Nature reserve optimization with buffer zones and wildlife corridors for rare species

The creation of protected areas is an important public policy strategy for protecting species, as mentioned in the Aichi targets. This paper formulates spatial integer programming (set covering) models to protect both rare species (arbitrarily defined here as species breeding in 1% or less of the territory) and common species. Spatial constraints are used to form buffer zones around core areas that protect rare species, and cost-efficient corridors linking these buffered cores are then designed. The models are applied on a portion of the State of Oregon and results are evaluated in light of the expected United Nations post-2020 targets for area-based conservation measures. It is estimated that such results aimed at covering all species and enhancing protection of at-risk species seem locally consistent with the global biodiversity objectives for 2030.