Département de biologie, ArcticNet, Québec Océan, Université Laval, Québec, QC, Canada.
Institut des sciences de la mer, Université du Québec à Rimouski, Rimouski, QC, Canada.
Ecol Lett. 2021 Oct;24(10):2219-2237. doi: 10.1111/ele.13841. Epub 2021 Jul 19.
Evaluating the effects of multiple stressors on ecosystems is becoming increasingly vital with global changes. The role of species interactions in propagating the effects of stressors, although widely acknowledged, has yet to be formally explored. Here, we conceptualise how stressors propagate through food webs and explore how they affect simulated three-species motifs and food webs of the Canadian St. Lawrence System. We find that overlooking species interactions invariably underestimate the effects of stressors, and that synergistic and antagonistic effects through food webs are prevalent. We also find that interaction type influences a species' susceptibility to stressors; species in omnivory and tri-trophic food chain interactions in particular are sensitive and prone to synergistic and antagonistic effects. Finally, we find that apex predators were negatively affected and mesopredators benefited from the effects of stressors due to their trophic position in the St. Lawrence System, but that species sensitivity is dependent on food web structure. In conceptualising the effects of multiple stressors on food webs, we bring theory closer to practice and show that considering the intricacies of ecological communities is key to assess the net effects of stressors on species.
随着全球变化，评估多种胁迫对生态系统的影响变得越来越重要。尽管物种相互作用在传播胁迫效应方面得到了广泛认可，但尚未对其进行正式探讨。在这里，我们概念化了胁迫如何通过食物网传播，并探讨了它们如何影响模拟的三个物种模式和加拿大圣劳伦斯系统的食物网。我们发现，忽略物种相互作用总是会低估胁迫的影响，并且通过食物网存在协同和拮抗作用。我们还发现，相互作用类型会影响物种对胁迫的敏感性；杂食性和三营养级食物链相互作用的物种特别敏感，容易受到协同和拮抗作用的影响。最后，我们发现由于圣劳伦斯系统中的营养位，顶级捕食者受到负面影响，而中型捕食者受益于胁迫的影响，但物种敏感性取决于食物网结构。在概念化多种胁迫对食物网的影响时，我们使理论更接近实践，并表明考虑生态群落的复杂性是评估胁迫对物种的净影响的关键。
