State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China.
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China.
J Environ Manage. 2022 Sep 1;317:115310. doi: 10.1016/j.jenvman.2022.115310. Epub 2022 May 26.
Dispersal is an essential natural process that influences community assembly, yet directional dispersal through wind and water may have distinctive effects. Environmental and spatial factors jointly influence community structure, but their relative importance is anticipated to vary with spatial distance, dispersal mode, and season. Accordingly, a systemic survey was conducted in subtropical Chinese mountain lotic systems to distinguish the relative contributions of environmental control and spatial structuring upon communities of macroinvertebrates with different dispersal ability. Macroinvertebrate samples were collected from the upper reaches and five tributaries of the Hanjiang River in October 2017 (autumn) and April 2018 (spring). These macroinvertebrates were identified and classified into three dispersal groups: aquatic passive (AqPa), terrestrial passive (TePa), and terrestrial active (TeAc). Variation partitioning analyses were performed on environmental factors and different sets of spatial factors (overland dispersal: Overland, directional downwind dispersal: AEM_Wind, along watercourse dispersal: Watercourse, and directional downstream dispersal: AEM_Water). Findings showed that both environmental filtering and spatial structuring influenced the structure of macroinvertebrate metacommunities. For AqPa and TePa groups, pure environmental effects were stronger than pure spatial effects based on most distance matrices; however, in AEM_Water, the effects of spatial processes surpassed those of environmental filtering. For TeAc group, the role of environmental control and spatial structuring varied depending on different spatial models. The results also highlighted seasonal shifts in metacommunity structuring processes. Spatial structures featuring direction, especially AEM_Water, were predominant in explaining the construction of macroinvertebrate communities. This work suggests that directional dispersal should be explicitly considered when examining the structure of ecological communities.
扩散是影响群落组装的一个重要自然过程，但风传和水传的定向扩散可能具有独特的影响。环境和空间因素共同影响群落结构，但它们的相对重要性预计会随着空间距离、扩散模式和季节的变化而变化。因此，在中国亚热带山区流水系统中进行了系统调查，以区分环境控制和空间结构对具有不同扩散能力的大型无脊椎动物群落的相对贡献。2017 年 10 月（秋季）和 2018 年 4 月（春季），从汉江上游和五条支流采集了大型无脊椎动物样本。这些大型无脊椎动物被鉴定并分为三种扩散组：水生被动（AqPa）、陆地被动（TePa）和陆地主动（TeAc）。对环境因素和不同空间因素集（陆上扩散：Overland、下风定向扩散：AEM_Wind、沿河道扩散：Watercourse 和下游定向扩散：AEM_Water）进行了方差分解分析。结果表明，环境过滤和空间结构都影响了大型无脊椎动物元群落的结构。对于 AqPa 和 TePa 组，基于大多数距离矩阵，纯环境效应强于纯空间效应；然而，在 AEM_Water 中，空间过程的影响超过了环境过滤。对于 TeAc 组，环境控制和空间结构的作用因不同的空间模型而异。研究结果还强调了元群落结构过程的季节性变化。具有方向性的空间结构，特别是 AEM_Water，在解释大型无脊椎动物群落的构建方面起着主导作用。这项工作表明，在研究生态群落的结构时，应明确考虑定向扩散。
