Northern hardwood forests cover 5.9 million acres in Michigan and are highly valued for forest products, wildlife and recreation. These stands are important in Michigan and their future is being carefully monitored. Northern hardwood stands typically contain a variety of species, such as sugar maple, American beech, basswood, white ash, red maple, hemlock, white pine and red oak.
Declining tree diversity has caused concern among natural resource managers and researchers.
College of Agriculture and Natural Resources researchers Mike Walters and Gary Roloff are teaming up to study ways to increase sustainability and diversity of Michigan’s valuable northern hardwood forests. The Michigan Department of Natural Resources Forest Resources and Wildlife divisions are partnering with MSU to fund the six-year, $1 million project.
The study is one of the largest in the country, with Walters and Roloff examining almost 150 30-acre forest stands on public and private land in the Upper and Lower peninsulas.
“There are really two big challenges facing our forests,” said Walters. “The first is ensuring that a healthy diversity of tree species are regenerating in these forests, and the second is restoring the northern hardwood forests that have been degraded by beech bark disease.
“When we manage forests for diversity, they are less susceptible to invasive pests, and they contain multiple sources of food for wildlife,” said Walters.
The loss of tree species diversity and, in some cases, reduced stocking levels in Michigan’s northern hardwood forests are linked to many factors. Walters and Roloff identified three that they think are particularly important:
- The resurrection of the practice of removing individual trees to create smaller canopy gaps and promote regeneration of more shade-tolerant species). The process, known as single-selection silviculture, used to be the favored method for managing northern hardwoods; today,.
- Plants being eaten by animals, most often deer
- Pest and disease outbreaks-- e.g., beech bark disease and emerald ash borer.
Other factors likely include climate change, availability of certain tree seeds and seedling establishment limitations.
“Deer are an important part of the northern hardwood forests, both ecologically and recreationally,” Roloff says. “Our challenge is to figure out ways that deer and other wildlife and diverse northern hardwoods can co-exist, because both are critical elements of Michigan’s natural resources.”
Walters and Roloff will measure hardwood seedling growth and survival, quantify deer use and browsing behaviors in harvested areas, and assess the impacts of competing vegetation resulting from a variety of forest management techniques.