Study On Low Trophic Level Ecohydrological Relationship In Piedmont Wetlands Around Qinghai Lake

Wetlands,forests and oceans were listed as most important ecosystems on earth in World Conservation Strategy.The ecological problem of wetlands caused by unreasonable utilization of water resources is one of the main problems that restrict the sustainable development of China's economy and society.Ecological hydrology was independently proposed as a discipline at the International Conference on Water and Environment held in Berlin,Germany in 1992.The research of wetland ecology and hydrology is the foundation to solve the problems of wetland and to protect and restore wetland ecological.Qinghai lake wetland is the largest inland plateau saltwater lake wetland in China and is one of the first wetlands of international importance to join the International Wetland Convention.The study of slope in Qinghai basin is focus on plant community.At first,the basic distribution of plant community was studied.Then,the study of vegetation succession with environmental gradient was gradually started.In recent years,the studies have begun to analyze the mechanism of soil and vegetation distribution based on source factors.The investigation of waterborne focused on the changes of lake water level and biological composition.It focuses on the study of the hydrological evolution of rivers and the analysis of the migration and spawning of naked carp and the construction of fishways.In recent years,the study of ecological hydrology based on hydrological models began to appear,and the ecological hydrology of Qinghai Lake wetland gradually became the focus of many scholars.However,with the development of tourism and animal husbandry,human activities have caused different degree of damage to the ecological environment in Qinghai lake wetland.Bird island and sand island scenic area have been closed in order to protect the habitat.Taking the lakeside plain wetland of Qinghai Lake as the research object,this paper clarified the distribution status of the wetland around Qinghai Lake.Combined with plant investigation and benthic animal sampling methods,we investigated and studied different types of wetland in the lakeside plain.The results are as follows:(1)The basic distribution of hydrology,soil and vegetation as well as wetlands around the lakeside plain of Qinghai lake are clarified.The surface water distribution in the lakeside plain of Qinghai Lake is uneven,and the groundwater types mainly include pore water of loose rocks,fractured water of bedrock and fractured rock fractured pore water.The groundwater distribution of recharge,runoff and discharge is like a ring around the lake.The soil types were absolutely dominated by chestnut soil,and most of the sample points were dominated by silt and clay particles.Combined with remote sensing interpretation and soil distribution,the distribution of natural plants was reversed,and a total of 10 natural plant formation were determined.In this paper,Qinghai Lakeside wetland was divided into 7 types,including nearshore river wetland(including permanent and intermittent river),permanent inland delta,lakeside flood land,marsh,fresh water spring,geothermal wetland and marsh meadow(2)In this paper,the distribution characteristics of different dominant plant populations were determined.And the habitat similarity of dominant plant populations and their quantitative relationship with water driving factors were established.At the same time,this paper preliminarily reveals the decisive environmental conditions of the distribution of plant communities,establishes the groundwater response relationship of typical plant communities based on the measured data and the natural vegetation distribution.It also corrects the distribution of plant communities in the lakeside plain through the in-depth excavation of its distribution mechanism.(3)The composition,structure and biodiversity of typical wetland waters in the lakeside plain around Qinghai Lake were expounded in this paper.Then the potential mechanism of different types of benthic fauna distribution was explained from the perspective of feeding structure and the quantitative relationship between large benthic communities and food sources in the detrital food chain of intermittent freshwater spring wetland and coastal river wetland was established.At the same time,the environmental driving factors of benthic fauna distribution were determined by sequencing analysis,and the potential reasons for the spatial-temporal differences in community distribution were explained.The differences of biological composition and community structure between typical lakeside waters and permanent wetlands were also compared.