Firewood and the Forest

Charlene Donahue, MFS Entomologist

(originally appeared in the 2009 North Maine Woods magazine)

Ninety years ago the threat humans posed to the Maine forests was fire. Woodsmen, hunters and fishermen left campfires burning. Smokers threw matches or cigarettes on the ground. Brush was burned on dry windy days. People did not think a lot about fire and the effect their actions could have on the forest. A huge campaign was undertaken to raise awareness of how people are often responsible for starting forest fires. As far back as 1916 the Forest Service was soliciting help in protecting the forests and Smokey Bear just had his 60th birthday celebrating his promotion of “Only You Can Prevent Forest Fires”. Everyone knows about the dangers of being careless with fire in the woods.

1916 Maine Forest Service Poster: Help Wanted to Protect The Foersts of Maine from Fire.

1916 Poster

Now there is a new threat to the forest. Just like years ago it is something people were not aware of. It is a behavior that has been going on for eons and in the past there was nothing wrong with it. But times have changed, the world has changed and now some of us need to change as well. Once again the Forest Service is asking for the public’s help in protecting the forests.

What threatens our forest today? Something that has really only come to light in the twenty-first century - moving firewood.

Anyone who has camped or owns a camp has probably at one time or another brought firewood along on a trip. You have firewood in the backyard, it is easy to obtain, it’s dry, you won’t have to stop, it doesn’t cost anything. So you bring it along. WE ALL HAVE DONE IT. It has been okay.

So what is the problem? The problem is invasive insects that now are traveling with that firewood. With global trade we also have global spread of insects. Unfortunately some of these insects “from away” find their new home very hospitable and they are destroying the forest.

One of the nastiest examples is the Emerald Ash Borer (EAB). This is a metallic woodborer from Asia that kills any type of ash tree in North America. In Asia it is a minor pest of ash but the North American ash trees have no defenses against this insect. The trees can die within as little as two years after attack by the beetles. The EAB adult female lays her eggs on the bark of the tree. The larvae hatch and feed beneath bark creating tunnels that cut off the tree’s flow of food and water and eventually kill it.

Emerald Ash Borer was first discovered in Michigan in 2002. Since that time it has been found in Ontario, Ohio, Maryland and Virginia in 2003; Indiana in 2004; Illinois in 2006; Pennsylvania and West Virginia in 2007; Wisconsin and Quebec 2008. In the past two years it has been found in Minnesota, Iowa, Kentucky, Tennessee, and New York (25 miles from the CT/MA borders). Tens of millions of ash trees have died from attack by EAB already and the concern that these species of trees will be lost is so great that seeds are being saved.

The majority of EAB infestations (as much as 78%) have been attributed to the movement of firewood – people bringing wood to their camp or second home, on their camping trip or in their travel trailer. Woodboring insects typically spread from tree to tree at a rate of a few miles per year. Firewood traveling at 60 miles per hour can spread insects hundreds of miles in a day.

emerald ash borer

Emerald Ash Borer

Another example of an invasive insect that threatens Maine forests is the Asian Longhorned Beetle (ALB). It arrived, like EAB, from Asia in packing crates. This insect attacks a wide range of hardwood trees: especially maple and birch. The ALB was first found in cities – New York and its environs, Chicago and Toronto. And just last summer ALB was found in Worcester, Massachusetts where it has been for 15 YEARS. It is in the forested area north of the city as well as in city trees. Worchester, MA is less then 90 miles from the Maine border; less then two hours by car. Do you think anyone from that area has brought firewood to Maine in the past 10 years?

Asian Longhorned Beetle

It is not easy to tell if firewood is infested with insects. They can be in, on or under the bark or in the wood. We do not always know when a pest has moved in to an area – note the 10-15 years it took us to find ALB in Worcester. We need to change our habits. We need to leave our firewood at home. We need to take the time to buy or gather firewood near where we burn it.

There are federal quarantines in on invasive pests. These quarantines prohibit the movement of firewood out of KNOWN infested areas. But what about problems that have not been identified yet? Do you know if there are invasive insects in your backyard?

There is a new law banning the movement of firewood into Maine. Now we need is for people to change their habits. Just as 90 years ago people needed to be more careful with fire today people also need to be more careful with firewood.

Change is not easy but neither is dealing with invasive insects.