Spatio-temporal patterns of zooplankton in a main-stem dam affected tributary: a case study in the Xiangxi River of the Three Gorges Reservoir, China
Spatio-temporal patterns of zooplankton in a main-stem dam affected tributary: a case study in the Xiangxi River of the Three Gorges Reservoir, China
复制标题
主坝影响支流浮游动物时空格局——以三峡水库湘西河为例
DOI：
10.1007/s11427-018-9523-0
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发表时间：
2019-08-01
影响因子：
9.1
通讯作者：
Song, Weibo
中科院分区：
文献类型：
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作者：
Li, Xinghao;Huang, Jie;Song, Weibo
支流作为河流生态系统重要的受体通道，为微生物提供了独特的微生境，其中浮游动物是最重要的异养生物。特别是水坝造成的水流流速降低更有利于浮游动物的发育；因此，筑坝河流预计将支持极其多样化和丰富的浮游动物群落以及明显不同的时空分布模式。然而到目前为止，只有很少的分子研究支持这些假设。利用高通量测序，从三峡大坝上游最近的大型支流香溪河采集的 30 个样本中检索到了 350 个操作分类单元（OTU；97% 截止值）。浮游动物在河道中没有表现出明显的空间分布。相反，群落结构在采样日期内显着变化，证实了亚热带地区湖泊和池塘中发现的季节性模式。正如预期的那样，群落组成由环境过滤过程（系统发育聚类）决定性地控制，其中水流速度似乎比其他研究的环境因素重要得多。此外，大多数检测到的系统发育型（OTU）与先前保藏的序列具有相对较高（>90%）的序列相似性，表明香溪河浮游动物群落的遗传新颖性程度中等。
As the ecologically important recipient channels for riverine ecosystems, tributaries provide unique microhabitats for microorganisms, among which zooplankton constitutes the most important heterotrophic organisms. In particular, the reduced water velocity caused by dams is more favorable for zooplankton development; therefore, dammed rivers are expected to support extremely diverse and abundant zooplankton communities and notably different spatiotemporal distribution patterns. So far, however, only very few molecular studies support these assumptions. Using high-throughput sequencing, a high number of 350 operational taxonomic units (OTUs; 97% cutoff) were retrieved from 30 samples collected in the Xiangxi River, the nearest large tributary upstream of the Three Gorges Dam. Zooplankton did not show significant spatial distribution in the channel. Instead, the community structures varied significantly over sampling dates, corroborating the seasonal patterns found in lakes and ponds in the subtropical zone. As expected, the community compositions were deterministically governed by environmental filtering processes (phylogenetic clustering), in which water velocity appeared to be much less important than other investigated environmental factors. Moreover, most of the detected phylotypes (OTUs) had a relatively high (>90%) sequence similarity to previously deposited sequences, suggesting a mediocre degree of genetic novelty within the zooplankton communities in the Xiangxi River.