Month: April 2022

Kiln Drying In The Lake States – What Happens Inside A Lumber Dry Kiln

By Scott Bowe, Professor of Wood Products at the University of Wisconsin’s Kemp Station and Scott Lyon, DNR Forest Products Specialist, Green Bay

The Great Lake States region produces some of the best hardwood and softwood lumber globally. Most of us have driven by a sawmill or concentration yard and have seen lumber dry kilns — rows of large rectangular buildings with massive doors.

What goes on inside these kilns? What value is added during drying? How many days does it take to dry lumber? Why dry lumber at all?

We dry lumber for several reasons. The first is to prevent fungal degradation and insect attack—a tree in the forest lives in a tough world. Decay fungi, stain fungi and insects are always looking for their chance to use the tree for a food source, home or both. Continue reading “Kiln Drying In The Lake States – What Happens Inside A Lumber Dry Kiln”

New Technology Highlighted In Publication

The Wisconsin Department of Natural Resources (DNR) Forest Products Services recently worked with UW-Extension and the Department of Agriculture Forest Products Lab to develop a technical primer highlighting vacuum drying technologies for lumber manufacturing.

This research was completed by using the vacuum kiln at Northcentral Technical College. Vacuum drying technology has recently gained attention in Wisconsin because of the availability of lower-cost vacuum kilns for smaller wood product manufacturers.

Vacuum drying utilizes a pressure vessel, a heat source and a vacuum pump to control the drying conditions under less-than-atmospheric pressure. This process is an economical alternative to conventional drying for many species under various environmental and economic conditions.

Vacuum drying can reduce drying time and be more energy-efficient than conventional steam drying. However, there are many factors to consider when comparing the two technologies. Ideal applications for vacuum kilns include high-value wood species, difficult-to-dry species (e.g. oak), timbers, large sections of logs and lumber (including live-edge slabs and wooden rounds), decorative or thick veneer and small-scale woodworking operations.

The new report describes the principles and practices of vacuum drying and discusses its advantages and disadvantages. To learn more about this technology and drying lumber, please view the recent technical report by visiting this webpage.

Lake States Woodshed Mapping Project

A group of researchers and Extension professionals from Michigan, Minnesota, and Wisconsin are working on a “Woodsheds” mapping project (similar to the concept of a watershed) to develop an interactive web-based mapping application they hope will be useful for forest landowners, forestry professionals, and wood products industry professionals. A 5-10 minute survey is intended to find out what your information needs are, and to see if you’d like to be part of a user testing group that helps them refine this tool. Direct any survey questions to Please use this link to complete the survey by April 18th:

Restoring Coastal Wetlands With Low-Value Woody Material

By Scott Lyon, DNR Forest Products Specialist, Green Bay

Conservation partners, including Ducks Unlimited, Wisconsin DNR, U.S. Fish and Wildlife Service, City of Green Bay and UW-Green Bay, worked together to construct a woody breakwater to restore and enhance wetlands for wildlife and more.

The project took place in fall 2021 at the mouth of Duck Creek, offshore from the Ken Euers Nature Area in Green Bay, Wisconsin. The project involved several years of planning that brought together a team of fish and wildlife biologists, wetland and aquatic plant scientists, foresters and engineers to discuss ideas and plans to restore wetland vegetation in the Duck Creek Delta.

Steve Kaufman, DNR Forester on the Oconto Falls team, and Scott Lyon, DNR Forest Products Specialist with Forest Products Services, participated in technical advisory committee meetings and assisted in connecting the project coordinators with woody materials to be used in the structure.

The resulting breakwater structures were predominantly trees rather than a traditional breakwall composed of mostly rock and is one of the first for the bay of Green Bay and the broader Great Lakes system. Continue reading “Restoring Coastal Wetlands With Low-Value Woody Material”

Black Walnut Trends In Wisconsin

By Brian Anderson, DNR Forest Inventory Analyst, Rhinelander and Alex Rosenflanz, DNR Forest Inventory Specialist, Madison

Acres Of Black Walnut Forests
Black walnut is a valuable and highly sought-after species found in the Midwest and Eastern United States. In Wisconsin, its distribution is primarily limited to the state’s southern region, although scattered sites are found farther north. The total acreage of black walnut in the state has increased nearly three times, from approximately 35,065 acres in 2004, to 101,274 acres in 2019.

Of that total, surprisingly, only 10% is attributed to stands established by artificial regeneration. The distribution of acres by stand age shows a boon in stands aged 31 to 90 years since 2004, with younger age classes remaining relatively steady since 2009 (Figure 1). Relatively few stands have reached ages over 90 years.
Continue reading “Black Walnut Trends In Wisconsin”

New Forest Products Specialist In Dodgeville

By Collin Buntrock, DNR Forest Products Team Leader

I am very pleased to announce that Brian Zweifel has accepted the statewide Forest Products Specialist position in Dodgeville. Brian’s first day was Feb. 14.

