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Agricultural lands provide a wide array of services including water storage and cycling. Enhanced water regulation services by flooding ranchlands were tested in a pilot water storage payment for environmental services (PES) program in the Northern Everglades watershed to reduce damaging excessive flows to the Lake Okeechobee and connected estuaries and the Everglades. As part of the PES, south Floridian ranchers raised the drainage ditch spillage elevations to reduce surface flows and store water. Ecohydrological models were developed to evaluate biodiversity services using data from 15 wetlands on four previously-drained ranches that participated in the PES program. Seven indicators of biodiversity, plants (wetland, forage, and weedy/exotic), fish, amphibian, mosquito, and macroinvertebrates, were measured. Biodiversity services and dis-services were estimated for a tradeoff analysis using spatiotemporal measures of inundation (%, area, volume, hydroperiod, connectivity). Three general regression models for wetland vegetation cover (R2=0.28;p<0.001), forage vegetation cover (R2=0.33; p<0.001) and fish abundance (R2=0.33; p<0.001) had reasonable amount of predictability. The models were applied for two of the ranches participating in the water storage PES using water availability predictions from an integrated spatially explicit hydrological model, for a wide range of drainage levels. Generally, diversity-related services increased with increased spillage levels. However, not all ranches responded the same. At one ranch services occurred at intermediate spillage levels while at another, maximum services were predicted for the highest spillage levels. Although significant uncertainty existed in predictions, they were directionally correct with increasing spillage levels resulting in increased biodiversity services. The results from these analyses indicate that biodiversity services can be successfully linked to water storage services with different levels of uncertainties. Although ecohydrological models are not accurate enough to develop a PES program which is designed to pay landowners for the provision of biodiversity services, they can provide decision makers with a method for selecting ranches which may be able to better provide ecosystem services above and beyond water storage alone. Future efforts should be focused on improving accuracy of models, with larger datasets (multiple years and sites), for biodiversity specific PES programs. |