projects > use of amphibian communities as indicators of restoration success > project summary
Project Summary Sheet
Fiscal Year 2005 Study Summary Report Study Title: Use of Amphibian Communities as Indicators of Restoration Success 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:
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 have begun 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 is done along a hydrologic gradient from very long hydroperiod sloughs to the extremely short hydroperiod rocky glades of eastern Everglades National Park. We have initiated sampling including call count, visual encounter surveys, PVC refugia captures, and trapping in over 20 sites. Field sampling will conclude in Fall 2005 and modeling will be completed in FY06. Recent & Planned Products: Through the first 3 quarters of FY05, 1 peer-reviewed journal article, 3 USGS open-file reports (in-press), and 1 book chapter were published. We also gave several presentations at National and International Meetings and 2 additional manuscripts were submitted to peer-reviewed journals. 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/]:
Key Findings:
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U.S. Department of the Interior, U.S. Geological Survey
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Last updated: 24 February, 2006 @ 02:33 PM(KP)