Sunday, 14 August 2016

Effects of an ongoing oak savanna restoration on small mammals in Lower Michigan

Volume 367, 1 May 2016, Pages 120–127

  • a Biology Department, Grand Valley State University, 1 Campus Drive, 3300a Kindschi Hall of Science, Allendale, MI 49401, USA
  • b United States Forest Service, Huron-Manistee National Forests, 605 N. Michigan Avenue, Baldwin, MI 49304, USA


Mechanical thinning and burning recruited small mammals associated with grasslands.
Mechanical thinning increased diversity of small mammals relative to control plots.
Small mammal assemblages responded within 1–2 years to mechanical thinning.
Brush pile retention following thinning provided refugia for small mammals.


Oak (Quercus spp.) savannas have declined drastically in the midwestern United States since European settlement. Oak savanna restoration projects are primarily driven by species closely linked to this habitat type, such as the federally endangered Karner blue butterfly (Lycaeides melissa samuelis). However, it is essential that other species are monitored during restoration. Small mammals, due to their importance in ecosystem function, are particularly useful to study. The United States Forest Service is currently conducting an oak savanna restoration in the Manistee National Forest in Lower Michigan using forest thinning and prescribed burning. To understand management impacts on small mammal communities, we live trapped small mammals in each of the mechanically thinned plots (i.e., bulldozer, masticator, and shear cutter) and control plots in five blocks over six years (2008–2013), as well as measured vegetation variables each year. Initially, we used a permutation multivariate analysis of variance (perMANOVA) to determine if there were treatment and year interactions for both small mammal community assemblages and vegetation variables. We then compared changes in small mammal diversity, relative abundance, and vegetation variables among treatments using exploratory randomized block design analysis of variances (ANOVAs). Canopy cover was significantly lower in bulldozer and shear cutter thinned plots than control plots five years following thinning. We observed significant treatment by year interactions in how the small mammal community responded. A large increase in relative abundance of white-footed mice occurred one year post-thinning in all treatments. Within 1–2 years of treatment, thirteen-lined ground squirrels and meadow jumping mice, both open-canopy grassland species became established on thinned plots. The retention of brush piles in bulldozer and shear cutter plots provided important refuge habitat for small mammals following thinning. Restoration efforts were beneficial to the small mammal community overall and promoted grassland species to immigrate into the restored area.


  • Small mammals;
  • Thinning;
  • Oak savanna;
  • Quercus spp.;
  • Habitat restoration;
  • Michigan
Corresponding author.
Present address: Biology Department, University of North Carolina-Greensboro, 312 Eberhart Building, Greensboro, NC 27402, USA.