A crackling fire is a big part of most family camping expeditions. After all, a marshmallow roasted over a stove burner just isn’t the same. But building that fire may pose a risk to the forest shading your campsite — even if you do everything Smokey Bear tells you to do.


The firewood you feed the fire may be a greater risk to the forest than the flames.


Dozens of invasive insects, fungi and disease accidentally brought to North America are ravaging swaths of woodland from sea to shining sea. The emerald ash borer — a beetle that got here from Asia in shipping crates and pallets made of infested wood — has killed tens of millions of ash trees in North America since its discovery here in 2002. The redbay ambrosia beetle, which causes laurel wilt disease, is marching through Georgia and Florida.


“You have the same problem of invasive species everywhere, but you have different species in each region of the country,” says Leigh Greenwood, the Don’t Move Firewood campaign manager with The Nature Conservancy.


Native forest ecosystems have complex checks and balances that combat native insect populations and plant diseases. Imported bugs are often resistant to these natural controls, causing greater harm than native pests. And the destructive insects and diseases often hitch a ride on firewood, speeding the spread of the devastation.


The emerald ash borer flies further on its own that most beetles, says Greenwood, but still moves just two or three miles a year.


“But when you move firewood, it can move hundreds of miles in a day,” she says.


The goldspotted oak borer, a beetle native to Mexico and southeastern Arizona, has killed more than 20,000 oak trees in the Cleveland National Forest and Cuyamaca Rancho State Park in eastern San Diego County in California. The beetle got a ride across the natural barriers of desert in shipments of firewood from Mexico, says Greenwood.


“Bringing in your own firewood seems like the smart and economical thing to do,” says James Johnson of the Georgia Forestry Commission. “In reality, just a few microscopic fungus spores or tiny insects hiding in non-local firewood can wreak havoc on our native environment.” 


And don’t think burning all the wood in the campfire will prevent the spread of insects or fungi.


“Even a small chip of bark containing invasive insect larvae can fall unnoticed to the ground,” says Johnson. “A sudden rainstorm can wash fungus spores off wood or out of your pickup, so the danger is very real.”


Experts say campers should burn only local firewood bought at, or near, the campground. A rule of thumb, Greenwood says, is don’t haul firewood more than 50 miles and 10 miles or less is best. Many states across New England, the Midwest and Appalachians have laws restricting movement of firewood with rules, regulations, and quarantines that clearly state how far is too far. Campgrounds in national parks ban firewood from outside the area. Failure to comply may result in a citation or seizure of firewood.