Functional responses in habitat use explain changes in animal-habitat interactions during forest succession

摘要

The growing rate of resource extraction forces increasing numbers of late-seral species to occupy habitats that are in early stages of succession. Sustainable management must maintain habitat features that are required for recovery of these species, which may be challenging because their response to those features can vary following nonsystematic trends during stages of succession. We investigated whether simple movement rules could explain such variations by assessing how movements of a late-seral species, the red-backed vole (Myodes gapperi (Vigors, 1830)), vary during postlogging forest succession using the spool and line technique in recent cuts, mid-successional forests, and old-growth forests. We found that voles moved selectively along coarse woody material (CWM), and this selection was weaker in mid-successional forests. This change was best explained by a simple functional response, whereby voles selected CWM more strongly in stands where canopy cover availability was moderately high. Likewise, voles more rapidly left patches that had high canopy cover when it was less available in stands and tended to spend more time in patches with high CWM volumes. Our study demonstrates that the highly dynamic nature of animal-habitat relationships observed during forest succession can be summarized by a few simple functional responses in movement and habitat selection.