纵向梯度下安宁河流域鱼类多样性格局与河流环境

As one of the most abundant biodiversity areas in China, the upper Yangtze River is one of the global biodiversity hotspots for the conservation of fishes. Meanwhile, this area has become one of the most highly impacted rivers in the world due to the cascade reservoir development. The Anning River Basin is located in the transitional zone of the Qinghai-Tibet Plateau, Yunnan-Kweichow Plateau, and Sichuan Basin. The transitional zone maintains high fish diversity and plays significant role in the ecological security and ecological construction of Sichuan Province. Eco-environmental problems, such as minerals, hydropower, agriculture and animal husbandry resources, in the Anning River Basin pose a threat to the ecological security in the region. Therefore, there is an urgent need to understand the relationship between the fish diversity pattern and environmental factors affected by dams in the Anning River Basin. Based on our previous work, fish diversity and river environment investigations will be conducted in the Anning River and its main tributaries along the longitudinal gradient from river source to the estuary. Fish species composition, community structural diversity, functional diversity and its relationship with the environmental factors will be studied, in order to reveal the patterns of fish biodiversity and environmental characteristics under the background of hydropower development. Combined with historical data, the ecological process of fish diversity and distribution pattern caused by the environmental change will also be clarified. Based on the related results, the adaptive management countermeasures for fish resources and biodiversity conservation in the Anning River Basin will be proposed.

长江上游是生物多样性的热点地区，同时也是我国受水电开发影响最大的区域。揭示水电开发影响下鱼类多样性格局及其与环境的关系是河流适应性管理与保护的前提。本研究在前期工作的基础上，拟以雅砻江一级支流安宁河流域为研究区域，以河流纵向梯度的鱼类多样性格局和河流环境特征为研究重点，分析鱼类物种组成、群落结构多样性和功能多样性特征及其与河流环境的关系，揭示安宁河流域鱼类多样性格局及环境特征。结合历史数据，阐明鱼类多样性和分布格局随河流环境变迁的生态学过程。基于相关结果，提出水电开发背景下安宁河流域鱼类资源和多样性保护的适应性对策。

本项目按照申请书设置的研究内容和实施计划有序进行，在安宁河干支流上共设置28个样点，对环境因子和鱼类多样性进行了调查，系统分析了安宁河纵向梯度下的鱼类多样性格局和河流环境特征。结果表明，安宁河河流环境、饵料生物组成、鱼类群落结构和功能群在纵向梯度均呈现明显的空间格局。安宁河上游和支流的鱼类群落结构较为接近，聚为一类，中游和下游聚为一类，海拔和底质类型是影响鱼类分布的主要环境因子。结合历史资料发现，安宁河中下游的梯级水电改变了原有的河流环境，水体流速降低、石质类型生境减少，导致原有的西昌白鱼、圆口铜鱼等土著鱼类消失，进而以麦穗鱼、棒花鱼、鲫和粗唇鮠等广适性鱼类为主。基于相关结果，提出了拆除小水电、划定安宁河鱼类保护区、严控河道无序采砂及外来种防控等保护对策。目前已发表研究论文7篇，其中SCI论文2篇，授权软件著作权1项。