Three-lattice metapopulation model: Connecting corridor between patches may be harmful due to “hub effect”

Abstract

Many authors have reported the risk of habitat fragmentation and the importance of connecting corridors between subpopulations (patches). However, we report that the connection of corridors may be harmful to species conservation. The paper deals with the birth and death processes of a single species living in a network composed of three patches. The disturbance due to a changing environment is assumed to affect only one patch. Two types of metapopulation models are applied. One is the lattice simulation model where we set a lattice as a patch. The other is based on metapopulation theory, which utilizes reaction-migration equations. The lattice simulation reveals that the connecting corridor between patches may be disadvantageous; the complete graph or a network with fully connected corridors is found not to be optimal for species conservation. Similar results are indicated by the application of metapopulation theory. We discuss the relationship between the risk of corridor construction and the effect of the hub patch.