Effects of size of protected areas on ecological and economic effectiveness

This research analyzes how the size of protected areas influences the ecological and economic effectiveness through a return-on-investment in conservation (ROI) to help conservation organizations prioritize protected areas. Using the case study, we focus on whether the size variation has implications on ROI that is estimated by local richness (i.e., the total number of target species represented within a set of protected areas) divided by acquisition cost. We found that (i) local richness on a dollar invested to acquire a parcel is greater for smaller parcels than larger parcels and (ii) almost a half of the total effect of protected size on ROI is spillover effects. Our findings suggest that smaller land parcels should be prioritized for protection as part of an ecological and economic conservation strategy with understanding of spatial spillover effect of size of protected area on ROI.