projects > use of amphibian communities as indicators of restoration success in the greater everglades
> project summary
Project Summary Sheet
U.S. Geological Survey, Greater Everglades Priority Ecosystems Science (GE PES) Initiative
Fiscal Year 2006 Study Summary Report
Project Title: Use of Amphibian Communities as Indicators of Restoration Success
Project Start Date: 2004 Project End Date: 2007
Web Site: sofia.usgs.gov
Location (Subregions, Counties, Park or Refuge): Total System
Funding Source: USGS GE PES, USNPS CESI in 07
Principal Investigator(s): Kenneth G. Rice, Frank J. Mazzotti
Project Personnel: Valerie Johnson and Brian Jeffery, University of Florida; Hardin Waddle, USGS-FISC
Supporting Organizations: University of Florida
Associated/Linked Projects: CESI: Effects of Public Land Use on Threatened, Endangered, and Indicator Species
Overview & Objective(s): Declines in amphibian populations have been documented by scientists worldwide from many regions and habitat types. No single cause for declines has been demonstrated, but stressors like acid precipitation, environmental contaminants, the introduction of exotic predators, disease agents, parasites, and the effects of ultraviolet radiation have all been suggested. Because of their susceptibility to these and other stressors, amphibians are important as indicators of ecosystem health. Amphibians are present in all habitats and under all hydrologic regimes in the Everglades. The species present and the occupancy rate of a given species differ greatly across those gradients. These differences are due to hydropattern, vegetation, and other environmental factors. The combination of species composition and proportion of each habitat occupied at a given time form unique communities defined by those environmental factors. Therefore, if these communities can be reliably defined and measured, Everglades restoration success can be evaluated, restoration targets can be established, and restoration alternatives can be compared. This study will develop methodologies for defining and measuring the membership and area occupancy of amphibian communities. Further, we will investigate the relationship of occupancy of amphibians with hydroperiod and other environmental factors. Finally, we will provide a method for measuring restoration success based on these communities. Our objectives include:
- Define amphibian communities appropriate for evaluating restoration success.
- Develop methods for measuring the area occupancy of amphibian communities across habitats and environmental gradients.
- Investigate the relationship of occupancy with hydroperiod and other environmental factors.
- Develop restoration targets for the amphibian community of the Greater Everglades.
- Develop a restoration tool for amphibian communities that measures restoration success and compares restoration alternatives.
- Develop an index of biological integrity for amphibians that provides a framework for scientifically defensible decisions by restoration managers.
Status: We continue to use data previously collected from Everglades National Park and Big Cypress National Preserve to develop methods and models for defining amphibian communities using the Proportion Area Occupied (PAO) model and multivariate statistical techniques (see Fact Sheet 2004-3106). In Everglades National Park and adjacent Water Conservation Areas 3A and 3B, we completed fieldwork on a large scale study to determine the PAO by each amphibian species across habitats defined by hydropattern. The PAO method estimates the abundance of sites at which each species occurs based on the capture results of several visits to each site. This method takes into account that some species are more difficult to detect, given that they are present, than others. This sampling was conducted along a hydrologic gradient from very long hydroperiod sloughs to the extremely short hydroperiod rocky glades of eastern Everglades National Park. Our sampling included call count, visual encounter surveys, PVC refugia captures, and trapping in over 20 sites. Our work in FY07 will include:
- Collection of additional field data on amphibian distributions in the Ten Thousand Islands and Florida Panther National Wildlife Refuge to supplement existing data from Big Cypress National Preserve and Everglades National Park.
- Collection of further information on cryptic species including aquatic amphibians within Big Cypress National Preserve.
- Acquisition of hydrologic data from different state and federal sources in southwest Florida and elsewhere in the Everglades to estimate hydrologic parameters of interest (mean annual hydroperiod, days since dry down, etc.) at our sampling locations. This will include cooperation with the Everglades Depth Estimation Network funded by USGS-PES and ACOE. This data will be used to finalize models of amphibian presence due to hydropattern in the Everglades.
- Finalizing models and methods to measure restoration success across these communities and compare restoration alternatives.
- Finalizing an overall index of amphibian community integrity.
Recent & Planned Products:
In FY06, 3 peer-reviewed journal articles, 2 USGS open-file reports (1 in press), and 2 factsheets were published. We also gave 7 presentations at National and International Meetings and 1 additional manuscript was submitted to a peer-reviewed journal. Future project products include:
- Tools and scientific data necessary for evaluation of restoration success and comparison of restoration alternatives.
- Methods and data necessary for RECOVER's adaptive assessment process and monitoring program.
- Development of a cost-effective monitoring program for amphibians.
- Development of performance measures for amphibian communities.
- Peer-reviewed publications and published methodology for evaluation of restoration success.
Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan): [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]:
- Monitoring of ecological responses of amphibians to hydrologic change was specifically listed as a science need in the Southern Golden Gate Estates Hydrologic Restoration Project as well as the need for amphibian larval sampling.
- The study supports the Arthur R. Marshall Loxahatchee NWR Internal Canal Structures project as it (1) provides monitoring and assessment of responses of aquatic communities and habitats (p. 37) and (2) helps understand the ecological effects of hydrology and water quality on refuge resources (p. 40).
- The study support the Southwest Florida Feasibility Study project by providing modeling to predict species-level responses to habitat change (p. 50) and monitoring of key indicators (p. 51).
- The need for monitoring and modeling of ecological communities and indicator species is specifically mentioned in the Florida Bay and Florida Keys Feasibility Study (p. 78), Ten Mile Creek Reservoir Assisted Stormwater Treatment Area Project (p. 34), Henderson Creek/ Belle Meade Restoration Project (p. 56), Southwest Florida Feasibility Study (p. 52), Florida Bay and Florida Keys Feasibility Study (p. 76), Landscape-Scale Modeling (p. 81), and Everglades National Park Fire Ecology Science Action Plan (p. 125).
- Further, this study will establish the system-wide monitoring program for amphibians as outlined in CESI - MAP.
- We have been able to define the amphibian communities of Everglades National Park based on habitat using a repeatable and cost-effective monitoring method. Our next step is to further define these communities based on hydropattern and use this pattern to establish restoration targets for the entire Everglades system.
- We have developed a cost-effective and repeatable amphibian monitoring program for use in CERP throughout the Everglades system.
- We have illustrated the use of an entire group of indicator species to assess restoration success.
- We have established baseline conditions for evaluation of restoration success for amphibian communities in Everglades National Park, Big Cypress National Preserve, Biscayne National Park, and Water Conservation Areas 3A and 3B.
- The findings of this project have been used to develop index models for comparison of restoration alternatives in the Southwest Florida Feasibility Study.