[APWG] NEWS: Conservation Strategies Must Shift with Global Environmental Change

Mon Feb 4 15:10:36 CST 2008

Hi Bill
Thanks for posting. These issues are worthy of discussion.

As long as there is international contact between nations there will be 
introductions of pests, diseases and plants that affect native plants and 
animals and alter currently existing ecosystems regardless of how diligent 
we try to be to avoid them and I am not saying we should not be diligent in 
this regard.  There is nothing wrong in trying to preserve the ecosystems 
and the plants that we currently enjoy. I guess I question some of the 
means we are using.  Our annual flu outbreaks, which kill many people, are 
a good example of an annual unwanted and unintended "invasive" pathogen 
introduction. We could probably save many lives each year by simply not 
letting anyone into or out of this country.  It is naive to think that we 
can isolate ourselves or our current ecosystems to become completely immune 
to the potential biological threats from the rest of the world given the 
fact that we are a global society.

The question is "What do we do about this situation?"

It seems that one of the politically correct approaches in the case of 
plants is to label them with value laden, emotional terms like "alien, 
exotic, invaders" and kill them using whatever methods we want without 
really knowing the long term consequences of our actions or bothering to 
investigate what the long term consequences of the "invasions" may be. It 
is much easier to justify killing things once they have been sufficiently 
demonized by rhetoric such as this. "Wars" are difficult to support without 
mustering appropriate propaganda.

Certain plants labelled as invasive are what are known as C4 plants because 
they utilize carbon dioxide differently and much more efficiently than C3 
plants. This certainly gives them an edge in this globally changed climate 
with double the Co2. Couple this with human disturbance as pointed out by 
Craig in the original post on Yellow Star Thistle that started this 
dialogue and you start to see the root of the problem.
Craig wrote,
"The article states that "It pushes out native plants", but we have 
measured just the opposite interaction between the YST and natives.YST only 
grows well, wherever the native understory has been completely removed, 
like it has in 99% of lower elevation California.  Wherever you have a good 
density of native plant understory, the YST is never any problem"

  So is YST the problem or is it the removal of the native understory?

Even a few degrees warmer temperatures has profound effects on any plant 
species ability to survive. Does anyone not think that the proliferation of 
Zone 6 plants (USDA hardiness Zones) in Zone 5 is not related to climate 
change? The link between climate change (higher Co2 and temperatures) and 
success of invasive plants is really pretty obvious to most people who 
understand a little about how plants grow.

Chestnut blight disease reduced the % of American chestnuts in my local 
forest here by 99% and at one time more than 50% of all the trees growing 
here locally were American chestnut according to historical records.  The 
chestnuts were replaced by mostly Sugar maple trees over the past 90 years 
or so. Is is fair to say that sugar maple "destroyed" the previous chestnut 
dominated ecosystem? If you can say that "destroy" means the same thing as 
"alter" or "change" then that is indeed true. Was this a good or bad thing? 
Well, I guess that depends on whether you favor eating chestnuts or using 
maple syrup. These are human distinctions, the forest remains as a forest. 
It will still be a forest even if it becomes dominated by Ailanthus 
altissima. The sugar maple dominated ecosystem may very well be replaced by 
an Ailanthus dominated ecosystem but unless it all gets bulldozed, it will 
remain as a forest ecosystem.

Pathogens such as chestnut blight and pests like the hemlock Wooly adelgid 
that usually kill their hosts present an evolutionary dead end to 
themselves. We are already seeing American chestnut seedlings growing back 
in some areas as well as some resistance to the hemlock wooly adelgid. If a 
completely blight resistant strain of chestnut is discovered should we 
clear cut all the sugar maple trees and plant back the chestnuts in the 
name of restoration ecology?

