"A prescribed burn cycle approaching five years should balance the conflicting needs of amphibians and longleaf pines without placing the entire community in danger of catastrophic fire," say Jamie Schurbon and John Fauth in the October issue of Conservation Biology. Schurbon and Fauth did this work while at the College of Charleston in South Carolina, and are now at the Anoka Conservation District in Ham Lake, Minnesota, and the University of Central Florida in Orlando, respectively.
To keep the pine savannahs from being replaced by hardwoods, the U.S. Forest Service burns sections of South Carolina's Francis Marion National Forest every two-to-three years. While prescribed burns appear to have little effect on amphibians in some ecosystems, the effects of fire on amphibians in pine savannahs are unknown. Fire could drive amphibians out by making the soil hotter and drier, and by reducing the leaf litter that provides cool, moist refuges.
To test whether prescribed burning affects amphibians in southeast U.S. pine savannahs, Schurbon and Fauth determined the diversity and abundance of 25 amphibian species in 15 temporary ponds in areas that were burned 0-12 years ago in the Francis Marion National Forest. Pine savannahs are home to several sensitive species (including the flatwoods salamander and the Carolina gopher frog) and have among the greatest amphibian diversity in the U.S., with 31 species in the Francis Marion National Forest alone. "A single pond can easily harbor more species of frogs than inhabit entire states in the northern and western U.S.," says Fauth.