Optimal reserve site selection with distance requirements

The reserve set covering problem minimizes the total cost or area of sites needed to represent all species within a system of nature reserves, but does not address spatial characteristics such as distances between reserve sites. Inter-site distance, as a surrogate for connectivity, is likely to affect species persistence and other functional aspects of reserve systems. Two new 0–1 programming models that build upon the reserve set covering problem are formulated for controlling inter-site distance.