Effects of habitat destruction in model ecosystems: Parity law depending on species richness

Habitat destruction is one of the primary causes of recent mass extinction of biospecies. Even if the destruction is limited to a local and small area, the cumulative destruction increases the risk of extinction. In this paper, we explore the effect of habitat destruction in lattice ecosystems composed of multiple species. Simulations reveal a parity law: the response of the system shows different behaviors by whether the species richness of system is even or odd. The mean-field theory partially predicts such a parity law.