I don't know that this point needs further emphasis, but I will do it
anyway.
Nature doesn't give a damn about any species or any context or order. Chaos
works.
Species arise when one gene or set of genes is favored more by its context
than another, even within the same species, and among species.
Different contexts drive adaptation.
Some contexts are insufficient for any life at all.
Some contexts are good enough for only one species, or at most, a few.
Some contexts are so "good" (fit the requirements for life so well) that a
very broad diversity of species and variations within species is possible.
Varied contexts tend to be associated with varied life forms.
Similar contexts exist in widely separated places.
Organisms do what they can, when they can, where they can.
No context stays exactly the same forever.
There are both short- and long-term phenomena that cause slower or faster
changes in context.
Organisms that can "keep up" with change or move from an less-suitable
context to a more suitable one tend to survive and reproduce, persist.
If humans are truly as sapient as they believe they are, they will
eventually take actions that lead to ultimate survival.
So far, beginning ten or fifteen thousand years ago, a psychic state of mind
developed that resulted in culture. That culture altered contexts
increasingly over time; as such, it could be considered a "successful"
strategy, at least in terms of survival and reproduction, but it did so by
becoming increasingly dependent upon an ever-increasing rate and intensity
of exploitation of resources, producing a cornucopia of excess rather than
sufficiency. Evidence abounds that scarcity of resources increasingly
threatens the very culture that created it.
There ain't no free lunch.
WT
----- Original Message -----
From: "Martin Meiss" <[email protected]>
To: <[email protected]>
Sent: Tuesday, April 24, 2012 2:54 PM
Subject: Re: [ECOLOG-L] Invasion, or progression?
Hi, Ling Huang and other Ecologers,
Here where I live in central New York, we have a large wetland call
the Montezuma Marsh. It has had nearly half of its over 3,200 acres under
management dominated by purple loosestrife, which crowds out other plants
and eliminates nesting areas and forage for animals that depend on those
other plants. This URL is for one of many websites with information about
loosetrife in Montezuma: http://www.fws.gov/r5mnwr/mnwrls.html
People taking a narrow view might say, "Well, if those plants can't
compete, they're less fit and deserve to decline, and the same for those
animals that can't eat loosestrife or make nests in it." Natural
selection, and all that.
But I think that's the narrow view. Montezuma is a stopover place
for migrating waterfowl on an important flyway, so the birds that stop
there for forage don't find as much. This can of course affect the success
of their migration, and so in this case an invasive species in a relatively
small area can have an effect on species and habitats hundreds of miles
away. Again, some might say, "Well, tough for those birds; the fit ones
will find a way to survive."
I don't believe this stance is based upon deep respect for the
struggle for existence that plays out in nature. Rather, people with this
view are really just indifferent to any protection of the natural world
that may cause them inconvenience, a bit of money, or restriction on their
freedom to do whatever they want whenever and wherever they want.
I believe that if we humans can, by reasonable precautions, prevent
such disruptions of natural systems, then it is better for the world if we
do so. Can I prove that a marsh with 1000 species is better than a marsh
with 500 species? Obviously, the economics, aesthetic, and other
considerations of such a determination could be vastly complex, but I think
we can agree that holding the line against disruption where we can is
easier and cheaper than reversing it after it has occurred.
People can argue forever about the definition of terms like "native"
and "invasive," and I have no problem with that. However, I think we
should in the meantime accept operational definitions that allow us to take
action that will avoid difficult-to-reverse disruption.
Perhaps I have violated my own rule about sticking to a single point
in a single posting, but I had to get my two cents in. Thank you to David
I. and other who make that possible.
Martin M. Meiss
2012/4/23 Julian D. Olden <[email protected]>
Hi Steve,
One potential place to start is where the general idea of the native
invader was recently defined (Simberloff 2011) and the forthcoming review
paper by Carey et al. (in press).
Carey, M.P., Sanderson, B.L., Barnas, K.A. and J.D. Olden. In press.
Native invaders create novel challenges for science, management, society
and policy. Frontiers in Ecology and the Environment (online early
shortly)
Simberloff D. 2011. Native Invaders. In Simberloff D and Rejmánek M
(Eds.). Encyclopedia of Biological Invasions. Berkeley and Los Angeles,
CA.
University of California Press, Ltd.
