spatial scaling in northern landscapes : habitat selection by small mammals
abstract
i examined a series of simple and repeated northern landscapes in the hudson bay
lowland of ontario to document regional and local patterns of population abundance
of red-backed voles {clethrionomys gapperi). i tested whether a spatially-explicit
ecological process, density-dependent habitat selection, could account for population
regulation of voles across a range of spatial scales. over a large regional scale,
multiple regression analysis indicated that population density of voles was primarily
predicted by location of sampling and measures of microhabitat. regional abundance
patterns, therefore, appear to be independent of nonadditive landscape effects and
probably result from large-scale biogeographic influences or differences in average
habitat quality between sites. at a local scale, my analysis identified density-dependent
habitat selection as a universal process structuring abundance patterns,
regardless of regional differences in population density. habitat selection, at the
dispersal and perhaps microhabitat scales, thereby provides a feasible mechanism
linking landscape structure directly to population regulation.
collections
- retrospective theses [1604]