When do ecosystem services provide an economic incentive for biodiversity conservation?
Many conservation organizations and scientists have argued for a shift from preserving biodiversity for its own sake towards promoting biodiversity protection for its contributions to human well-being. Rather than pitting biodiversity protection against economic well-being, this approach posits that the interests of humans and biodiversity are often aligned. Numerous studies have shown that biodiversity can play a key role in producing the values and benefits that nature provides humans (i.e. ecosystem services). This suggests that protecting biodiversity is crucial to maintaining ecosystem services and that biodiversity’s benefit extends beyond its intrinsic value. While significant effort has been devoted to the question of whether biodiversity has a positive impact on ecosystem services, an equally important, but unresolved question is whether conservation aimed at preserving ecosystem services benefits biodiversity by providing an economic incentive for conservation. We develop theory to explore the level of biodiversity protection that optimizes the value of ecosystem services, given uncertainty over the links between biodiversity and ecosystem services. To do so, we employ stochastic dynamic programming methods. The theory predicts how much protection of biodiversity would arise if we base conservation decisions solely on optimizing the value of ecosystem services.
Our results suggests that decisions based upon optimizing ecosystem services do not universally benefit biodiversity and, in fact, may provide less economic incentive for biodiversity conservation than many people suspect. We find the conditions for which ecosystem services justify protecting all species and when they justify protecting nothing (and cases in between). Ecosystem services can provide an economic incentive for biodiversity protection, but the amount of protection that is justified will depend on (1) the benefits from the service relative to the direct and indirect costs of conservation, (2) the number of critical species and services involved, (3) how beneficiaries value present versus future benefits, and (4) uncertainty over which species provide benefits. For instance, high opportunity costs will lower the level of biodiversity protection that is justified based on ecosystem services objectives. In contrast, ecosystem service approaches will provide a greater incentive for conservation when considering multiple services or when coupled with well-designed payment for ecosystem service programs.