[APWG] Ecosystems Invasion resistance? Re: Do ecosystems resist invasion? Invasion and cropping Re: rate of change
Philip Thomas
pt at hear.org
Fri Mar 2 15:57:33 CST 2012
"...if any island is more "invaded" than that place, please (I don't
wanna know but I have to) let me know."
Mauritius :(
pt at hear.org
Wayne Tyson wrote:
> John, I ain't due no more respect than anyone else, and you have an
> excellent point. I took John's (Jack Ewel's) word for it (admittedly a
> bad practice). See Ewel, J. J. 1987. Restoration is the ultimate test of
> ecological theory. pp. 31-33 /in/: W. R.Jordan, M. E. Gilpin, and J. D.
> Aber (eds.). Restoration Ecology: a synthetic approach to ecological
> research. Cambridge University Press, Cambridge.
>
> Ewel's crucible was Hawaii, I believe, and if any island is more
> "invaded" than that place, please (I don't wanna know but I have to) let
> me know. If any place could test the hypothesis, that must be among the
> severest.
>
> WT
>
> PS: I'm inserting some comments into John's text below [[thus WT]].
>
> Suggestion: When changing the subject line, retain previous ones if
> relevant.
>
> ----- Original Message -----
> *From:* John <mailto:jmbarr at academicplanet.com>
> *To:* apwg at lists.plantconservation.org
> <mailto:apwg at lists.plantconservation.org>
> *Sent:* Thursday, March 01, 2012 9:02 PM
> *Subject:* [APWG] Do ecosystems resist invasion?
>
> With all due respect, and not to be a bother, but ...... I'd like to
> question the notion that intact ecosystems resist invasion, but I do
> not know who proposed it nor what evidence they have for it. None
> the less I hear it bandied about again and again.
>
> [[Ok, well, all generalizations have exceptions. But then, the devil
> is in the details, right? In ecology (lacking, as it does, laws and
> other absolutisms) some of us rush in where angels fear to tread and
> try out ideas supported by some pretty thin threads. Lacking
> sufficient information upon which better "conclusions" might be
> based, we conjecture from inference and provisionally accept the
> preponderance of the evidence rather than "beyond a reasonable
> doubt" or a "scientific certainty," at lease until better evidence
> shows up. Similarly, these workaday hypotheses should always remain
> under the gun of contrary evidence. This works us forward rather
> than backward. So I would put it this way: Based on what we know
> now, does the reasonable-man/woman standard lead one to
> provisionally accept the proposition that resistance to invasion is
> more true than untrue or more untrue than true? Then we keep testing
> and evaluating new information. WT]]
>
> Questions:
> 1) How does any species ever colonize an island? [[Let me count the
> ways--by wind, by wave, by ship, by flotsam and jetsam . . . WT]]
> Aren't the island's ecosystems as "intact" as any other? [[I
> dunno--maybe they're more vulnerable? WT]]
> 2) Fire ants like many invasives arrived in North American (and
> around the globe) without their natural adversaries. How can a
> native fire ant "resist" invasion when they have long developed
> adversaries and the invasive species has none? This same pattern is
> repeated again and again with species after species, else why would
> "biocontrols" be effective or even considered? [[Good question; why
> would they? Because we yearn for magic bullets? WT]]
> 3) I fear a circular argument, invasion occurred, hence the
> ecosystem was not intact. [[I don't know anyone else who has made
> this argument. Please enlighten me. WT]] Is there any ecosystem
> that is intact? Really, with very few exceptions, if you name an
> ecosystem, I bet I can find: A) a prior human impact on that
> ecosystem and B) a species that will successfully invade. [[I
> wouldn't argue these points, but what's your evidence? WT]]
