[APWG] Altering is too kind, destroy not strong enough

[steveyoung at aol.com]

 Bob, read Doug Tallamy's book, "Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens" and then see whether you will still want to contend that "If a scientist studying any particular ecosystem did not know ahead of time that it was dominated by invasive, exotic plants, it would be impossible for he or she to determine if the plants present on site were native or exotic based on the biology of the plants and their interactions." 


 In my opinion, Tallamy makes a strong case that, if you look at the ecosystem level, prominently including the insect fauna, it is very evident when the plants in an area are exotic. My own observational experience has been that many exotic invasive plants tend to show very little insect feeding damage, because our insects are not adapted to feed on them, and of course this is one reason why they are invasive in the first place. Of course there are exceptions, and yes we also have exotic insects that feed on exotic plants; e.g. Japanese Beetles (Popillia japonica) will gladly feed on Porcelainberry (Ampelopsis brevipedunculata), unsurprising since their native ranges overlap and the beetle is adapted to feed on the Ampelopsis. But anyway, read Tallamy for a thoughtful discussion backed by data (he is a professor and chair of the Department of Entomology and Wildlife Ecology at the University of Delaware). In my view, he makes an especially compelling case regarding the impact of exotic invasive plants on birds. 

It is difficult for many of us not to be passionate about preserving what we can of what's left of our natural ecosystems, and I will argue that an unnaturally impoverished ecosystem that has been stripped of its native biodiversity is a very bad thing all around. I think this is more than a matter of human judgments and values. We are placing plenty of stress on our biodiversity and ecosystems and I think we have an obligation to do what we can to mitigate major sources of stress such as species introductions. Cheers,

???? Steve Young


 

-----Original Message-----
From: Bob Beyfuss <rlb14 at cornell.edu>
To: Craig Dremann - Redwood City Seed Company <Craig at astreet.com>; apwg at lists.plantconservation.org
Sent: Tue, 4 Mar 2008 4:22 pm
Subject: Re: [APWG] Altering is too kind, destroy not strong enough










Hi Craig and all,
Replaced is the correct term.
Destroying implies a value judgment that the invasive plants are "bad" and 
the plants that they are replacing are "good". In science there are no 
"good" or "bad" plants as there are no "good" or "bad" ecosystems. Nature 
lovers may not like or may not find attractive the ecosystems that occur, 
for example, in a vacant lot in an inner city but that does not make those 
ecosystems "bad'. There are particular ecosystems that humans want to 
protect for many reasons and that is fine but these are human value 
judgements. If a scientist studying any particular ecosystem did not know 
ahead of time that it was dominated by invasive, exotic plants, it would be 
impossible for he or she to determine if the plants present on site were 
native or exotic based on the biology of the plants and their 
interactions.  Let me cite a real life example to make my point. A few 
weeks ago a client called me looking for information on how to eradicate 
invasive, Asiatic bittersweet that she had found on her property.  I asked 
her if she was certain that it was the Asiatic variety and not the native 
bittersweet. She replied that she no idea how to distinguish them. I asked 
her if it turned out that the bittersweet on her property were the native 
variety, would she still want to eradicate it? Her answer was "of course 
not". Her only criteria for wanting to eradicate the plant was the 
supposition that it was exotic. In my mind that is not a good reason to 
eradicate anything, especaill\y when there are no guarantees that the 
plants eradicated will not be replaced by something even less desirable. 
When science is reduced  to name calling to provoke an emotional response, 
it is not science.
Bob



At 03:13 PM 3/4/2008, Craig Dremann - Redwood City Seed Company wrote:
>Dear All,
>
>I am very surpised to read the discussions on the semantics, of what to
>call exotic plants and their impacts on local native ecosystems.
>
>I can only speak from the California perspective, where 99% of the
>understory of our native ecosystems between 2 and 2,000 feet elevation,
>have been replaced by over 1,000 species of exotic plants.
>
>What do you call that effect, using words that express such a complete
>extermination of native ecosystems, within only 150 years or less?
>
>Ecosystem genocide?  Permanent native vegetation extinction, continuing
>through geologic time?
>
>Sincerely,  Craig Dremann (650) 325-7333
>
>
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>opinion of the individual posting the message.



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