Wildlife of Northern Hardwood Forests Prior to Timber Harvests in Michigan
By Gary Roloff
There’s a huge ongoing, forest regeneration study occurring across the northern forests of Michigan. One of the aspects involves use and impacts by wildlife, especially white-tailed deer.
Northern hardwoods occur over millions of acres in the Great Lakes Region. This forest type includes a variety of tree species that currently include maples, oaks, birches, beech, and ironwood, and secondarily conifers (like white pine and hemlock), aspen, and basswood.
Northern hardwoods are valued for timber production and wildlife habitat but concerns about the ability to grow new trees after timber harvest prompted the Michigan Department of Natural Resources (MDNR) to study alternative approaches for managing this important resource. These concerns prompted the “big northern hardwoods study”.
This study started in winter of 2017 with collection of data prior to timber harvest. In winter of 2018, MDNR and forest industry partners harvested timber from 140 30-acre sites spread throughout Michigan. One of four timber treatments was assigned to each site. These treatments ranged from the typical, historical way of managing northern hardwoods using what is known as selection silviculture, to more aggressive techniques like seed tree, where most trees are cut leaving 6-8 seed trees per acre. Although a primary focus of the research project is tree regeneration and recruitment, the MDNR Wildlife Division was also interested in wildlife responses to the different treatments.
For 48 of the 140 study sites, the Applied Forest and Wildlife Ecology Lab (AFWEL; https://www.afwelsite.com/) at Michigan State University deployed four trail cameras within the 30-acre harvest areas to monitor wildlife activity prior to timber harvesting. Although the focus of the project is deer use and behavior and how that affects tree recruitment, cameras offer an opportunity to learn about other species. These cameras collected data for about a year prior to timber harvest and accumulated over 250,000 photos.
One question the AFWEL needed to answer was whether four cameras were enough to reliably portray deer use of the study sites. To answer this question, the AFWEL deployed 25 cameras on one site (a camera every 1.2 acre) and compared deer use among different combinations of the 25 cameras. Although there was considerable variability, the AFWEL found that four cameras portrayed deer use almost as good as 25 cameras for a 30-acre site. Thus, the AFWEL was confident that the camera design would provide meaningful information on deer use to the project.
In the process of sorting through 250,000 photos, the AFWEL quickly recognized that there was an opportunity to collect information on wildlife other than deer, particularly for some of the medium to large-sized animals using the sites. The AFWEL ultimately looked at two broad groups of wildlife: herbivores (or plant eaters) and omnivores/carnivores (or meat eaters). Within these groups, the AFWEL further summarized photos for medium- and large-sized animals. For example, large herbivores included deer and moose, and medium herbivores included snowshoe hare and porcupine. Large carnivores included black bear and wolf, and medium carnivores included bobcat, coyote, fisher, marten, and red fox.
Not surprisingly, the AFWEL found that deer used all 140 sites prior to timber harvest. As part of the study, the AFWEL will quantify deer residence time (e.g. how long deer stay in front of the camera, exposing the trees to potential browsing) and behaviors by season. The AFWEL predicts lower residence times and less deer browsing behaviors in some timber harvest types, particularly those designed to restrict deer access to portions of the harvest areas (e.g., by leaving tree tops to shelter seedlings).
Research indicates that predators also affect herbivore behaviors. The camera data provide the AFWEL an excellent opportunity to look at activity times of predator-prey combinations on study sites. For example, the AFWEL found that in the western Upper Peninsula, morning and evening deer and wolf activity peaked at the same times, but wolves also showed an increase in afternoon activity when deer were not active. This frequent wolf activity may reduce the time that deer spend on particular sites, thereby giving the trees that deer like to browse a better chance to recruit into the overstory. This pattern was not as clear in the eastern Upper Peninsula, where deer and wolf activity did not closely synchronize. For medium sized animals, the AFWEL found that activity of snowshoe hares and porcupines peaked at night, whereas fisher and marten activity peaked during the day.
A big part of AFWEL’s work is to continue monitoring sites for wildlife use now that timber harvest is complete. After timber harvest, the AFWEL added four cameras around study sites to monitor deer activity in the surrounding area. This is an important part of the research because a timber treatment that successfully recruits desirable tree species in a landscape heavily used by deer (thus, likely exposing the trees in harvest areas to browse pressure) is a win for forest and deer management; which is the ultimate goal of the project. Hence, knowing how deer are using the areas around timber treatment sites is important.
All of the AFWEL’s cameras have a metal tag that read “MSU Forestry Research”. So, if you are in the Michigan woods and come across a camera with this tag you are standing in part of the “big northern hardwoods” study.
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Trailer: This long-term study is being conducted in cooperation with Michigan State University, the Michigan DNR, the forest products industry, and Safari Club International, Michigan Involvement Committee. For more information, contact Gary Roloff (email@example.com) or Mike Walters (firstname.lastname@example.org).
A fisher foraging on an experimental plot.
Note: image resolution is poor.
A curious spring buck at the camera.
Afternoon browsing on research plot before stand treatement.
Deer browsing on sugar maple.
Note: image resolution is poor.
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This website is maintained by Bill Cook, Michigan State Extension Forester/Biologist.
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