Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Hi all– One point regarding Neahga Leonard's observations: Tamarisks (like cottonwoods and cattails) are primarily anemochores, so seed dispersal doesn't strongly depend on their position in any particular watershed. They may spring up in any damp patch, often many miles from a seed source, up, down or across elevational gradients. Our 'Nature' essay cites two papers regarding tamarisk, one describing what we know about tamarisk introduction and identifying the moment and the reason tamarisks were recategorized from being a solution (to accelerated erosion) to being a problem (by the Phelps Dodge Mining Co.); the other reviews the more recent literature and draws attention to a variety of shortcomings in traditional tamarisk-related science. Both can be downloaded at my Academia site (below) Matthew K Chew Assistant Research Professor Arizona State University School of Life Sciences ASU Center for Biology Society PO Box 873301 Tempe, AZ 85287-3301 USA Tel 480.965.8422 Fax 480.965.8330 mc...@asu.edu or anek...@gmail.com http://cbs.asu.edu/people/profiles/chew.php http://asu.academia.edu/MattChew
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Dear Katie and Others, I can understand (and partially agree with) some of the negative reaction that many have had to the Davis et al. article in Nature. I do not share the authors' desire to extol the virtues of non-native species (except perhaps for agricultural and medicinal species). However, after reading the article, I came away with a very different impression of what the authors were trying to say than have many of the posters. The main points I took away from the article were 1) there have been unsubstantiated claims of harm by non-native species 2) the costs of dealing with successful non-native species may in some cases outweigh the benefits, and 3) there should be no double-standard with regard to how we view native and non-native species that have negative impacts on ecosystems. I agree with all three points. The Wilcove et al. 1998 study claiming that the invasive species were the second leading cause of extinctions needed to be addressed. There was not much empirical data to back up this claim (at the time at least), and yet it and similar reviews get cited often. Empirical support is necessary for scientific credibility. Contrary to what one poster said, I do not agree that empirical evidence is not needed when there is observational evidence. Looks are deceiving, and most of the examples of observational harm he cited are in fact also supported by empirical studies. Purple loosetrife, on the other hand, is notorious for decimating native plant diversity, but the empirical support for this claim is at best conflicting. Furthermore, some species (e.g., Microstegium vimineum) may have greater *per capita* impacts on relatively species-rich ecosystems in which they are not the most productive or abundant (Brewer 2011, Biological Invasions). This would not have been revealed by simple observation. I think the numbers of studies showing negative effects of non-native species since the Wilcove et al. 1998 study have been increasing (judging from what I've seen in issues of Biological Invasions). But this may be in large part because an increasing number of ecologists have recognized the lack of data (or conflicting data) on harm for some notorious invaders and have taken it upon themselves to investigate the issue. I was partly inspired to investigate effects of cogongrass (Imperata cylindrica) on longleaf pine vegetation after reading Farnsworth's study of purple loosestrife, which surprisingly showed little effect of this species on native plant diversity. I don't think these efforts to obtain empirical data are a waste of time. The limited supply of conservation funding requires that we take a cost-benefit approach to control of non-native species perceived to be invasive. In north Mississippi, a funding priority of the National Forest is the control of kudzu. While it almost certainly retards succession (although I'm not aware of scientific studies demonstrating this), I can find no evidence that it has displaced native species. It was largely planted in eroding, agricultural wastelands that were devoid of diversity in the first place. Yes, it's expanding into adjacent forests, but very slowly, as it is the least shade tolerant vine in the southeast US. It creates its preferred light environment by killing a tree at a time, but this is not a rapid process. I'm not saying it shouldn't be controlled, but should its control be given priority over, say, reversing the effects of fire suppression in upland forests in north Mississippi (as is the case now)? The latter management activity would be much more effective at restoring native biodiversity and perhaps a better use of limited biodiversity conservation dollars. I demonstrated that cogongrass dramatically reduced resident plant species diversity AND the abundance of plant species indicative of longleaf pine ecosystems (Brewer 2008, Biol Inv. 2008). I think this non-native species is certainly deserving of its bad reputation and control efforts. But what about native eastern red cedar (Juniperus virginiana)? In the black belt prairie of north Mississippi, fire suppression has led to a dramatic increase in its abundance, which in turn has resulted in catastrophic reductions in native plant and animal diversity and the displacement of numerous endemic state-listed plant and animal species. It has converted a diverse grassland ecosystem into a species-poor cedar thicket. Indeed, I would argue that it has had a greater impact on diversity and biotic homogenization in Mississippi than has cogongrass (certainly much more than kudzu). Yes, there is concern about this native species, and there are some efforts to control/remove it, but there is no Eastern Red Cedar Task Force in Mississippi. There is no Cooperative Weed Management Area formed around its control in Mississippi (as there is for cogongrass and kudzu). Is this a double standard? I'm not sure. I will say,
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
A lot of good points and examples being brought up on both sides of the issue here. Wayne's comment about healthy ecosystems needing far less intervention by us than we think is particularly interesting. From my experience, that is true, but the problem is in finding a healthy ecosystem. Pretty much wherever we go we, pave, plow, cut, dig, and trample. Those activities are not conducive to a healthy, robust ecosystem which can either fend off invasive or gracefully accept them. Those activities promote organisms which can cope with fragmented and disturbed habitats. Malcolm rightly reminds us that not all invasives are exotic, Even native organisms can occupy an invasive niche when the environment changes, often as a result of the previously mentioned activities. And a final note about tamarisk... it's called the Willow leaf flycatcher for a reason, it's not called the Tamarisk flycatcher. True, the birds are now sometimes nesting in tamarisk, but that's only because in may places it is the only remaining dense stand of vegetation they can nest in. From my reading and conversations with friends who have worked in tamarisk blighted areas there is less food in tamarisk vegetation for the birds, and the decline of both cottonwoods and willows does appear to be pretty closely linked with the spread of tamarisk. I think the main point to keep in mind when thinking of managing invasives is more one of practicality and well though out approaches. Not to belabor the tamarisk example, but many of the management approaches are doomed to failure because the removal begins at the bottom of the watershed (easier access) rather than at the top of the watershed (the point of origin for propagules). In this and other conservation areas I think we need to sit down and have a really deep think about what our goals are, how we will achieve them, and why we set those specific goals. Neahga Leonard
