Density, climate and varying return points: an analysis of long-term population fluctuations in the threatened European tree frog

Oecologia. 2006 Aug;149(1):65-71. doi: 10.1007/s00442-006-0432-1. Epub 2006 May 24.

Abstract

Experimental research has identified many putative agents of amphibian decline, yet the population-level consequences of these agents remain unknown, owing to lack of information on compensatory density dependence in natural populations. Here, we investigate the relative importance of intrinsic (density-dependent) and extrinsic (climatic) factors impacting the dynamics of a tree frog (Hyla arborea) population over 22 years. A combination of log-linear density dependence and rainfall (with a 2-year time lag corresponding to development time) explain 75% of the variance in the rate of increase. Such fluctuations around a variable return point might be responsible for the seemingly erratic demography and disequilibrium dynamics of many amphibian populations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anura / physiology*
  • Climate*
  • Conservation of Natural Resources / statistics & numerical data
  • Ecosystem*
  • Longitudinal Studies
  • Models, Theoretical*
  • Population Density
  • Population Dynamics
  • Switzerland