| 摘要: |
| 为了解向家坝水电工程对金沙江下游鱼类多样性的影响，基于2016-2018年邵女坪(库首)、绥江(库中)和桧溪(库尾)3个江段的鱼类群落调查数据，分析了向家坝库区鱼类物种、分类和功能多样性空间格局，结合蓄水前(2011年)和蓄水初期(2015年)绥江江段的资料，探讨了蓄水后向家坝库区不同维度鱼类多样性的变化趋势。向家坝库区各江段以广适性的瓦氏黄颡鱼(Pelteobagrus vachelli)和静水性的?(Hemiculter leucisculus)等占优势，两者的数量百分比分别为30.15%±14.82%和13.91%±11.16%。非度量多维尺度分析(non-metric multi dimensional scale, NMDS)显示，蓄水后向家坝库区库首邵女坪和库中绥江鱼类群落差异最小，库首邵女坪和库尾桧溪鱼类群落差异最大；库中绥江在蓄水前，蓄水初期和2016-2018年等3个时期的鱼类群落差异均较大，表明蓄水后绥江江段鱼类群落经历了剧烈变化。库区不同江段鱼类Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均表现为：桧溪>邵女坪>绥江，鱼类分类多样性指数(Δ)和分类差异指数(Δ*)均表现为：桧溪>绥江>邵女坪。库区鱼类摄食、运动和繁殖等不同维度的功能多样性(功能丰富度FRic、功能均匀度FEve、功能离散度FDiv)空间格局不同，但总体上库中绥江鱼类功能丰富度最高，功能均匀度最低。与蓄水前相比，绥江江段鱼类物种、分类多样性呈下降趋势，鱼类功能丰富度和均匀度也有下降趋势。蓄水后绥江江段鱼类群落主要功能性状发生了明显变化，如蓄水前以下位口、纺锤形体型鱼类占优势，蓄水后以端位口、侧扁形体型鱼类占优势。不同维度多样性指数侧重于鱼类多样性的不同方面，结合多种指数分析有利于更全面地了解鱼类群落对环境变化和外界干扰的响应。研究结果有助于深入了解水电工程建设对金沙江下游鱼类多样性的影响，为鱼类多样性保护提供依据，也可为长江“十年禁渔”效果评估提供本底资料。 |
| 关键词: 物种多样性，分类学多样性，功能多样性，大坝，鱼类，金沙江 |
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| 基金项目:国家自然科学基金(51779105,51979123)和湖北省高等学校优秀中青年科技创新团队计划项目(T2020034)联合资助. |
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| Changes of species, taxonomic and functional diversity of fish assemblages in the Xiangjiaba reservoir of the lower Jinsha River after impoundment |
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Xiongfei1, Zhangwei, Zhaidongdong, Liuhongyan, Chenyuanyuan, Duanxingbin2, Tianhuiwu, Chendaqing
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1.School of Life Sciences, Hubei Engineering Research Center for Protection and Utilization of Special Biological Resources in the Hanjiang River Basin, Jianghan University;2.Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Science
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| Abstract: |
| Effects on fish from the construction of hydropower projects attract much attention. To understand the effects on fish diversity from the Xiangjiab reservoir in the lower Jinsha River, quantitative surveys were conducted for the spatial distribution of taxonomic and functional diversity of fish assemblages in Shaonvping, Suijiang and Huixi sections, located in the lower, middle and upper streams of the reservoir, respectively, during 2016-2018. Combined with the data before (2011) and at the beginning of (2015) impoundment, the change trend of fish diversity in different dimensions in the lower reaches of the Jinsha River after impoundment was discussed. Eurytopic and limnophilic fish species such as Hemiculter bleekeri and Pseudobagrus vachelli dominated the Xiangjiaba Reservoir. H. bleekeri and P. vachelli accounted for 30.15%±14.82% and 13.91%±11.16% in abundance, respectively. Nonmetric multidimensional scaling (NMDS) showed that the fish community structure was more similar between Shaonvping and Suijiang sections. In contrast, fish community differed from Shaonvpin and Suijiang sections. In the Suijiang River section, fish communities in the three periods (before, during and after the impoundment) were significantly different, indicating that fish communities in the Suijiang River section have undergone dramatic changes after the impoundment. Higher values of Margalef index, Shannon-Wiener index and Pielou index of fish in different river sections of the reservoir area were shown as follows: Huixi>Shaonvping>Suijiang; Taxonomic diversity index (Δ) and taxonomic differencess index (Δ*) were shown as follows: Huixi>Suijiang>Shaonvping. The spatial pattern of functional diversity (Functional richness FRic, Functional evenness FEve, Functional divergence FDiv) in different dimensions of fish feeding, movement and reproduction in the reservoir area was different. Generally, the highest FRic and the lowest FEve were found in Suijiang Section. The species and taxonomic diversity in Suijiang section showed a decreased trend compared with that before impoundment, and the functional richness and evenness also showed a decreased trend. After impoundment, functional traits of different dimensions, such as feeding, movement and reproduction, also had some significant changes. For example, the dominant fishes changed from the species with inferior position mouth and fusiform body shape to those with terminal position mouth and compressiform body shape. Different diversity indices focus on different aspects of fish diversity, and the combination of multiple index analysis is conducive to a more comprehensive understanding of the response of fish communities to environmental changes and external disturbances. The results contribute to comprehensively understand the effects of hydropower projects on fish diversity in the lower Jinsha River, provide theoretic references for fish conservation, and accumulate background data for ecological effect assessment of Ten-Year fishing Ban. |
| Key words: Species diversity, taxonomic diversity, functional diversity, dam,fish,Jinsha River |
