Ling Huang and Ecolog:
Soil is a major factor, nay, determinant, in/of what goes on with respect to
organisms on the surface, and soil chemistry (structure and biology) plays
an important role therein.
I hope that you can get a handle on just how differences in soil chemistry
are reflected in differences in ecosystem composition and function. This is
a fertile field, so to speak.
Ecosystems tend to sequester available nutrients in their tissues, thus
depriving upstarts like weeds from moving into the neighborhood, as it were.
When nutrients are increased significantly, as when standing biomass is
removed, colonization by "pioneer" species like "invasive" weeds is a common
response.
But that is far from what is really going on. Decomposition of roots is
thought by some to reduce available N, for example, and this would be a
fertile place to start the kind of investigations Huang proposes. Many
"pioneer" species have long thought to have played a role in "making" N
through the intermediary action of symbiotic bacteria, and free-living
bacteria, mostly in the rhizosphere of certain plants are thought to supply
N to "pioneer" and "secondary succession species," albeit in lesser
amounts--at least this is the way the more or less standard story has gone
for decades or generations. Those assumptions, and the work that has given
rise to them, certainly might bear confirmation or refutation by some
original thinker.
Most of the soil work that has been done until relatively recently has been
done in agronomics, the practices of which tend toward the weedy side of
things (many crop plants either are or are related to weeds), so ecologists
need to beware how they interpret that literature. Wildland soils tend to be
heterogeneous and highly complex, whereas agricultural soils tend to be
homogeneous and simple (yes, this is an oversimplification, but it will do
for the moment). This makes it difficult to reasonably mimic wildland soils
in pots. Field studies are notoriously difficult, but hey, all the more
reason to undertake them, eh? Faint hearts do not win fair ladies and Nobel
Prizes, no?
WT
----- Original Message -----
From: "ling huang" <[email protected]>
To: <[email protected]>
Sent: Tuesday, April 24, 2012 9:09 PM
Subject: Re: [ECOLOG-L] Invasion, or progression?
Hi
I would like to ask the group for any information on this:
Native - Invasive - Soil
Can anyone provide references for this type of work?
As a chemist I would be interested in looking carefully at the soil. Hence
bunch of soil plots with same soil, plant in one plot only native plants, in
another a (few invasive, many native), then in another (many invasive, a few
native) and in another all invasive - with different gradual increase in
relative densities. Repeat with controls. Repeat with different levels and
combinations of native and also repeat with control of environment / water
etc.
Then look carefully at what is going on with the soil - chemical analysis.
Look at phosphates, nitrates, potassium, calcium, sulphates,...
The questions I would ask are: Do the invasive plants change the soil
chemistry so much and so quick to starve/kill the native plants? If so can
it be reversed through reversal of soil conditions etc.?
As an example: I've found this but need to go to the local UNI to get a
copy:
J Chem Ecol. 2010. 36(1): 59-69. Direct and indirect effects of invasive
plants on soil chemistry and ecosystem function by Weidenhamer and Callaway.
This provides a great example of the co-operation between those in chemistry
and those in ecology.
Thank you.
Ling Huang
Sacramento City College
--- On Tue, 4/24/12, Steve Young <[email protected]> wrote:
From: Steve Young <[email protected]>
Subject: Re: [ECOLOG-L] Invasion, or progression?
To: [email protected]
Date: Tuesday, April 24, 2012, 7:39 PM
Good point. Actually, I was thinking of lightning strikes as a natural cause
of fire, which predates the Native Americans. There are estimates of how
often these occur
(http://www.newton.dep.anl.gov/askasci/wea00/wea00239.htm).
As for ample historical evidence, it appears that you have expertise on this
(http://fireecology.net/docs/Journal/pdf/Volume06/Issue03/045.pdf), so maybe
you could enlighten us with what you hypothesize as the cause of fires prior
to recent history (e.g., eighteenth to early twenty-first centuries). I'd be
interested to know.
Thanks,
Steve
-----Original Message-----
From: Ecological Society of America: grants, jobs, news
[mailto:[email protected]] On Behalf Of DeSantis, Ryan
Sent: Tuesday, April 24, 2012 9:54 AM
To: [email protected]
Subject: Re: [ECOLOG-L] Invasion, or progression?
The comment that-
"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."
-is misleading.
By "naturally occurring fire", were you referring to Native Americans
burning the area prior to European settlement?
If so, a different point of view would be that humans were actively
preventing eastern redcedar encroachment prior to European settlement.
Therefore, it is possible that prior to Native American land management,
there was "naturally" more eastern redcedar than there was during European
settlement.
If you were not referring to Native Americans burning the area prior to
European settlement, I am curious to know what evidence you were referring
to? Is there ample historical evidence for non-anthropogenic fire in the
central prairie?
________________________________________
From: Ecological Society of America: grants, jobs, news
[[email protected]] on behalf of Steve Young [[email protected]]
Sent: Monday, April 23, 2012 8:22 PM
To: [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]
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]> wrote:
From: Amanda Newsom <[email protected]>
Subject: Re: [ECOLOG-L] Invasion, or progression?
To: [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]> 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]>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
