Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Ziyang Road 99, Nanchang, 330022, China.
School of Mathematics, Statistics and Actuarial Sciences, University of Kent, Parkwood Road, Canterbury, CT2 7FS, United Kingdom.
Ecology. 2020 Jun;101(6):e03026. doi: 10.1002/ecy.3026. Epub 2020 Mar 30.
Omnivores have long been known to play an important role in determining the stability of ecological communities. Recent theoretical studies have suggested that they may also increase the resilience of their communities to habitat destruction, one of the major drivers of species extinctions globally. However, these outcomes were obtained for minimal food webs consisting of only a single omnivore and its prey species, while much more complex communities can be anticipated in nature. In this study, we undertake a systematic comparative analysis of the robustness of metacommunities containing various omnivory structures to habitat loss and fragmentation using a mathematical model. We observe that, in general, omnivores are better able to survive facing habitat destruction than specialist predators of similar trophic level. However, the community as a whole does not always benefit from the presence of omnivores, as they may drive their intraguild prey to extinction. We also analyze the frequency with which these modules occur in a set of empirical food webs, and demonstrate that variation in their rate of occurrence is consistent with our model predictions. Our findings demonstrate the importance of considering the complete food web in which an omnivore is embedded, suggesting that future study should focus on more holistic community analysis.
杂食动物长期以来一直被认为在确定生态群落的稳定性方面发挥着重要作用。最近的理论研究表明，它们还可能提高其群落对栖息地破坏的恢复力，栖息地破坏是全球物种灭绝的主要驱动因素之一。然而，这些结果是针对仅由单一杂食动物及其猎物物种组成的最小食物网获得的，而在自然界中可以预期存在更复杂的群落。在这项研究中，我们使用数学模型对包含各种杂食结构的后生境群落对生境丧失和破碎化的稳健性进行了系统的比较分析。我们观察到，一般来说，杂食动物在面对栖息地破坏时比具有相似营养级的专业捕食者更能生存。然而，整个群落并不总是受益于杂食动物的存在，因为它们可能会导致其同营养级的猎物灭绝。我们还分析了这些模块在一组经验食物网中出现的频率，并证明它们的出现频率变化与我们的模型预测一致。我们的研究结果表明，在考虑嵌入杂食动物的完整食物网时，必须考虑到这一点，这表明未来的研究应侧重于更全面的群落分析。
