Friends Research Grant Update

Written by; Dan Engelke, FPSP (920) 854-4468

Autumn Sabo and Katie Frerker at work

Peninsula State Park staff have just received the final report from our first Student Research Grant, Impact of Deer Browse. Research results can help the DNR staff make informed decisions in planning, usage and preservation measures for the Park’s precious public resources. This Friends Grant is believed to be one of the first grants of this type and to date has been extremely successful for all parties. Besides benefits to the Park, University students have an excellent opportunity to connect with a real-life working situation; making contacts and improving their chances of becoming outstanding professionals in their chosen fields.

This research comes from University of Wisconsin graduate students Autumn Sabo and Katie Frerker being awarded a grant. The grant comes from the Endowment Fund initiated and managed by the Friends of Peninsula State Park.

The Friends set up a Research Endowment several years ago and are now in the middle of their second year awarding grants. This is the first final report. See the condensed report below.

While the grant process is new to the DNR Park Staff and the Friends of the Peninsula State Park, there have been some real eye-opening pieces of information produced already. The Grant process works like this:

Each year the Park Staff and DNR Naturalists set topical priorities. Next, students from any College or University in Wisconsin are invited to make applications. The stipulation is that a faculty member from their University must be an advisor and also, all monetary requests must come in the form of expenses. After the deadline for submission, all grants are reviewed and awards are made.

Current Friends research at the Park 2012

  • Michelle Birnbaum of UW- Milwaukee. Michelle has already provided fascinating insight into the importance of ceramic material in “Shanty Bay” (Nicolet Bay).
  • Spencer Siddons of UW-Stevens Point completing a survey of snakes and frogs in areas where there exists Species of Special Concern. His proposal was exactly what the DNR had listed as having a high priority for research. His efforts to date has been very productive.

Both researchers have also given excellent presentations in the Park this summer.

by Autumn E. Sabo, Ph.D. student in Forestry (
Funding: Friends of Peninsula State Park, WDNR, and UW-Madison Botany Department

Frerker stands next to a heavily browsed pine. Note that little foliage exists within easy reach of deer. At the base of the pine, a small spruce is left untouched because it is a less palatable species.

After noticing that low cedar foliage and yew shrubs were becoming rare as deer populations grew, folks in Door County wanted to demonstrate how lowering deer numbers would affect forest plants. About 20 years ago, local citizens partnered with DNR staff to build three deer exclosures at Peninsula State Park. School kids monitored plants in the exclosures and adjacent outside control areas over several years. Kathleen Harris, Park Naturalist, counts the number of flowering trillium inside and outside the Nature Center exclosure to track population changes. In 2011, I sampled two of these exclosures with another graduate student, Katie Frerker, and a team of undergraduates from University of Wisconsin-Madison. We also visited two other exclosures in Door County, plus 13 more around the region, to learn about the long-term consequences of deer browsing and exclusion.

The obvious change in cedar tree form was an excellent clue that deer were impacting the forest. Our measurements from the Nature Center exclosure found abundant cedar saplings inside the fence but none outside. Across the four Door County State Park areas that we sampled, we counted 13 different species in the sapling stage inside exclosures but only three species in outside areas accessible by deer. Heavy deer pressure appears to be reducing sapling diversity.

Understory plant communities, on the other hand, had similar numbers of species outside the fence compared to inside the fence. Once we looked beyond just the number of species, we found that the composition differed. Non-natives and grass-like species were more abundant outside the fence. Habitat specialists, like rough dogwood and maple-leaved viburnum, frequented the exclosures. The overall quality of the plant community was lower in areas open to deer.

Sabo and Frerker used fish-eye lens photos, like this one, to estimate the amount of shade cast by forest canopy. This picture was taken near the Nature Center Exclosure.

We compared ground flora information from all our 17 exclosure/control areas against another dataset that tracked community changes over 50 years in unfenced Wisconsin forests. We found that deer are likely responsible for shifting forests across Wisconsin to lower quality, more heavily invaded communities with less vertical structure. This could spell trouble for the many critters that rely on forest plants, as well as the trees, shrubs, and wildflowers that contribute to the region’s allure. Exclosures provide evidence that stronger deer control and protection of browse-sensitive species can help reverse, or at least slow, forest quality decline. Thanks to Peninsula State Park for providing these wonderful exclosures that allow researchers and curious park visitors to study interactions between deer and other forest dwellers!