[APWG] Ecosystems Invasion resistance? Re: Do ecosystems resist invasion? Invasion and cropping Re: rate of change
John
jmbarr at academicplanet.com
Tue Mar 6 07:07:01 CST 2012
Wayne,
re Haiti,
There is something funky on Google's part with that image! I've heard
this same thing before, l and looked at the image. Look at Boca de
Cana, well into in the Dominican Republic, and note how the color
changes and the linearity and right angles of the changes. I'm not
saying that they do not have serious problems with deforestation,
however do not use google images for reference.
john
On Mar 2, 2012, at 7:10 PM, Wayne Tyson wrote:
> 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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>>
>> --
>> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>>
>> 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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>
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