The metaecosystem framework has been proposed to conceptualize the interactive effects of dispersal and resource flows on the structure and functioning of communities in a heterogeneous environment. Here, we model a two-patch metaecosystem where two species with a trade-off in resource requirements compete for two limiting resources—generalizing the so-called gradostat experimental setup. We study the competition outcome in dependence of resource heterogeneity and between-patch diffusion for different combinations of resource supply ratios. Our numerical simulations show that community composition and local and regional diversity are determined by the interplay of resource heterogeneity, resource supply stoichiometry, and diffusion rate. High resource heterogeneity increases regional diversity, with species coexisting due to spatial segregation, whereas low resource heterogeneity favors local diversity, as species coexist mainly by local resource partitioning. Regional diversity averaged across a gradient of resource ratios decreases monotonically with diffusion rate, while local diversity follows a unimodal dependency. However, these dependencies become bimodal for high resource heterogeneity because various bistable states occur at intermediate diffusion rates. We identify three kinds of bistable states with species priority effect: (i) bistability between the dominance of one or the other competitor, (ii) bistability between one species dominance or species coexistence, and (iii) two alternative coexistence regimes differing in species-relative abundances. Most bistable states appear at high resource levels when biomass fluxes strongly interact with resource fluxes. Our analysis provides new insights for the potential effects of metaecosystem dynamics on biodiversity patterns.

中文翻译：

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两补丁元生态系统模型中的资源竞争与物种共存

已经提出了元生态系统框架，以概念化分散和资源流动对异构环境中社区的结构和功能的交互作用。在这里，我们建立了一个两补丁元生态系统模型，其中两个在资源需求上进行权衡的物种竞争两个有限的资源-概括了所谓的gradostat实验装置。我们研究了资源异质性和补丁间扩散对不同资源供应比率组合的竞争结果。我们的数值模拟表明，社区组成以及局部和区域多样性是由资源异质性，资源供应化学计量和扩散率之间的相互作用决定的。高资源异质性增加了区域多样性，由于空间隔离，物种并存，而资源异质性低则有利于本地多样性，因为物种主要通过本地资源划分而共存。在资源比率梯度上平均的区域多样性随扩散率单调减少，而局部多样性遵循单峰依赖性。但是，由于各种双稳态在中间扩散速率下发生，因此这些依赖性对于高资源异质性成为双峰的。我们确定了三种具有物种优先效应的双稳态：（i）一个或另一个竞争者的优势之间的双稳性；（ii）一种物种的优势或物种共存之间的双稳性；以及（iii）物种不同的两种替代性共存体制-相对丰度。当生物量通量与资源通量强烈相互作用时，大多数双稳态状态出现在高资源水平。