Data from: Carrying capacity in a heterogeneous environment with habitat connectivity

A large body of theory predicts that populations diffusing in heterogeneous environments reach higher total size than if non-diffusing, and, paradoxically, higher size than in a corresponding homogeneous environment. However, this theory and its assumptions have not been rigorously tested. Here, we extended previous theory to include exploitable resources, proving qualitatively novel results, which we tested experimentally using spatially diffusing laboratory populations of yeast. Consistent with previous theory, we predicted and experimentally observed that spatial diffusion increased total equilibrium population abundance in heterogeneous environments, with the effect size depending on the relationship between r and K. Refuting previous theory, however, we discovered that homogeneously distributed resources support higher total carrying capacity than heterogeneously distributed resources, even with species diffusion. Our results provide rigorous experimental tests of new and old theory, demonstrating how the traditional notion of carrying capacity is ambiguous for populations diffusing in spatially heterogeneous environments.大量理论研究预测，在异质环境中扩散的种群，其总规模将高于不扩散的种群，且反常的是，其总规模也高于对应同质环境中的种群。然而，该理论及其假设尚未经过严格的实验验证。 本研究将前人理论拓展至包含可利用资源的场景，推导得到了定性上全新的结论，并利用空间扩散的实验室酵母种群开展了实验验证。 与前人理论一致，我们预测并通过实验观察到，在异质环境中，空间扩散会提升种群的平衡总丰度，且该效应的强度取决于内禀增长率（r）与环境容纳量（carrying capacity）之间的关联。但与前人理论相悖的是，我们发现即使存在物种扩散，均匀分布的资源所能支撑的总环境容纳量仍高于异质分布的资源。 本研究的结果为新旧理论提供了严格的实验验证，阐明了在空间异质环境中扩散的种群，其传统的环境容纳量概念存在歧义性。