The Comparison In Ecosystem Structure And Aquatic Organisms’ Evolution Of The Five Lake Distracts In China

Abstract:There are many lakes in China, generally facing environmental issues such as eutrophication and pollution, which not only exacerbate the shortage of water resources, but also a threat to water quality safety and the lake ecosystem structure, thereby restricting the sustainable development of China’s economy. Thus, there is an urgent need to strengthen the comprehensive study of lake pollution control and governance. However, due to the natural environmental differences, pollution reasons and degrees’ differences between the lakes, we have urgent need study for the dynamic evolution and current situation of China’s Lakes, lake ecosystem structure, and the driving force, to carry out the water degradation’ governance and management according to local conditions. We analyzed from the changes of climate and water chemistry, aquatic biota, sensitive Species and dominant species in15representative lakes of the five lake distracts in China respectively, and the aquatic species, density, biomass, diversity and lake ecosystem structure were analyzed too, to reveal the differences of lake ecosystem evolution trends and the current ecosystem structure in the five lake distracts in China.(1) Changes of climate and water environmental:There have been great changes in lake ecosystem structure and function in the double stress of natural and human activities Since the1960s. The overall trend is there are serious water pollution and siltation in the role of human activities in East Plain Area of China. There are water salinization and mineralization because of the western arid climate and the human activities in Inner Mongolia-Xinjiang Plateau of China. There are differences in Yunnan-Guizhou Plateau of China, the lakes which are affected by human activities mainly like Dianchi Lake, have serious water pollution, the others which are affected by human activities smaller relatively, are more than in the oligotrophic and mesotrophic. The lake areas shrink substantially and even disappear, water storage plummets, and the salinity increases in the role of climate change in Qingzang Plateau of China. The water pollution is serious in Songnen plain lakes, but the water is in the middle nutritional level in the other regions in Northeast China.(2) Aquatic organisms’ dynamic evolution in lakes:The aquatic organisms have changed substantially since the1960s, including Dianchi Lake in Yunnan-Guizhou Plateau of China, Taihu Lake and Chaohu Lake in East Plain Area of China, Jingbo Lake in Northeast China, and the change is relatively smaller in Mongolia-Xinjiang Plateau and Qingzang Plateau of China.(3) Sensitive Species and dominant species:There are tolerance species and eurythermal species mainly in East Plain Area of China; There are euryhaline, wide alkaline species and salt, alkali resistance species as dominant species in Mongolia-Xinjiang Plateau; There are species which addicted to warm and wide temperature in Yunnan-Guizhou Plateau of China; There are species which resistant to mineralization, eurythermal, euryhaline and wide alkaline; There are species which addicted to cold and eurythermal mainly in Northeast China, and there are stain resistance species in some lakes, too.(4) Recent aquatic species’Quantity difference:The phytoplankton quantity is264,and it is the most in Yunnan-Guizhou Plateau of China, followed by the East Plain Area, the Mongolia-Xinjiang Plateau and the Northeast China, the last is Qingzang Plateau of China, it’s species’Quantity is88; The zooplankton quantity is the most in East Plain Area of China, it’s338, then it’s the Mongolia-Xinjiang Plateau, Yunnan-Guizhou Plateau and the Northeast China, the last is Qingzang Plateau, it’s19; The benthic fauna quantity is136in the East Plain Area, then it’s the Yunnan-Guizhou Plateau, Qingzang Plateau and the Northeast China, Mongolia-Xinjiang Plateau has the least, and it’s16; There are173fishes in the East Plain Area of China, and it’s the most. Followed by Qingzang Plateau, Northeast China and Mongolia-Xinjiang Plateau, Yunnan-Guizhou Plateau has the least, its48; There are93aquatic vegetations in the East Plain Area of China, and it’s the most. Followed by Northeast China, Mongolia-Xinjiang Plateau and Qingzang Plateau, Yunnan-Guizhou Plateau has the least, it’s21.(5) Recent aquatic density difference:The phytoplankton density is the most in Mongolia-Xinjiang Plateau, its1281.57×104ind/L, followed by the Northeast China, Yunnan-Guizhou Plateau and the East Plain Area of China, the last is the Qingzang Plateau, it is just7.32×104ind/L; The zooplankton density is the most in Yunnan-Guizhou Plateau, it is9259.23ind/L, and it is higher than other Lakes Significantly.The last is the East Plain Area, it is242.60ind/L; The benthic fauna density is the most in Yunnan-Guizhou Plateau, it is3122.70ind/m2, followed by Mongolia-Xinjiang Plateau, the Northeast China, the East Plain Area, and the last is Qingzang Plateau, it is297.60ind/m2.(6) Recent aquatic biomass difference:The phytoplankton biomass is the most in the Northeast China, it is43.42mg/L, followed by the East Plain Area of China, Yunnan-Guizhou Plateau, Mongolia-Xinjiang Plateau, the last is Qingzang Plateau, it is1.01mg/L; The zooplankton density is higher Significantly in the East Plain Area than in the others, it is135.82mg/L, and the other districts are Similar, the last is the Qingzang Plateau, it is just0.845mg/L; The benthic fauna biomass is higher Significantly in the East Plain Area of China than in the others, it is151.70g/m3.It is the least in Qingzang Plateau, and it is0.56g/m3.(7) Recent Margalef diversity difference:The phytoplankton diversity is the most in Qingzang Plateau, it is43.72. The least is in the East Plain Area, it is18.52; The zooplankton diversity is the most in the East Plain Area, it is61.37. The least is in Qingzang Plateau, it is3.22; The zooplankton diversity is the most in the East Plain Area, it is22.27. The least in Mongolia-Xinjiang Plateau, it is2.10. (8) Recent ecosystem structure differences:Ecosystem structure is the most complex in the East Plain Area, its total number of trophic species and total number of web links are71and475, respectively. It is the simplest in Qingzang Plateau, its total number of trophic species and Total number of web links are46and333, respectively; Predation pressure is the biggest in the East Plain Area, and its predator-prey ratio is2.00, the least in Yunnan-Guizhou Plateau, and its predator-prey ratio is1.05; The connectance is0.09in the East Plain Area, and it is the least; The link density is8.19in the Northeast China,,and it is the highest. The least is6.69in the East Plain Area; The top links is about60%mainly in web links, and it’s68.50%in the Northeast China. It’s the least in Yunnan-Guizhou Plateau, and it is about59.80%.