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Friends, While I am devoted to all the plants, of course, sometimes vilifying invasive plants is the right thing to do. For example, we need to vilify the strawberry guava (Psidium cattleianum) in Hawaii that displaces native forests across watersheds (http://www.fs.fed.us/psw/programs/ipif/strawberryguava/). And, of course another one to vilify is Miconia calvescens. Unfortunately, this horrible invasive species was used as the lead photo in that Nature comment, just above text that advocated for less concern about the spread of alien weeds. That mismatch was really unfortunate because M. calvescens has displaced a huge fraction of native forest in Tahiti, where it is known as the green cancer and threatens to create the same ecodisaster in Hawaii, where it is known as the purple plague. http://en.wikipedia.org/wiki/Miconia_calvescens . Another really clear case of an invasive plant to be vilified is the Giant Hogweed (Heracleum mantegazzianum), which is expanding its range across NE and NW US and Canada and can cause blindness, burns all over the body and death, because its sap triggers extreme and persistent photosensitivity. http://en.wikipedia.org/wiki/Giant_Hogweed There are several fascinating and creepy videos on YouTube about it! e.g., http://www.youtube.com/watch?v=LTktmNiMRxIfeature=fvsr or http://www.youtube.com/watch?v=KaV2jwNT0MQ . For those who love awesome music, there is an 8 minute classic song by Genesis about it (http://www.youtube.com/watch?v=7j6fr4TQzMg ) It would be wrong to use that Nature Comment to justify diverting resources away from important work controlling the spread of invasive species. The weak arguments in that Comment have to be balanced against the consensus of the thousands of others who have justly advocated for the preservation of native-dominated ecosystems and for targeting invasive alien species (see e.g., the Millenium Ecosystem Assessment) so we can leave the earth in as good condition as we found it, or better. Lawren Sack UCLA At 06:20 PM 6/11/2011, David Duffy wrote: Matt Chew has presented an interesting perspective on how the Nature editorial (Davis et al. 2011, Don't judge species by their origins) came into being. I have significant concerns about the paper, which while certainly interesting and provocative, does not live up to the standards of Nature. While this may be in part a product of the editing process and limitations that Matt described, responsibility for the commentary remains with the authors. Nature informed me that the piece was not peer-reviewed. While peer reviewing would not be appropriate for the message of any editorial, it should help ensure that facts are correct and interpretations are fairly presented. I won't comment here (until the bottom) about the message, but I will comment about facts and what is best described as unfortunate presentation that should have received the attention of an editor or the self restraint of the authors, assuming they all read the final product. This is a scientific commentary. Words like vilified and beloved `native' species, pervasive bias, apocalyptic and rightful are best left to bodice rippers or American talk radio. Classifying biota according to their adherence to cultural standards of belonging, citizenship, fair play or morality does not advance our understanding of ecology. It does seems to be advancing an argument that plants have a consciousness that makes them capable of culture and ethics. Tomkins (1973: The Secret Life of Plants) advanced this hypothesis but it has not really received scientific support until this editorial in Nature. Poor editing or ? Six of ten references are by co-authors. There is a near absence of literature from the invasive species biology that they are commenting on, the sole exception being a 1998 paper, while all the others are from 2009-2011. Fairness should have called for citing one or more current references about how invasive species biology and management are actually practiced, rather than presenting their one sided picture. Again poor editing? They give an example of a long term eradication effort in Australia involving devil's claw plant (Martynia annua). They claim There is little evidence that the species ever merited such intensive management, quoting a paper by one of the co-authors (Gardner et al. 2010. Rangeland J. 32: 407-417). In reality, this species is considered a pest because of its clawed fruits cause injury and discomfort to animals having been know to work their way into soft body parts (Smith 2002, Weeds of the wet/dry tropics of Australia, Environment Centre NT.) and Gardner wrote that it is of moderate annoyance to the cattle industry (Gardner et al. 2010). As we know from the Yellowstone/Montana wolf situation, what is little evidence to academics but a moderate annoyance to cattlemen can trigger control and eradication efforts. The authors ask
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Exotic does not equal invasive!!! Exotic species are introductions (generally by humans [anthropochore]) that did not previously occur in the area. Invasive species are those species that can readily take over a habitat when conditions are right. Classic exotic invasive species: fire ants in North America, European house finch, European starling. Classic native invasive species: sweet gum in the SE US cypress-tupelo forest, bullfrogs, sugar maples in oak hickory forests. Classic exotic noninvasive species: This is harder to come up with, but you could argue Mediterranean Geckos or cattle egrets. However, invasiveness is condition dependent and one could argue that any species can become invasive when the conditions are right. Malcolm McCallum On Sat, Jun 11, 2011 at 11:21 PM, Warren W. Aney a...@coho.net wrote: Empirical evidence is not needed when observational evidence shows severe and widespread adverse effects of invasive species on local systems. Examples I know of include: Reed Canary Grass (Phalaris arundinacea) monocultures replacing diverse native sedge and forb wetland species mixes and reducing wildlife habitat productivity. Himalyan (Armenian) Blackberry (Rubus discolor) monocultures taking over meadows, pastures and field edges and reducing native wildlife use. Feral Horse (Equus cabalus) overuse of steppe grasslands and damage to streambanks, increasing soil erosion and stream degradation. Feral Pig (Suus scrufa) soil disturbance, vegetation removal and disease transmission. Knapweeds (Centaurea and Acroptilon spp.) taking over both disturbed and undisturbed rangelands, replacing native grasses and forbs, and reducing herbivory; some species also supress native grasses and forbs through allelopathy. Garlic mustard (Alliaria petiolata) takeover of forest floor systems by outcompeting native species and effective allelopathy. English and Irish Ivy (Hedera spp.) monocultural takeover of forest floor and shrub systems, excluding native forbs and shrubs, adversely affecting tree survival and severely reducing native wildlife use. Cheatgrass (Bromus tectorum) invasion of rangelands outcompeting native grasses by usurping soil water and promoting early wildfire (after which it quickly reseeds). As is the case with many ecological concepts, invasive is a subjective and relative term and not an absolute categorization. Some may consider dandelions to be invasive and others may say they're just a weed (another subjective term) adding diversity to lawn monocultures -- they are seldom a takeover species causing localized extirpation of native species as is the case with too many other prolific exotics. And not all invasives are non-native to a particular continent or region -- but they are usually and typically non-native to a particular adversely affected ecosystem. My conclusion: There have been successes in invasive control (e.g., tansy ragwort), and there are numerous cases where lack of control efforts will seriously deplete natural system diversity and value (both ecological and economic). All of the species I've listed above, and many more, are worth controlling or eliminating, and not all of this effort will make Monsanto richer. Warren W. Aney Senior Wildlife Ecologist Tigard, Oregon -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Jeff Houlahan Sent: Saturday, 11 June, 2011 16:19 To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Hi all, not that Esat needs me to defend him but the list of species that can be 'googled' and identified as invasive scourges is, I suspect, longer than the list that actually are scourges. One of the species that was identified in Amyarta's list, purple loosestrife, is a classic example. You can go to hundreds of websites that will identify it as a species that competitively excludes native plant species and causes local extirpations. The empirical evidence to support this claim is almost non-existent (or was a couple of years ago when I checked last). There have been several reviews done on the topic and most conclude that there is little evidence that loosestrife causes extinctions at almost any scale. This isn't to suggest that invasives are never a problem but my understanding of the literature is that there is lots of evidence of extinctions caused by invasive predators and relatively little evidence of extinctions caused by competitive exclusion (zebra mussels are probably an exception to that general statement). I don't think it's a bad idea to actually step back and see if the investment in controlling invasive species is warranted. Jeff Houlahan -- Malcolm L. McCallum Managing Editor, Herpetological Conservation and Biology Peer pressure is designed to contain anyone with a sense of drive - Allan Nation 1880's: There's lots of good fish
