Citation:

Abstract:

Hydrological changes can lead to biodiversity responses that are complex and challenging to quantify. We present a framework that uses biodiversity as a criterion to address “where to buy” and “how much to buy” in a payment-for-environmental-services (PES) program focused on water storage service in the Everglades basin, USA. The PES program was designed to pay for added water storage on private cattle ranchlands by raising the spillage level in drainage control structures to reduce surface flows. We predicted that increased hydration of previously drained wetlands would benefit biodiversity, a previously unquantified but desirable co-benefit of the original program, and that a PES program offering bundled services (e.g., storage and biodiversity) can better achieve restoration goals. We quantified desirable biodiversity services (abundance of native flora and fauna such as cover of wetland and forage plants, and abundance of fishes, amphibians, and macroinvertebrates), disservices (e.g., abundance of invasive plants and mosquitos), and hydrologic signatures (e.g., wetland water depth, inundation area and duration) at four ranches to develop eco-hydrological relationships (models) between hydrological changes and biodiversity responses. Next, a hydrologic model (MIKE-SHE/MIKE-11) was used to predict surface and subsurface water levels and flows and resulting wetland hydrologic signatures for 13 water storage alternatives on the ranches, which were used as example PES proposals. A decision-support-system (DSS) was developed to integrate (i) storage predicted by the hydrologic model, (ii) biodiversity responses predicted by eco-hydrologic models, and (iii) a user-defined preference scheme to assign importance weights to storage, biodiversity, and implementation cost. The DSS calculated a cumulative score for ranking PES proposals. By considering desirable services and dis-services, stakeholders can decide on their preferred level of services, e.g., buyer(s) may settle for less storage if there is a gain in desirable biodiversity. The DSS can identify trade-offs among services, helping stakeholders negotiate.