The following was published in the Biddeford-Saco Journal Tribune and Making It At Home Sunday editions, 3/2/2014.

The home we purchased last spring came with a wood stove, but up until last month, we hadnt used it. Just in time for Januarys second polar vortex, we got our chimney re-lined and, just like that, we had a cozy living room.

The only problem was that, by this point in the winter, seasoned firewood was scarce. We went through the small poplars Id cut down in our yard last March within two weeks and then had to rely on those $5 kiln-dried bundles from Home Depot and Hannaford. Soon, even those were hard to find.

What burned me up even more than their price was that I had enough firewood stored up for the next five winters — 200 miles south of here.

Id split and stacked two seasoned cords at my mothers house in Connecticut last October. If I could just get it up here to Maine, my family could have a toasty fire every night.

I almost rented a U-Haul to bring up a cord. Almost. But then my environmental conscience, the better angel of my nature, reminded me why theres big blue sign at the state border that declares no outside firewood. Had I brought in wood from away, I would have been abetting the illegal immigration of at least one invasive species and possibly many more.*

It has happened before. Furniture makers in the post-WWI economic boom brought European elm trees infected by an Asian fungus to America and unwittingly unleashed genocide. Since 1930, Dutch elm disease has claimed more than 100 million elm trees in North America. Chestnut blight, accidentally introduced in 1904, had virtually wiped out the American chestnut by 1940. Both trees are rarities in our state now. My na?ve introduction of firewood from away could have brought the emerald ash borer, the hemlock wooly adelgid, or the Asian longhorn beetle into Maine. My selfishness could have ultimately doomed the forests of the Pine Tree State.

Here in Maine, where we depend so much on our unspoiled natural beauty and timber resources, invasive species are a clear and present danger to our economy and way of life. At the Wells Reserve at Laudholm, the snows will eventually melt, the Oriental bittersweet, barberry, phragmites and purple loosestrife will reemerge, and our battles against these scourges will begin again. This is a war being fought across the country: invasive species now cost America more than $120 billion a year. (Roughly 40% of that annual damage comes from crop weeds and aquatic weeds, forest funguses, and nasty blights. In next weeks column, Ill take a closer look at animal invaders.) Every one of us is paying for these plagues through higher food costs, higher taxes, and other impediments.

Of course, the ultimate invasive species, the one that has penetrated to every corner of the map, left no waters or winds untouched, and helped all the others spread so quickly, is Homo sapiens. We have met the enemy and he is us, as Walt Kelly wrote for Earth Day back in 1970. As usual with the environment, the problem is one of our making, and so the solutions must be as well. The price of a state free of yet more invasive pests is eternal vigilance, combined with costly efforts to contain the ones already here. Until I can get some seasoned Maine cordwood delivered this summer, Ill have to keep buying those outrageous $5 kindling bundles. The cost of wood from away is just too high.

Post-publication note: On the way to the Reserve recently, I saw this bumper sticker: "Don't Move Firewood - It Bugs ME." NICE!

Nik Charov is president of Laudholm Trust, the nonprofit partner of the Wells National Estuarine Research Reserve in Wells, Maine. His Sunday column, Between Two Worlds, ventures forth from the intersection of art and science, past and future, cost and benefit. More at wellsreserve.org/twoworlds.