Conserving metapopulations in human-altered landscapes at the urban–rural fringe

Abstract

The conversion of natural areas to human-dominated land uses results in loss, degradation, and fragmentation of wildlife habitat which often lead to species endangerment and local extinction. The risk of endangerment may be particularly acute for species that exist as metapopulations in which viability of the species is contingent upon dispersal of individuals among local sub-populations. This paper uses an optimization framework to investigate the problem of conserving metapopulations residing in areas at the urban–rural fringe. We compare the optimal allocation of preservation to outcomes of four other policy alternatives including the reserve-site-selection option that fully preserves habitat patches while allowing full development of the intervening dispersal matrix. In general, the optimal allocation includes some amount of preservation in both habitat patches and dispersal matrix, with the level of protection typically greater in habitat patches. The reserve-site-selection conservation option is optimal in only a few cases. Heterogeneity in terms of land use and landscape structure adds complexity to the optimal solution such that no one policy works well across all land units and in situations where the landscape structure is skewed, full protection of some land units and full development of others becomes more common.