辽河干流自然保护区鱼类群落结构及其多样性变化

2010年9月、2011年5月和8月对辽河干流自然保护区开展了鱼类调查。结果显示,保护区共有鱼类28种,以杂食性耐污小型鱼类为主,其中鲤科鱼类占65.52%。与历史资料相比,鱼类种类大幅减少,且表现出营养结构简单化、鱼类资源小型化的特征。保护区鱼类群落组成存在显著的空间变化,可分为石佛寺水库上游、石佛寺水库下游和感潮河段3个区段。保护区上游鱼类多样性和物种丰富度指数高于下游;鱼类物种数秋季高于春季,而鱼类个体数均匀程度春季高于秋季。典范对应分析发现秋季TN(F=3.25,P=0.012)和水温(F=2.86,P=0.016)为显著影响鱼类群落的环境因子。

Community structure and diversity of fishes in the Liao River Nature Reserve

The investigations on the fish community were carried out in Sep 2010,May and Aug 2011.The results showed that the captured 28 fish species was dominated by small,omnivorous,high tolerance fishes.Cyprinidae took up 65.62% of the total species.There was apparent decline in the number of species and the complexity of trophic structure compared with the history data.Fish community in the Liao River Reserve could be divided into three groups:group one was the upper region of Shifosi reservoir,group two was the lower region of Shifosi reservoir,and group three was around the estuary region.The Shannon-Wiener diversity index and Margalef's diversity index in the upper river were higher than those in the lower river.Species abundance in autumn was higher than that in spring,but fish number was better distributed in spring.The environmental factors affecting fish community significantly were different in two seasons.No key factors were found in spring,whereas the key factor in autumn was total nitrogen(F=3.25,P=0.012) and water temperature(F=2.86,P=0.016).