Population Ecology of Clethrionomys rufocanus Seasonal Forcing on the Dynamics of Clethrionomys rufocanus: Modeling Geographic Gradients in Population Dynamics
Abstract. We interpret gradients in population dynamics of the gray-sided vole from the southwestern part of the island of Hokkaido to its northeastern part within the framework of a phenomenological model involving the relative length of summer and winter. In Hokkaido, as in other northern regions,...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.452.443 http://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/17001/1/RPE40-1-85.pdf |
| Summary: | Abstract. We interpret gradients in population dynamics of the gray-sided vole from the southwestern part of the island of Hokkaido to its northeastern part within the framework of a phenomenological model involving the relative length of summer and winter. In Hokkaido, as in other northern regions, both spring and fall is considered as short transition periods between the two main seasons- summer (the primary breeding season) and winter (the non-reproductive or secondary breeding season). We show that the geographic transition in dynamics may be understood as the combined consequence of different patterns of density-dependence during summer and winter, and geographically varying season lengths. Differences are shown to exist between summer and winter with respect to strength of density-dependence. Direct density-dependence, in particular, is stronger during winter than during summer. A model is presented to show how relative lengths of seasons can induce both stable and periodically fluctuating population dynamics. The results are compared and con-trasted with what is otherwise known about the gradient in rodent dynamics in Fennoscandia. Key words: density-dependence, length of summer and winter, phenomenological model, seasonal and annual dynamics, the gray-sided vole. |
|---|