884)%, (0.577,0.635,0.569)%, (0.214,0.508,0.319) mg/g, (14.533,18.398,18.095) mg/g and (0.300,0.656,0.562) mg/g, respectively. The results shows that the distribution of microbial biomass takes on a gradually decrease trend along the gradiant from the open water to the land while the distribution of Fe and Mn take an opposite trend;The high concentrations of organic matter,TN and TP are mostly in eulittoral zone.