黄河下游支流大汶河鱼类多样性及影响因子分析

为了解黄河下游支流大汶河鱼类多样性及其与环境因子的关系，分别于2017年4月和10月对大汶河24个采样点进行鱼类及环境调查，采用冗余分析方法识别了影响大汶河鱼类个体数量和多样性指数的主要环境因子。结果表明:2017年共采集到鱼类8 299尾，隶属于4目16科25种，其中鲤科鱼类共15种；鱼类多样性和均匀性较差，优势种以鲫(Carassius auratus)、(Hemiculter leucisclus)和乌鳢(Channa argus)等耐受性较强的平原性鱼类为主；大汶河鱼类物种数量、生物量和多样性指数的季节性变化不显著，但是秋季个体数量显著大于春季；影响大汶河鱼类个体数量的主要环境因子是水深和河宽，而影响鱼类多样性指数的主要环境因子是DO。

Fish diversity and its influencing factors in the Dawen River, a tributary of the lower Yellow River

In order to understand the fish diversity and its relationship with environmental factors in the Dawen River, a tributary of the lower Yellow River, fish and environmental surveys were conducted at 24 sampling sites in April and October 2017, respectively. Redundancy analysis was used to identify the main influencing factors on the individual number and diversity index of fish in the Dawen River. The results showed that a total of 8 299 fish were collected in 2017, belonging to 25 species of 16 families and 4 orders, including 15 species of Cyprinidae. The diversity and evenness of fish were poor, and the dominant species were Carassius auratus, Hemiculter leuciscus and Channa argus. The seasonal variation of fish species number, biomass and diversity index was not significant, but the individual number in autumn was significantly higher than that in spring. Water depth and river width are the main environmental factors affecting the fish population in the Dawen River, while DO is the main environmental factor affecting fish diversity index.