乐安河源区水库表层沉积硅藻与水质的相关性分析

Analysis of Correlation Between Diatoms in Surface Sediments and Water Quality of Reservoirs in Source Region of Le’anhe River

为探究乐安河源区水库的营养程度及表层沉积硅藻对水环境的响应,选取乐安河源区段莘水库、鄣公山水库、钟吕水库、大塘坞水库以及石井水库进行研究。基于综合营养指数法(TLI)、主成分分析以及冗余分析,以水质环境为研究对象,表层沉积硅藻为研究载体,定性地分析了乐安河源区水库的营养状态以及表层沉积硅藻与水质的关系。研究结果表明:①乐安河源区段莘水库的水质为Ⅰ类水,处于中营养状态;石井水库严重超标,已超出Ⅴ类水标准,达到了中度富营养状态;其余水库均为Ⅲ类水,处于中营养状态;②硅藻群落分布特征对乐安河水环境具有良好的指示效应,如Aulancoseira grannulata等属种主要分布在水质较好、中营养程度的水体中;Cyclostephanos tholiformis等属种对乐安河源区水质较差且营养程度较高的水体指示性较强;③冗余分析(RDA)表明,SD、DO、TP三项水质因子较高程度的解释了当地硅藻属种组合的变化规律。

To explore the trophic level and the response of diatoms in surface sediments of reservoirs in the source region of Le’anhe River to the water environment,this paper conducts research on Duanxin Reservoir,Zhanggongshan Reservoir,Zhonglyu Reservoir,Datangwu Reservoir,and Shijing Reservoir in the source region of Le’anhe River.By the trophic level index(TLI),principal component analysis,and redundancy analysis(RDA),the water quality environment and the diatoms in surface sediments are taken as the research object and the research carrier,respectively,and the trophic state of reservoirs and the relationship between diatoms in surface sediments and water quality are qualitatively analyzed.The research results reveal that①the water quality of Duanxin Reservoir belongs to Class I,i.e.,in a mesotrophic state;the water quality of Shijing Reservoir seriously exceeds Class V,i.e.,in a mid-eutrophic state;the water quality in other reservoirs are in ClassⅢ,namely,in a mesotrophic state.②The distribution characteristics of diatom communities have a good indicator effect on the water environment of Le’anhe River.For example,genera and species such as Aulancoseiragrannulata are mainly distributed in water bodies with good water quality and at a mesotrophic level,and genera and species such as Cyclostephanos tholiformis are more indicative of water bodies with poor water quality and a high trophic level in the source region of Le’anhe River.③RDA indicates that the three water quality factors of SD,DO,and TP can explain the variation laws of diatom assemblage to a great degree.