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
That someone would suggest that 19 authors is equivalent to 6 times as much peer review shows a fundamental misunderstanding of peer review. Nature itself lists independence from the authors and their institutions first among criteria for referees. To suggest that authors serve as their own peer reviewers is like suggesting that U.S. banks regulate themselves. The fact of the matter is that the commentary was not peer reviewed. The authors included journal editors quite familiar with the scientific publication process, very practiced writers and meticulous reviewers. The problems with mis- and and self citation, misrepresentation or at least gross oversimplification of facts, lurid language and sophomoric rhetorical tricks suggest that either not all the authors read the final draft or collectively they and the Nature editorial process failed to produce a paper that can withstand scrutiny and command respect. I am asking Nature to review its editorial process for commentaries, based on the present case. There is a serious issue here, but it is one of nuance. I would have expected a commentary in Nature to lead the way toward consensus, not to regurgitate extremes of a debate. David Duffy Matt Chew wrote:An observation or two: an opinion paper with 19 authors effectively receives 6 times as much peer review in the process of its drafting and revision as any typical research paper receives under normal circumstances. The authors included journal editors quite familiar with the scientific publication process, very practiced writers and meticulous reviewers. Nature was under no obligation to publish the piece if it failed to meet their standards. We were under no obligation to submit one that didn't meet our standards. Our purpose in writing was to expand a conversation already well underway by presenting our views formally and in the most accessible and noticeable forum possible. That is readily distinguishable from trying end a conversation by telling you what to think. Indeed, we are encouraging you to critically examine issues that are most often presented as axiomatic. Some of you are doing just that. We appreciate your efforts, and we are paying attention. Matthew K Chew Assistant Research Professor Arizona State University School of Life Sciences David Cameron Duffy Ph.D. Professor/PCSU Unit Leader/CESU Director PCSU/CESU/Department of Botany University of Hawaii Manoa 3190 Maile Way, St John 410 Honolulu, HI 96822 USA Tel 808-956-8218, FAX 808-956-4710 http://www.botany.hawaii.edu/faculty/duffy/ - Original Message - From: Matt Chew anek...@gmail.com Date: Sunday, June 12, 2011 4:10 am Subject: [ECOLOG-L] EcoTone: Speaking of species and their origins To: ECOLOG-L@LISTSERV.UMD.EDU An observation or two: an opinion paper with 19 authors effectively receives 6 times as much peer review in the process of its drafting and revision as any typical research paper receives under normal circumstances. The authors included journal editors quite familiar with the scientific publicationprocess, very practiced writers and meticulous reviewers. Nature was under no obligation to publish the piece if it failed to meet their standards. We were under no obligation to submit one that didn't meet our standards. Our purpose in writing was to expand a conversation already well underway by presenting our views formally and in the most accessible and noticeableforum possible. That is readily distinguishable from trying end a conversation by telling you what to think. Indeed, we are encouraging you to critically examine issues that are most often presented as axiomatic.Some of you are doing just that. We appreciate your efforts, and we are paying attention. Matthew K Chew Assistant Research Professor Arizona State University School of Life Sciences ASU Center for Biology Society PO Box 873301 Tempe, AZ 85287-3301 USA Tel 480.965.8422 Fax 480.965.8330 mc...@asu.edu or anek...@gmail.com http://cbs.asu.edu/people/profiles/chew.php http://asu.academia.edu/MattChew
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Conservationists DO devote resources judiciously because they they have too. Conservation is grossly under-funded and under-manned. Its amazing how little gets done in environmental and public health while we throw trillions at a millitary that would still be the most dominant force in the world with half the budget, considering we already spend more than the next 10 nations combined. That doesn't even count dozens of agency offices in the U.S. that used to be part of the U.S. Dept. of Defense, and whose functions in other countries remain under their respective defense departments. Our expenditures are actually much more than this!! I challenge anyone to find 10 nations who can agree on attacking another entity, let alone the next 10 nations in total miliatry spending. Its time to spend money on other things besides policing the rest of the world. M On Fri, Jun 10, 2011 at 11:30 PM, Stephanie Jones stephjon...@yahoo.com wrote: If I may interrupt, briefly, I think Esat is not denying the negative impact of invasives eg. the lionfish. He seems to suggest that many efforts to eradicate invasives might be futile, and even might exploit the fear of invasives for profit. It also seems that Esat is highlighting the importance of studying and even targeting the root cause of introduced species--globalization. Indeed, as long as trade expands, as long as opportunities for movement across boundaries increase, so will chances for ecological invasion. Yet many ecologists, even those sympathetic to the anti-globalization movement(s?), do not devote their careers to this. Even if this is not what Esat intended to say, I would offer that conservationists should devote their resources judiciously, and invasives removal can become a Sisyphean task when the cause of species invasion is not abated. I'm sure many of you must acknowledge this in your own work already. Great minds discuss ideas; Average minds discuss events; Small minds discuss people. Eleanor Roosevelt From: Amartya Saha as...@bio.miami.edu To: ECOLOG-L@LISTSERV.UMD.EDU Sent: Fri, June 10, 2011 6:46:31 PM Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Dear Esat, Over the past three decades, there are hundreds of examples worldwide of exotic invasives negatively impacting ecosystems, and these span both plants and animals. Whether expensive exotic removal programs work is another matter, case-specific Often the focus is on removal that is hard to do, maybe even futile while there are hardly any efforts to prevent further introductions. Ecosystems have always been in flux, the ranges of organisms have always expanded. However the speed of man-caused introductions of exotic invasives does not allow natives adequate time to develop survival or coexistence strategies. Google lantana in india, water hyacinth, purple loosestrife, brazilian pepper, lampreys in great lakes, burmese pythons iand african jewelfish in everglades, nile perch in rift valley lakes, brown tree snake in guam, feral cats and songbirds, cane toadsthe list goes on and on. Sent on the Sprint® Now Network from my BlackBerry® -Original Message- From: Esat Atikkan atik...