Zhang Chen, Zhang Yuzhou, García-Girón Jorge, Tan Kai, Wang Lei, Ge Yihao, Yan Yunzhi
School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China.
Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-Founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China.
Animals (Basel). 2022 Jul 3;12(13):1721. doi: 10.3390/ani12131721.
Environmental filtering, spatial factors and species interactions are fundamental ecological mechanisms for community organisation, yet the role of such interactions across different environmental and spatial settings remains mostly unknown. In this study, we investigated fish community organisation scenarios and seasonal species-to-species associations potentially reflecting biotic associations along the Qiupu River (China). Based on a latent variable approach and a tree-based method, we compared the relative contribution of the abiotic environment, spatial covariates and potential species associations for variation in the community structure, and assessed whether different assembly scenarios were modulated by concomitant changes in the interaction network structure of fish communities across seasons. We found that potential species associations might have been underestimated in community-based assessments of stream fish. Omnivore species, since they have more associations with other species, were found to be key components sustaining fish interaction networks across different stream orders. Hence, we suggest that species interactions, such as predation and competition, likely played a key role in community structure. For instance, indices accounting for network structure, such as connectance and nestedness, were strongly correlated with the unexplained residuals from our latent variable approach, thereby re-emphasising that biotic signals, potentially reflecting species interactions, may be of primary importance in determining stream fish communities across seasons. Overall, our findings indicate that interaction network structures are a powerful tool to reflect the contribution of potential species associations to community assembly. From an applied perspective, this study should encourage freshwater ecologists to empirically capture and manage biotic constraints in stream ecosystems across different geographical and environmental settings, especially in the context of the ever-increasing impacts of human-induced local extinction debts and species invasions.
环境过滤、空间因素和物种相互作用是群落组织的基本生态机制，然而，这些相互作用在不同环境和空间背景下所起的作用仍大多未知。在本研究中，我们调查了秋浦河（中国）鱼类群落组织情况以及可能反映生物关联的季节性物种间关联。基于潜在变量方法和基于树的方法，我们比较了非生物环境、空间协变量和潜在物种关联对群落结构变化的相对贡献，并评估了不同的组装情景是否受到鱼类群落跨季节相互作用网络结构伴随变化的调节。我们发现，在基于群落的溪流鱼类评估中，潜在物种关联可能被低估了。杂食性物种由于与其他物种有更多关联，被发现是维持不同溪流等级鱼类相互作用网络的关键组成部分。因此，我们认为捕食和竞争等物种相互作用可能在群落结构中起关键作用。例如，反映网络结构的指标，如连通性和嵌套性，与我们潜在变量方法中无法解释的残差密切相关，从而再次强调，可能反映物种相互作用的生物信号在决定跨季节溪流鱼类群落方面可能至关重要。总体而言，我们的研究结果表明，相互作用网络结构是反映潜在物种关联对群落组装贡献的有力工具。从应用角度来看，本研究应促使淡水生态学家在不同地理和环境背景下，特别是在人为导致的局部灭绝债务和物种入侵影响不断增加的背景下，实证捕捉并管理溪流生态系统中的生物限制因素。
