Volume 85, July 2016, Pages 9–16
Highlights
- •
- Mean abundance of total herbs and grasses were similar among treatments.
- •
- Wildfire did not generate high populations of voles and significant damage to tree seedlings.
- •
- Mean mortality of trees higher in control clearcut than burned plantation sites.
- •
- Total small mammal numbers similar in burned and control plantation sites, but less than clearcuts.
Abstract
Early
successional forest habitats that develop after wildfire may provide
ideal conditions for population build-ups and subsequent fluctuations by
Microtus voles. Regeneration of burned-over forest land may be
hindered by consumption of planted trees by voles. A high abundance of
voles, occurring in the second growing season after a wildfire, may
result in serious feeding damage to seedlings leading to major
plantation failures. A wildfire occurred near Golden, British Columbia,
Canada in the spring of 2011 and may have initiated the successional
conditions to generate a vole population outbreak with consequent
feeding damage to tree seedlings. We tested the hypotheses (H) that (H1) abundance of herbaceous plants (grasses and forbs) will be greater, and (H2) abundance of voles and incidence of feeding damage to tree seedlings will be higher, in burned than unburned (control) sites. Microtus
voles and other forest-floor small mammals were live-trapped for four
years (2011–2014) in replicated sites of a wildfire (burned plantation),
control (unburned) plantation, and a new control clearcut. Abundance of
total herbs and grasses, incidence of feeding damage, and mortality to
tree seedlings by voles were measured in all sites. Mean abundance of
total herbs and grasses were similar among treatments during the
post-wildfire period. Mean annual peak numbers of Microtus in
clearcut sites ranged from 18 to 30 per index-line. Annual peak numbers
in the burned and control plantation sites ranged from 5 to 8 voles per
index-line and were essentially stable at these numbers. Vole
populations in the control and burned plantation sites were dominated by
the meadow vole (Microtus pennsylvanicus Ord), and those in the clearcut sites by the long-tailed vole (Microtus longicaudus
Merriam). Mean mortality of trees was significantly higher in the
control clearcut sites at 30% compared with 13% in the burned plantation
sites. These results did not support either H1 or H2.
Wildfire, at least in this case, did not generate high populations of
voles and significant damage to tree seedlings. Mean abundance of total
small mammals was similar in burned and control plantation sites, but
less than in clearcut sites. Populations of the deer mouse (Peromyscus maniculatus Wagner) increased after wildfire and those of the southern red-backed vole (Myodes gapperi Vigors) declined. Populations of the northwestern chipmunk (Neotamias amoenus J.A. Allen) and Sorex
spp. did not show a clear preference for any of the treatments.
Disturbance by clearcutting or wildfire seemed to reduce species
richness and diversity, but all eight species of small mammals were
present in each of the treatments.
Keywords
- Coniferous tree seedlings;
- Feeding damage;
- Long-tailed voles;
- Microtus voles;
- Plantations;
- Small mammals;
- Wildfire
© 2016 Elsevier Ltd. All rights reserved.
