Trade-offs and synergies in a payment-for-ecosystem services program on ranchlands in the Everglades headwaters

Increasingly, agriculture is recognized as valuable not only for food production, but also for regulating and supporting ecosystem services such as those encompassing biodiversity and water. Various government programs provide incentives to farmers and ranchers to maintain ecosystem services, with an emerging focus on payment-for-ecosystem services (PES) programs. However, interactions among ecosystem services, including synergies or trade-offs, at spatial scales relevant to land managers are not well understood. Here, we examined how a PES program for enhanced water retention on subtropical ranchlands in the headwaters of the Everglades affected seven indicators of ecosystem services and three indicators of disservices within wetlands (local scale) and among wetlands (wetland scale) at four different ranches. We used general linear mixed models and model selection to evaluate the feasibility of explicit, a priori hypotheses using data from 15 wetlands sampled across four participating ranches. Our study indicated that managing for increased water retention could result in both synergies and trade-offs among ecosystem services. Higher water retention increased wetland plants at both local and wetland scales and was associated with reduced mosquitoes. Trade-offs included significant declines in forage plant cover and decreases in amphibian abundance with higher water retention. Unimodal non-linear relationships described responses of macroinvertebrates, fish, mosquito, and non-native plant abundance to increasing water retention. These complex relationships indicate that optimizing water retention, provisioning services, and wetland biodiversity in ranchlands may not be straightforward. Unimodal non-linear relationships among water retention and biodiversity suggest there is a threshold of water retention that represents a trade-off for also maintaining biodiversity. Land use was an important driver of ecosystem disservices, with more intensely managed ranches having a greater potential for ecosystem disservices such as increased cover of non-native plants, abundant mosquitoes, and lower amphibian abundance. Multidisciplinary collaboration was required to design, implement, monitor, and assess this PES program for trade-offs and synergies. © 2019 The Authors.