Use of Amphibian Communities as Indicators of Restoration Success in the Greater Everglades

Science Center Objects

Habitat alteration and climate, when combined, are serious threats to amphibians and other wildlife. Habitat suitability models are being used to predict the responses of an amphibian community to hydrological and habitat restoration in the Greater Everglades Ecosystem. 

Use of Amphibian Communities as Indicators of Restoration Success in the Greater Everglades
Habitat suitability models predict how amphibian communities respond to restoration in the Greater Everglades

PROJECT COMPLETED

The Science Issue and Relevance: Currently, one of the potentially most serious conservation problems for amphibians and other wildlife is the synergistic effect of habitat alteration and climate change. Large scale efforts to restore hydrological processes in freshwater systems offer an opportunity to evaluate how climatic factors may interact with both local and landscape-level habitat variables to influence restoration success across an ecological landscape. In collaboration with other USGS scientists, we helped develop habitat suitability models that predict the responses of an amphibian community to hydrological and habitat restoration in the Greater Everglades Ecosystem. We also monitored calling anuran amphibians at key sites throughout the Big Cypress Basin ecosystem to estimate the actual occupancy dynamics of anuran assemblages in this region. These occupancy estimates can be used to evaluate this newly-developed habitat suitability model, which serves as a promising tool for assessing the potential impact of climate change on amphibians occupying a hydrologically modified/restored landscape.

Methodology for Addressing the Issue: 2012 marked our fourth continuous year of conducting surveys for anuran amphibians in the Picayune Strand State Forest of southwestern Florida, which is within the area targeted by the Picayune Strand Restoration Project. From 2008 to 2011, we also conducted surveys in the adjacent Fakahatchee Strand Preserve State Park, Big Cypress National Preserve, and the Florida Panther National Wildlife Refuge. We have used a variety of techniques (manual vocalization and visual encounter surveys; automated recording units) to detect frogs. In collaboration with other USGS scientists and the Conservancy of Southwest Florida, we recently modified and expanded our sampling design based on existing integrated surface water-groundwater models that predict the changes in water levels that will occur with the hydrological restoration that is underway (e.g., construction of pumping stations; plugging of the Faka Union Canal System that drains the Picayune Strand). We are currently monitoring (using automated recording units) 60 sites distributed throughout the Picayune Strand with a focus on the area surrounding each of the canals that comprise the Faka Union Canal System.

Future Steps: The first step of our planned research is to generate annual estimates of site occurrence for an assemblage of anuran amphibians associated with a diverse array of habitats and hydroperiods in the degraded Picayune Strand and its more intact neighboring subunit, the Belle Meade CARL area. Based on our earlier surveys, we anticipate that community-level estimates of site occupancy will be much lower in Picayune, compared to the Belle Meade area. Also, based on the predictions of the integrated surface water-groundwater model, we anticipate that the composition of amphibian communities following restoration will vary with predicted differences (pre- versus post-restoration) in water depths across the Picayune landscape. The second phase of our research will be to use these occupancy estimates to test our recently developed model and to forecast potential responses of the amphibian community to the ongoing hydrological restoration of Picayune Strand. The results of this model validation will likely lead to predictions concerning the responses of amphibians (in terms of site occupancy) under an array of various restoration alternatives. These predictions can then be considered in making management decisions with respect to targeting a specific overall habitat suitability model for amphibians of southwest Florida.

Use of Amphibian Communities as Indicators of Restoration Success in the Greater Everglades
Habitat alteration and climate change threaten amphibian communities. 
Use of Amphibian Communities as Indicators of Restoration Success in the Greater Everglades
Amphibian surveys were conducted in Picayune Strand State Forest.