@yahoo.com Sender: Ecological Society of America: grants, jobs, news ECOLOG-L@LISTSERV.UMD.EDU Date: Fri, 10 Jun 2011 14:51:41 To: ECOLOG-L@LISTSERV.UMD.EDU Reply-To: Esat Atikkan atik...@yahoo.com Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Interesting points. At the same time alien/introduced/invasivespecies that truly alter an environment, out compete others, and in general, lead to ecological mayhem - I am not aware of any examples outside of, maybe, humans. There exists serious economics benefits to many in the realm of 'alien species battles'. The lionfish, Pterois volitans and, possibly, P. miles, are a good example. Even quasi-scientific articles continue to villify them, describing their voracious appetites and ability to out-compete all native species. Yet stomach anlysis fails to support those contentions. There is no question that it has successfully established itself, do date from New Hampshire to Colombia, throughout the Caribbean and it would be a miracle if it is eradicated. But significant ecological perturbation has yet to be proven. That does not stop dive shops, REEF, and a plethora of other organizations from putting together derbies, round-ups, and the like geared to the illusion that this is the way to eradicate the pest. It should be noted that all that organize such events charge for it, thus deriving a benefit from the lionfish. In areas where scuba diving was waning, the arrival of the lionfish has been a boost. Thus, despite the generally accepted view that eradication is near impossible, it is turned into a cash cow - cash fish. Indeed a fresh assessment of this issue
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Hi all, not that Esat needs me to defend him but the list of species that can be 'googled' and identified as invasive scourges is, I suspect, longer than the list that actually are scourges. One of the species that was identified in Amyarta's list, purple loosestrife, is a classic example. You can go to hundreds of websites that will identify it as a species that competitively excludes native plant species and causes local extirpations. The empirical evidence to support this claim is almost non-existent (or was a couple of years ago when I checked last). There have been several reviews done on the topic and most conclude that there is little evidence that loosestrife causes extinctions at almost any scale. This isn't to suggest that invasives are never a problem but my understanding of the literature is that there is lots of evidence of extinctions caused by invasive predators and relatively little evidence of extinctions caused by competitive exclusion (zebra mussels are probably an exception to that general statement). I don't think it's a bad idea to actually step back and see if the investment in controlling invasive species is warranted. Jeff Houlahan
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Hi y'all! Houlahan has touched (as have others) upon perhaps the most gigantonormous of all the elephants in the invasive alien room--money and power. A lot of people (not to mention corporations) make a lot of money getting a lot of people to stay poor out of concern for the environment; the financially attached love and support (mainly moral support) the emotionally attached. The former operate, Cheshire-cat style, in the background, while the environmentalists volunteer their hearts out and march against the evil infidels who would dare to suggest that proof should be derived from scientific analysis and real data. If you will permit a small anecdote: About ten years ago I was vigorously verbally attacked (Just kill them ALL, kill them all--that's all you need to know!) at a seminar sponsored by Cal-IPCC and was shunned for the rest of the meeting by the weed-whackers. Posting on this subject on listservs like the one operated on behalf of CNPS, Cal-IPCC, and APWG, for example will be met with cries of outrage or stony silence. A CNPS group has, at great expense and labor, greatly reduced biodiversity on one site near my house, planting common native shrubs that will suppress or kill uncommon indigenous grasses, which they have whacked along with a few weeds, the latter of which were in the process of being suppressed by an increasingly healthy and diverse indigenous plant community. Hell hath no fury like the self-righteous. I have become the veritable skunk at a garden party, if not branded as an outcast by various organizations, including those I once thought were on the right hand of God. The Davis et al paper could not tell all, but it did put some respectability on this volatile issue. I may not fully agree with every detail, and perhaps even less with some of its generalities, but I welcome it as what it is apparently intended to be, a catalyst for reasoned examination of questionable conclusions. Over the last several decades I have vacillated a bit on this issue, but tend to hover around the middle somewhere. In particular, I have found that healthy ecosystem need far less intrusion by us than we think; they may take their time about it, but once we have stopped whacking, grazing, grading, and otherwise messing them up, they do tend to self-repair--maybe not to the extent that we prefer, but most often better than we can by demanding that they live up to our expectations. This is not to say that all whacking is always bad (maybe a little highly selective poisoning can be, on occasion, useful), nor is all restoration ill-advised. But it is to say that more restraint in both areas is needed, and our track-record is spotty. We should start by paying attention to what the feedback loops are trying to tell us about consequences and the righteousness of our goals going without honest examination. WT - Original Message - From: Jeff Houlahan jeffh...@unb.ca To: ECOLOG-L@LISTSERV.UMD.EDU Sent: Saturday, June 11, 2011 4:18 PM Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Hi all, not that Esat needs me to defend him but the list of species that can be 'googled' and identified as invasive scourges is, I suspect, longer than the list that actually are scourges. One of the species that was identified in Amyarta's list, purple loosestrife, is a classic example. You can go to hundreds of websites that will identify it as a species that competitively excludes native plant species and causes local extirpations. The empirical evidence to support this claim is almost non-existent (or was a couple of years ago when I checked last). There have been several reviews done on the topic and most conclude that there is little evidence that loosestrife causes extinctions at almost any scale. This isn't to suggest that invasives are never a problem but my understanding of the literature is that there is lots of evidence of extinctions caused by invasive predators and relatively little evidence of extinctions caused by competitive exclusion (zebra mussels are probably an exception to that general statement). I don't think it's a bad idea to actually step back and see if the investment in controlling invasive species is warranted. Jeff Houlahan - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1375 / Virus Database: 1513/3695 - Release Date: 06/11/11
