Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

Photo of gypsy moth egg mass © Nick Meiers

Gypsy moth egg masses look like cottony brown tufts.
© Nick Meiers

April 2010

Use local firewood

Limiting the movement of firewood is a key to slowing the spread of invasive forest pests and diseases.

Colleen Robinson Klug

The warmth, smell and light from a wood fire is soothing, protective and primal; small wonder that it is a treasured comfort at campsites and in fireplaces alike. The flip-side of that experience is we know fires release pollutants and we have to be careful to avoid being burned. These days, there is another downside – transporting invasive bugs and fungi. Unless we are careful, insects like the emerald ash borer beetle or gypsy moth travel and spread much farther and much faster in transported firewood. Left on their own, these insects might move only a mile or two from where they hatched in a year. When carried in firewood, these diseases can move in cars, trucks and airplanes much greater distances in little time to infest areas where they've never been seen before. We need to be aware, and we need to take precautions with firewood to keep from giving invasives a quick ride to new turf which could be your neighborhood or favorite campground.

The message that firewood can be an efficient insect and disease carrier is becoming more familiar each season. Foresters, arborists and park managers are encouraging everyone to use firewood more wisely. How? Either don't move it far from where it was cut or buy wood treated specifically to kill pests and diseases lurking inside it. By using wood within 25 miles of where it was cut you can reduce the risk of bringing in pests that aren't already established in your area. Wood can also be treated by approved firewood dealers who meet set guidelines by heating, aging, debarking or spraying it with certain fumigants to kill pests or diseases inside the wood.

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) inspects and certifies firewood dealers who treat their wood in one of these ways. Wood certified by DATCP will have a seal on its label. Don't move uncertified wood more than 25 miles for heating homes, cabins, occasional campfires or for any other purpose. The risk of spreading tree-killing invasive species from place to place on the surface or under the bark of firewood is high. Many invasive killers gain an aggressive foothold and destroy the natural balance in native habitats after hitching a ride and being introduced to a new area. These invaders often do not have native predators and can increase rapidly.

The impacts reach far beyond the woods or parks. As trees die, local economies fall too if we lose the value of timber, pulpwood, protective cover, a food source for wildlife, erosion protection and aesthetics. Healthy trees are important features in maintaining quality outdoor recreation, bolstering property values as well as providing shade and wind protection that cut energy use. Dead and dying trees also become a public safety concern and a costly liability for homeowners. Oak wilt, gypsy moth, emerald ash borer and beech bark disease are just a few of the tree diseases borne on firewood that are already in our midst in Wisconsin. On the horizon and near our borders are other species such as the Asian long-horned beetle.

"Though the battle against invasive species is long-term and can seem difficult, changing our firewood habits is actually very easy," says Andrea Diss-Torrance, invasive insect specialist with DNR's forestry program. "Far fewer invasive species can gain a foothold without human help," Diss- Torrance says. "These beetles, moths and fungi would naturally spread their range at a very slow rate. We stand a much better chance of containing invasive species and preventing new disease introductions when firewood stays put."

While containing invasive outbreaks is costly, simple inexpensive steps can prevent a lot of problems. Both Wisconsin residents and visitors are helping by:

  • staying updated on restrictions on moving firewood in the state. State and federal land managers limit what firewood is allowed onto their properties; so do many county and private campgrounds. For updates on Wisconsin state lands regulations and currently quarantined areas, go to emerald ash borer.wi.gov. Contact other properties directly for their regulations.
  • buying or harvesting firewood within a few miles of where you plan to burn it.
  • buying Wisconsin certified wood that has been treated to kill internal pests and diseases. You can find a list of certified firewood dealers online at: Wisconsin's Emerald Ash Borer Information Source.