>
> Enlighten me, please......is there scientific evidence for this
> notion? [[I look forward to your further contributions in support of
> the contrary. WT]]
>
> john in Austin
>
>
>
>
>
> On Mar 1, 2012, at 2:49 PM, Ty Harrison wrote:
>
>> APWG: I like Tyson's metaphor (sexist?): Whizzing up wind is
>> what many of use are doing rather than using locally relevant
>> ecological models as he recommends. Or as others ecologists have
>> said: weeds and other invaders occupy "emtpy niches in the old
>> corral". But this only goes so far. Many weeds can insinuate
>> themselves into these "empty niches" in disturbance prone
>> (drought?) ecosystems which we have out west (eg. Cheatgrass,
>> Cranesbill, Star Thistle, Dalmatian Toadflax etc. etc. etc.). Ty
>> Harrison
>>
>> ----- Original Message -----
>>
>> *From:* Wayne Tyson <mailto:landrest at cox.net>
>> *To:* Michael Schenk <mailto:schenkmj at earthlink.net> ; Marc
>> Imlay <mailto:ialm at erols.com>
>> *Cc:* apwg at lists.plantconservation.org
>> <mailto:apwg at lists.plantconservation.org>
>> *Sent:* Wednesday, February 29, 2012 4:41 PM
>> *Subject:* [APWG] Invasion and cropping Re: rate of change
>>
>> Y'all:
>>
>> When you change something in an ecosystem, other things
>> change, including "invasions" (aka colonization). Ecosystems
>> tend toward sequestering most or effectively all of the
>> nutrients in the biomass--or try to. Much of colonization
>> consists of a drive in that direction. This is why some
>> ecologists have said that an ecosystem in equilibrium resists
>> invasion. This is a sustained/sustainable situation, but that
>> is far different from the invented and spun context in which
>> "sustainable" is bandied about today.
>>
>> To cut to the chase, modern agronomic practice is 180 degrees
>> out of phase with this principle, hence with ecosystems. Study
>> sites where the best ginseng grows, and study them completely.
>> Then compare those conditions with the ones in which you are
>> attempting to grow it as a crop. If there is any significant
>> difference, it is likely that you are whizzing upwind.
>>
>> This is already indulging in more conjecture than justified by
>> the scant information about the ecological context of your
>> project, so take it with a grain of salt and see if any of the
>> principles mentioned help. I hope so.
>>
>> WT
>>
>>
>>
>> ----- Original Message -----
>> *From:* Michael Schenk <mailto:schenkmj at earthlink.net>
>> *To:* Marc Imlay <mailto:ialm at erols.com>
>> *Cc:* apwg at lists.plantconservation.org
>> <mailto:apwg at lists.plantconservation.org>
>> *Sent:* Tuesday, February 28, 2012 4:21 PM
>> *Subject:* [APWG] rate of change
>>
>> Bingo! It's the rate of change that counts. When a new
>> species arrives every thousand years, a time scale
>> roughly consistent with "natural" climate change
>> disturbances, the ecosystem has a chance to respond
>> and integrate the new species.
>>
>> If you keep on rocking the boat and never give it a
>> chance to steady out, somebody's gonna get wet.
>> Sometimes I feel like we're arguing over angel dancing
>> space. The fact is, the boat is swamping, and we need
>> to slow down the rate of change.
>>
>> I'm a small landholder, trying to plant sustainable
>> harvests of ginseng, etc., in the face of encroachment
>> from garlic mustard, stiltgrass, tearthumb. I don't
>> have the time or resources for massive intervention. I
>> need affordable, time-efficient methods of non-toxic
>> removal. I've already spent hundreds of hours and
>> many dollars on weedwhackers and native seed. For me,
>> the combination of mechanical removal and planting
>> native grasses is at least holding the stiltgrass
>> steady. I'd like to learn about other successful
>> practices that fit with a modest budget and a working
>> schedule.
