Abstract
Habitat fragmentation is recognized as the most serious threat to biodiversity worldwide and has been the focus of intensive research for a few decades. Due to the complexity of the problem, however, there are still many issues that remain poorly understood. In particular, it remains unclear how species extinction or persistence in a fragmented habitat consisting of sites with randomly varying properties can be affected by the strength of inter-site coupling (e.g., due to migration between sites). In this paper, we address this problem by means of numerical simulations using a conceptual single-species spatially-discrete system. We show how an increase in the inter-site coupling changes the population distribution, leading to the formation of persistence domains separated by extinction domains. Having analysed the simulation results, we suggest a simple heuristic criterion that allows one to distinguish between different spatial domains where the species either persists or goes extinct.