[APWG] Invasion and cropping Re: rate of change
ialm at erols.com
ialm at erols.com
Fri Mar 2 20:05:29 CST 2012
Evidently it is worse primarily because the artificial disturbances are
larger
in scope. Marc
Original Message:
-----------------
From: Philip Thomas pt at hear.org
Date: Fri, 02 Mar 2012 11:35:41 -1000
To: ialm at erols.com
Subject: Re: [APWG] Invasion and cropping Re: rate of change
Marc,
I can't help wondering about the precision of your statement "A good
example is Japanese Stiltgrass which takes advantage of natural erosion
disturbance when a tree comes down naturally but is much worse with
artifical erosion disturbances." Is it worse because the artificial
disturbances are artificial, or because they are larger in scope (than
"a tree [coming] down naturally")?
Aloha,
pt at hear.org
Wayne Tyson wrote:
> All:
>
> I don't doubt this. No handy generalization is going to be 100 percent
> true, and again, context is everything. And, of course, not all aliens
> are equal. But whatever the requirements happen to be for any given
> species, genotype or ecotype, to the degree that the environment tends
> to match them, they will come--provided the vectors are up to the job of
> moving the propagules into position.
>
> But all things being equal (they never are, but sometimes a variable has
> to be set aside to understand how phenomena operate in their absence),
> the question remains whether or not a given species is, or tends to be
> more rather than less dependent upon disturbance for colonization,
> especially an initial colonization, and whether or not it continues to
> find habitats adequate for further colonization. Then one should look at
> things like spread and the conditions that foster it, and the rate of
> spread and its causes.
>
> Some organisms are going to be "better" at insinuating themselves into
> new places, but the conditions of habitat are going to have to be
> suitable. Organisms that evolved under certain habitat conditions are
> likely to be "better" able to persist in those conditions than those
> which didn't. For this reason, indigenous species should be able to
> persist under the long haul--PROVIDED that those conditions stay the
> same. Disturbances cause change--different conditions which may (for a
> short or a long time) mean that species adapted to undisturbed
> conditions may not be able to persist but others, adapted to the
> different conditions, will. Such conditions may last a long time (e.g.,
> the effects of acid rain--a continuing disturbance), but change when a
> particular kind of continuing disturbance is reduced or eliminated from
> the dynamic ecosystem picture. Then (puff, puff,), it is exceedingly
> difficult to know whether or not a habitat is undisturbed. Again, an
> organism doesn't "know" whether or not a site is disturbed; it can
> either "make it" under "those" conditions or it can't.
>
> WT
>
> ----- Original Message -----
>
> *From:* Marc Imlay <mailto:ialm at erols.com>
> *To:* 'Wayne Tyson' <mailto:landrest at cox.net> ; 'Ty Harrison'
> <mailto:tyju at xmission.com> ; 'Michael Schenk'
> <mailto:schenkmj at earthlink.net>
> *Cc:* apwg at lists.plantconservation.org
> <mailto:apwg at lists.plantconservation.org>
> *Sent:* Thursday, March 01, 2012 7:42 PM
> *Subject:* RE: [APWG] Invasion and cropping Re: rate of change
>
> *We are finding that typically about half of the invasives are about
> 20% as bad in natural, undisturbed habitats. Given time we find that
> they do take over natural areas but at a slower rate. A good example
> is Japanese Stiltgrass which takes advantage of natural erosion
> disturbance when a tree comes down naturally but is much worse with
> artifical erosion disturbances. *
>
> * Marc Imlay, PhD,*
>
> *Conservation biologist, Park Ranger Office*
>
> *(301) 442-5657 cell*
>
> * <mailto:Marc.Imlay at pgparks.com>
> <mailto:Marc.Imlay at pgparks.com> 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:* Wayne Tyson [mailto:landrest at cox.net]
> *Sent:* Thursday, March 01, 2012 5:53 PM
> *To:* Ty Harrison; Michael Schenk; Marc Imlay
> *Cc:* apwg at lists.plantconservation.org
> *Subject:* Re: [APWG] Invasion and cropping Re: rate of change
>
> APWG:
>
> Relevance, relevance, RELEVANCE! Why do we so often forget this?
> Context is EVERYTHING. At least without it you are drawing against
> the Lone Ranger (or arm-wrestling with Superwoman). GIGO!
>
> Most "invasive" species are disturbance-dependent rather than
> invasive of dynamically stable (dynamic equilibrium
> state) ecosystems or insinuated into open niches (let the ecosystem
> without at least some open niches please stand up and be counted).
> In the Intermountain west and many other areas where grazing and
> trampling of livestock unlike the indigenous species with which the
> vegetation evolved, proceeds unabated, cheatgrass and other scabby
> plants, indigenous and foreign, are bound to attempt to bind up the
> wounds where Mother Earth has been so scarred, and the scabs are
> bound to remain in some form for years to come. Pick off the scabs
> in such cases all you want, Monsantoize it all you will, but as long
> as the processes that caused the wounds in the first place continue,
> the scabby cheatgrass and its pals will continue to reform.
> "Experts" make careers and fortunes pulling rabbits out of the hat,
> convincing the rubes that the magic will last, but sooner or later
> the piper will have to be paid. And the rubes invite the experts
> back for another dose of salts, having refused to take his/her
> incantations with a grain of it.
>
> WT
>
> ----- Original Message -----
> *From:* Ty Harrison <mailto:tyju at xmission.com>
> *To:* Wayne Tyson <mailto:landrest at cox.net> ; 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:* Thursday, March 01, 2012 12:49 PM
> *Subject:* Re: [APWG] Invasion and cropping Re: rate of change
>
> 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
> Cc: 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]
> *On Behalf Of *Hempy-Mayer,Kara L (CONTR) - KEC-4
> *Sent:* Monday, February 27, 2012 2:14 PM
> *To:* 'apwg at lists.plantconservation.org'
> *Cc:* '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]
> *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;
> 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
> [apwg-bounces at lists.plantconservation.org] On Behalf
> Of Robert Layton Beyfuss [rlb14 at cornell.edu]
> *Sent:* Monday, February 27, 2012 10:26 AM
> *To:* Katie Fite; Wayne Tyson
> *Cc:* apwg at lists.plantconservation.org;
> 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]
> *On Behalf Of *Katie Fite
> *Sent:* Monday, February 27, 2012 9:12 AM
> *To:* Wayne Tyson
> *Cc:* apwg at lists.plantconservation.org;
> 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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