open access

https://hdl.handle.net/2115/33873

Effects of acorn abundance on density dependence in a Japanese wood mouse (Apodemus speciosus) population

Density dependence in wood mouse

英語

Nonlinear perturbation effect

2008-04

Springer Japan

Population Ecology

50(2)

159-167

We analysed the effects of Quercus crispula acorn abundance on the density dependence of the large Japanese wood mouse Apodemus speciosus using time series data (1992-2007). The data were obtained in a forest in northern Hokkaido, Japan, by live-trapping rodents and directly counting acorns on the ground. Acorn abundance in one year clearly influenced the abundance of wood mice in the following year in all models examined based on the Gompertz and Ricker model; in addition, the abundance of wood mice had effects on the population. Acorn abundance influenced the strength of density dependence (intraspecific competition) of the wood mouse population. When the abundance of acorns was high, density dependence was relaxed, and as a result the equilibrium density at which the population growth rate decreased to zero became higher. Those effects of acorn abundance were regarded as a nonlinear perturbation effect (sensu Royama 1992). The nonlinearity of density dependence was also detected; higher densities had stronger effects on population growth rates.

学術雑誌論文

Accepted Manuscript

The original publication is available at www.springerlink.com

1438-3896

1438-390X