三峡水库鱼类群落多尺度时空格局及其驱动过程研究

The study on the ecological and environmental effects of large hydraulic project is a hot research topics in the field of ecological hydraulics. The Three Gorges Reservoir (TGR), with unique environmental heterogeneity and a short history, can serve as a natural experimental laboratory to examine the forming and maintaining mechanisms of fish communities under severe human disturbances. In this study, by using experimental sampling gears, fishery catch surveys, and hydro-acoustic methods, we will sample fish communities in the TGR on multiple spatial (regional and local areas such as vertical gradient from head to tail of the reservoir, vertical gradient along water depth, mainstream-tributary-confluence habitats, and littoral-pelagic habitats) and temporal (seasonal and annual) scales. With multivariate statistics, biodiversity models and indices, and measurements on functional traits and structural morphology, we will explore the spatial-temporal variations of fish communities in the TGR, including functional group compositions, species abundance distributions, biomass spectrum curves, species diversity, and functional diversity. We will investigate the utilization patterns of the fish communities for space and food resources as well as their adaptation characteristics in the TGR. And we will try to identify different key ecological processe and environmental factors under different spatial-temporal scales for these community patterns. We believe that this work will be helpful in understanding and predicting the ecological effects of this kind of large hydraulic project. Meanwhile, it is expected to provide some theoretic references for the optimization of ecological hydrology operation and artificial fish stocking in the TGR.

大型水利工程的生态环境效应是生态水利的研究热点，三峡水库独特的水环境时空异质性和较短的历史，使其成为研究人类剧烈干扰下鱼类群落格局形成与维持机制的天然试验场。本项目着眼于三峡水库多重空间（纵向梯度、水深梯度、干支流及交汇区、沿岸带及敞水区等区域和局域范围）与时间（季度和年度）尺度下的环境异质性，通过自制渔具采样、鱼探仪探测、渔民渔获物调查、生态形态学度量和多变量统计模型等技术手段，定量研究鱼类群聚组成、群落结构模式、alpha和beta多样性指数、功能群组成和功能多样性指数等群落格局的时空变化，分析鱼类群落对空间和食物资源的利用格局及适应性特征，进而解析影响三峡水库鱼类群落多尺度时空格局的关键生态过程和环境因素。项目的开展不仅有助于科学地评价和预测大型水利工程的生态学效应，还将为三峡水库生态水利调度和鱼类增殖放流方案制定提供理论参考。

大型水利工程的生态环境效应是生态水利的研究热点，三峡水库独特的水环境时空异质性和较短的历史，使其成为研究人类剧烈干扰下鱼类群落格局形成与维持机制的天然场所。本项目着眼于三峡水库多重空间（纵向梯度、水深梯度、干支流及交汇区、沿岸带及敞水区等区域和局域范围）与时间（季度和年度）尺度下的环境异质性，运用多种类型网具采样、水声学鱼探仪探测和渔民渔获物抽样调查等综合手段，同时系统收集三峡水库鱼类和环境等方面的历史资料，保障了鱼类群落数据的可靠性和完整性。在野外工作的基础上开展了样品处理和数据分析，包括鱼体测量、年龄鉴定、食性分析、水质分析、水声学图像处理、群落数据分析和食物网模型构建等具体研究任务。通过项目的实施和完成，查明了三峡水库鱼类物种组成的空间差异和历史变化，定量研究了库区鱼类群落结构、密度和生物量的时空分布格局，以及与水深和流速等关键环境因子的关系；阐释了鱼类垂直分布和水平迁移等活动行为，评估了鱼类群落营养结构及在食物网能量传递过程中的作用；从功能形态特征、营养生态位分化、繁殖和生长差异等方面，探讨了鱼类对空间和食物等资源的利用格局及生态适应性。总体上丰富了群落生态学的研究范畴和技术途径，为三峡水库及其他大型水库的鱼类资源评估和养护管理提供了基础数据与理论支撑。