Cheers,
Julian
---
Julian D. Olden
Freshwater Ecology & Conservation Lab
School of Aquatic and Fishery Sciences
University of Washington, Seattle WA 98195
e: [email protected]<mailto:[email protected]>, t: (206) 616-3112
w: http://www.fish.washington.edu/research/oldenlab/
skype: goldenolden
On Apr 23, 2012, at 7:52 PM, "Steve Young" <[email protected]<mailto:
[email protected]>> wrote:
Does anyone know of a good reference on this topic of when native plants
become invasive? It seems like many of us know of examples, but it would
be
nice if there were something actually written (e.g., published) on it.
(The
article Ling referenced is on ants.) If not, at the very least, is there a
list of these plants that has been put together for different regions of
the globe?
Steve
-----Original Message-----
From: [email protected]<mailto:[email protected]> [mailto:
[email protected]]
Sent: Monday, April 23, 2012 9:20 PM
To: Steve Young; [email protected]<mailto:
[email protected]>
Subject: Re: [ECOLOG-L] Invasion, or progression?
Hi Steve and Ling, another example of a native becoming invasive is
cattail (typha) in the phosphorus oligotrophic Florida Everglades. Usually
present in low population densities, cattail populations take off with
increased phosphorus concentrations in water and soil (usually
anthropogenic). Yet another example is the spreading populations of
Vouchesia divergens in the Pantanal that are associated with drier
conditions over the past couple decades.
A plant community is dynamic and responds to changes in both biotic and
abiotic factors that affect ecosystem structure and function. Thus a
species once present in small numbers can dominate the community for a
while..
The other question, when does an invasive become native, goes back to how
we define what is native, or for how long does a species have to be
present
in an ecosystem to get naturalized. For instance, cocos nucifera, the
coconut palm ubiquitous to tropical and subtropical coasts all over the
world.. It is still a matter of conjecture as to where coconuts palms
originated. If they were dispersed by ocean currents, then I suppose they
would be considered native wherever they occur. If man were the agent of
dispersal, they would be exotics. If brought in by man thousands of years
ago, they would be naturalized exotics. If they invaded and dominated upon
arrival, they would be invasive exotics. An exotic or native can bide
their
time in low numbers, and with an environmental change, suddenly take off,
thus earning the term invasive.
Regards, amartya
Sent on the Sprint® Now Network from my BlackBerry®
-----Original Message-----
From: Steve Young <[email protected]<mailto:[email protected]
>>
Sender: "Ecological Society of America: grants, jobs, news" <
[email protected]<mailto:[email protected]>>
Date: Tue, 24 Apr 2012 01:22:05
To: <[email protected]<mailto:[email protected]>>
Reply-To: Steve Young <[email protected]<mailto:[email protected]
>>
Subject: Re: [ECOLOG-L] Invasion, or progression?
Interesting question, can a native become invasive? I would suggest that
in some instances this is the case. For example, eastern redcedar in the
Central Prairie is native, but has now become invasive in many locations.
The main reason is the lack of fire that used to occur naturally prior to
settlement by Europeans.
For those who want to know more, we will be addressing this topic at the
NAIPSC later in June. I expect the discussion will be quite good. Maybe
I'll post a summary to ECOLOG then.
Steve
___________________
Stephen L. Young, PhD
Weed Ecologist
University of Nebraska-Lincoln
-----Original Message-----
From: Ecological Society of America: grants, jobs, news [mailto:
[email protected]] On Behalf Of ling huang
Sent: Sunday, April 22, 2012 8:37 PM
To: [email protected]<mailto:[email protected]>
Subject: Re: [ECOLOG-L] Invasion, or progression?
Hi
I am a chemist and not an ecologist but I'm very interested in this thread
since I enjoy the wetlands area close to Sacramento near the Davis Yolo
Causeway. I wondered and am interested in this invasive or progression
type
question. I saw that there was a species called Purple Loosestrife
(Lythrum
salicaria) that was introduced in the 1800s (?) and is a wetland flower
that has invaded wetlands. I suppose my question is how far do we go back
to determine if a species is invasive. Is there a time or case when an
invasive becomes a native? I did see this interesting online article where
the question asked was "Can native species become invasive?"
http://ipmsouth.com/2010/11/23/can-native-species-become-invasive/
Thanks. Ling
Ling Huang
Sacramento City College
--- On Sun, 4/22/12, Amanda Newsom <[email protected]<mailto:
[email protected]>> wrote:
From: Amanda Newsom <[email protected]<mailto:[email protected]>>
Subject: Re: [ECOLOG-L] Invasion, or progression?