>>
>> Cheers,
>> Mike
>>
>> -----Original Message-----
>> From: Marc Imlay
>> Sent: Feb 28, 2012 7:35 AM
>> To: "'Hempy-Mayer,Kara L (CONTR) -
>> KEC-4'" , apwg at lists.plantconservation.org
>> <mailto:apwg at lists.plantconservation.org>
>> Cc: rwg at lists.plantconservation.org
>> <mailto:rwg at lists.plantconservation.org>
>> Subject: Re: [APWG] [RWG] Ecosystem Restoration Collapse
>>
>> *Just to clarify, ecosystems are dynamic and
>> constantly changing, but not at the present rate of
>> change. When endangered species were protected with
>> national and international laws and programs several
>> decades ago, we agreed that species naturally become
>> extinct over time. It is just the rate of extintion
>> that had increased a thousand fold and needed to be
>> reversed so new species had an ecosystem to evolve in.*
>> **
>> *
>> *
>> *Marc Imlay, PhD,*____
>> *Conservation biologist, Park Ranger Office*____
>> *(301) 442-5657 cell*____
>> * ialm at erols.com <mailto:ialm at erols.com>*____
>> *Natural and Historical Resources Division*____
>> *The Maryland-National Capital Park and Planning
>> Commission*____
>> *www.pgparks.com <http://www.pgparks.com/>*____
>>
>> *
>> *
>> **
>> ------------------------------------------------------------------------
>> *From:* apwg-bounces at lists.plantconservation.org
>> <mailto:apwg-bounces at lists.plantconservation.org> [mailto:apwg-bounces at lists.plantconservation.org] *On
>> Behalf Of *Hempy-Mayer,Kara L (CONTR) - KEC-4
>> *Sent:* Monday, February 27, 2012 2:14 PM
>> *To:* 'apwg at lists.plantconservation.org
>> <mailto:'apwg at lists.plantconservation.org>'
>> *Cc:* 'rwg at lists.plantconservation.org
>> <mailto:'rwg at lists.plantconservation.org>'
>> *Subject:* Re: [APWG] [RWG] Ecosystem Restoration Collapse
>>
>> Agreed. I’ve heard many people argue against the
>> ideas of “ecosystem preservation” and “restoration,”
>> but it’s usually a matter of semantics. What
>> restoration and preservation are trying to accomplish
>> is to maintain diversity on a global scale: there are
>> ecosystems here that worked well before we starting
>> impacting them so profoundly: we attempt to “restore”
>> them by taking out what we put in (exotic weeds), or
>> trying to repair what we damaged (soil structure,
>> hydrology, etc.). Then, hopefully, the previous
>> ecosystem processes can reestablish.
>>
>> As to the argument about increased carbon dioxide
>> levels: I’ve always wondered about this. The argument
>> that increased CO2 in the atmosphere has a profound
>> effect on plant growth assumes that nothing else is
>> limiting plant growth. From my limited background in
>> plant physiology, there are usually many things
>> limiting plant growth: macronutrients, micronutrients,
>> water, and light. In balance, can CO2 have that big
>> of an effect, even if it is limiting? Are there field
>> studies that have found evidence for this?
>>
>> Thank you for the opportunity to comment -Kara
>>
>> *From:* apwg-bounces at lists.plantconservation.org
>> <mailto:apwg-bounces at lists.plantconservation.org> [mailto:apwg-bounces at lists.plantconservation.org] *On
>> Behalf Of *William Stringer
>> *Sent:* Monday, February 27, 2012 8:41 AM
>> *To:* Robert Layton Beyfuss; Katie Fite; Wayne Tyson
>> *Cc:* apwg at lists.plantconservation.org
>> <mailto:apwg at lists.plantconservation.org>; rwg at lists.plantconservation.org
>> <mailto:rwg at lists.plantconservation.org>
>> *Subject:* Re: [APWG] [RWG] Ecosystem Restoration Collapse
>>
>> As to ecosystem restoration , we are not proposing to
>> make a man-made Hope Diamond here. We are proposing
>> to work from our admittedly limited knowledge base of
>> what should be there, and what should not. We take
>> out, to the degree that we can, the should-nots,
>> particularly the known exotic invasive should-nots.
>> We then try to place into the site local-source
>> propagules of known natives in a patchwork of mixtures
>> of relatively compatible species. At that point we
>> have probably done most of what we can contribute. We
>> can manage the site to the degree that we can simulate
>> natural disturbance phenomena. But mostly at this
>> point we stay out of the way and let natural phenomena
>> drive the restoration. The only exception would be if
>> outbreaks of exotic invasive species begin to
>> threaten. Then, we monitor and learn
>>
>> What we cannot do is let micro-analysis of the term
>> restoration immobilize us into total inaction.
