Mechanisms of population limitation in the southern red-backed vole in conifer forests of western North America: insights from a long-term study

摘要: Our goals were to characterize multiannual population changes of the southern red-backed vole (Myodes gapperi) determine potential cycling behavior, and specify possible causes these changes. We analyzed a detailed, 21-year record in abundance M. gapperi late successional coniferous forest British Columbia, Canada, from 1995 2015. evaluated 3 hypotheses (H), namely that are related to: (H1) food supply cone crops trees; (H2) habitat associated with beetle-killed lodgepole pine (Pinus contorta) (H3) territorial reorganization leading breeding season declines abundance. There cyclic fluctuations (6- 7-year periodicity) where voles reached mean fall numbers 19–25, 15–16, 26–27 per ha, respectively; contrast, only 2–5 ha occurred during lows. Breeding 17 21 years, particularly precipitous drops ranging 49% 69% loss voles. had more successful pregnancies, juvenile recruits, adult recruits high than low years. Mean index early survival was 22% higher summer (58%) consistently lower winter (83%). Population increases positively tree species. Thus, H1 partially supported 4 seedfall events. Positive habitat, resulting seed rain as fallen debris trees cover, may have 2011–2012 (H2). A spring event limited number animals by density-dependent inhibition maturation voles, led (H3). Rigorous field experiments needed test their interactions mechanisms driving change.