乐安河源区水库底栖硅藻分布特征及环境响应分析

Distribution Characteristics and Environmental Responses of Benthic Diatoms in Reservoirs in Headstream Area of Le’an River

为研究乐安河源区水库底栖硅藻种的群落分布特征及其与环境因子之间的响应关系,在2020年冬季测定了婺源县大塘坞水库、清华水库和石井水库3个水库的底栖硅藻群落组成和水体理化指标,并采用Pearson相关性分析和冗余分析探讨底栖硅藻空间分布特征及其与环境因子的响应关系。结果表明,从11个采样点共鉴定出硅藻24属73种,其中优势种Cyclotella stelligera的丰度为21.91%,同时Melosira、Cocconeis、Achnanthes属分布广泛。硅藻分布特征及环境响应分析显示:Melosira varians等与水体营养化水平的联系较为显著;Cyclotella stelligera与COD_(Mn)呈现为显著的正相关关系;Cymbella perpusilla与TP表现为负相关的关系,NH^(+)_(4)-N、NO^(-)_(3)-N是影响硅藻属种差异的显著因子,共同解读了硅藻信息的43.1%。初步判定乐安河源区水库底栖硅藻群落结构与NH^(+)_(4)-N、NO^(-)_(3)-N、COD_(Mn)、TP等多种指标共同响应。

This study aims to investigate the community distribution characteristics of the benthic diatom species in the reservoirs in the headstream area of the Le'an River and the response relationships of those species with environmental factors.For this purpose,the composition and water physicochemical parameters of benthic diatom communities in Datangwu reservoir,Qinghua reservoir,and Shijing reservoir in Wuyuan County were measured in the winter of 2020.Pearson correlation analysis and redundancy analysis were performed to explore the spatial distribution characteristics of benthic diatoms and the abovementioned response relationships.The results show that a total of 73 species,belonging to 24 genera,of diatoms are detected from 11 sampling sites.Specifically,the abundance of the dominant species Cyclotella stelligera is 21.91%,and the Melosira,Cocconeis,and Achnanthes genera are widely distributed.The following observations can be made from the analysis of the distribution characteristics and environmental responses of the diatoms:The relationship between Melosira varians and water eutrophication level is significant;a marked positive correlation is observed between Cyclotella stelligera and COD_(Mn);Cymbella perpusilla and total phosphorus(TP)are negatively correlated.NH^(+)_(4)-N and NO^(-)_(3)-N are significant factors affecting the differences among diatom genera and species,altogether explaining 43.1%of the diatom information.A preliminary determination is made that the structure of the benthic diatom communities in the reservoirs in the headstream area of the Le'an River responds simultaneously to NH^(+)_(4)-N,NO^(-)_(3)-N,COD_(Mn),TP,and other parameters.