>>
>> Bill Stringer
>> ------------------------------------------------------------------------
>>
>> *From:* apwg-bounces at lists.plantconservation.org
>> <mailto:apwg-bounces at lists.plantconservation.org> [apwg-bounces at lists.plantconservation.org
>> <mailto:apwg-bounces at lists.plantconservation.org>] On
>> Behalf Of Robert Layton Beyfuss [rlb14 at cornell.edu
>> <mailto:rlb14 at cornell.edu>]
>> *Sent:* Monday, February 27, 2012 10:26 AM
>> *To:* Katie Fite; Wayne Tyson
>> *Cc:* apwg at lists.plantconservation.org
>> <mailto:apwg at lists.plantconservation.org>; rwg at lists.plantconservation.org
>> <mailto:rwg at lists.plantconservation.org>
>> *Subject:* Re: [APWG] [RWG] Ecosystem Restoration Collapse
>>
>> I do not understand how ecosystems can be restored
>> since I consider them as dynamic and constantly
>> changing. It is not possible to completely re-create
>> the environmental conditions that led to a given
>> ecosystem at any given time in the past. If ecosystems
>> represent the interactions of living and environmental
>> factors, to restore an ecosystem requires replicating
>> the previous environmental factors that affect the
>> living organisms. The level of carbon dioxide in our
>> atmosphere has doubled in the past 80 years. Plant
>> growth, reproduction and survival is profoundly
>> affected by carbon dioxide levels. I consider attempts
>> to restore ecosystems as no more than human’s
>> creating new ecosystems using species of plants that
>> previously occurred because humans liked the previous
>> once more than the current one.
>>
>> *From:* apwg-bounces at lists.plantconservation.org
>> <mailto:apwg-bounces at lists.plantconservation.org> [mailto:apwg-bounces at lists.plantconservation.org] *On
>> Behalf Of *Katie Fite
>> *Sent:* Monday, February 27, 2012 9:12 AM
>> *To:* Wayne Tyson
>> *Cc:* apwg at lists.plantconservation.org
>> <mailto:apwg at lists.plantconservation.org>; rwg at lists.plantconservation.org
>> <mailto:rwg at lists.plantconservation.org>
>> *Subject:* Re: [APWG] [RWG] Ecosystem Restoration Collapse
>>
>>
>> Wayne,
>>
>> I am interested in the discussion.
>>
>> And discussions of what ecological restoration is, and
>> also discussions of how the term "restoration" is
>> currently being used by agencies or at times industry
>> - to describe imposing major disturbances on mature
>> or old growth woody vegetation communities - with
>> such disturbances often then leading to weed invasions.
>>
>> Katie Fite
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>> _______________________________________________
>> PCA's Alien Plant Working Group mailing list
>> APWG at lists.plantconservation.org
>> <mailto: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.
>>
>> ------------------------------------------------------------------------
>>
>> No virus found in this message.
>> Checked by AVG - www.avg.com <http://www.avg.com>
>> Version: 10.0.1424 / Virus Database: 2113/4840 - Release
>> Date: 02/28/12
>>
>> ------------------------------------------------------------------------
>>
>>
>> _______________________________________________
>> PCA's Alien Plant Working Group mailing list
>> APWG at lists.plantconservation.org
>> <mailto: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.
>>
>> ------------------------------------------------------------------------
>>
>> No virus found in this message.
>> Checked by AVG - www.avg.com <http://www.avg.com>
>> Version: 2012.0.1913 / Virus Database: 2114/4844 - Release
>> Date: 03/01/12
>>
>>
>> _______________________________________________
>> PCA's Alien Plant Working Group mailing list
>> APWG at lists.plantconservation.org
>> <mailto: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.
>
> ------------------------------------------------------------------------
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 10.0.1424 / Virus Database: 2113/4846 - Release Date: 03/02/12
>
>
> ------------------------------------------------------------------------
>
>
> _______________________________________________
> 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.
--
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hawaiian Ecosystems at Risk project (HEAR) - http://www.hear.org
P.O. Box 1272, Puunene (Maui), Hawaii 96784 USA
Philip A. Thomas - pt at hear.org
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
More information about the APWG
mailing list