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

[Steve Erickson]

My comments marked *.
-Steve
 
> Hi Steve
> The Asian people who colonized North America did not leave
detailed  records of what plants they brought with them (or
any other written records for that matter) but we know that
the 5,000 year old "ice man" discovered in the alps had wheat
seeds with him (not native to Northern Europe) so the
assumption that ancient people brought exotic plants with
them as they migrated from place to place is most certainly
valid, just as the European settlers  brought their useful
plants with them. Just because something is not written down
somewhere in English language in a 20th or 21st century peer
reviewed paper does not mean that it did not happen. <

*And the Polynesians moved quite a few plants and animals in
the Pacific. Wheat was undergoing domestication at the time
when the "ice man" got mummified. The evidence of these
movements is not from written records and I never suggested
that written records were the only type of evidence of pre -
and semi- historic movement of plants by people. Its quite
possible that indigenous people moved Cammassia spp. and
Quercus garryana to some islands in the Pacific Northwest.
However, I know of no evidence suggesting that they brought
plants with them from Asia. You made an unequivocal
statement. Can you point to any particular species of plants
that you believe were brought to North or South America
from other continents by the indigenous people before
European contact? 

> I never stated that post Europeans introductions were not
injurious at all and clearly many have been beneficial or 90% of
our diet would not be comprised of them. <

*I believe that cultural history and bias provide an equally
compelling explanation for the dominance of Eurasian species in
our diets.

>I do not need to withdraw a statement that is clearly proven
by common sense.
> 
> You state in reference to the plants in the west you
described   "All three of these species are successfully
invading without disturbance beyond the natural disturbance
regime" What is a "natural disturbance regime"? 

* For example, regular and cyclic tidal inundation, fire, and
riverine flood events. The scale of different disturbance
regimes may vary by their extent and frequency. 

>Is this something invented by people who want to justify
their arguments? The fact that these plants were introduced
by humans tells me that the  area they were introduced into
to, has been disturbed, or else how did they get there?
Spontaneous generation?>

* Planting Epilobium hirsutum into a garden explains why its in a
garden and how it got there. It does not explain why this
species has invaded and is increasing exponentially in areas
where it was NOT planted. Ditto for the other two species I
used as examples. They don't just occur where people have
deliberately introduced them. THEY ARE INVASIVE! If you
are going to define as disturbed any area subject to human
influence than you've included the entire planet.
 
> Don't misquote me, I never stated "that large monocultures
created by invasive species will break up in time frames of
50-100 years" That may or may not be true. What I said was
in reference to these plants and the environments they have
colonized was "It might be 50 years or maybe even 100 years
but if there is anything we know for sure, we know that it
("it" being the 2007 forest ecosystem and plants growing in
it) will not be there forever." 
> More than 70% of the forest cover in the Northeast was
absent 100 years ago.The "native" ecosystems in the
Northeast are a relatively "new" occurrence as my reference
to the history of the Catskills was designed to convey.  
> This reinforces my point (and your point) that these
ecosystems are never static. If you think that by simply
outlawing plants that are "potentially" invasive we can maintain
the existing ecosystems exactly as they are now in the face
of global warming and other human induced or natural
disturbances, 
> I disagree.

*I never said (and I haven't heard anyone else say) that their
purpose in preventing introduction of new invasive species is
to:
>maintain the existing ecosystems exactly as they are now in
the face of global warming and other human induced or natural
disturbances, <
* The most common purposes I've heard are:
Maintain remaining indigenous systems (i.e. prevent
homogenization of the flora with common alien plants that are
widespread and common.
Maintain the structure and function of existing systems.
Protect rare species and systems from degradation via
homogenization ad alteration of their structure and function. 
 
> You also say "The three invasive species I named are in
absolutely no trouble in their native ranges." This makes me
wonder how then we can preemptively identify potentially
invasive species in their homelands before they get here? It
also raises the question of what potentially valuable plants are
we black balling because they might be a problem, in certain
sitautions, maybe, sometime in the future?

*There are predictive methods. Requiring closely monitored
field trials could also be done. I think the disagreement here
is who has the burden of proof. Since long experience has
shown that once invasive species are "out of the bag" they can
not be easily, if at all, controlled, its time for those who
beleive they'll profit from the introduction of new species to
bare the risk, and not shift costs to other people now and in
the future.   

> There are dozens of references that describe the wildlife
value of certain "invasive" species such as multiflora rose,
Autumn olive, and exotic honeysuckles. Anyone who spends any
time at all in areas where these plants grow sees this every
single day. Wild turkeys, ruffled grouse, and many other birds
readily feed on these introduced plants.> 

*To truly determine what "benefit" to wildlife there is
requires looking at more than just whether a particular
species will eat it. What habitat did the invasive species
displace and what was its functional relationship with the
fauna? What is the conservation status of fauna able to
exploit some aspect of the invasive species? What is the
conservation status of fauna that have lost habitat duedue to
the invasion? If a common species can exploit an invasive
species but a rare species has suffered from the invasion, I
don't think "wildlife" has particularly benefitted.

> You also state "However, they are all seriously impacting (or
threatening to negatively impact) native species or systems in
northwestern North America which are in trouble".
> In the case of American ginseng, according to the leading
ginseng researcher in the US, the biggest threat to this
uncommon species may be from our "native" white tailed deer.
At "native" deer populations of 25 or more per square mile
quite a few native species disappear such as trilliums.>

*First, my statement was explicitly in regard to the three
species I used as examples, not american Ginseng. Second, this
is a straw man argument. I never stated (and I've heard no
one else state) that invasive plants are the only threat to
rare plants. Third, the abundance of deer is the result of land
use pattern and lack of predators. Try reintroducing wolves.
However, that's a different thread.
 
> Like it or not, humans are part of the ecosystem and we
have altered it dramatically since we learned how to use fire.
We continue to do so by bringing plants from point A to point
B. Humans will continue to so with both positive (most of my
food) and negative results (the garlic mustard in my woods) .
> Bob

* And we could learn to look before we leap.
-Steve 
> 
> 
> At 01:36 PM 1/2/2007, you wrote:
> >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?
> >
> >  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
> > > >âË˝Helping Nature HealâËΩ
> >Ω
> > > >Box 53
> > > >Langley, WA  98260
> > > >=======================================
> > >
> >---------------------------------------------
> >Frosty Hollow Ecological Restoration
> >╲Helping Nature Heal╡
> >Box 53
> >Langley, WA  98260
> >=======================================
> 
-- 
Steve Erickson