Abstract：
The hydrographic and environmental factors along the Three Gorges Reservoir (TGR) have been significantly altered since the Three Gorges Dam (TGD) began working in 2006. Here, we collected 54 water samples, and then measured the environmental factors, followed by sequencing of the 18S rRNA gene and subsequent analysis of community assembly mechanisms. The findings indicated that the majority of environmental variables (such as AN, TP, Chl-a, CODMn, and Cu) exhibited both temporal and spatial variations due to the influences of the TGD. The distribution of different environmental factors and microeukaryotic plankton communities is influenced by the changing seasons. The community structure in TGR showed variations across three seasons, possibly due to variations in their environmental preferences, inherent dissimilarities, and seasonal succession. Furthermore, different communities exhibited a comparable distance-decay trend, suggesting that distinct taxa are likely to exhibit a similar spatial distribution. In addition, the community formation in TGR was influenced by both deterministic and stochastic factors, with the balance between them being mainly controlled by the season. Specifically, deterministic processes could explain 33.9-51.1% of community variations, while stochastic processes could contribute 23.5-32.2%. The findings of this research demonstrated that the varying ecological processes\' significance relied on environmental gradients, geographical scale, and ecological conditions. This could offer a fresh outlook on comprehending the composition, assembly mechanisms, and distribution patterns of microeukaryotic plankton in reservoir ecosystems.
摘要：
自2006年三峡大坝（TGD）开始工作以来，三峡水库（TGR）沿线的水文和环境因素发生了重大变化。这里,我们采集了54个水样,然后测量环境因素，然后对18SrRNA基因进行测序，随后分析群落组装机制。研究结果表明，大多数环境变量(如AN，TP,Chl-a,CODMn,和Cu）由于TGD的影响而表现出时间和空间变化。不同环境因子和微真核浮游生物群落的分布受季节变化的影响。TGR中的群落结构显示出三个季节的变化，可能是由于他们环境偏好的变化，固有的差异，和季节性演替。此外，不同的群落表现出可比的距离衰减趋势，这表明不同的分类单元可能表现出相似的空间分布。此外,TGR中的群落形成受确定性和随机性因素的影响，它们之间的平衡主要由季节控制。具体来说,确定性过程可以解释33.9-51.1%的社区变异，而随机过程可能占23.5%-32.2%。这项研究的结果表明，不同的生态过程的意义依赖于环境梯度，地理尺度,和生态条件。这可以为理解构图提供新的前景，装配机构,微真核浮游生物在水库生态系统中的分布规律。
