倭肯河着生硅藻群落结构及其与环境因子的关系

Community structures of periphyton and their relationship with aquatic environmental factors in the Woken River, China

为了合理的评价倭肯河水生态健康状况,2018年8月(丰水期),调查了19个点位的着生藻类群落结构和水环境特征.使用Mcnaughton优势度分析、聚类分析和生态型分析3种方法研究了倭肯河着生藻类群落结构和清洁度,使用Spearman相关分析、除趋势对应分析和典范对应分析等方法研究了倭肯河着生硅藻群落和环境因子的响应关系.结果表明:倭肯河共鉴定出着生硅藻89种,物种丰富,不同采样点位之间生物多样性差异较大,Nitzschia palea等富营养指示种是倭肯河的优势种.聚类分析结果表明,倭肯河采样点位可分为3组,从组1到组3,优势种清洁度逐渐下降,低度需氧型、中腐-高度腐生型和极度富营养型硅藻比例逐渐上升.影响倭肯河着生硅藻群落结构的主要水环境因子为TN、DO和pH,其中DO和TN是组3着生硅藻群落的主要影响因子,pH是组2着生硅藻群落的主要影响因子.由此可见,除河流源头区域外,倭肯河水生态环境质量状况较差,着生硅藻群落可以有效的指示倭肯河水体营养状况和腐生状况.

In order to reasonably evaluate the eco-environmental health of Woken River, a tributary of the Songhua River in China, community structures of periphyton and cleanliness of the benthic diatom at 19 sampling sites were investigated using McNaughton′s dominance index, clustering and ecotype analysis, while the relationship between the environmental factors and the diatom communities were studied by the Spearman correlation test, detrended correspondence and canonical correspondence analysis during the flood season on August 2018. The results indicated that a total of 89 species of periphyton algae have been identified with significant differences in biodiversity among sampling sites. Nitzschia palea and other diatoms which can be used as eutrophication indicators were the absolute dominant species in the Woken River. Sampling sites can be divided into three groups based on clustering analysis. The cleanliness of dominant species gradually decreased from group 1 to group 3, while the results from ecotype analysis show an increase of the proportion of low-aerobic diatoms, α-mesosaphrobe, polysaprobe diatoms, and hypereutrophic diatoms. The predominant aquatic influencing factors of diatom community structures for three groups in Woken River were total nitrogen(TN), dissolved oxygen(DO) and pH, among which TN and DO were the main factors for group 3 and pH was for group 2. As a result, except for the headwater of the river, the eco-environmental quality of the Woken River was poor, and the benthic diatoms were found to be an effective indicator for the nutritional conditions and saprophytic status.