Study On The Communities Of Ecosystem And Classification For The Shallow Lakes In Wuhan

Aquatic ecosystem is the important habitat of biology, gestate abundant biologic resource and make up of the stucture of community.It keep balance of the ecosystem through the nutrients cycle and energy flow.For the correct evaluation of pollute and disturb or impact by the environmental factor,in addition,provide the elementary data and foundation for the Wuhan water environment plan, ecological investigate and assessment to the shallow lakes in Wuhan should be performed. In this paper, 13 lakes and 2 large-scale reservoirs in Wuhan were investigated, the makeup of species , dominance species and standing biomass of plankton, benthon, hydrophyte, fish and et al were carried out. And the bio-indicate method , diversity index are used to evaluate the water body.The research indicate that the aquatic ecosystem of Wuhan city lakes now is: elementary production and consumption keep high amount, and accumulate in the water bodies, then the benthon ,so much as fish's community to decline seriously, cause the main nutrients cycle and energy circulation in the system is obstructed, that means the "elementary production-elementary consumption-advanced consumption" replaced by the "elementary production-elementary consumption-analyze by itself – reproduction", this circulation of the the nutrients is unfavorable to the system. At the same time as regards whole system, the nutrients and energy in the ecosystem are distributed in the extremely unreasonable state. Restore and improve the structure state of middle-and-high-ranking consumers of water body, may be the only way to resume and improve above-mentioned bad states . The improved cluster analysis method is used to divided the water ecosystem types of Wuhan which based on the investigated and analysed for the ecosystem structure , divide the ecosystem water body into A , B , C and D, and this classification can be confirmed by the appraise result and physics & chemistry character. It also offer more information than water quality assessment , for instance, biological characteristic , eutrophication state , main pollutant and type of polluting ,etc.. It solving the problem better than the assessment of water quality, in other words, distinguish the water body according to the ecological characteristic, is useful to restore and make the further objectives plan for the water body. Principal component analysis can simplify multiple relevant ecological index to less main component, which is independence and function-clearly. Cluster analysis on this basis , the primitive index is replaced by the score coefficient of every principal component of water body,prevent the cluster deviation by the relativity of primitive indexes, cluster's result is comparatively objective and accurate. Otherwise,the service value of aquatic ecosystem of Wuhan is calculated according the the method of shadow engineering techique,market value techique, substitute cost method, forestation cost method and expenditure method , etc.. The result indicate that the service value of aquatic ecosystem is $5,556,910,000 , equal to 3.34 percent of Wuhan city's GDP in 2004.We can make out that the water ecosystem has enormous indirect value besides offering the direct products for society.