城市有机污染对嘉陵江南充段硅藻多样性影响

The Influence of Organic Pollution on Diversity of Diatom in Nanchong Section of Jialing River

采集了嘉陵江南充A*段5个城市15个采样点藻类样品,研究城市有机污染对硅藻多样性的影响.结果表明:有机污染程度的增加,导致硅藻物种数减少、细胞密度增加、多样性指数值和均匀度指数值降低;硅藻群落相似性聚类图表明,15个采样点根据有机污染程度及水质状况分成3类,B-7.5由清洁水体的LZ1,LZ3和NB1组成,C-7.5由污染较严重(α-中污)的NC2和NC3组成,A-7.5主要由污染较轻(β-中污或微污)的LZ2,NB3,NC1等10个采样点组成;聚类结果与其它指标及实际观测的水环境状况相吻合,较好地揭示了有机污染对硅藻多样性的影响.

To reveal the influence of organic pollution on diatom diversity in Nanchong section of the Jialing River, fifteen diatom samples were collected and diatom species numbers, cell density, diversity index and evenness index were studied. The results showed that. Organic pollution resulted in the decrease of diatom species numbers, increase of cell density and the decline of diversity and evenness index value. According to organic pollution degree and water quality conditions, fifteen sampling sites were classified into three types by clustering dendrogram of similarity of diatom community. B- 7.5 was composed of LZ1, LZ3 and NBlwith clear water-body; C--7.5 was composed of LZ2, NB3 and NC1 whose water quality belonged to α-mesosaprobic Zone; A--7.5 was mainly composed of LZ2, NB3, NC1, and so on whose water quality belonged to β-mesosaprobic Zone or Oligosaprobid Zone. The clustering result, which was coincidental with other indices and real water environmental conditions, preferably revealed the influence of organic pollution on diatom diversity.