Firewood quarantines

Forest protection agencies institute quarantines when and where pest or disease infestations are found. Emerald ash borer and gypsy moth are two such federally quarantined pests. Restrictions on moving raw wood and wood products help prevent the speedy spread of invasives. For instance, products that can carry gypsy moth, such as firewood, tree nursery stock, mulch and Christmas trees must be certified clear of the pest before being taken out of the eastern half of the state quarantined for gypsy moth. Hardwood firewood, ash logs, nursery stock and wood products made from species of ash are not allowed outside of counties quarantined for the emerald ash borer. To prevent a variety of wood-borne pests and diseases from spreading to state lands, no uncertified firewood harvested from more than 50 miles away has been allowed onto Wisconsin state-managed properties since 2007.

Due to the emerald ash borer and beech bark disease finds in 2009, the Natural Resources Board at its January 2010 meeting authorized even tighter firewood restrictions. Only certified firewood cut within 25 miles of a state property can be brought in by campers and day users. Federal lands and many county parks and private campgrounds also restrict firewood on their properties. Campers and picnickers should be clear about the rules before bringing firewood along on their travels to avoid having their firewood confiscated at the gate. To make sure that campers can still enjoy a campfire, both public and private campgrounds sell local firewood onsite and at nearby locations.

Those who handle nursery stock or wood for a living are already onboard where quarantines have been issued. Garden centers, nurseries, landscapers, timber and pulp industries are well organized and want to sell quality products that do not pose a risk of introducing an invasive pest. Thanks to their diligence and swift compliance along with Wisconsin regulations and inspections, merchants helped quickly stop movement of emerald ash borer on nursery and wood industry products. This left only firewood as the main way the ash borer was being moved by people.

Preventing movement of uncertified firewood has been a greater challenge because the public doesn't always hear about new restrictions or they figure it does not apply to them and the small amount of firewood they pack in on a weekend trip. They are wrong. A lot of firewood is moved in every direction among homes and weekend cabins, campgrounds, picnic areas, boat docks and other recreation sites, and pests moving in this wood are introduced right into the areas we value most. Getting the message out about firewood and getting compliance from people who may only handle firewood a few times a year is much more difficult than dealing with businesses that handle wood on a daily basis.

"We can't overemphasize the importance of citizen help to contain invasives," says Diss-Torrance. "Limiting ourselves to using locally harvested firewood or treated wood offers long-term benefits. We can slow the spread of pests that are already here and help prevent future introductions of harmful pests and diseases that haven't reached Wisconsin. We need to change our habits and our mindset to maintain these benefits. It will be hard to see the effects of our efforts immediately as we continue to find populations of emerald ash borer and other invasive pests that may have been introduced years ago. Eventually though, we will make headway.

"It's a long term process and preventative defense. Due to global trade and travel, we move goods faster and farther than ever before. Invasive species move with these items and as a new reality, we must prepare for and adjust to these changes."

How can I make sure I have firewood for my camping weekend, hunting trip, or home heating?

Cut your wood locally or find a local supplier near your destination. If you are camping, nearly every state property has wood for sale. Call your destination for hours, availability and information about nearby private firewood sellers. A contact list for state properties is at Parks, Forests, Recreation Areas & Trails. You can also search for firewood retailers near your destination in the Yellow Pages online or by calling the area's chamber of commerce.

What does the park do with confiscated wood?

Some properties burn confiscated wood immediately, before any spores or other life-stages of invasive species have a chance to exit the wood. At properties where this is not possible, confiscated wood is double-bagged in thick, loose plastic bags. Research found that when properly done, this technique was completely successful in containing emerald ash borer. These bags are left for the season to bake in the sun. Emerging adult insects and larvae are trapped inside, overheat and die. Property staff then chip the wood to specific dimensions at the end of the season and use it for mulch on-site.

Colleen Robinson Klug writes about invasive pest management for DNR's Division of Forestry.

Firewood restrictions

For up-to-date information on firewood restrictions:

  • Phone: 1 (877) 303-WOOD or see information about emerald ash borer quarantines at Wisconsin's Emerald Ash Borer Information Source
  • Information about gypsy moth quarantines at Wisconsin Gypsy Moth
  • Details about the types of firewood allowed on state properties and maps showing allowable distances firewood can originate from each propertyn at Firewood Facts, Rules & Advice