That would be most of them, if by "eradicate" you mean to remove all reproducing individuals from a defined region such that all individuals are put at risk, and reinvasion or recovery is unlikely. The implication being that after an eradication no further management investment is needed, since the targeted invasive species is "eradicated".
By the time most invasive plant problems are detected or recognized they are uneradicable with normally available resources. Some notable exceptions exist and many eradications have been successful under the right conditions.... Chris Buddenhagen On Apr 26, 2012 11:11 PM, "Martin Meiss" <[email protected]> wrote: > How about if we consider that invaders have become native when all efforts > to eradicate them are futile? > > Martin M. Meiss > > > 2012/4/26 David Duffy <[email protected]> > > > "I feel that competition without a doubt is beneficial, perhaps > necessary, > > for an ecosystem to continue progressing towards a more complex and > > stronger state." > > > > "However, my thought was that ecosystems are cyclical and > self-regulating." > > > > "native (albeit weaker) species" > > > > I am not sure there is much evidence that ecosystems progress towards a > > "more complex and stronger state", even if we do not ask whether if > > competition is "beneficial" or even a dominant force. Nor is there > > evidence, with a few exceptions, that ecosystems are cyclical, much less > > self regulating and then only if you carefully pick your scale. One > might > > argue that much of ecological theory has been a repeat of the > > Gleason-Clements debate, an argument between those who seem life > dominated > > by random events and those who see homeostasis and orthogenesis, perhaps > > with a pinch of Nietzchian "der Wille zur Macht" thrown in. This colors > > current discussions of invasive species, probably far more than any > > confusion over what "invasive" means. > > > > David Duffy > > > > > > On Thu, Apr 26, 2012 at 3:11 PM, Joshua Wilson > > <[email protected]>wrote: > > > > > 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 <[email protected]> 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" < > > [email protected]> > > > > To: <[email protected]> > > > > 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 <[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 > > > <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 > > > > > > > > > > > > ----- > > > > 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 > > > > > > > > > > > > > > > -- > > > > Pacific Cooperative Studies Unit > > Botany > > University of Hawaii > > 3190 Maile Way > > Honolulu Hawaii 96822 USA > > 1-808-956-8218 > > >
