渭河流域河流着生藻类的群落结构与生物完整性研究

以渭河流域为研究范例,调查了全流域范围河流内45个样点的着生藻类群落和水环境理化特征,并在此基础上应用着生藻类生物完整性评价指数(P-IBI),对渭河流域水生态系统进行健康评价.同时讨论了水环境理化因子与着生藻类群落结构的相互关系,并对比分析了渭河流域不同区域水生态系统健康水平差异的原因.结果表明,渭河流域着生藻类群落结构具有明显的空间异质性,典范对应分析结果显示,驱动着生藻类群落结构形成的水环境因子为电导率和流量.P-IBI结果表明,渭河干流的上游及渭河干流的右岸支流健康状况较好,而渭河干流中下游区域及左岸支流的健康状况较差.泾河全流域及洛河下游地区健康状况较差,而洛河中上游区域永生态系统着生藻类生物完整性较高.

Community structure and biological integrity of periphyton in the Weihe River Basin, China

In this work, the community structure of periphyton and characteristics of environmental factors among 45 sample sites in the Weihe River Basin, Northwest China, were investigated. Using the periphyton assemblages, we assessed stream conditions of Weihe River based on Periphyton Index of Biological Integrity (P-IBI). The results indicated that there were great differences in the periphyton community structure in Weihe River. Canonical correspondence analysis (CCA) showed that conductivity and flux significantly influenced the community structure of periphyton in Weihe River basin. The results of P-IBI showed that upstream and right tributary area of main Weihe River were in excellent ecological integrity, whereas the downstream and left tributary area of main Weihe River were in severe impairment. Though the biological integrity of periphyton in Jinghe River and downstream of Luohe River was in severe integrity, the upstream of Luohe River was in relatively good biological integrity. In this paper, we also discussed the relationship between environmental factors and periphyton community, and analyzed the possible reasons that caused the variation in biological integrity of periphyton community in the Weihe River Basin.