生态廊道建设对洱海不同类型湖湾鱼类群落分布及多样性的影响

ECOLOGICAL CORRIDOR CONSTRUCTION ON THE DISTRIBUTION AND DIVERSITY OF FISH COMMUNITIES IN DIFFERENT TYPES OF BAYS IN ERHAI LAKE

为探究湖滨带生态廊道建设对湖泊近岸带水生生物群落分布及多样性的影响,研究比较了洱海湖滨带生态廊道建设前后不同类型湖湾(S型和L型)鱼类群落结构的变化,结果表明:(1)生态廊道建设导致S型湖湾鱼类优势度降低,而L型湖湾增加;(2)生态廊道建设后L型湖湾鱼类多样性指数增加明显,其中H′指数在生态廊道建设前后显著差异(P<0.05);S型湖湾多样性指数下降;(3)S型湖湾鱼类密度较建设前下降而生物量增加,主要是中大型鱼类丰度增加;而L型湖湾的小型鱼类丰度增加;鱼类生物量丰度ABC曲线结果显示S型湖湾建设后为中度干扰,而L型湖湾建设后为轻度干扰,鱼类群落结构更加稳定;(4)环境因子RDA分析显示,影响S型湖湾和L型湖湾鱼类生物量的环境影响因子均为水体透明度、pH和水深,且优势鱼类影响最大的均为鲢。综上,洱海生态廊道建设对S型湖湾鱼类群落结构影响较大,导致了鱼类结构组成的快速改变,建议生态廊道建设以L型湖湾改造为主。研究为鱼类多样性保护及生境恢复提供理论依据。

The construction of ecological corridor in lakeside zone is a a novel approach to restoring the ecology of the lakeside,but little attention has been paid to the effects of corridor on the distribution and diversity of aquatic communities in this zone.In this study,we investigated the changes in fish community characteristics in different types of bays(S-type and L-type) before and after the construction of the ecological corridor in Erhai Lake.The results showed that:(1) The construction of ecological corridor caused decrease of fish dominance in S-type bays,but an increase in Ltype.(2) The fish diversity index in L-type increased significantly after construction,with the H′ showing a significant difference compared to before(P<0.05),however,the diversity index decreased in S-type.(3) The fish density decreased in S-type,but the biomass increased due to an increase in the abundance of medium and large-sized fish,while the abundance of small-sized fish increased in L-type.The fish abundance biomass comparison curve showed that the S-type was a moderate disturbance after construction,while,the disturbance of L-type was mild and the fish community structure was more stable.(4) RDA analysis showed that water transparency,pH and water depth were the main environmental factors affecting fish biomass in both S-type and L-type bays,and silver carp was the dominant fish.In conclusion,the construction of ecological corridor has a significant impact on the structure of fish community,particularly in S-type where it leads to a rapid change in fish composition community.Therefore,it is suggested that ecological corridor construction should focus on the transformation of L-type.This study provides a theoretical basis for the protection of fish diversity and habitat restoration.