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Matt Chew has presented an interesting perspective on how the Nature editorial (Davis et al. 2011, Don’t judge species by their origins) came into being. I have significant concerns about the paper, which while certainly interesting and provocative, does not live up to the standards of Nature. While this may be in part a product of the editing process and limitations that Matt described, responsibility for the commentary remains with the authors. Nature informed me that the piece was not peer-reviewed. While peer reviewing would not be appropriate for the message of any editorial, it should help ensure that facts are correct and interpretations are fairly presented. I won’t comment here (until the bottom) about the message, but I will comment about facts and what is best described as unfortunate presentation that should have received the attention of an editor or the self restraint of the authors, assuming they all read the final product. This is a scientific commentary. Words like “vilified” and “beloved `native’ species”, “pervasive bias”, “apocalyptic” and “rightful” are best left to bodice rippers or American talk radio. “Classifying biota according to their adherence to cultural standards of belonging, citizenship, fair play or morality does not advance our understanding of ecology.” It does seems to be advancing an argument that plants have a consciousness that makes them capable of culture and ethics. Tomkins (1973: The Secret Life of Plants) advanced this hypothesis but it has not really received scientific support until this editorial in Nature. Poor editing or ? Six of ten references are by co-authors. There is a near absence of literature from the “invasive species biology” that they are commenting on, the sole exception being a 1998 paper, while all the others are from 2009-2011. Fairness should have called for citing one or more current references about how invasive species biology and management are actually practiced, rather than presenting their one sided picture. Again poor editing? They give an example of a long term eradication effort in Australia involving devil’s claw plant (Martynia annua). They claim “There is little evidence that the species ever merited such intensive management”, quoting a paper by one of the co-authors (Gardner et al. 2010. Rangeland J. 32: 407-417). In reality, this species is considered a pest because of its “clawed fruits cause injury and discomfort to animals having been know to work their way into soft body parts” (Smith 2002, Weeds of the wet/dry tropics of Australia, Environment Centre NT.) and Gardner wrote that it is “of moderate annoyance to the cattle industry” (Gardner et al. 2010). As we know from the Yellowstone/Montana wolf situation, what is “little evidence” to academics but a moderate annoyance to cattlemen can trigger control and eradication efforts. The authors ask whether the “effort is worth it?” for this eradication effort. They ignore the conclusion of co-author Gardner (et al. 2010), that the effort was a valuable training exercise for 200 or 400 participants (both are given), especially for 82 “Aboriginal Rangers” from “Traditional Owners” of the land who subsequently took over management of the area. Did Gardner actually read the final draft or did the other authors not read Gardner’s paper? Similarly for tamarisk in the western U.S., the three references are problematic. Two are by co-authors. In the third, they reference Aukema et al Bioscience 60: 886-897 in support of their statement that “Tamarisks. . .arguably have a crucial role in the functioning of the human modified river bank environment”. Unfortunately Aukema et al wrote on the historical accumulation of nonindigenous forest pests in the Continental United States and I can find no reference to tamarisk, much less documentation for the statement. Finally, tamarisk management is not settled science in the West, so a more balanced selection of literature might have been helpful. The reference to the number of successful plant eradications in Galapagos has no citation. The authors cite the Ring-necked Pheasant as one among “many of the species that people think of as native are actually alien.” It isn’t clear who “the people” are. Most ecologists know the pheasant is introduced if they work in the area. In any event the pheasant is irrelevant. It is managed as a game bird, not controlled as an invasive species, unless there are local efforts which the authors do not mention. Editing should have removed this whole section. Finally, the authors use straw dog arguments which, while effective propaganda, are poor writing. Claiming that the “native versus non-native dichotomy in conservation is declining and even becoming unproductive” they cite Flieschman et al. (Bioscience 61) as proof that “many conservationists still consider the distinction a core guiding principle”. The paper in question lists 40 top
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Empirical evidence is not needed when observational evidence shows severe and widespread adverse effects of invasive species on local systems. Examples I know of include: Reed Canary Grass (Phalaris arundinacea) monocultures replacing diverse native sedge and forb wetland species mixes and reducing wildlife habitat productivity. Himalyan (Armenian) Blackberry (Rubus discolor) monocultures taking over meadows, pastures and field edges and reducing native wildlife use. Feral Horse (Equus cabalus) overuse of steppe grasslands and damage to streambanks, increasing soil erosion and stream degradation. Feral Pig (Suus scrufa) soil disturbance, vegetation removal and disease transmission. Knapweeds (Centaurea and Acroptilon spp.) taking over both disturbed and undisturbed rangelands, replacing native grasses and forbs, and reducing herbivory; some species also supress native grasses and forbs through allelopathy. Garlic mustard (Alliaria petiolata) takeover of forest floor systems by outcompeting native species and effective allelopathy. English and Irish Ivy (Hedera spp.) monocultural takeover of forest floor and shrub systems, excluding native forbs and shrubs, adversely affecting tree survival and severely reducing native wildlife use. Cheatgrass (Bromus tectorum) invasion of rangelands outcompeting native grasses by usurping soil water and promoting early wildfire (after which it quickly reseeds). As is the case with many ecological concepts, invasive is a subjective and relative term and not an absolute categorization. Some may consider dandelions to be invasive and others may say they're just a weed (another subjective term) adding diversity to lawn monocultures -- they are seldom a takeover species causing localized extirpation of native species as is the case with too many other prolific exotics. And not all invasives are non-native to a particular continent or region -- but they are usually and typically non-native to a particular adversely affected ecosystem. My conclusion: There have been successes in invasive control (e.g., tansy ragwort), and there are numerous cases where lack of control efforts will seriously deplete natural system diversity and value (both ecological and economic). All of the species I've listed above, and many more, are worth controlling or eliminating, and not all of this effort will make Monsanto richer. Warren W. Aney Senior Wildlife Ecologist Tigard, Oregon -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Jeff Houlahan Sent: Saturday, 11 June, 2011 16:19 To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Hi all, not that Esat needs me to defend him but the list of species that can be 'googled' and identified as invasive scourges is, I suspect, longer than the list that actually are scourges. One of the species that was identified in Amyarta's list, purple loosestrife, is a classic example. You can go to hundreds of websites that will identify it as a species that competitively excludes native plant species and causes local extirpations. The empirical evidence to support this claim is almost non-existent (or was a couple of years ago when I checked last). There have been several reviews done on the topic and most conclude that there is little evidence that loosestrife causes extinctions at almost any scale. This isn't to suggest that invasives are never a problem but my understanding of the literature is that there is lots of evidence of extinctions caused by invasive predators and relatively little evidence of extinctions caused by competitive exclusion (zebra mussels are probably an exception to that general statement). I don't think it's a bad idea to actually step back and see if the investment in controlling invasive species is warranted. Jeff Houlahan
