Invasive Plant Species in New England
Lo and behold, she was right.
When Dave Jacke has a strong opinion on something, which is often, he speaks loudly–yells, really–then leans forward from the waist and punctuates his point with this exclamation: “WHAT THE HELL?” As in: “People say ‘native’ and ‘non-native’ as if they were scientifically valid terms. But no quote-unquote ‘native map’ has no date on it.” He leaned forward: “WHAT THE HELL?”
And: “If we’re going to start calling these plants ‘invaders,’ and not take ownership for our own human behavior …” He leaned forward: “WHAT THE HELL?”
Finally: “Black locust is illegal to plant here, yet we’re importing pressure-treated lumber from the Southeast and polluting our soils.” He leaned forward: “WHAT THE HELL?”
I’d found Jacke through my friend Ben Falk, who runs a permaculture design school called Whole Systems Design in Vermont’s Mad River Valley. Permaculture has a complex and somewhat malleable definition, but at its essence is based on the interconnectedness of natural and human ecosystems; it seeks to foster a philosophy of working in accordance with nature, rather than attempting to control nature for humancentric purposes. Falk encouraged me to speak with Jacke in part because of his knowledge of the region’s plant species, in part because he’s the co-author of two books on the subject of permaculture, and in part, I suspect, because he knew that Jacke’s stance on invasive species would be well articulated, well researched, and passionate in the extreme.
All of which was true. Within minutes of meeting Jacke at the door of his second-floor apartment in Greenfield, Massachusetts, he was challenging the very foundation on which the basis of our battle against invasive species is waged: that there is any scientific basis for our determination regarding what is native to the region.
To make his point, Jacke pulled up the National Oceanic and Atmospheric Administration’s pollen viewer, an interactive online map that lets the user select a species, then a time frame. Click on “enter,” and you can watch species drift across hundreds and thousands of years, carried by unidentified vectors.
“Check this out,” he said, as he typed in Castanea dentata, the Latin name for the American chestnut, a tree species that has largely been lost from New England owing to blight. It’s a loss that has been much bemoaned, and restoration efforts are ongoing. Castanea dentata, it should be said, is considered native to the Northeast.
Except that it’s not, really. At least not according to NOAA, which has the species first appearing in New England about 3,000 years ago, on a march northward from its origins in the Deep South via the mid-Atlantic region. Now, 3,000 years is a very long time, and Jacke’s not claiming any differently. Rather, he’s making what seems to me a quite valid point: Without an agreed-upon definition of “native,” how are we to determine which species meet that definition and which don’t? Furthermore, our forest ecology isn’t static, and many species that we now consider “native” were, in fact, once invasive.
Except in Jacke’s view, the word “invasive” isn’t right, either, because it ascribes human intent to species that are simply trying to do what plants do best: survive and propagate. “Where do human values come into the equation?” he asked. “The word ‘invasive’ has values implied. Besides, if we’re going to start calling all these plants ‘invaders’ and not take ownership for our own behavior …” He leaned forward, and I knew what was coming next.