Ecosystem Health Assessment Of Yitong Riverine Wetland In Changchun City

As an important method of ecological assessment and management,ecosystem health is becoming a very important issue in scientific research.Ecosystem health,ecosystem risks and ecosystem security,these three concepts are closely related.Confusion between these three concepts makes the evaluation results less significant to guide practice.In analogy to human's health,risks and security,this article distinguish the concepts of ecosystem health,ecosystem risks and ecosystem security.What is more,based on literature metrologies,this article analysis the trends and hot spots in recent years in the area of ecosystem health,and according to the results aquatic ecosystem health evaluation is one of the hotspots in this field.To obtain accurate results,ecosystem health of wetland should be assessed from both network system(macroscopic scale)and conditions(microcosmic scale).Macroscopic aspect: this article first visualize the Yitong riverine wetlands in Changchun in 2001 ? 2006 ? 2011,and then analyze the construction and connection.Microcosmic aspect: based on our newly revised ecosystem health conceptual model,by adopting water quality,water quantity,biological indicators and indicators of other aspects,ecosystem health of the mainstream of Yitong riverine wetland has been assessed.Results of macroscopic aspect show: a.length of rivers in all these four riverine wetlands(Yitong mainstream riverine wetland,Yongchun riverine wetland,Shuanglong riverine wetland and Xixinkai riverine wetland)except Yongchun riverine wetland shows a decline during the research period;b.river density of all these four wetlands declines and there exists a simplification trend in rivers of all these wetlands;and stability of river construction of three riverine wetlands,except for Yitong mainstream wetland,declines either.Results of microcosmic aspect show: the ecological health status of the wetland in Yitongmainstream riverine wetland in Changchun City has gradually improved from 2003 to 2010,and the ecological health status has improved significantly from 2005 to 2006.However,the ecosystem health states of Yitong mainstream riverine wetland in Changchun city from 2003 to 2010 is in an unhealthy state as a whole.The evaluation results in 2015 shows that the ecological health status of the upstream wetland in Yitong River in Changchun City is significantly better than that in the downstream.At last,this article analyzes the main factors that threaten the ecological health of the Yitong riverine wetland,and puts forward some reasonable suggestions.