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Dave and others, I haven't read the Nature article yet, but I believe that tamarisk is actually one (or two) of the species about which there is some dispute. Not that it is a boon to the environment, but that much of its reputation is exaggerated and effects might be site (and river regulation) specific (see Stromberg et al. 2009: http://onlinelibrary.wiley.com/doi/10./j.1526-100X.2008.00514.x/full). The reasons for such things as cottonwood and willow displacement are sometimes complex, and may have as much to do with changes in hydrologic regime from flow regulation as any direct effects of tamarisk (although tamarisk itself could certainly be a contributing factor). I know that there was also some recent controversy over whether widespread tamarisk control (via biocontrol agents) could threaten nesting habitat for the endangered SW Willow Flycatcher. Mark D. From: Ecological Society of America: grants, jobs, news [ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of David L. McNeely [mcnee...@cox.net] Sent: Friday, June 10, 2011 1:45 PM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Katie Kline ka...@esa.org wrote: An essay published in the June 8 issue of Nature is causing something of a stir. Eighteen ecologists who signed the essay, titled Don't judge species on their origins, argue that conservationists should assess organisms based on their impact on the local environment, rather than simply whether they're native, as described in a recent Scientific American podcast. In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and colleagues argue that adherence to the idea of non-natives as the enemy is more a reflection of prejudice rather than solid science, wrote Brandon Keim in a Wired Science article. As the authors wrote, the preoccupation with the native-alien dichotomy among scientists, land managers and policy-makers is prohibitive to dynamic and pragmatic conservation and species management in a 21st century planet that is forever altered by climate change, land-use changes and other anthropogenic influences. As a result of this misguided preoccupation, claim the authors, time and resources are unnecessarily spent attempting to eradicate introduced species that actually turn out to be a boon to the environment; the authors cite the non-native tamarisk tree in the western U.S. as an example of this... Read more and comment at http://www.esa.org/esablog/ecologist-2/speaking-of-species-and-their-origins/ Exactly how have tamarisks (there are two invasive species in the western U.S. unless I have been misinformed) been a boon to the environment? They have displaced native willows and cottonwoods. Their transpiration rates far exceed those of the native species they replace, lowering the water table in the area and drying streams, playas, and cienagas. By concentrating salts in their foliage, then dropping the foliage to the ground, they increase the salinity of surface soils. Animal species that depend on the riparian vegetation they displace lose out. So do those that depend on the streams and cienagas as aquatic habitat. mcneely
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
IMHO, they are attacking a straw man. I haven't seen many scientists, managers, policy-makers etc. getting all worked up about non-indigenous species who integrate well into the environment, get a green card, pay their taxes etc. The ones that are being attacked and for which they are spending lots of money are the truly invasive ones that cause ecological and economic damage - eating up everything in sight, outcompeting native species for food, space etc. - and generally taking over - affecting the environment in negative ways. An essay published in the June 8 issue of Nature is causing something of a stir. Eighteen ecologists who signed the essay, titled Don't judge species on their origins, argue that conservationists should assess organisms based on their impact on the local environment, rather than simply whether they're native, as described in a recent Scientific American podcast. In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and colleagues argue that adherence to the idea of non-natives as the enemy is more a reflection of prejudice rather than solid science, wrote Brandon Keim in a Wired Science article. As the authors wrote, the preoccupation with the native-alien dichotomy among scientists, land managers and policy-makers is prohibitive to dynamic and pragmatic conservation and species management in a 21st century planet that is forever altered by climate change, land-use changes and other anthropogenic influences. As a result of this misguided preoccupation, claim the authors, time and resources are unnecessarily spent attempting to eradicate introduced species that actually turn out to be a boon to the environment; the authors cite the non-native tamarisk tree in the western U.S. as an example of this... Read more and comment at http://www.esa.org/esablog/ecologist-2/speaking-of-species-and-their-origins/
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Interesting points. At the same time alien/introduced/invasivespecies that truly alter an environment, out compete others, and in general, lead to ecological mayhem - I am not aware of any examples outside of, maybe, humans. There exists serious economics benefits to many in the realm of 'alien species battles'. The lionfish, Pterois volitans and, possibly, P. miles, are a good example. Even quasi-scientific articles continue to villify them, describing their voracious appetites and ability to out-compete all native species. Yet stomach anlysis fails to support those contentions. There is no question that it has successfully established itself, do date from New Hampshire to Colombia, throughout the Caribbean and it would be a miracle if it is eradicated. But significant ecological perturbation has yet to be proven. That does not stop dive shops, REEF, and a plethora of other organizations from putting together derbies, round-ups, and the like geared to the illusion that this is the way to eradicate the pest. It should be noted that all that organize such events charge for it, thus deriving a benefit from the lionfish. In areas where scuba diving was waning, the arrival of the lionfish has been a boost. Thus, despite the generally accepted view that eradication is near impossible, it is turned into a cash cow - cash fish. Indeed a fresh assessment of this issue should be welcome as if it is accepted that the 'Earth' is changing, why is it blieved the biota of the various localities will remain unchanged. International trade, globailzation, and like activities are conducive to such introductions and it would be through such new thinking that the issue would receive a fresh understanding. Esat Atikkan --- On Fri, 6/10/11, Judith S. Weis jw...@andromeda.rutgers.edu wrote: From: Judith S. Weis jw...@andromeda.rutgers.edu Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins To: Date: Friday, June 10, 2011, 2:30 PM IMHO, they are attacking a straw man. I haven't seen many scientists, managers, policy-makers etc. getting all worked up about non-indigenous species who integrate well into the environment, get a green card, pay their taxes etc. The ones that are being attacked and for which they are spending lots of money are the truly invasive ones that cause ecological and economic damage - eating up everything in sight, outcompeting native species for food, space etc. - and generally taking over - affecting the environment in negative ways. An essay published in the June 8 issue of Nature is causing something of a stir. Eighteen ecologists who signed the essay, titled Don't judge species on their origins, argue that conservationists should assess organisms based on their impact on the local environment, rather than simply whether they're native, as described in a recent Scientific American podcast. In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and colleagues argue that adherence to the idea of non-natives as the enemy is more a reflection of prejudice rather than solid science, wrote Brandon Keim in a Wired Science article. As the authors wrote, the preoccupation with the native-alien dichotomy among scientists, land managers and policy-makers is prohibitive to dynamic and pragmatic conservation and species management in a 21st century planet that is forever altered by climate change, land-use changes and other anthropogenic influences. As a result of this misguided preoccupation, claim the authors, time and resources are unnecessarily spent attempting to eradicate introduced species that actually turn out to be a boon to the environment; the authors cite the non-native tamarisk tree in the western U.S. as an example of this... Read more and comment at http://www.esa.org/esablog/ecologist-2/speaking-of-species-and-their-origins/
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
