Wednesday, February 8, 2012

Native vegetation of Hawaii

Months ago I promised to write a series of posts exploring various aspects of the native versus exotic plant debate.  The idea was to publicly moderate my 25 year internal debate - trust me, it wouldn't have been as thrilling as it sounds - on the issue of planting native versus non-native trees.
I got into this whole glamorous and wildly lucrative forestry racket coming from a strong "nativist" position.  Nature knew better than we about what plants to put where, and moving plants willy-nilly around the globe had unleashed Pandora's boxes full of ecological disasters (see also:  Chestnut blight, Dutch elm disease, kudzu, etc).  I primarily viewed myself as, if not a preservationist - I have always been too much the conservationist/"wise use" advocate to fit that particular mold - then as a restorationist; our management and planting activities should be conducted with an eye toward restoring native landscapes.

My thinking has changed over the years.  Depending on the day, or even the minute, I can argue equally passionately in favor of planting non-natives when appropriate (by which I mean appropriate according to me).  The arguments in my head get very heated at times.  I'm hoping therapy will help. Or drugs.
My basic thoughts in favor of planting non-natives (such as a highly productive southeastern hybrid oaks on corn-deprived Midwestern soils) are:
1) We live in a "post native" world - our soils and ecosystems have been disturbed and altered to the point where they are no longer able to support a "native" ecosystem

2) Plant ranges shift over time - what is native today might not be native on that same spot tomorrow.   In the course of our lifetime the range in which paper birch is "native" has shifted a couple hundred miles north in my "native" Minnesota (to which my ancestors immigrated by way of Missouri, Switzerland and Alsace).

3) Every single plant species growing on Earth was, at some point, non-native to the spot in which it now grows.

I was reminded of one post I had intended to write when I went to watch the movie The Descendants last weekend.  Actually, the movie reminded me of three things:

1) Oscar-caliber movies ain't what they used to be (what did George Clooney pay those critics?)

2) Hawaii has vegetation

3) A guy I really hate

Point #2 is one of my dozens of half finished posts, so this is a good chance to check one off of that list.

Read that again:  Hawaii has vegetation.  An archipelago formed from molten rock spewing from underwater volcanoes has plants.  By definition, not one single species is native to the islands.  By definition, every single one of Hawaii's "native" species was planted there unintentionally and without giving thought to the wisdom of their actions by animals.  Without question some of those introduced plants created huge ecological disturbances and forced some earlier species to the margins of the ecosystem.

I have also mulled this same concept when paging through Sibley's Guide to Birds and seeing the section on accidental bird sightings (a phrase that amuses me for some reason). Every so often some Eurasian bird gets lost, or maybe decides to have a gap year abroad, and gets spotted in North America.  And one would suspect that some of these wayward travelers deposit decidedly non-native plant seeds on North American soil, without the express written consent of the USDA.

Plants ranges move.  They move faster and farther than we really think.  We humans love to do two things: Move plant materials, and beat ourselves up over the consequences.  But really when we choose to plant a non-native species we're really doing nothing new.  

We also tend to look at a forest or a landscape and assume that it always looked like that, that it is supposed  to look like that, and that any changes are therefore bad.

... then again maybe all of this is just a l-o-o-o-n-g way to go to justify to myself the planting of Korean sawtooth oak here in North America as part of a woody perennial agriculture system that beats the hell out of beating the hell out of our soil with corn.

As to point #3:  Every time I see George Clooney I'm reminded of the surgeon who performed a minor procedure on our daughter a couple of years ago.  The guy looked like George Clooney's younger, better looking brother.  Even more annoyingly, he was a really nice guy and a highly skilled surgeon.

God how I loathed him.

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