栖息地异质性与扩散网络结构对 metacommunity dynamics 的驱动作用

空间结构与物种相互作用共同塑造生态系统的动态与生物多样性，但大多数理论模型要么忽略空间异质性，要么牺牲解析可行性。本文提供了一个统一的微观、机制性框架，用于从任意扩散网络上的个体基生态动力学推导有效的 metapopulation 和 metacommunity 模型。 resulting coarse-grained description features an effective dispersal kernel that encodes both microscopic dynamical parameters and network topology。 Based on this framework, we demonstrate exact analytical results for species persistence in both homogeneous and heterogeneous landscapes, including a generalization of the classical concept of metapopulation capacity to non-uniform local extinction rates. Incorporating stochasticity arising from finite carrying capacities, we obtain a reduced one-dimensional description that reveals universal finite-size scaling laws for extinction times and fluctuations. Extending the approach to multiple competing species, we prove that in homogeneous environments monodominance can be avoided only in a fine-tuned, marginally stable coexistence state, and that the classic metapopulation capacity gives only a necessary but not sufficient condition for persistence. We demonstrate that heterogeneous habitats can support stable coexistence, but only above a critical level of heterogeneity. Finally, we outline how additional ecological processes can be systematically incorporated within the same formalism. Together, these results provide analytical benchmarks and a general route for constructing spatially explicit ecological theories based on an interpretable underlying mechanistic foundation.