INVASIVE OR ADAPTIVE ?
This blurb was taken from:
Saturday, December 02, 2006
Morning Sentinel, Kennebeck
“The notion of the state’s invasive species posing threats to our outdoors life has kept my mind busy this autumn. Introductions of certain milfoils or northern pike overwhelm us, but historical perspective makes the problem less intimidating.
An incident five years ago started me thinking seriously about invasive species in Maine’s history. Jolie, my intrepid companion, and I were kneeling in front of a clump of common St. Johnswort near a busy parking lot in the Camden Hills State Park. The flowers on top of the 2-foot plant look plain from a distance, but up close, all is not what it seems. Each blossom has clusters of slender, frail stamens with anthers that look like miniature blossoms, explaining our close scrutiny, and the leaves on the plants have transparent spots.
“That’s St. Johnswort!” she said loudly enough to stop the small crowd. Some of them began asking questions, making me feel like a geeky botanist.
In the 21st century, St. Johnswort has become an ultra-popular plant as an herbal cure for depression, explaining the interest on that morning in Camden. This invasive plant arrived in the New World with settlers, mostly in hay brought aboard for livestock and as an herbal plant. Folks planted St. Johnswort seeds in gardens for decoration and medicinal use, and it spread into the wild across the continent.
Acceptance of this invasive species in North America did not happen overnight, though. In 1758, John Bertram, a well-known colonial-era botanist, wrote, “The common English Hypercium (St. Johnswort) is a very pernicious weed. It spreads over whole fields, and spoils their pasturage, not only choking the grass, but infecting our horses and sheep with scabbed noses and feet, especially those that have white hair on their faces and legs.”
When this quote caught my eye 30 years ago, the part about scabbed noses and feet struck me as an ignorant superstition, but this plant increases the skin’s susceptibility to sunburn, so Bertram had it right. Livestock ate St. Johnswort along with grasses, and in that era when agriculture ruled the young nation, this plant threatened our colonial livelihood. These days, we love St. Johnswort, and whether it is right or wrong, a friend calls it “yuppie medicine.”
That’s the way with invasive plants. For the vast majority of species, it takes two generations, certainly no more than three, for humans to accept a new plant or critter completely.
For example, oxeye daisy, Queen Anne’s lace, dandelions, yarrow, chicory, hawkweed, lupine and many clovers came from the Old World centuries ago, and today, they have spread across the country and have become an accepted part of the landscape. Maine has dozens and dozens of invasive plants and animals that we’ve adopted as if they were native plants and indeed, we would lament the loss if they disappeared tomorrow.
Here’s another intriguing point. Native Americans adopted many invasive plants as soon as settlers introduced them. Mullein pops to mind, one of many examples. This 6-foot tall, tropical-looking plant has a spike-like cluster of yellow flowers clinging on top of the stem, and Indians utilized the plant for medicinal purposes. Two millennium ago, Roman soldiers around the Mediterranean dipped mullein in grease and used it as a torch, so this utility species has done multiple duties during its long history of helping humans.
Honeybees came from Europe, an introduction to help with pollination. Settlers realized they needed honeybees for the honey and particularly pollination in vegetable gardens. When European settlers arrived in Maine, landlocked salmon lived in but four river drainages near the coast, but man has spread them across the state. Today, landlocks live in 15 of our 16 counties. Mainers have done the same thing with rainbow smelts, which originally lived near the coast.
These days, in waters such as Moosehead Lake, fisheries biologists have problems managing salmon and smelts, but indigenous brookies and particularly lake trout thrive.
Is Moosehead trying to tell us something? If so, few folks are listening because we continue pushing Moosehead’s salmon population at the expense of the native sons (In fact, the introduction of salmon to Moosehead doomed its whitefish population).
Surely, it’s difficult to accept new milfoils, one of the introduced plant villains in Maine, but many bass anglers think milfoil creates great cover for black bass, which by the way are invasive species, too.
Also, salmonid lovers hate northern pike, but this toothy predator has developed a die-hard following in this state, particularly with the hardware and bait crowds.
“As the old saying goes, one man’s meat is another man’s straw, as invasive species show.”
Ken Allen, of Belgrade Lakes, is a writer, editor and photographer.
Milfoil is not in Montana, as of this date. Why is that?