Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, SL5 7PY, UK.
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
Ecol Lett. 2021 Feb;24(2):298-309. doi: 10.1111/ele.13643. Epub 2020 Nov 18.
How species coexistence (mathematical 'feasibility') in food webs emerges from species' trophic interactions remains a long-standing open question. Here we investigate how structure (network topology and body-size structure) and behaviour (foraging strategy and spatial dimensionality of interactions) interactively affect feasibility in food webs. Metabolically-constrained modelling of food-web dynamics based on whole-organism consumption revealed that feasibility is promoted in systems dominated by large-eat-small foraging (consumers eating smaller resources) whenever (1) many top consumers are present, (2) grazing or sit-and-wait foraging strategies are common, and (3) species engage in two-dimensional interactions. Congruently, the first two conditions were associated with dominance of large-eat-small foraging in 74 well-resolved (primarily aquatic) real-world food webs. Our findings provide a new, mechanistic understanding of how behavioural properties can modulate the effects of structural properties on species coexistence in food webs, and suggest that 'being feasible' constrains the spectra of behavioural and structural properties seen in natural food webs.
物种共存（数学上的“可行性”）如何在食物网中出现，仍然是一个长期存在的开放性问题。在这里，我们研究了结构（网络拓扑和体型结构）和行为（觅食策略和相互作用的空间维度）如何相互作用，影响食物网中的可行性。基于整体生物消耗的食物网动态的新陈代谢约束建模表明，只要（1）存在许多大型捕食者，（2）普遍存在放牧或坐等觅食策略，以及（3）物种进行二维相互作用，那么在由大食小觅食（消费者吃更小的资源）主导的系统中，可行性就会得到促进。一致地，前两个条件与 74 个良好解析（主要是水生）现实世界食物网中大食小觅食的主导地位有关。我们的研究结果提供了一种新的、机械的理解，即行为特性如何调节结构特性对食物网中物种共存的影响，并表明“可行性”限制了自然食物网中出现的行为和结构特性的范围。
