颐和园湿地生态系统健康评价研究

Assessment of Wetland Ecosystem Health in the Summer Palace

从水质环境、底泥环境、生态系统功能和生物群落结构4个方面选取26个指标构建颐和园湿地生态系统健康评价体系,采用层次分析法对颐和园湿地的健康状况进行评价。结果表明:45个调查样点中,仅有4个样点的健康状况为"健康",其余41个为"亚健康";颐和园湿地生态系统的健康综合指数为0.41,处于"亚健康"状态;健康指数值低于0.2的因子包括水体总磷、水体五日生化需氧量、底泥有机质、底泥中Cd浓度、湿地植物生物量和底栖生物的多样性综合指数。建议从改善入水水质、降低水体氮磷浓度、对各小水体开展净化清淤整治、优化湿地植物配置及提高水生生物多样性等方面开展颐和园湿地生态系统的保护与管理。

A health assessment system for wetland ecosystem in the Summer Palace was built based on 26 indicators representing the water/sediment quality,ecological status and biological community structure.The analytic hierarchy process(AHP)method was used to evaluate the wetland ecosystem health of Summer Palace.The results showed that:only 4 of the 45 survey sites had a status of“health”and the remaining 41 were“sub-health”;the integrated health index of wetland ecosystem of the Summer Palace was 0.41,indicating that the wetland ecosystem health was at a“critical”[0.40.6)level;the factors that negatively contribute to the health index of the wetland ecosystem are total phosphorus(TP),biochemical oxygen demand(BOD)of water,contents of organic matter in sediment,heavy metals(Cd)contentsof sediment,wetland plant biomass and the biodiversity of phytoplankton,zooplankton and benthos.Based on this study,to filtrate the water at water inlet,reduce the contents of nitrogen and phosphorus in water,launch small water bodies dredging and remediation projects and to optimize vegetation configuration and promote aquatic biodiversity are recommended in the protection and management of wetland ecosystems in Summer Palace.