论文标题
互动强度的异质性及其对生态系统的后果
Heterogeneity of Interaction Strengths and Its Consequences on Ecological Systems
论文作者
论文摘要
生态系统由物种网络及其相互作用形成。这种相互作用的传统模型假设给定的物种之间具有恒定的相互作用强度。但是，即使在同一物种中，各个生物体之间也经常存在显着的性状差异，从而导致其与其他物种的相互作用强度异质性。这种异质相互作用对生态系统的后果尚未系统地研究。作为一种理论探索，我们通过两个捕食者与共享猎物之间的营养相互作用分析了一个简单的生态系统，这将在具有均匀相互作用的模型中表现出竞争性排斥。我们考虑了几种情况，其中猎物物种的个体分化为具有不同相互作用强度的亚群。我们表明，在所有这些情况下，无论异质性是固有的，可逆的还是自适应的，生态系统都可以在所有三个物种共存的新平衡处稳定。此外，与没有异质性相比，与其捕食者有异质相互作用的猎物人群达到的密度要高，甚至在两个捕食者存在下甚至可以达到更高的密度。我们的结果表明，异质性可能是生态相互作用的自然选择的特征，对生态系统的稳定性和多样性产生重要影响。
Ecosystems are formed by networks of species and their interactions. Traditional models of such interactions assume a constant interaction strength between a given pair of species. However, there is often significant trait variation among individual organisms even within the same species, causing heterogeneity in their interaction strengths with other species. The consequences of such heterogeneous interactions for the ecosystem have not been studied systematically. As a theoretical exploration, we analyze a simple ecosystem with trophic interactions between two predators and a shared prey, which would exhibit competitive exclusion in models with homogeneous interactions. We consider several scenarios where individuals of the prey species differentiate into subpopulations with different interaction strengths. We show that in all these cases, whether the heterogeneity is inherent, reversible, or adaptive, the ecosystem can stabilize at a new equilibrium where all three species coexist. Moreover, the prey population that has heterogeneous interactions with its predators reaches a higher density than it would without heterogeneity, and can even reach a higher density in the presence of two predators than with just one. Our results suggest that heterogeneity may be a naturally selected feature of ecological interactions that have important consequences for the stability and diversity of ecosystems.
