Center for Models of Life, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
Phys Rev E. 2017 Sep;96(3-1):032406. doi: 10.1103/PhysRevE.96.032406. Epub 2017 Sep 8.
Ecological diversity is ubiquitous despite the restrictions imposed by competitive exclusion and apparent competition. To explain the observed richness of species in a given habitat, food-web theory has explored nonlinear functional responses, self-interaction, or spatial structure and dispersal-model ingredients that have proven to promote stability and diversity. We return instead here to classical Lotka-Volterra equations, where species-species interaction is characterized by a simple product and spatial restrictions are ignored. We quantify how this idealization imposes constraints on coexistence and diversity for many species. To this end, we introduce the concept of free and controlled species and use this to demonstrate how stable food webs can be constructed by the sequential addition of species. The resulting food webs can reach dozens of species and generally yield nonrandom degree distributions in accordance with the constraints imposed through the assembly process. Our model thus serves as a formal starting point for the study of sustainable interaction patterns between species.
尽管受到竞争排斥和明显竞争的限制，但生态多样性无处不在。为了解释在特定栖息地中观察到的丰富物种，食物网理论探索了非线性功能反应、自我相互作用或空间结构和扩散模型成分，这些成分已被证明可以促进稳定性和多样性。在这里，我们转而回到经典的洛特卡-沃尔泰拉方程，其中物种-物种相互作用由简单的乘积来描述，并且忽略了空间限制。我们量化了这种理想化如何对多种物种的共存和多样性施加限制。为此，我们引入了自由和受控物种的概念，并利用这一概念来演示如何通过顺序添加物种来构建稳定的食物网。由此产生的食物网可以达到数十个物种，并且通常会根据组装过程中施加的约束产生非随机的度分布。因此，我们的模型可以作为研究物种之间可持续相互作用模式的正式起点。
