嘉陵江源鱼类群落结构特征与环境因子的关系

Fish community structure and its relationship withenvironmental factors in the source region of Jialing River

为进一步了解和掌握嘉陵江源头水域鱼类群落变化特征,本研究于2019年在嘉陵江源头水域开展了春夏两季的鱼类调查工作。结果显示:两次调查共采集到鱼类19种,分属2目6科,其中鲤科10种,鳅科5种,平鳍鳅科、鳍科、鲇科和鲿科各1种;嘉陵江源干流和支流小峪河鱼类群落优势度指数较高,各河段优势种以鲤科鱼类为主。物种多样性分析结果显示,调查河流鱼类多样性指数(H′)、均匀度指数(J)和丰富度指数(D)的变化范围分别为1.36~2.06、0.59~0.73和1.52~2.63,嘉陵江源干流河段和小峪河鱼类多样性指数和均匀度指数高于其他河流,而安河鱼类丰富度指数最高;与嘉陵江源历史记载相比,鱼类群落结构为中等相似。鱼类群落稳定性分析结果表明,除小峪河鱼类群落较为稳定外,其余河段鱼类群落均受到了不同程度的扰动。冗余分析(RDA)结果显示,河道曲折系数是影响调查区域内优势鳍种分布的主要环境因子。

This study was carried out in the spring and summer of 2019 to understand further the characteristics of fish community changes in the source region of the Jialing River.The results showed that a total of 19 species of fish belonging to two orders and six families were collected in the two surveys,including ten species of Cypriniformes,five species of Cbobitiolae,one species of Homalopteridae and Sisoridae and Siluridae and Bagridae,respectively.The dominant species of the fish community in the mainstream of Jialing River and Xiaoyuhe River was relatively high,and the dominant species in each river section belonged to Cypriniformes.The diversity analysis showed that the range of Shannon-Wiener index(H′),Pielou uniformity index(J)and Margalef richness index(D)were 1.3~2.06,0.59~0.73 and 1.52~2.63,respectively.Shannon-Wiener index(H′)and Pielou uniformity index(J)in the source region of the mainstream of Jialing River and Xiaoyuhe River were higher than that of the other rivers,while the Margalef richness index(D)of Anhe River was the highest.Compared with the historical records,the similarity of fish community was moderately similar.The results of the fish community stability analysis showed that the fish communities had been disturbed to varying degrees in the main stream and tributaries in the source region of Jialing River,except for the Xiaoyuhe River.Redundancy analysis(RDA)showed that river sinuosity was the main environmental factor affecting the dominant species in the survey area.