This study was designed to 1) address the impact of vole feeding damage to red alder plantations within the Sunshine Coast, 2) recommend strategies for minimizing vole damage, 3) suggest objectives for future investigations, and 4) summarize the scientific literature on the topic of minimizing vole feeding damage to forest plantations (see attached lit review). Suspected vole damage was confirmed by performing an inventory (live trapping) to determine the presence/not detected of small mammals within four young alder plantations. In addition to other small mammals, both southern red-backed voles (Clethrionomys gapperi) and long-tailed voles (Microtus longicaudus) were confirmed to inhabit these plantations. Damage surveys indicated that vole damage was, in general, quite low throughout these plantations (~10% of trees damaged), however, could be quite severe in localized areas. The damage was, therefore, described as having a patchy distribution throughout these plantations. Tree measurements indicated that voles may be selecting for larger and more vigorous trees, presumably due to the increased palatability of these stems compared with suppressed stems. In addition, because all of the observed damage was classified as old, alders appear to be able to survive sub-lethal injuries caused by vole feeding, although height growth may be compromised. Habitat assessments indicated that cover, and in particular, shrub cover, appeared to be well correlated with incidence of feeding damage. As a result, management recommendations focus on reducing cover throughout plantations and several alternative vegetation management strategies are suggested. In addition, supplemental feeding is briefly discussed as a management strategy if damage is suspected to occur primarily during the overwinter period. Hypotheses to be addressed by future investigations are also discussed.
Ransome, Douglas B., Lindgren, Pontus M.F.. 2004. Vole damage to red alder plantations: field assessments, small mammal trapping, damage surveys and habitat sampling. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2004MR039