All:
3.9 decades ago, I did a different sort of "restoration" project in which I
"used" "invasive" (I prefer "colonizing") species. In the following ten
years of observation (could find no ecologists to independently and
critically study and quantify; hence no scientific publication was ever
done) I noticed that as the indigenous species developed, the alien species
almost entirely disappeared or became a minor element, apparently dependent
upon disturbance for their persistence. In this particular context, no
"eradication" was done, and in the ensuing 2.1 decades of practice I have
found that eradication efforts often caused more problems than they solved;
that a healthy indigenous ecosystem could almost always suppress colonizing
species. Further, it has been my observation that most "invasiveness" is
primarily dependent upon disturbance (e.g., grazing and trampling by
domestic livestock and other perturbations under which the indigenous flora
and fauna did not evolve).
Over the period 1972-2000 other projects exhibited similar characteristics.
WT
----- Original Message -----
From: "Annette Olson" <[email protected]>
To: <[email protected]>
Sent: Monday, July 18, 2011 11:29 AM
Subject: Re: [ECOLOG-L] New paper about "invasive species" debate
Two decades ago, the late Walter Westman wrote thoughtfully on the subject
of positive and negative effects of invaders. He suggested a phased
strategy
in which eradication of invasive plants would be balanced with restoration
of native vegetation to minimize both ecological and aesthetic impacts.
Westman, W.E. 1990. Park management of exotic plant species: problems and
issues. Conservation Biology 4 (3): 254-256.
Westman, W.E. 1990. Managing for biodiversity: unresolved science and
policy
questions. BioScience 40 (1): 29.
Annette Olson
Seattle, Washington
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