Interannual variations of the fish assemblage in the transitional zone of the Three Gorges Reservoir: persistence and stability
Interannual variations of the fish assemblage in the transitional zone of the Three Gorges Reservoir: persistence and stability
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DOI：
10.1007/s10641-011-9936-6
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发表时间：
2012-02
影响因子：
1.4
通讯作者：
Shaorong Yang;Xin Gao;Mingzheng Li;Baoshan Ma;Huanzhang Liu
中科院分区：
文献类型：
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作者：
Shaorong Yang;Xin Gao;Mingzheng Li;Baoshan Ma;Huanzhang Liu
大坝的建设可能会导致戏剧性的变化，鱼类组合由于水库蓄水造成的湖泊栖息地的损失，这已经有很好的记录。然而，知识的过渡带，这是一个过渡带之间的湖泊和湖泊环境的鱼类组合的时间变化，仍然是非常罕见的。1997 - 2002年和2006 - 2009年对三峡库区过渡带鱼类进行了采样，研究了过渡带鱼类群落的年际变化。结果表明，该过渡带共有9科77种，以鲤科为优势类群。通过聚类分析（CLUSTER）和非度量多维尺度分析（MDS），组合分为两组，在Bray-Curtis相似性值为77.26%，代表蓄水前和蓄水后的时期。通过物种贡献相似性百分比（SIMPER）分析，对两个类群的差异贡献最大的是圆嘴铜鱼、柱吻鱼和异齿铜鱼等的丰度变化。令人惊讶的是，相对于湖相区的剧烈变化，过渡带的鱼类组合似乎相对稳定，因为每年捕获的10个核心物种是一致的，在我们的研究期间没有发生明显的物种更替。此外，中等的持久性指数表明，鱼类组合的持久性，以及，尽管一些物种的转移。排序和时滞分析结果表明，过渡带鱼类群落没有发生方向性变化。三峡库区过渡带鱼类群落在各调查年中基本保持稳定。根据我们的研究结果，我们建议，在水库中的动态过渡带的维护将是有益的鱼类，特别是对栖息在长江上游的特有种的保护。
The construction of dams may lead to dramatic changes in fish assemblages due to the loss of lotic habitat caused by impoundment, which have been well documented. However, knowledge of the temporal variation of fish assemblages in the transitional zone, which is an ecotone between lotic and lentic environments of the reservoir, is still very rare. In the present study, fishes in the transitional zone of the Three Gorges Reservoir were sampled from 1997 to 2002 and from 2006 to 2009 to investigate interannual variations of fish assemblages. The results showed that 9 families, composed of 77 species, were found in the transitional zone with Cyprinidae as the dominant group. By cluster analysis (CLUSTER) and non-metric multidimensional scaling analysis (MDS), assemblages were separated into two groups at a Bray-Curtis similarity value of 77.26%, representing the pre-impoundment period and post-impoundment period. Following analysis of similarity percentages of species contributions (SIMPER), shifts in abundances ofCoreius guichenoti,Rhinogobio cylindricusandCoreius heterodon, etc. contributed most to the difference between the two groups. Surprisingly, contrasting to the drastic changes in lacustrine region, the fish assemblage in the transitional zone appeared to be relatively stable, since the ten core species caught were consistently recorded every year, and no significant species replacement occurred during our study period. Besides, the moderate index of persistence indicated persistence of the fish assemblage as well, in spite of the shift of some species. Based on the results of ordination and time-lag analysis, the fish assemblage in the transitional zone showed no directional change. We conclude that fish assemblage in the transitional zone of the Three Gorges Reservoir was stable across the surveyed years. Based on our results, we propose that maintenance of dynamic transitional zones in reservoirs will be useful for the preservation of fishes, particularly for the endemic species inhabiting the upper Yangtze.