A metapopulation model is investigated to explore how the spatial heterogeneity affects predator–prey interactions. A Rosenzweig–MacArthur (RM) predator–prey model with dispersal of both the prey and predator is formulated. We propose such a system as a well mixed spatial model. Here, partially mixed spatial models are defined in which the dispersal of only one of the communities (prey or predator) is considered. In our study, the spatial heterogeneity is induced by dissimilar (unbalanced) dispersal rates between the patches. A large difference between the predator dispersal rates may stabilize the unstable positive equilibrium of the model. The existence of two ecological phenomena are found under independent harvesting strategy: stability switching and hydra effect. When prey or predator is harvested in a heterogenious environment, a positive stable steady state becomes unstable with increasing the harvesting effort, and a further increase in the effort leads to a stable equilibrium. Thus, a stability switching happens. Furthermore, the predator biomass (at stable state) in both the patches (and hence total predator stock) increases when the patch with a higher predator density is harvested; resulting a hydra effect. These two phenomena do not occur in the non-spatial RM model. Hence, spatial heterogeneity induces stability switching and hydra effect.

研究了一个元种群模型，以探索空间异质性如何影响捕食者-猎物相互作用。制定了一个 Rosenzweig-MacArthur (RM) 捕食者 - 猎物模型，其中猎物和捕食者都分散。我们提出这样一个系统作为一个混合良好的空间模型。在这里，定义了部分混合空间模型，其中仅考虑一个群落（猎物或捕食者）的分散。在我们的研究中，空间异质性是由斑块之间不同（不平衡）的扩散率引起的。捕食者扩散率之间的巨大差异可能会稳定模型的不稳定正平衡。独立采伐策略下存在两种生态现象：稳定性转换和水螅效应。当在异质环境中收获猎物或捕食者时，随着收获努力的增加，正稳定的稳态变得不稳定，努力的进一步增加导致稳定的平衡。因此，发生了稳定性切换。此外，当捕食者密度较高的斑块被收获时，两个斑块中的捕食者生物量（稳定状态）（以及总捕食者种群）都会增加；产生水润效果。这两种现象在非空间RM模型中不会发生。因此，空间异质性会导致稳定性转换和九头蛇效应。当捕食者密度较高的斑块被收获时，两个斑块中的捕食者生物量（稳定状态）（以及总捕食者种群）都会增加；产生水润效果。这两种现象在非空间RM模型中不会发生。因此，空间异质性会导致稳定性转换和九头蛇效应。当捕食者密度较高的斑块被收获时，两个斑块中的捕食者生物量（稳定状态）（以及总捕食者种群）都会增加；产生水润效果。这两种现象在非空间RM模型中不会发生。因此，空间异质性会导致稳定性转换和九头蛇效应。