上海市河道周丛藻类群落特征与环境因子间的关系研究

通过对上海地区主要水体黄浦江、苏州河7个断面周丛藻类群落及水质情况的全年连续监测,同时结合研究区域的物理生境、水文学指标等环境因子,采用多元统计方法,分析藻类群落的种类组成与数量特征,以及环境因子对藻类群落的主要影响关系.结果表明,①周丛藻类群落具有明显的时空变化趋势,藻类数量及群落密度均在上游区域以及水温较高条件下增加,而群落多样性则在下游及低温条件下显著降低（p<0.05）;②水质、水域功能区划类型以及氮、磷等营养物质浓度是影响藻类种类组成及分布差异的主要环境因子;③一些具有较高优势度的周丛藻类,如系带舟形藻（Navicula cincta）、微小色球藻（Chroococcus minutus）和钝脆杆藻（Fragilaria capucina）对水体氮、磷营养物质变化具有很高的敏感性,从而可作为不同区域水体水质的有效指示藻类.

Environmental impacts on periphyton assemblage in Shanghai's main urban rivers, China

A monthly monitoring program of periphyton was conducted on two main urban rivers of Shanghai from April 2005 to March 2006. Parameters of periphyton assemblage and main environmental variations, including physical habitation and hydrological factors, were analyzed by multivariate analyses (Cluster Analysis, Indicator Species Analysis and Canonical Correspondence Analysis). It showed that a remarkable spatial-temporal variation pattern was observed for periphyton assemblage: taxa numbers and density were abundant at upstream in warm weathers, while diversity decreased significantly at downstream in cold seasons (p<0.05). The results also indicated that water quality, watershed function zone and nutrients (i.e. nitrogen and phosphorus) were the main environmental factors influencing periphyton species composition. The findings further suggested 12 periphyton species, including Navicula cincta, Chroococcus minutus, Fragilaria capucina, had significant indicator values for water quality and highly sensitive to the concentrations of nitrogen and phosphorus, and these species could serve as a good bio-indicator of urban watersheds.