SREL Reprint #2121

Structure and dynamics of an amphibian community: evidence from a 16-year study of a natural pond

Raymond D. Semlitsch1, David E. Scott2, Joseph H. K. Pechmann2, and J. Whitfield Gibbons2

1Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211
2University of Georgia's Savannah River Ecology Laboratory, Aiken, South Carolina 29802

Summary: Our 16-year study of amphibians in a natural temporary pond found that hydroperiod is a primary source of variation in community structure. Larval competition and predation also have a detectable influence, but the strength of their influence on the success of species is mediated by pond hydroperiod. Although hydroperiod, competition, and predation all had a detectable influence on the amphibian community at Rainbow Bay, the effects of these factors were often difficult to separate. Juvenile production for all species was virtually episodic, with large numbers of metamorphs being produced in only a small number (1-7) of the 16 years. Although hydroperiod was highly variable, it was still a significant predictor of the number and diversity of metamorphosing amphibians at Rainbow Bay. Our data show that temporal variation may favor the reproductive success of different species in different years. Nevertheless, in many cases a good year for a species was also a good year for its competitors and predators. Juvenile recruitment of all species was limited by a short hydroperiod in the driest years. In years with longer hydroperiods, the density of competitors affected the number of metamorphosing juveniles per breeding female for some species. The density of salamander larvae was also a significant predictor of per-capita juvenile recruitment for anurans. A significant negative relationship was detected for two of four anuran species analyzed, most likely due to predation by the salamander larvae on the anuran. These results indicate that community structure, at least in terms of relative abundances, varied continuously. However, regulation of community structure within a pond occurs through the predictable interaction of rainfall, sandhills, hydroperiod, competition, and predation.

SREL Reprint #2121

Semlitsch, R.D., D.E. Scott, J.H.K. Pechmann, and J.W. Gibbons. 1996. Structure and dynamics of an amphibian community: evidence from a 16-year study of a natural pond. pp. 217-248 In: M. L. Cody and J. Smallwood. (Eds.). Long-term Studies of Vertebrate Communities. Academic Press, Inc.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).