Early changes in forest structure and deer use in a 140-site northern hardwoods alternative silviculture systems study.


  • Mike Walters Michigan State University


Inadequate stocking of desirable stems in sapling classes of northern hardwood forest in some regions of Michigan inspired a 140-site evaluation of silvicultural alternatives to current management by selection silviculture. The study’s goal is to identify combinations of silvicultural treatments that increase the diversity and density of sapling recruits over forested landscapes where deer-browsing pressure and other limiting factors are at play. Here we summarize pre-harvest and early post-harvest (1-2 years) vegetation and deer use data. Pre-harvest data bolstered justification for the research; over most of the Michigan northern hardwood resource stands remain even-aged despite 3-4 partial harvests since the 1960s, with sapling classes often old (>70 yrs, understocked with desirable species, and dominated by American beech and ironwood. Deer use, high basal area, and lack of local seed sources were related to low regeneration density and diversity.   Although insufficient to predict long-term outcomes, early post-harvest regeneration (50-137 cm tall (smaller) and >137 cm tall-< 11.4 cm DBH (larger)) densities differed among species and harvest treatments relative to pre-harvest; e.g., American beech declined in smaller and larger classes, especially in the most open treatment (i.e., seed tree harvest);  sugar maple and ironwood declined in the  larger class but increased in the smaller class,  especially when protected from deer by tree tops; pin cherry and paper birch were near absent in pre-harvest forests,  with  post-harvest density highest in the seed tree harvest. Deer use varied spatially and increased following harvesting, especially in more intense harvest treatments. Browsing preferences varied regionally and among species; e.g., low: American beech, balsam fir, high: yellow birch, pin cherry, elm. We anticipate the combination of early regeneration responses to treatments, and interspecific and environmental differences in growth rates and filtering by deer browsing pressure will drive future canopy composition.  

Author Biography

Mike Walters, Michigan State University

Early experiences tagging along on field forestry work with my uncle, working on forest inventory crews in Montana, and farming Christmas trees and holly,  inspired me to pursue a career in forest ecology and management. After earning a Ph. D. in Forest Ecology from the University of Minnesota, in 1994, my first academic position was at University of Northern British Columbia. There I taught classes primarily in silviculture, but also in growth and yield and measurements and my research focused on tree regeneration limitations in wet-belt spruce-fir forests and interior cedar-hemlock forests. Returning home to Michigan in 1998, I started a new position at Michigan State University as a PERM (Partnerships in Ecosystem Research and Management) professor of applied ecology. The position carries with it the mandate that I work with the Michigan DNR, managers of > 1.6 million ha of forestland, on issues of management concern. My work at MSU has largely focused on tree regeneration dynamics in northern hardwood forests. Given their high cultural, wildlife and economic values and the myriad of challenges to their sustainable management, my work on northern hardwood forests has kept me busy. Now nearing retirement, I am co-leading a spatially robust, 140-site experiment evaluating silvicultural options for northern hardwoods management with the goal to improve sustainability and resilience.