To: [email protected]<mailto:[email protected]>
Date: Sunday, April 22, 2012, 3:40 PM
Very intelligent members of the public have asked me this question when
they approach me in the field and I have some time to chat. It's a great
question, because invasions biology is attacked politically on this front,
so it's one to which professionals really must craft a coherent response
in
friendly conversation.
Another point to consider is the evolutionary history of native vs.
introduced (non-native) species in any particular system. One of the
reasons non-natives are of concern is that they do not share evolutionary
history with the native community, and this contributes to the
unpredictable biodiversity loss cited by other comments presented here.
This can also be discussed in light of the homogenization of life on
earth, because there are many species favored, facilitated, or directly
cultivated by humans that are now distributed worldwide. Some of these
species threaten regional biodiversity (Check out the book Ecological
Imperialism for a really interesting perspective on colonialism as an
ecological process via introduction of new dominant species). There's a
lot coming out now on evolution and invasive species as well that is, at
least in part, reasonably accessible to a general audience or the academic
in ecology/evolution who is wanting to step into invasion biology.
Related to this (somewhat tangentially) is that the buildup of introduced
and invasive species in systems like San Francisco Bay has also increased
the number and complexity of biological interactions, both
introduced-introduced and introduced-native. Increasing professional
interest in introduced-introduced interactions hasn't yet yielded a whole
lot of generalized hypotheses, but it has opened new windows to how
complex
this issue is biologically and how best to protect species of interest as
well as local biodiversity.
That was a far longer and more convoluted comment than I originally
intended! Hopefully, Joshua, some of that is useful perspective. Thanks
for posing the question to ECOLOG! It can be intimidating to put
something
like this out there as an undergrad, and I'm glad you took the initiative.
It comes up a lot, as you can see, and ECOLOG is a great forum for this
discussion.
A.
On Sun, Apr 22, 2012 at 9:19 AM, Ruhl, Nathan <[email protected]<mailto:
[email protected]>> wrote:
I posed a very similar question to a group of graduate students and
professors during a theoretical ecology seminar a few years ago. The
central premise was that humans, by virtue of our
innate-desire/ability to alter our surroundings, have caused a general
decline in biodiversity globally. That is,humans are the primary
vector for a loss of global biodiversity, not the
"non-native"/"invasive" species. The question was, is reduction of
biodiversity bad or is it simply evolution in favor of species better
adapted to live in a human-altered landscape?
After much debate, the consensus was more or less that we don't know
what all the ecological implications of a rapid global reduction in
biodiversity will be and, because we have only one habitable planet
currently, it would be a good idea not to break it. Therefore, in the
absence of a rigorous ecological understanding that we may never
actually achieve, humans should be taking steps to promote the
conservation of biodiversity whenever possible.
N Ruhl
Ohio University
________________________________________
On Sun, Apr 22, 2012 at 10:01 AM, Joshua Wilson
<[email protected]<mailto:[email protected]>>wrote:
Good morning,
I know that invasive and non-native species have been getting a
great
deal
of attention lately, and justly. I understand the basic ecological
impacts
and concerns invasive species cause, and the disruption of the
native system. My main question is:
Why are invasive species considered a nuisance, instead of
adaptation, progression, or perhaps ecosystem evolution?
Yes, human beings have been a main cause of the large majority of
these invasions. But even so, I feel we are part of the natural
system. If an invasive species exhibits more plasticity or is more
competitive and adaptive than the present species in an ecosystem,
does that necessarily imply catastrophic impacts? There are
multiple arguments against this, I know, many of them strong and
verified. I am not an advocate of invasive species dominated
ecosystems, but am just curious why this change and
shift
is considered so extremely detrimental. I feel that stable and
progressive
change and adaptation is the basis of a strong ecological system.
I would welcome any thoughts on this, or perhaps to start a discussion.
I
am still an undergrad, so my question may seem farfetched and
ridiculous
to
some. Even so, just something to ponder on a lovely Sunday morning.
Have a good day all,
Josh Wilson
--
Gary D. Grossman, PhD
Professor of Animal Ecology
Warnell School of Forestry & Natural Resources University of Georgia
Athens, GA, USA 30602
http://grossman.myweb.uga.edu/ <http://www.arches.uga.edu/%7Egrossman>
Board of Editors - Animal Biodiversity and Conservation Editorial
Board - Freshwater Biology Editorial Board - Ecology Freshwater Fish
--
Amanda Newsom
Graduate Student
Bodega Marine Laboratory
``Life shrinks or expands according to one's courage'' -- Anais Nin
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