Friday, April 15, 2011

What Is Native? Ongoing, half-baked musings on "native" versus exotic trees

I grew up in the Minneapolis suburbs, but I have spent much of my “adult” life in two different small upper Midwest towns: Baraboo, WI and Northfield, MN. Baraboo is home to the International Crane Foundation, which absolutely everyone should visit someday. It’s an amazing place which has accomplished amazing things, on land close to Aldo Leopold’s Sand County farm.

Shortly after moving to Baraboo I gave my visiting brother in law a driving tour of the town. As we circled the old-fashioned town square I said,

“Every Thursday on the square we have…”

“Hangin’s?” he interrupted, in an exaggerated drawl.

“No, smart ass, those are Mondays at noon. I was going to say concerts.”

I currently reside in Northfield, MN which is famous (in its own collective mind) as the last place where the James & Younger gang tried – and failed – to rob the bank, six minutes of drama which is faithfully reenacted the first weekend after Labor Day every year.

The two towns are similar in several respects: both are old river mill towns, both have smallmouth bass populations skilled at avoiding my lures. But one similarity is particularly striking: The way locals give directions to disoriented strangers.

“Yah, okay, you take this road to where Betty’s Diner used to be, and you take a right.”

“You know where the Casey’s used to be? Yah, turn left there.”

And the stranger is thinking, You idiot, if I knew enough about this Podunk town to know where Betty’s Diner used to be I wouldn’t be asking you for directions.  It occurred to me that we sometimes think of the landscape the way small town locals think of their towns: In terms of what used to be there.

Central Minnesota? Yah, that’s where the paper birches used to be before their range started shifted north in response to Global Warming.

But clinging to what we remember – to the way things used to be – is not a very instructive or helpful way (and can, in fact, be a dangerously limiting way) to understand our natural world, and is especially not a very instructive way to think about the concept of “native” plants.

Aldo Leopold, in A Sand County Almanac, tells us how his land changed cover type dozens if not hundreds of times over the years, as the forest moved south only to be pushed back north by the prairie.

Is the climate warming? Probably. Is it due, at least in part, to human activity? Quite possibly. But the fact is the climate is always in a state of change, which means by definition it is always either warming or cooling, and the landscape is constantly changing in response.

Add to that the fact that no landscape is static; landscapes follow an inexorable successional march from a ‘pioneer’ landscape to a mature or ‘climax’ landscape, only to experience a major disturbance or change (often fire, often human caused in an attempt to manage and influence the landscape) and start all over again.

So what is native? The answer seemed simple to me 25 years ago in forestry school (a lot of things seemed simple to be 25 years ago). Now I’m not so sure.

What is native? Hawaii has vegetation. (Think about it.)

What is native? My son enjoys looking through and sketching birds in the Sibley Guide which has a section on European “accidentals.” Birds sometimes cover unfathomable distances, disoriented or blown by storms. And when they do they no doubt plant some exotic and invasive seeds on that foreign ground before trying to figure out where they are, how they got there, and where they can get a proper cup of tea or a suitable croissant.

What is native? Despite repeated archaeological finds that tell us humans of thousands of years ago travelled and traded across vast distances, we seem to express surprise each time another such finding is published. Regardless of the merit of his scientific theories, the minute Thor Heyerdahl’s Ra II landed in Barbados it probably deposited totora seeds on the shore. How did totora get to Easter Island? Was it birds (as most scientists theorize) or South American travelers as Heyerdahl conjectured? Either way, at one point it was an invasive.

What is native?  The place where I am now sitting was, not that long ago, covered in ice.  Actually that was only two weeks ago.  But what I meant was that it was covered by a massive glacier year round.  Whereas now it's only nine months per year.

OK, I better get back to work. And a bottle of my second favorite tree crop (and John Adams’ favorite), hard cider, is also calling my name on this Friday afternoon.

Oh, and if you’re ever in Northfield, look me up. I’m not far from where the Ole Store used to be.

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