>Exotics are often a problem at some level
>(Purple Loosestrife and Spartina are two examples from the plant world
>that have raised temperatures locally in recent years) but the fact of
>the matter is that a fight against them is virtually bound to fail (as it
>will in the case of those two weeds), but a whole lot of people make a
>whole lot of money trying (and doing real high powered *research* in the
>case of the scientific *community*).

While I agree with your assessment that there's not much point in
worrying about those exotics which obviously are not going explode
in population, and that some introductions are benign, I must disagree
with your view of the value of research on controlling those that have.

Such research isn't always doomed to failure. The tansy ragwort
stands as an example of such research that works. Tansy used to
be rampant in open areas, at least in the Willamette Valley. I
used to get paid 50 cents an hour as a kid to pull it by hand from
horse pastures (horses die eating this stuff). Now, one rarely
sees it. Indeed, the last time I did, it had been long enough that
it brought me up short - "what's THAT doing here?".

Obviously, examples of success are rare. It may be as related
to the amount of money available as to any intrinsict value
of the research - tansy was a big money problem in Oregon, so
big money was available to find, test, and introduce a biological
control.

- Don Baccus, Portland OR <donb at rational.com>
Nature photos, on-line guides, at http:://www.xxxpdx.com/~dhogaza