Brian brings a diverse background in forestry and partnership development and will play a key role in forest products training, business and market development regionally and across Wisconsin. He has worked as a DNR forester and consulting forester and has experience with international marketing and forest products extension.

He is excited to bring his experience as a field forester and forest products extension to the forest products services team to support, promote and grow Wisconsin’s forest products industry.

Upcoming Forest Products Events

Wisconsin Local Use Dimension Lumber Grading Classes (WI LUDL) – Woodruff, Wisconsin
May 31, June 1 – 2, 2022
To register for one of these courses, please visit this webpage.

Hardwood Sawmilling Certificate – Antigo, Wisconsin
June 6 – July 1, 2022
This unique certificate prepares learners for hands-on, in-demand positions within the hardwood lumber industry. This short four-week certificate will help launch you into a lifelong, rewarding career. All classes are taught in person and utilize Northcentral Technical College’s 27,000 square foot state-of-the-art Wood Technology Center of Excellence.

The training will focus on hardwood lumber inspection; sawing, edging and trimming to maximize profits; hardwood log scaling and grading; and species identification for hardwood lumber and logs.

To learn more about this program, please visit this webpage. To register, visit the registration page.

Small Live Edge Slab Business Workshop – Grafton, Wisconsin
June 9, 2022
This one-day educational and networking workshop focuses on the business and operational skills needed to operate a live-edge slab producing sawmill business successfully. There will be on-site slab sawing demonstrations. To learn more about this workshop and register, please visit the event’s registration page.

National Firewood Workshop – Arlington, Wisconsin
June 15 – 16, 2022
This firewood industry event combines education and networking opportunities. The workshop offers discussions on business and equipment topics and outdoor sawing and firewood splitting demonstrations by multiple equipment manufacturers.  To learn more about this workshop and register, please visit the event’s registration page.

Spring Yard Cleanup – Safety First!

“Don’t like the weather? Wait five minutes.” A saying that rings true during spring in Wisconsin. While March signals the beginning of spring fire season for us, it can be interrupted by rainfall and snowstorms. Wet weather gives firefighters a chance to recharge and can be an opportunity for people to burn yard debris while it’s safer to do so.

The yard around your home may currently be filled with an assortment of fallen leaves, pine needles and branches. Recent ice storms in northern Wisconsin have contributed significantly to the volume of debris around our homes. If the recent widespread ice storms have damaged the trees on your property, take some time to assess the damage and realistically determine if you can handle the cleanup yourself or if it’s time to call in some professionals. Watch for damaged branches and bent trees that could fall. Prioritize your physical safety before attempting any cleanup activities.

Recent ice storms have caused lots of branches to fall

Many places in Wisconsin have experienced damage to trees due to recent ice storms.

You may now wonder what to do with all this debris leftover after winter and those recent ice storms. Some communities have brush collection services or a site where you can drop off leaves, pine needles and branches. Perhaps there’s enough debris on your property to warrant the rental of a brush chipper. Or, if your property is large enough, creating a brush pile away from buildings could serve as a shelter for wildlife. Larger pieces of hardwood could be cut for future use as firewood or campfire logs. If none of these alternatives works for your situation and your community allows for burning the material, timing your burn around periods of wet weather may be the safer choice.

Before you light that match, take the following precautions:

– Check for burning restrictions and permit requirements first. You can find this information on the DNR burning restrictions webpage or by calling your nearest DNR office or fire department.  – Check the weather forecast. Delay burning if dry or windy weather is predicted. Be aware of your county’s fire danger forecast by calling 1-888-WIS-BURN or searching “burn” on the DNR website.
– Keep your piles small, with the area around the pile cleared of any burnable vegetation.
– Have an attached hose or other water source handy.
– Stay with the fire until you have completed the burn. Make sure it’s out before you leave by dousing the ashes with water and mixing it in. Then, just to be safe, add more water. If any unburned branches or larger pieces of wood remain unburned, check back frequently to make sure this material hasn’t reignited.

Winter burning when the ground is completely snow covered

Taking advantage of wet weather to conduct debris burning is a safer option.

In Wisconsin, spring fire season typically lasts from snowmelt to “green up” (when the grasses are green and leaves are budding out again). Many parts of our state are still experiencing drought conditions, even coming out of winter. Fire officials will be suspending outdoor burning as needed when fire danger conditions become elevated.

For more information, contact Catherine Koele, fire prevention specialist or Jolene Ackerman, wildland urban interface specialist.