潮白河北京段着生藻类群落结构及其优势种生态位特征

为明确北京市潮白河流域浮游植物群落变化特征，于2021年5月和9月对潮白河17个样点的着生藻类进行调查。应用着生藻类种类数和细胞密度对群落结构进行分析，计算优势种的优势度指数（Y） 、优势种更替率（R），运用生态位宽度（B_i）、生态位重叠指数（O_ik）、总体相关性分析优势种的生态位特征。结果表明：2次调查共鉴定着生藻类109种，隶属4门41属，着生藻类优势种（Y>0.2）共8种，优势种的生态位宽度为0.140 6~0.420 9，优势种的生态位重叠指数为0.055 1~0.897 1，总体关联性测度结果均为显著正关联，优势种受季节更替的影响较大，优势种间对资源的利用共性较小，着生藻类群落结构趋于稳定，整体朝正向演替发展。研究表明，着生藻类作为一项生物指标对环境条件的变动能够进行较为敏感的响应，基于着生藻类优势种生态位特征，能够对着生藻类群落结构及其演替特征进行描述。

Community structure and dominant species niche characteristics of periphytic algae in the Beijing section of the Chaobai River

To clarify the changes in phytoplankton communities in Chaobai River basin of Beijing, 17 sampling sites of periphytic algae were selected and two surveys were conducted in May 2021 and September 2021. Community structure was analyzed by applying the number of periphytic algae species and cell density, and the dominance index of the dominant species(Y) and dominant species turnover rate (R) were calculated. The niche width (Bi), niche overlap (Oik) and overall relevance were used to analyze the niche characteristics of the dominant species. The results showed that a total of 109 species of periphytic algae belonging to 4 phylums and 41 genera were found and recorded in two phases. There were 8 dominant species (Y>0.2) of periphytic algae in all sampling periods. The niche width values of dominant species ranged from 0.140 6 to 0.420 9. The niche overlap values of the dominant species ranged from 0.055 1 to 0.897 1, and the overall correlation measurement results were significantly positive correlations. The dominant species were greatly affected by seasonal alternation, and the commonality of resource utilization among dominant species was relatively small. The structure of the periphytic algae tended to stabilize, and the overall development was toward positive succession. The research shows that periphytic algae, as a biological indicator, can respond sensitively to changes in environmental conditions. Based on the niche characteristics of the dominant species of periphytic algae, the community structure and succession characteristics of periphytic algae can be described.