三峡库区古夫河着生藻类分布与水质因子的关系

于2010年12月至2011年12月,对位于长江三峡库区内的湖北省兴山县古夫河着生的藻类和水体共采样10次,共鉴定出着生藻类28属,检测水质指标12项。对水质变量进行因子分析,根据特征值大于1的原则选取4个主成分,第一主成分主要代表总氮（TN）和硝酸盐氮（NO3--N）,第二主成分主要代表pH和化学需氧量（CODCr）,第三主成分主要代表磷酸盐磷（PO34--P）、总磷（TP）和氨氮（NH4＋-N）,第四主成分主要代表电导率（Cond）和总有机碳（TOC）。将提取的9项主要水质因子与着生藻类重要属进行典型对应分析（CCA）,结果可见,古夫河主要水质因子与着生藻类类群分布相关性大小为：CODCr〉pH〉TN〉NO3--N〉TOC〉TP〉PO34--P〉Cond〉NH4＋-N。Monte Carlo显著性检验表明,CODCr和pH对古夫河着生藻类物种组成及空间分布的影响最大,其次为TN、NO3--N和TOC。pH与CODCr呈极强的负相关关系,古夫河着生藻类大多数类群均与CODCr表现出正相关关系,仅胶毛藻属（Chaetophora）倾向低CODcr和偏碱性的环境。TN和NO3--N有很强正相关性,而两者均与TOC有强负相关,它们将古夫河着生藻类大体上分为两类,即亲碳元素的类群和亲氮元素的类群。TP通常是河流生态系统中的限制性营养因子,但在古夫河流域中并不是影响着生藻类物种分布的主要水质因子。

Relationship between Periphyton Distribution and Water Quality of Gufu River of Three Gorges Reservoir Area

Periphyton and water samples were collected ten times from Gufu River in Xingshan County,Hubei Province,from December 2010 to December 2011.A total of twenty-eight genera were identified from the periphyton samples,and twelve water quality parameters were tested.Factor analysis was performed on the twelve water quality factors,with four major components,whose eigenvalues were greater than 1,selected.The first major component was accounted by TN and NO-3-N,the second by pH and CODCr,the third by PO3-4-P,TP and NH＋4-N,and the fourth by Cond and TOC.The relationships between the nine extracted dominant water quality parameters and the main genera of periphyton were analyzed by CCA.According to CCA ordination,the sequencing of the correlations between the main water quality parameters and periphyton distribution was：CODCrpHTNNO-3-NTOCTPPO3-4-PCondNH＋4-N.Monte Carlo significance test showed that the distribution of the periphyton taxa was most influenced by CODCr and pH,and less by TN,NO-3-N and TOC.Both pH and CODCr were strongly negatively correlated with each other.Most of the periphyton taxa in Gufu River were strongly correlated with CODCr,while only Chaetophora was fit for the low CODCr and slightly alkaline environment.TN and NO-3-N were strongly correlated,but both of them were negatively correlated with TOC.These three factors roughly classified the periphyton into two ecological groups：one preferring nitrogen,and the other carbon.Though usually a limited nutrient factor for algae,TP was not a dominant influencer on the distribution of periphyton in Gufu River.