鄱阳湖湿地碟形湖水质生态学基准的确定研究

Shallow dish lakes in Poyang Lake wetland are widely distributed, and have huge ecological values in the ecological structure and functions of Poyang Lake wetland. Thus carry out research on the ecological water quality criteria in shallow dish lakes is particularly important and urgent. Identifying the ecological status of shallow dish lakes ecosystem is the key to define the ecosystem status of the "good - impaired", and developing biological indicators is very important. To establish a method of ecological water quality criteria, typical and shallow dish lakes in Poyang Lake named Zhanbei lake, was chosen, and the contents are (1) based on the water ecological investigation, establish the reference condition which is based on the human activities, and choose three main aquatic biological communities, such as submersed macrophyte, benthic macroinvertebrate and phytoplankton, to develop the index of biological integritys; (2) based on the local punishment model of variable weights in order to comprehensive assement; (3) the application of comprehensive biological index definition ecosystem boundary of "good - impaired " condition, through the classification of the regression tree method to determine the ecological water quality criteria concentration of total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH3-N) and chlorophyll a(Chl a) . This research can provide ecological water quality criteria for Shallow dish lakes in Poyang Lake wetland, and enriches the water quality criteria formulation method, and help for further researches in the lake wetland ecosystem health bioassessment.

碟形湖在鄱阳湖湿地广泛分布，其生态价值巨大且在鄱阳湖湿地生态系统结构与功能的维持中不可替代，开展碟形湖水质生态学基准的研究尤为重要。研究水质生态学基准的关键在于确立生态系统“良好-受损”状态，而开发综合生物指标是评估生态系统状态的重要手段。本课题针对鄱阳湖典型碟形湖生态水质基准的确立方法，开展以下研究：（1）通过水生态调查，建立基于人类活动干扰状况的参照状态，选择沉水植物、大型底栖动物和浮游植物三类主要水生生物群落，开发生物完整性指数；（2）基于局部惩罚型变权的模糊综合评价方法对三种不同生物指标进行综合；（3）应用综合生物指标定义碟形湖生态系统“良好-受损”状况的边界，通过分类回归树方法确定总氮、总磷、氨氮和叶绿素a的水质生态学基准。研究成果可以为鄱阳湖湿地碟形湖水生态管理提供研究基础，且能够丰富湖泊湿地的水生态学基准制定方法，深化湖泊湿地生态系统健康评价理论。

湖泊水质生态学基准是湖泊水量、水质和水生态系统管控的核心依据。开展我国中东部碟形湖水质生态学基准的研究尤为重要。本项目综合运用生态监测、实验分析、综合评估和计算模型等方法，以生态结构复杂、碟形湖分布多样的鄱阳湖南矶湿地保护区为例，选择战备湖和白沙湖为代表的南矶湿地保护区作为主要研究区，开展水质生态学基准研究。完成了鄱阳湖典型碟形湖湿地水生态系统状况资料收集与调查，明确了区域参照状态的建立方法，构建了碟形湖浮游植物和大型底栖动物完整性指标体系，应用局部惩罚型变权综合法进行了指标的综合，运用分类回归树方法确定了鄱阳湖南部碟形湖水质生态学基准。本研究创新了水质生态学基准的研究方法，成果可以应用于鄱阳湖典型的湿地保护区。这也有助于丰富湖泊湿地水质生态学的研究内容与方法体系，为我国长江中下游湖泊综合管理提供科学方法与定量技术依据。