And here's a similar attack by Mark Ludwig, fellow with online progressive Truthout news: http://www.truth-out.org/pesticides-and-politics-americas-eco-war/1307539754 Ludwig claims invasive control is inspired and promoted by the likes of Monsanto. Warren W. Aney Tigard, Oregon -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Judith S. Weis Sent: Friday, 10 June, 2011 11:31 To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins IMHO, they are attacking a straw man. I haven't seen many scientists, managers, policy-makers etc. getting all worked up about non-indigenous species who integrate well into the environment, get a green card, pay their taxes etc. The ones that are being attacked and for which they are spending lots of money are the truly invasive ones that cause ecological and economic damage - eating up everything in sight, outcompeting native species for food, space etc. - and generally taking over - affecting the environment in negative ways. An essay published in the June 8 issue of Nature is causing something of a stir. Eighteen ecologists who signed the essay, titled Don't judge species on their origins, argue that conservationists should assess organisms based on their impact on the local environment, rather than simply whether they're native, as described in a recent Scientific American podcast. In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and colleagues argue that adherence to the idea of non-natives as the enemy is more a reflection of prejudice rather than solid science, wrote Brandon Keim in a Wired Science article. As the authors wrote, the preoccupation with the native-alien dichotomy among scientists, land managers and policy-makers is prohibitive to dynamic and pragmatic conservation and species management in a 21st century planet that is forever altered by climate change, land-use changes and other anthropogenic influences. As a result of this misguided preoccupation, claim the authors, time and resources are unnecessarily spent attempting to eradicate introduced species that actually turn out to be a boon to the environment; the authors cite the non-native tamarisk tree in the western U.S. as an example of this... Read more and comment at http://www.esa.org/esablog/ecologist-2/speaking-of-species-and-their-origins /
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Re lionfish: Actually that's what I had in mind when I said eating everything in sight. They have been well documented to reduce populations of reef fish, due to predation on juveniles. There are plenty of peer reviewed papers to this effect, even demonstrating phase shifts of coral to algae-dominated systems, due to lionfish eating herbivores. One example: Mark Albins documented the recruitment of newly settled reef fishes on 20 patch reefs: 10 reefs with lionfish and 10 reefs without. Fish censuses were conducted at one week intervals for five weeks. Recruitment was significantly lower on lionfish reefs than on control reefs at the end of the experiment. On one occasion, a lionfish was observed consuming 20 small wrasses during a 30 minute period. It was not unusual to observe lionfish consuming prey up to 2/3 of its own length. Results of the experiment show that lionfish significantly reduce the net recruitment of coral reef fishes by an estimated 80%. The huge reduction in recruitment is due to predation. Interesting points. At the same time alien/introduced/invasivespecies that truly alter an environment, out compete others, and in general, lead to ecological mayhem - I am not aware of any examples outside of, maybe, humans. There exists serious economics benefits to many in the realm of 'alien species battles'. The lionfish, Pterois volitans and, possibly, P. miles, are a good example. Even quasi-scientific articles continue to villify them, describing their voracious appetites and ability to out-compete all native species. Yet stomach anlysis fails to support those contentions. There is no question that it has successfully established itself, do date from New Hampshire to Colombia, throughout the Caribbean and it would be a miracle if it is eradicated. But significant ecological perturbation has yet to be proven. That does not stop dive shops, REEF, and a plethora of other organizations from putting together derbies, round-ups, and the like geared to the illusion that this is the way to eradicate the pest. It should be noted that all that organize such events charge for it, thus deriving a benefit from the lionfish. In areas where scuba diving was waning, the arrival of the lionfish has been a boost. Thus, despite the generally accepted view that eradication is near impossible, it is turned into a cash cow - cash fish. Indeed a fresh assessment of this issue should be welcome as if it is accepted that the 'Earth' is changing, why is it blieved the biota of the various localities will remain unchanged. International trade, globailzation, and like activities are conducive to such introductions and it would be through such new thinking that the issue would receive a fresh understanding. Esat Atikkan --- On Fri, 6/10/11, Judith S. Weis jw...@andromeda.rutgers.edu wrote: From: Judith S. Weis jw...@andromeda.rutgers.edu Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins To: Date: Friday, June 10, 2011, 2:30 PM IMHO, they are attacking a straw man. I haven't seen many scientists, managers, policy-makers etc. getting all worked up about non-indigenous species who integrate well into the environment, get a green card, pay their taxes etc. The ones that are being attacked and for which they are spending lots of money are the truly invasive ones that cause ecological and economic damage - eating up everything in sight, outcompeting native species for food, space etc. - and generally taking over - affecting the environment in negative ways. An essay published in the June 8 issue of Nature is causing something of a stir. Eighteen ecologists who signed the essay, titled Don't judge species on their origins, argue that conservationists should assess organisms based on their impact on the local environment, rather than simply whether they're native, as described in a recent Scientific American podcast. In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and colleagues argue that adherence to the idea of non-natives as the enemy is more a reflection of prejudice rather than solid science, wrote Brandon Keim in a Wired Science article. As the authors wrote, the preoccupation with the native-alien dichotomy among scientists, land managers and policy-makers is prohibitive to dynamic and pragmatic conservation and species management in a 21st century planet that is forever altered by climate change, land-use changes and other anthropogenic influences. As a result of this misguided preoccupation, claim the authors, time and resources are unnecessarily spent attempting to eradicate introduced species that actually turn out to be a boon to the environment; the authors cite the non-native tamarisk tree in the western U.S. as an example of this... Read more and comment at http://www.esa.org/esablog/ecologist-2/speaking-of-species-and-their-origins/
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
Dear Esat, Over the past three decades, there are hundreds of examples worldwide of exotic invasives negatively impacting ecosystems, and these span both plants and animals. Whether expensive exotic removal programs work is another matter, case-specific Often the focus is on removal that is hard to do, maybe even futile while there are hardly any efforts to prevent further introductions. Ecosystems have always been in flux, the ranges of organisms have always expanded. However the speed of man-caused introductions of exotic invasives does not allow natives adequate time to develop survival or coexistence strategies. Google lantana in india, water hyacinth, purple loosestrife, brazilian pepper, lampreys in great lakes, burmese pythons iand african jewelfish in everglades, nile perch in rift valley lakes, brown tree snake in guam, feral cats and songbirds, cane toadsthe list goes on and on. Sent on the Sprint® Now Network from my BlackBerry® -Original Message- From: Esat Atikkan atik...@yahoo.com Sender: Ecological Society of America: grants, jobs, news ECOLOG-L@LISTSERV.UMD.EDU Date: Fri, 10 Jun 2011 14:51:41 To: ECOLOG-L@LISTSERV.UMD.EDU Reply-To: Esat Atikkan atik...