Amphibians Populations: Effects of Fire, Water, and Climate Change

Research Issue

Amphibians are an important component of biological diversity, and also play an important ecosystem role as both predators and prey. Concern over apparent declines in amphibian populations due to climate change, disease, reduced habitat amount and quality, and other factors, has focused attention on the need for long-term, landscape-level studies to distinguish between true population declines and natural fluctuations. Several Southern US amphibian species require fish-free temporary ponds for reproduction and use surrounding uplands for most of their adult lives. The timing and duration of wetland hydroperiod and precipitation have been correlated with breeding behavior, reproductive success and declines of some amphibian populations.

Our Research

For 19 years we have worked with University of Florida partners on a long-term study of amphibian and reptile use of ephemeral ponds in fire suppressed, hardwood-invaded and regularly burned, savannah-like longleaf pine-wiregrass sandhills of the Ocala National Forest, Florida. Amphibians and reptiles are sampled continuously and concurrently at eight ponds using drift fences with pitfall and funnel traps; data on rainfall, temperature, and pond depth are also obtained. This study addresses: (1) Population dynamics and life history of several species; (2) Whether habitat quality (fire suppressed, hardwood invaded versus regularly burned, savannah-like sandhills) in the surrounding upland matrix influences pond use and reproductive success; (3) Spatio-temporal use of ponds and metapopulation dynamics; (4) Hydrological pattern in ephemeral ponds, and implications for amphibians under different climate change scenarios. Despite a critical need for long-term, landscape-level studies of amphibian populations, no other study has continuously, concurrently sampled multiple ponds over an extended period.

Expected Outcomes

Results provide information on autecology of several amphibian species, long-term monitoring of amphibian populations and metapopulation dynamics at a landscape level, and insight into effects of habitat quality of surrounding uplands. Weather and pond hydrology data are currently being used to develop predictive models of climate variables and hydroperiods, for application to alternative climate change scenarios. Our results are useful to biologists, land managers and policy makers to implement management and conservation measures to sustain a diverse amphibian community in the long-term.

Photos by Steven Johnson

Amphibian Photograph Amphibian Photograph

Photos by Betsy Roznik

Pond in fire-maintained longleaf pine-
wiregrass sandhills

Pond in fire-maintained longleaf pine- wiregrass sandhills

Pond in fire-suppressed longleaf pine-wiregrass sandhills

Pond in fire-suppressed longleaf pine-wiregrass sandhills

Research Results

Greenberg, C.H. 2001. Spatio-temporal dynamics of pond use and recruitment in Florida gopher frogs (Rana capito aesopus). J. Herpetol. 35(1):74-85

Fire, habitat structure and herpetofauna in the southeast. Proc. Sympos. “The Role of Fire for Nongame Wildlife Management and Community Restoration: Traditional Uses and New Directions.” 7th Annual Conference of the Wildlife Society, Sept. 15, 2000. Nashville, TN. USFS NE-GTR-278

Greenberg, C.H., T.G. Forrest. 2003. Seasonal abundance of ground-occurring macroarthropods in forest and canopy gaps in the southern Appalachians. Southeast. Nat. 2:591-608.

Greenberg, C.H., G.W. Tanner. 2004. Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions. J. Herpetol. 38(4):569-577.

Greenberg, C.H., G.W. Tanner. 2005. Spatial and temporal ecology of eastern spadefoot toads on a Florida landscape. Herpetologica 61(1):20-27.

Greenberg, C.H., G.W. Tanner. 2005. Spatial and temporal ecology of oak toads (Bufo quercicus) on a Florida landscape. Herpetologica 61(4):422-434.

Greenberg, C.H., G.W. Tanner. 2005. Chaos and continuity: The role of isolated, ephemeral wetlands on amphibian populations in xeric sandhills. Pp 79-90 In: Meshaka, W.E., K.J. Babbitt (eds.). Amphibians and Reptiles: Status and Conservation in Florida. Krieger Publishing Company, Melbourne, Florida. 317pp.

Greenberg, C.H., G.W. Tanner. 2006. Amphibians using isolated ephemeral ponds in Florida longleaf pine uplands: population and metapopulation dynamics. Final Report. Florida Fish and Wildlife Conservation Commission, Tallahassee, FL, USA.

Greenberg C.H., G.W. Tanner, 2008. Long-Term Landscape scale Monitoring of Amphibians at Ephemeral Ponds in Regularly burned Versus Hardwood-Invaded Florida Longleaf Pine-Wiregrass Uplands of the Ocala National Forest, Florida. Final Report. Florida Fish and Wildlife Conservation Commission, Tallahassee, FL, USA.

Johnson, S.A., E.A. Roznik, G.W. Tanner, C.H. Greenberg. 2008. Habitat use by Florida gopher frogs in savanna-like versus hardwood-invaded longleaf pine-wiregrass uplands. Final Report, Florida Fish and Wildlife Conservation Commission, Project NG04-011.

Roznik, E.A., S.A. Johnson, C.H. Greenberg, G.W.Tanner. 2009. Terrestrial movements and habitat use of gopher frogs in longleaf pine forests: a comparative study of juveniles and adults. For. Ecol. Manage. 259:187-194.

Research Principal Investigators

George W. Tanner (retired), University of Florida

James Austin, University of Florida

Research Partners

Ocala National Forest

Bernard Parresol, Southern Research Station

Scott Goodrich, Southern Research Station

Steven Johnson, University of Florida