[APWG] Ecosystems Invasion resistance? Re: Do ecosystems resist invasion? Invasion and cropping Re: rate of change
Wayne Tyson
landrest at cox.net
Fri Mar 2 19:10:53 CST 2012
How about Haiti? Anybody got any data? The place looks awful from the
satellite.
WT
----- Original Message -----
From: "Philip Thomas" <pt at hear.org>
To: <apwg at lists.plantconservation.org>
Cc: "Wayne Tyson" <landrest at cox.net>
Sent: Friday, March 02, 2012 1:57 PM
Subject: Re: [APWG] Ecosystems Invasion resistance? Re: Do ecosystems resist
invasion? Invasion and cropping Re: rate of change
> "...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
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>>
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>>
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>> http://lists.plantconservation.org/mailman/listinfo/apwg_lists.plantconservation.org
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>
> --
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
> 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
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
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