Assessment of coastal wetland ecosystem health based on the press-state-response model: a case study on Liaohe delta

Based on press-state-response model,this paper selected population,economy,environment,resource exploitation,policies and laws,management decision etc.,as indicators for evaluating the health of coastal wetland ecosystem rated on scales of worst,worse,common,good and excellent.Results showed that the health of coastal wetland ecosystem of Liaohe delta was in a common health status.Due to over-cultivation,the natural wetland in Liaohe delta decreased by 11 072 hm2 from 1988 to 2007.The areas of Suaeda salsa wetland decreased 75%(2 440 hm2),while aquiculture land increased 182%(9 359 hm2).Water body was seriously polluted by COD(3.06 mg/dm3),TIN(795.45 μg/dm3),phosphate(44.01 μg/dm3) and Pb(6.46 μg/dm3).According to the analysis of the pollution status and distribution characters,agricultural and industrial pollutions from Liaohe river and adjacent area were important pollutant sources.Owing to environmental problems,wetlands of Phragmites communis and Suaeda salsa,species and abundance of birds,and benthic diversity in Liaohe delta degenerated seriously.Finally,actions for ecological protection and management were proposed for the ecosystem of Liaohe delta wetland.