人为扰动下扎龙湿地土壤环境对水质变化的影响

Impacts of Edaphic Environments on Water Quality under Artificial Disturbance in the Zhalong Wetland

通过野外定位观测和室内分析,探讨了人为扰动对扎龙湿地土壤性质及对湿地水质退化的影响和湿地的演替规律。结果表明:湿地退化的现状是受多种因素影响综合作用下演替的结果。湿地以粉砂质为主的土壤质地特征决定了湿地生在受到干旱胁迫下水体很容易发生污染。近20年来整个湿地水体富营养化程度较为严重。汇入湿地的径流量持续减小导致湿地水环境质量明显下降。含磷和含氮物质的富集是导致湿地水体富营养化程度不断增加的主要原因。湿地水质指数呈现从核心区向外逐渐增加的变化趋势;除了极少部分区域的水质为贫营养化水平外,大部分缓冲区域的水质已经处于富营养化水平,位于湿地东部的缓冲区地带的水体大部分都已经处于重富营养化状态。鉴于扎龙湿地地表水富营养化污染的严重性,有必要把水体当中的含磷和含氮物质污染防治作为治理湿地水环境的重点加以考虑。

Based on in-situ observation and laboratory analysis, we investigated the human influences on the edaphic characteristics and water quality degradation as well as their second succession in Zhalong Wetland. Results showed that the status-quo of wetland was the result of second succession by various driving factors. Large proportion of silt or clay along soil profile would increase the pollutant concentrations in the surface horizon caused by human disturbance, which deteriorated with natural drought. Actually, the results revealed the water-body eutrophication was very serious in recent decades. The enrichment of phosphorous and nitrogen was responsible for the water quality degradation. The large buffer zone area of wetland appeared to be at a severe eutrophication level, except in the core area which appeared to be slight polluted in past decades. It should take some special measures to dilute the phosphorous and nitrogen concentration or restrain free discharge of pollutant in the wetland.