[PCA] [MPWG] Electronic Public Discussion: Evaluating the Invasive Potential of Imported Plants

[Steve Erickson]

You are naming plants that were imported after European
settlement. In your earlier posting you stated that the
aboriginal Americans brought many plants with them. This
serves as a basis for your positon that post European
settlement introductions are not injurious or beneficial in all
cases. I again ask, could you name some of these and the basis
for your claim that these were imported by humans prior to
European settlement? Or would you prefer to withdraw this
unequivocal statement?

The three invasive species I named are in absolutely no
trouble in their native ranges. However, they are all seriously
impacting (or threatening to negatively impact) native species
or systems in northwestern North America which are in
trouble. I named those three species in response to your
earlier statement that absent human disturbance, new
establlishments won't/can't happen. You haven't stated a
basis for that statement either. All three of these species
are successfully invading without distubance beyond the
natural disturbance regime. 

You also stated that large moncultures created by invasive
species will break up in time frames of 50-100 years. This
serves in part as the basis for your position that such invasive
species are either not injurious or beneficial. This is a short
enough period so that you should be able to cite historical
examples. Please do so.

You state:
> Most plants that were introduced for wildlife habitat do
indeed provide wildlife benefits. >
Could please state the basis for that claim and does it
differentiate between, i.e., pattern of land use, and the plant
species? Does it consider the relative conservation status
(rarity and degree of threat) of native species and systems
displaced by the exotics and that impact to native wildlife?

You also argued that it was hypocritical to reject some
non-native species while accepting others. Yet, that is
precisely what you've done here. Why should you be held to a
lesser standard than you attempted to impose on me? Of
course, your previous "all or nothing" argument is a straw man. 

Finally, you state the reasons for several introductions, but do
not necessarily consider their impacts on the indigenous flora
or fauna. Simply because a species was deliberately introduced
for a  specific purpose does not mean that that purpose was
fulfilled or that it does not have other impacts which may
greatly transcend any assumed benefit from the introduction.
-Steve
=============================

> Hi Steve
> I have no problem eradicating weeds from my garden or my
property or  killing mosquitoes that transmit malaria. You are
blaming plants for people's mistakes. Most plants that were
introduced for wildlife habitat do indeed provide wildlife
benefits. Dandelions were brought here by European  settlers
because they happen to be one of the most nutritious plants
ever studied. Kentucky bluegrass was imported as a forage.
Queen Anne's Lace was  imported not as the wildflower it has
become but as carrots which we eat. 
> You seem to be able distinguish plants quite easily as "good"
or "bad" and I don't see it quite that simply.
> Bob
> At 01:15 PM 12/26/2006, you wrote:
> > > The Asian peoples that colonized the United States
before
> >European settlement brought plants with them and many of
> >those plants became naturalized and since they were here
> >before 1600 they are now considered as  "native".
> >
> >Could you please name three species in the Pacific
Northwest
> >that were brought there by aboriginal peoples before
> >European contact? How about three species for every
major
> >region of North and South America?
> >
> >The three species I used as examples (Cytisus scoparius;
> >Epilobium hirsutum; Spartina spp., including hybrids) were
> >introduced to this region in relatively recent times, two
> >deliberately as ornamentals and the last accidentally and as
> >"wildlife habitat." These species cause major changes in the
> >newly colonized systems because of wholesale displacement
of
> >the pre-existing plant community and/or changes to the
> >structure and function of the system.
> >
> >While you may smile at Purple Loosestrife because it makes
> >good honey, I see little environmental benefit when it forms
> >extensive monocultures completely displacing almost all
other
> >species. Even if from an ethical standpoint deliberate
> >displacement of indigenous species for purposes of human
> >exploitation was ethical, as a practical matter few of the
> >wetlands where this aggressive invader has taken over are
so
> >used by humans. And the colonization by Purple Loosestrife
> >eliminates and degrades services these wetlands do provide
> >for people. In this vein, I suppose you also think its alright
to
> >convert the Amazon rainforest to soy plantations and cattle
> >pastures, displacing and killing off the indigenous humans?
Hey,
> >there's lots of people, what's a few less injuns? We can
> >always bank their DNA (patent it too).
> >
> >Your statement that eventually the new monocultures will
> >break up seems to me to be an article of faith. Some of
these
> >new invaders cause fundamental changes such that the
> >structure and function of the system is so altered that this
> >may not occur. Examples are Spartina's trapping of mud,
> >thereby changing coastal elevation and Cheatgrass's
alteration
> >of fire frequency and intensity.
> >
> >Finally, your argument that its hypocritical to be concerned
> >about exotic plant species unless one rejects all
non-indigenous
> >species is, well . . . specious. Do you plant Poison Ivy around
> >your front door? If Poison Ivy started "spontaneously"
> >growing around your front door would you eradicate it?
> >Hypocrite! Got a problem with mosquitos that are vectors
of
> >Dengue Fever or Malaria? Hypocrite! They're just doing
their
> >thing. Parasitic worms? If you eliminate parasitic worms
from
> >you body you have no excuse not also wage war on the worms
in
> >your garden!
> >
> >-Steve
> >---------------------------------------------
> >Frosty Hollow Ecological Restoration
> >╲Helping Nature Heal╡
> >Box 53
> >Langley, WA  98260
> >=======================================
> 
---------------------------------------------
Frosty Hollow Ecological Restoration
“Helping Nature Heal”
Box 53
Langley, WA  98260
=======================================