Western hemlock has evolved resistance to the "invasive" adelgid pest on 
the west coast because the pest has been there for a long time. In the 
1980's NY State spent huge sums of money trying to first quarantine and 
eradicate an imported pathogen called Scleroderris canker. I still have 
filing cabinets full of bulletins on how to eradicate this disease which 
turned out not to be a serious problem after all. How many millions and 
millions of dollars have been spent trying to eradicate gypsy moths?

In retrospect, most will agree that these and many other specific attempts 
to kill off the bad guys have resulted in huge wastes of money and 
resources. I contend that 50 years from now most of our current war on 
invasives will be similarly judged.

  At 01:09 PM 2/4/2008, Bill Stringer wrote:
>At 11:41 AM 2/1/2008, Bob Beyfuss wrote:
>>This is the best article I have ever seen cited on this list serve. People
>>need to wake up the the fact that virtually every ecosystem on this planet
>>is now dramatically different than it was even 50 years ago due to human
>>activity on a global scale.
>
>>Efforts to "restore" ecosystems that have been
>>altered by irreversible global changes, such as doubling the carbon dioxide
>>levels in the atmosphere and rising temperatures, are a huge waste of money
>>and resources. Invasive plants are just one of the many symptoms of these
>>changes -
>
>>Invasive plants are clearly a symptom of our willingness to import exotic 
>>organisms.
>>I'm not so sure of the link between invasive plants and global climate 
>>changes.
>
>There's anthropogenic greenhouse gas increases, and then there's 
>introduction of
><http://www.cogongrass.org/>cogongrass , 
><http://www.nps.gov/ALIEN/fact/tama1.htm>saltcedar , and numerous other 
>examples.  These are different problems,
>and should not be lumped together under "huge waste of money and resources" .
>
>
>>yet we declare "war" on alien, exotic, species that "menace" us as
>>though killing off these plants will somehow solve the problem.
>
>Which problem, Bob, the Great Greenhouse, or Exotic invasive plants that are
>documented to be destroying native ecosystems, and throwing  the 
>bio-geo-chemistry
>out of whack.
>
>
>Tell that to American chesnut, and hemlocks.
>
>Thanx
>
>Bill Stringer
>
>
>>At 10:06 AM 2/1/2008, Olivia Kwong wrote:
>> > http://www.sciencedaily.com/releases/2008/01/080131101747.htm
>> >
>> >Conservation Strategies Must Shift With Global Environmental Change,
>> >Ecologists Urge
>> >
>> >ScienceDaily (Jan. 31, 2008) . Traditional ecosystems in which communities
>> >of plants and animals have co-evolved and are interdependent are
>> >increasingly rare, due to human-induced ecosystem changes. As a result,
>> >historical assessments of ecosystem health are often inaccurate.
>> >Scientists are now suggesting that efforts should focus less on restoring
>> >ecosystems to their original state and more on sustaining new, healthy
>> >ecosystems that are resilient to further environmental change. Accepting
>> >some permanent changes may increase health of ecosystems.
>> >
>> >See the link above for the full article text.
>> >
>> >
>> >_______________________________________________
>> >PCA's Alien Plant Working Group mailing list
>> >APWG at lists.plantconservation.org
>> > 
>> http://lists.plantconservation.org/mailman/listinfo/apwg_lists.plantconservation.org 
>>
>> >
>> >Disclaimer
>> >Any requests, advice or opinions posted to this list reflect ONLY the
>> >opinion of the individual posting the message.
>>
>>
>>
>>_______________________________________________
>>PCA's Alien Plant Working Group mailing list
>>APWG at lists.plantconservation.org
>>http://lists.plantconservation.org/mailman/listinfo/apwg_lists.plantconservation.org 
>>
>>
>>Disclaimer
>>Any requests, advice or opinions posted to this list reflect ONLY the 
>>opinion of the individual posting the message.
>
>Bill Stringer
>Editor, Journal of the SC Native Plant Society
>PO Box 491
>Norris, SC 29667
>
>864 656 3527
>
>www.scnps.org
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