permaculture

[Toby Hemenway <hemenway@jeffnet.org>]

On 8/30/04 7:57 PM, "Rain Tenaqiya" <raincascadia@yahoo.com> wrote:

> The idea that invasive species are only invasive in chronically disturbed
> ecosystems only applies to early-successional species.


It's my understanding that the earthworms in question are early-succession
critters, imported from Europe as one of the many camp followers that thrive
in plowed soil.

The more I study so-called invasive species, the more I have to agree with
David Theodoropoulos's book, "Invasion Biology: Critique of a
Pseudoscience." There's almost no evidence that any "invasive" (I loathe the
term) species itself is directly responsible for extinction or ecosystem
harm; they are generally a symptom of damage. In many cases, you'll see a
native species praised for its ability to "accumulate nutrients, form leaf
litter, shade bare soil, and attract pollinators," and also see an exotic
condemned for exactly the same qualities, labeled as "interfering with
natural succession patterns." We love to find easily identified enemies and
then eradicate them--it makes us feel very virtuous. But it distracts us
from the larger, more complex causes (kinda reminds me of the war in Iraq).

For my review of Theodoropoulos's book see
http://www.patternliteracy.com/exotics.html