Research

Controlling Buckthorn With Plants

By Olivia Witthun, DNR Urban Forestry Coordinator, Olivia.Witthun@wisconsin.gov or 414-750-8744 and Elton Rogers, DNR Urban Forestry Coordinator, Elton.Rogers@wisconsin.gov or 414-294-8675

buckthorn The Cover It Up project is a suite of related research projects conducted by multiple partners in Minnesota that are evaluating the ecology and management of buckthorn and other invasive plant species. Buckthorn is an invasive understory plant that was introduced to Wisconsin well over 100 years ago. It was used primarily in hedgerows, prized for its lack of pest issues and the fact it greens up early and holds its leaves well into the fall. These once desirable characteristics are also what turned this non-native into one of our state’s worst invasive species, easily outcompeting our natives, taking over Wisconsin’s forests, riparian woods, savannas, prairies, old fields, roadsides and vacant lots. Continue reading “Controlling Buckthorn With Plants”

Community Spotlight: Tree Canopy Cover On Milwaukee School Properties

By Dan Buckler, DNR Urban Forest Assessment Specialist
Daniel.Buckler@wisconsin.gov or 608-445-4578

The thought of increasing a community’s tree canopy cover is sometimes overwhelming given how many landowners are present. Think about all the stakeholders who have to buy into the initiative, not only with enthusiasm, but likely contributing money and time as well.

Contrast that with a more actionable approach focused on areas where there’s a single landowner or manager.

This was the route taken by graduate student Michelle Hess in a recent paper for a UW-Milwaukee Geography course. Michelle investigated tree canopy on Milwaukee Public Schools (MPS) properties to identify which schools should be prioritized for future greening initiatives, like those organized through ReFlo. The goal was to use canopy data provided by the DNR, identify which schools had lower canopy cover, merge those data with median household income of the local Census tract and come up with a prioritized list of schools in need of tree planting. Continue reading “Community Spotlight: Tree Canopy Cover On Milwaukee School Properties”

Register For Tour Des Trees 2026

Tour des Trees 2026The Tour des Trees is a multi-day bike ride that not only raises funds for TREE Fund but also hosts multiple outreach events throughout the week, getting people together to learn more about the importance of tree research, proper tree care and why the industry is so vital to maintaining our urban forests.

Ride dates are Sept.12-18, 2026, riding from Greenville, South Carolina, to Asheville, North Carolina. Can’t ride all five days? Ride one to four days as your schedule allows.

See information on this year’s ride and register today on the TREE Fund website.

The 2026 Tour des Trees will be an epic ride that you won’t soon forget, so make this the year that you sign up and ride with us to support tree research. Continue reading “Register For Tour Des Trees 2026”

Wisconsin Sees First Recovery Of EAB Parasitoid Oobius Agrili

A plastic pan trap for wasps is hung from a tree branch.

A yellow pan trap used for trapping Oobius agrili wasps. / Photo Credit: United States Department of Agriculture Animal and Plant Health Inspection Service

By River Mathieu, DNR Forest Health Specialist
River.Mathieu@wisconsin.gov or 608-772-2758

One small adult wasp collected by United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) staff at Riedel Redmond Nature Preserve in Mosinee (Marathon County) was recently identified as Oobius agrili.

USDA APHIS staff collected several wasp specimens in yellow pan traps and sent them to a U.S. Forest Service expert for identification. This marks the first recovery of O. agrili in Wisconsin.

Oobius agrili is an emerald ash borer (EAB) parasitoid that was first released in Wisconsin in 2011 and has been released annually since then. O. agrili parasitizes EAB eggs on the bark of ash trees, consuming the EAB larvae inside the egg. Continue reading “Wisconsin Sees First Recovery Of EAB Parasitoid Oobius Agrili”

Forest Health Annual Report Hot Off The Presses

The cover of the 2025 Wisconsin Department of Natural Resources Forest Health Annual Report.

The cover of the 2025 Wisconsin Department of Natural Resources Forest Health Annual Report. / Graphic Credit: Wisconsin DNR

By Art Kabelowsky, DNR Outreach and Communications, Fitchburg
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

The Wisconsin Department of Natural Resources (DNR) has made its 2025 Forest Health Annual Report ready to view and download.

This year’s edition contains 55 pages of reporting on forest health issues throughout Wisconsin, detailing methods employed by the DNR and other agencies to control pests, diseases and invasive plants.

Continue reading “Forest Health Annual Report Hot Off The Presses”

Upcoming Trainings

*These training opportunities are provided as an information service only and do not constitute an endorsement from the Wisconsin Department of Natural Resources (DNR).

See below for information on training topics and events, including ISA certification exam preparation, plant propagation, winter tree identification, urban forest restoration, research trends and electrical hazards. Continue reading “Upcoming Trainings”

Go-To Online Resources For Urban Forestry

By Allen Pyle, UW-Extension Horticulture Outreach Specialist and Jay Dampier, DNR IRA Grant Coordinator, Jason.Dampier@wisconsin.gov or 920-765-1935

Reliable and up-to-date research-based information is vital for tree care professionals and urban foresters to make sound, scientific management decisions. To make trusted resources more accessible, UW-Extension’s Horticulture Program and Wisconsin DNR’s Urban Forestry Program have developed this curated selection of useful webpages with free information and resources for urban forestry professionals and community tree managers. Continue reading “Go-To Online Resources For Urban Forestry”

Upcoming Trainings

*These training opportunities are provided as an information service only and do not constitute an endorsement from the Wisconsin Department of Natural Resources (DNR).

See below for information on training topics and events, including urban wood, invasive species, tree rot and decay, beech leaf disease, connecting people to urban forestry and research presentations on pruning regimens, tree science and solar power. Continue reading “Upcoming Trainings”

Biophilic Design & Urban Wood

By Dwayne Sperber, Wudeward Urban Forest Products

Trees grow, change and like all living things, eventually decline or die. Sometimes trees are removed from urban areas due to safety concerns, tree health or insufficient space. But when these urban and community trees are viewed not as waste, but as a valuable material resource, their story doesn’t end – it continues.

By transforming fallen trees into urban wood products, we can extend the benefits of living trees into the places we live, work and play. These materials – lumber, furniture, architectural woodwork – quietly connect us to nature. This is the basis of biophilic design, the concept of connecting humans to the natural environment.

Continue reading “Biophilic Design & Urban Wood”

Wisconsin’s Mass Timber Future: Building Strength From Forest To Facility

Various panels of cross-laminated timber awaits a return trip to Madison, Wisconsin, for testing at the USDA Forest Products Laboratory. / Photo Credit: Wisconsin DNR

By Ram Dahal, DNR Forest Economist, Madison;
Ram.Dahal@wisconsin.gov

A recent study conducted by Michigan State University and the Wisconsin Department of Natural Resources highlights Wisconsin’s strong potentiality to locate mass timber industry in the state, leveraging its abundant forest resources, existing forest products infrastructure and growing market demand.

Continue reading “Wisconsin’s Mass Timber Future: Building Strength From Forest To Facility”