Veronica Islas, University of Central Florida


Modeling Effects of Hydroperiod and Predation on Equilibrium Population Size of Temporary-Pond Amphibians

Abstract: Hydroperiod and predation are important factors that control equilibrium population size (N*) for aquatic organisms. Predicting N* can be useful for evaluating the carrying capacity of a habitat. Eight density-dependent equations based on the logistic equation dN/dt=rN(1-N/K) were examined to determine how hydroperiod and predation affect N*. Modifications consisted of adjusting carrying capacity to reflect pond hydroperiod and adding Type I, II and III predation terms. N* was determined by solving for N when dN/dt = 0. In all cases examined, pond hydroperiod had a greater effect on N* than predation, suggesting only Type I predation significantly affected equilibrium population size. Further study is required to determine whether Type III predation has a significant effect. In all cases examined, pond hydroperiod had a greater effect on N* than predation.

Advisor: Dr. John E. Fauth, Department of Biology, University of Central Florida