In the autumn of 2001, while on a cross-country car trip, I bought a small bundle of firewood in Lake Tahoe, California, and drove it to my home in suburban New York City. Though it burned nicely in our fireplace that winter, carrying that wood across the country was a dumb thing to do.
America is besieged by invasive species that threaten our forests, fields and waterways. These species travel the world on the bottoms of boats, on the shoes of travelers, and in bundles of firewood.
A particular species may be harmless in its native environment, where it is kept under control by the complex checks and balances of the surrounding environment, but can increase explosively, to the detriment of native species, when it is introduced to an ecosystem not equipped to handle its presence.
Before June of 2002, no one had ever found an emerald ash borer in the U.S. The beetles lived in eastern Russia, northern China, Japan, and Korea, far from North American ash trees. Now, the beetle has become an international problem, afflicting trees in the U.S. and Canada. Once the beetle gets inside a tree, it destroys the water and nutrient-conducting tissues under the bark, slowly killing off the tree’s canopy.
In Massachusetts, citizens and local governments are locked in battle with the Asian long-horned beetle. The entire City of Worcester has been placed under a vigilant watch and citizens are instructed to notify authorities if they “suspect that someone is transporting firewood or other wood materials from the regulated area.” The beetle, which attacks and kills hardwood trees, including maple, elm, horse chestnut, ash, birch, poplar and willow trees, most likely entered the U.S. in wood pallets holding pipe shipped from China for a sewer project in the late 1980s.
The Chestnut Inn in Deposit, N.Y., stands as a monument to the magnificent, now nearly extinct American chestnut tree. Two years after the inn was constructed, exclusively using chestnut wood, the fungus Diaporthe parasitica spread through the local population of trees. Nationwide, about 4 billion trees were destroyed over the course of the blight. The fungus probably traveled to the U.S. on imported chestnut lumber or trees between 1900 and 1908.
The famous Dutch elm disease epidemic that afflicted Europe in 1910 and hit North America in 1928 also was caused by an invasive species. The elm bark beetle, which spreads the fungal disease, is believed to be originally native to Asia, but was accidentally transported to Europe and North America. In 1976, I watched foresters at the University of Montana cut down the school's signature elm trees, which were first planted on the school's central oval in the 1890s.
Warm summer weather that draws boaters and fishermen to the water increases the opportunity for invasive species to hitch a ride. Zebra mussels reached the Great Lakes in commercial freighters, but recreational boaters have spread the damaging pest across the continent. More recently, officials in northern New England have struggled to contain the spread of Didymosphenia geminate, better known by the descriptive nickname “rock snot.” While driving through New Hampshire’s North Woods region this week I saw many signs urging boaters and canoeists to ensure that no plant matter travels with their craft from one watershed to another.
Invasive species can include creatures both great and small. In the Everglades, Burmese pythons have become a big problem. Pythons arrived in the area when some irresponsible pet owners, after realizing that a 13-foot snake might not make the best companion, left their unwanted snakes in the national park.
Frank Mazzotti, a University of Florida wildlife professor, said that at first, “There had been some hope that alligators can control Burmese pythons.” But, after discovering the remains of a python which had apparently attempted to consume an alligator, resulting in the death of both animals, Mazotti and other biologists have been forced to rethink the situation. Mazotti said of the fatal python-alligator clash, “This indicates to me it's going to be an even draw. Sometimes alligators are going to win, and sometimes the python will win.”
A python probably is not going to stowaway in my car (at least not without my finding out pretty quickly). A beetle or other lethal forest pest might, however. To avoid providing free transportation to invasive species, firewood should be consumed within 50 miles of where it is cut. It would be nice if prepackaged wood came with a notice to that effect, or if convenience stores and supermarkets that sell firewood would educate their customers.
I travel a lot, and I like a good fire as much as anyone. But now that I have been educated, I'm getting my wood locally.