Kelly, I think Bruce says it well. The speed and scale of human-aided long-distance dispersal of organisms is certainly way beyond what our current species and ecosystems have evolved with, and almost certainly unprecedented in earth's history. Ducks have never introduced organisms as frequently and from as far away as fisherman do now. We are, by far, the dominant force introducing species to distant ecosystems. To a very good approximation, we ARE the only means organisms have of relocating, when you're talking about relocating far enough away from their home ranges become invasive. And, yes, organisms and ecosystems adapt to environmental change, but the occurrence of mass extinctions in the past shows us that this capacity to adapt has its limits. You can dodge a bullet if someone throws it at you, but not if they fire it at you.
Philosophically, if we're going to ask why we should care about this flood of invasive species, we might as well ask why we should care about anything humans do to the environment. If someone wants to clearcut all of Canada to stage the biggest Burning Man event ever, and we get upset about it, are we focusing on negative effects because they impact things we humans value? Yes, we are. Inherently, if we care about anything, it must be something we humans value. What's wrong with that? Isn't preserving what we think is good and destroying what we think is bad the basis of all human morality, really? Jim Crants On Wed, Aug 26, 2009 at 1:49 PM, Bruce Robertson <rober...@msu.edu> wrote: > All, > > I think this argument is analogous to the question of why we should care > about global warming if current climatic variation is well within the > limits > of historical variation. It is parallel to the question of why we should > care about the current pace of species extinction if far more dramatic > extinctions have occurred in the past and will likely occur again. The > central reason we care is because of the rate at which all of these changes > are occurring, which to the best of our knowledge is unprecedented. The > negative impacts of invasives on ecosystem services, biodiversity, etc. are > of a pressing nature primarily because it is unclear what this will mean > for > human health. While this may not be the most important concern for some > scientists, it will be the primary issue for non-scientists. > > Bruce Robertson > Postdoctoral Fellow > W.K. Kellogg Biological Station > Michigan State University > 3700 East Gull Lake Drive > Hickory Corners, MI 49060 > > rober...@msu.edu > brucerobert...@hotmail.com > 269-671-2264 (office) > 206-718-9172 (cell) > 269-671-4485 (FAX) > > > > -----Original Message----- > From: Ecological Society of America: grants, jobs, news > [mailto:ecolo...@listserv.umd.edu] On Behalf Of Kelly Stettner > Sent: Wednesday, August 26, 2009 2:10 PM > To: ECOLOG-L@LISTSERV.UMD.EDU > Subject: Re: [ECOLOG-L] Biological control of invasive species by import of > alien species Re: [APWG] NEWS: Invasive Saltcedar Triggers Lively Debate > > ECOLOGgers all; > > I continue to be fascinated by the theory of invasion biology. Why is it > "bad" when a fly fisherman spreads a microscopic cell of algae to a new > water body, but it's apparently "okay" if a migrating duck spreads it? Why > are we so focused on the human impact of species introductions, as though > we > are the only means organisms have of relocating? I honestly want to talk > about this. I think that people's individual perspectives are what drives > debates such as this. Some people believe that human activity is bad, no > matter what; yet this seems to be short-sighted and narrow-minded. There > seem to be lots of vectors for species movement, from storms to migrating > creatures. > > Also, species adapt and change ~ a population of soapberry bugs, for > instance, adapted its mouthparts over the course of about 40 years to begin > eating the leaves on an introduced goldenrain tree in Florida. Who is to > say that an introduced species won't develop into an important food source > for another species that either it adapts to or that adapts to it? > > Taken on a case-by-case basis, are there benefits to the invasive species > in > question? Are we focusing on negative effects (or, worse, on PRESUMED > negative effects) because they impact things we humans value? > > I get excited by invasion biology theory, because, for me, it raises more > questions than it answers, and many of the questions are about perspective > and values, in addition to those about biological interactions. There is > still so much to observe about invasion biology theory, so much yet to > learn! > > Respectfully, > Kelly Stettner > > > Date: Mon, 24 Aug 2009 22:41:54 -0700 > From: Wayne Tyson <landr...@cox.net> > Subject: Fw: Biological control of invasive species by import of alien > species Re: [APWG] NEWS: Invasive Saltcedar Triggers Lively Debate > > Ecolog: > > Any comments? > > WT > > > ----- Original Message ----- > From: "Wayne Tyson" <landr...@cox.net> > To: <a...@lists.plantconservation.org> > Sent: Monday, August 24, 2009 10:41 PM > Subject: Biological control of invasive species by import of alien species > Re: [APWG] NEWS: Invasive Saltcedar Triggers Lively Debate > > > > APWG: > > > > Much as I would like to see the truly invasive "saltcedars" sent back > > where they came from, we're probably stuck with them--they're just too > > seedy. > > > > Much as I would like to see a savior, even in the form of a bug, the > > true-believers ("Now land managers are adding new biological control > > agents to their arsenal by releasing saltcedar leaf beetles (Diorhabda > > elongata) imported from China and Greece. The small insects strip > > saltcedar of its leaves, while ignoring native vegetation." > > http://www.wssa.net/WSSA/PressRoom/WSSA_SaltCedar.htm ) in > insect-messiahs > > > are at it again. These little buggers may "ignore" native vegetation for > a > > > while, have they been DEMONSTRATED in a peer-reviewed manner with > > replicated experiments to have left every species indigenous to the > > Western Hemisphere to continue to do so? I await the evidence, and I > > should not be expected to chase it down from a press-release. > > > > A more serious question remains to be answered--do we know, to a > > "scientific certainty," that such imported populations cannot and will > not > > > evolve to survive on other prey? > > > > WT > > > > > > ----- Original Message ----- > > From: "Olivia Kwong" <pl...@plantconservation.org> > > To: <a...@lists.plantconservation.org> > > Sent: Monday, August 24, 2009 7:27 AM > > Subject: [APWG] NEWS: Invasive Saltcedar Triggers Lively Debate > > > > > >> http://www.wssa.net/WSSA/PressRoom/WSSA_SaltCedar.htm > >> > >> Invasive Saltcedar Triggers Lively Debats Among Weed Scientists and Land > >> Managers > >> > >> Saltcedar (Tamarix spp.) is an invasive plant that is crowding out > native > >> vegetation and dominating the shorelines of southwestern rivers and > >> streams. But put a room full of weed scientists and land managers > >> together > >> to discuss how to tame the aggressive plant and you'll trigger a lively > >> debate about how -- or even whether -- it should be controlled. > >> > >> See the link above for the full text of the press release. > > > > -- James Crants, PhD Scientist, University of Minnesota Agronomy and Plant Genetics Cell: (734) 474-7478