@yahoo.com Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Interesting points. At the same time alien/introduced/invasivespecies that truly alter an environment, out compete others, and in general, lead to ecological mayhem - I am not aware of any examples outside of, maybe, humans. There exists serious economics benefits to many in the realm of 'alien species battles'. The lionfish, Pterois volitans and, possibly, P. miles, are a good example. Even quasi-scientific articles continue to villify them, describing their voracious appetites and ability to out-compete all native species. Yet stomach anlysis fails to support those contentions. There is no question that it has successfully established itself, do date from New Hampshire to Colombia, throughout the Caribbean and it would be a miracle if it is eradicated. But significant ecological perturbation has yet to be proven. That does not stop dive shops, REEF, and a plethora of other organizations from putting together derbies, round-ups, and the like geared to the illusion that this is the way to eradicate the pest. It should be noted that all that organize such events charge for it, thus deriving a benefit from the lionfish. In areas where scuba diving was waning, the arrival of the lionfish has been a boost. Thus, despite the generally accepted view that eradication is near impossible, it is turned into a cash cow - cash fish. Indeed a fresh assessment of this issue should be welcome as if it is accepted that the 'Earth' is changing, why is it blieved the biota of the various localities will remain unchanged. International trade, globailzation, and like activities are conducive to such introductions and it would be through such new thinking that the issue would receive a fresh understanding. Esat Atikkan --- On Fri, 6/10/11, Judith S. Weis jw...@andromeda.rutgers.edu wrote: From: Judith S. Weis jw...@andromeda.rutgers.edu Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins To: Date: Friday, June 10, 2011, 2:30 PM IMHO, they are attacking a straw man. I haven't seen many scientists, managers, policy-makers etc. getting all worked up about non-indigenous species who integrate well into the environment, get a green card, pay their taxes etc. The ones that are being attacked and for which they are spending lots of money are the truly invasive ones that cause ecological and economic damage - eating up everything in sight, outcompeting native species for food, space etc. - and generally taking over - affecting the environment in negative ways. An essay published in the June 8 issue of Nature is causing something of a stir. Eighteen ecologists who signed the essay, titled Don't judge species on their origins, argue that conservationists should assess organisms based on their impact on the local environment, rather than simply whether they're native, as described in a recent Scientific American podcast. In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and colleagues argue that adherence to the idea of non-natives as the enemy is more a reflection of prejudice rather than solid science, wrote Brandon Keim in a Wired Science article. As the authors wrote, the preoccupation with the native-alien dichotomy among scientists, land managers and policy-makers is prohibitive to dynamic and pragmatic conservation and species management in a 21st century planet that is forever altered by climate change, land-use changes and other anthropogenic influences. As a result of this misguided preoccupation, claim the authors, time and resources are unnecessarily spent attempting to eradicate introduced species that actually turn out
Re: [ECOLOG-L] EcoTone: Speaking of species and their origins
If I may interrupt, briefly, I think Esat is not denying the negative impact of invasives eg. the lionfish. He seems to suggest that many efforts to eradicate invasives might be futile, and even might exploit the fear of invasives for profit. It also seems that Esat is highlighting the importance of studying and even targeting the root cause of introduced species--globalization. Indeed, as long as trade expands, as long as opportunities for movement across boundaries increase, so will chances for ecological invasion. Yet many ecologists, even those sympathetic to the anti-globalization movement(s?), do not devote their careers to this. Even if this is not what Esat intended to say, I would offer that conservationists should devote their resources judiciously, and invasives removal can become a Sisyphean task when the cause of species invasion is not abated. I'm sure many of you must acknowledge this in your own work already. Great minds discuss ideas; Average minds discuss events; Small minds discuss people. Eleanor Roosevelt From: Amartya Saha as...@bio.miami.edu To: ECOLOG-L@LISTSERV.UMD.EDU Sent: Fri, June 10, 2011 6:46:31 PM Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Dear Esat, Over the past three decades, there are hundreds of examples worldwide of exotic invasives negatively impacting ecosystems, and these span both plants and animals. Whether expensive exotic removal programs work is another matter, case-specific Often the focus is on removal that is hard to do, maybe even futile while there are hardly any efforts to prevent further introductions. Ecosystems have always been in flux, the ranges of organisms have always expanded. However the speed of man-caused introductions of exotic invasives does not allow natives adequate time to develop survival or coexistence strategies. Google lantana in india, water hyacinth, purple loosestrife, brazilian pepper, lampreys in great lakes, burmese pythons iand african jewelfish in everglades, nile perch in rift valley lakes, brown tree snake in guam, feral cats and songbirds, cane toadsthe list goes on and on. Sent on the Sprint® Now Network from my BlackBerry® -Original Message- From: Esat Atikkan atik...@yahoo.com Sender: Ecological Society of America: grants, jobs, news ECOLOG-L@LISTSERV.UMD.EDU Date: Fri, 10 Jun 2011 14:51:41 To: ECOLOG-L@LISTSERV.UMD.EDU Reply-To: Esat Atikkan atik...@yahoo.com Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins Interesting points. At the same time alien/introduced/invasivespecies that truly alter an environment, out compete others, and in general, lead to ecological mayhem - I am not aware of any examples outside of, maybe, humans. There exists serious economics benefits to many in the realm of 'alien species battles'. The lionfish, Pterois volitans and, possibly, P. miles, are a good example. Even quasi-scientific articles continue to villify them, describing their voracious appetites and ability to out-compete all native species. Yet stomach anlysis fails to support those contentions. There is no question that it has successfully established itself, do date from New Hampshire to Colombia, throughout the Caribbean and it would be a miracle if it is eradicated. But significant ecological perturbation has yet to be proven. That does not stop dive shops, REEF, and a plethora of other organizations from putting together derbies, round-ups, and the like geared to the illusion that this is the way to eradicate the pest. It should be noted that all that organize such events charge for it, thus deriving a benefit from the lionfish. In areas where scuba diving was waning, the arrival of the lionfish has been a boost. Thus, despite the generally accepted view that eradication is near impossible, it is turned into a cash cow - cash fish. Indeed a fresh assessment of this issue should be welcome as if it is accepted that the 'Earth' is changing, why is it blieved the biota of the various localities will remain unchanged. International trade, globailzation, and like activities are conducive to such introductions and it would be through such new thinking that the issue would receive a fresh understanding. Esat Atikkan --- On Fri, 6/10/11, Judith S. Weis jw...@andromeda.rutgers.edu wrote: From: Judith S. Weis jw...@andromeda.rutgers.edu Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins To: Date: Friday, June 10, 2011, 2:30 PM IMHO, they are attacking a straw man. I haven't seen many scientists, managers, policy-makers etc. getting all worked up about non-indigenous species who integrate well into the environment, get a green card, pay their taxes etc. The ones that are being attacked and for which they are spending lots of money are the truly invasive ones that cause ecological and economic damage - eating up
