I sent a reference to the Brown et al. (2008) paper (http://www.bioone.org/doi/abs/10.1614/IPSM-08-082.1) to Huang offline. I think many other references were also sent offline. As for Joshua's comment that "certain invasive species have led to unforeseen benefits", there is a small (?) body of research and commentary on the impact that invasive species are having on ecosystem services. The increase in the distribution of invasive species is impacting ecosystems and not always to the detriment of the system. In fact, articles by Hershner and Havens (2008) (http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2008.00957.x/abstract), Pattemore and Wilcove (2011) (http://rspb.royalsocietypublishing.org/content/279/1733/1597), and others would support this premise and have raised considerable debate in other online communities. In contrast, one of the biggest issues currently being debated is how invasive plant species used for bioenergy production could have significant effects if they escape into the local region (http://www.nwf.org/News-and-Magazines/Media-Center/Reports/Archive/2012/04-04-12-Growing-Risk.aspx). Again, much has to do with how we define an "invasive", the context in which we're referring to, and the setting we may be working in. I'm not sure if this is the direction of the discussion for this thread, but it is something to consider.
Steve ___________________ Stephen L. Young, PhD Weed Ecologist University of Nebraska-Lincoln -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Joshua Wilson Sent: Thursday, April 26, 2012 8:11 PM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Plants Invasive natives? Re: [ECOLOG-L] Invasion, or progression? Good evening, First off, thank you for the wealth of responses, a number of them helped to solidify and clarify ideas on this issue. I had been waiting for all responses before I replied with a sort of meta-analysis of what came in. The replies were more numerous and substantial than I had anticipated, so thank you again. Now to clarify. When I mentioned progression, my idea was that an invasive species encourages competition, and in some cases extreme and insurmountable competition. I feel that competition without a doubt is beneficial, perhaps necessary, for an ecosystem to continue progressing towards a more complex and stronger state. The complication arises when an introduced species or a native species that becomes dominant are able to outcompete the other species in the ecosystem to the point of the only species able to compete is itself. In these instances, there are various stances to take, some of which I've heard through responses (again, thank you). From the complete control and restoration of native (albeit weaker) species, to letting nature run its course. However, my thought was that ecosystems are cyclical and self-regulating. And as Wayne Tyson said, we are interrupting and influencing this. This leads to many more questions. With what I've learned so far through this posting, exhaustive studies would be needed to determine the best course of action for a particular system or species. Even then, the needed actions to benefit one species might directly contradict the needs of another. There are multitudes of variables that need to go into project planning, not the least of which is *us, *and we cannot foresee the ripple effects of what we'll do. On the other hand, certain invasive species have led to unforeseen benefits. I will mention *Tamarix* *spp.* in this instance. But even with the detriments and benefits, there is a threshold to each. Likewise, invasive species seem to provide species-specific detriments (or benefits). One can call it a culling of the weak species and the establishment of stronger (which in my mind is necessary for progression), or unfair competition, invasive species are not by nature detrimental. I've rambled far more than I expected to, and not as cohesive as some might like. My knowledge and experiences are limited, hence my original question, but I've a sincere interest in these ideas. Again, I would welcome any thoughts, ideas, questions, or comments. Thank you all ECOLOG, this is a great resource for undergrads, post-docs, and interested individuals alike. Keep it up. Have a good night all, Josh On Thu, Apr 26, 2012 at 4:44 PM, Wayne Tyson <landr...@cox.net> wrote: > Ecolog, > > I am dismayed that there has been so little response to Huang's questions. > Perhaps I am wrong in that assumption and they have been. But it seems > to me that the questions should be addressed and some conclusions > concluded, even if they are two-headed. > > I suggest that everyone read the article to which Huang supplied a link. > It is not long, nor is it complicated. I suspect that there may be a > fundamental flaw in the article's premise, but I will leave that > judgment up to my betters . . . > > Coincidentally, Joshua Wilson's original post (Invasion or > progression?) did not define "progression," nor has anyone else, and > Wilson has not responded to my request for a definition. I think it is > essential that it be defined before his question can be answered. If > Josh was just joshing us, or he is incapacitated, I may have to lower > his grade from an A+ to, say, a "C" for mediocrity, due to his > unresponsiveness. Are you there, Josh? > > I will await the responses from others on the questions by Huang: > > 1. (When) do invasives become native? > > 2. Can natives become invasive? > > I hope that greater responsiveness will encourage Huang, the chemist, > to continue to take his cross-fertilization attempt seriously and not > to give up on ecologists. > > WT > > > ----- Original Message ----- From: "ling huang" > <ling.hu...@prodigy.net> > To: <ECOLOG-L@LISTSERV.UMD.EDU> > Sent: Sunday, April 22, 2012 6:37 PM > 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/ > <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 <ajnew...@ucdavis.edu> wrote: > > From: Amanda Newsom <ajnew...@ucdavis.edu> > Subject: Re: [ECOLOG-L] Invasion, or progression? > To: ECOLOG-L@LISTSERV.UMD.EDU > 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 <nr343...@ohio.edu> 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 >> <joshua.m.wils...@gmail.com>**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<http://www.arches.uga.edu/%7 >> Egrossman> >> > >> >> 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 > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1424 / Virus Database: 2411/4952 - Release Date: > 04/22/12 >
