Terrestrial protected area design through the coupled natural and human systems lens
Protected areas provide a centerpiece of conservation strategies, and much ecological research has focused on identifying principles for designing them effectively. However, a purely ecological approach will only get us so far. Protected areas are created by people. They can be expensive to establish; people establishing them have differing motivations; and multiple partners are often involved. If we are to deliver principles for designing protected areas that conservation organizations can use, ecologists will have to understand how the interplay of ecological and socioeconomic factors influences protected area effectiveness.
We focused on areas protecting forests in central and southern Appalachia that were established by a land trust, The Nature Conservancy. We combined detailed data on how the site was protected (how much it cost, what the motivation for protection was; which partners were involved; what type of contract was used; etc.) with data on community structure and composition and remote sensing.
We examined how the choice of ecological benefit metric would impact an assessment of the return-on-investment (ROI) offered to conservation by protecting each site. We also revisited a classic question in protected area design studies – how does the size of a protected area influence its effectiveness – to illustrate how combining ecological and socioeconomic data changes conservation recommendations.
Multiple metrics are relevant for evaluating the ecological benefits of protecting different sites in our system, but they show limited covariation. Combining ecological and socioeconomic data using a ROI approach leads to greater concordance in the relative effectiveness one would attribute to protecting each site.
We found that larger protected areas show pronounced economies of scale in their acquisition costs, and that the nature of these economies of scale was modified by contract type and the motivations behind protection. When integrating these acquisitions costs into an ROI framework, we would draw markedly different conclusions regarding the influence of protected area size on their effectiveness than those suggested when only considering relevant ecological data.
Protected areas have been and will remain a mainstay of conservation strategies. Only by taking a coupled natural and human systems approach to their study can we identify principles for designing them effectively.