A quick and simplistic response: There are very few "natural" ecosystems because nearly all have been anthropogenically altered. Even a Pacific Northwest forest wilderness has been altered by past overgrazing of its meadows, fire suppression, and introduction of exotic species. Perhaps the mid-Antarctic or the deep ocean has escaped anthropogenic alteration, but I would have a hard time identifying other systems where this is the case. So maybe it's not about whether or not a system has been altered by humans, maybe its more about how much of an alteration has occurred before we no longer consider it "natural."
Warren W. Aney Senior Wildlife Ecologist Tigard, Oregon -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[email protected]]on Behalf Of Wayne Tyson Sent: Saturday, February 28, 2009 15:26 To: [email protected] Subject: Re: [ECOLOG-L] Ecosystems and agronomy Definition of agroecosystem Re: [ECOLO G-L] The Role of Ecos Kristin and Ecolog: I hope I have not been misunderstood. I do not object to the study of species interactions and habitat conditions in agriculture; I am concerned, however, that the distinction between "natural" ecosystems and anthropogenic alterations of them. The distinction I believe useful, if not critical, is that between a "system" that is DEPENDENT upon external influence and displacement/destruction of indigenous ecosystems (e.g., plowing, planting and maintenance of monocultures and introduction of other organisms that did not co-evolve with them as a TREND. I certainly do recognize the value of the study of such phenomena, particularly when its trend is in the direction of preservation of genetic diversity, not its reduction. I do seriously question the habit of terming anthropogenic assemblages of species "ecosystems," as they are quite distinguishable from "natural" ecosystems. I think scientists in general, and ecologists in particular, have a duty to do no harm, to pass knowledge along in a clear and directly honest fashion to the population at large. I think the distinction is CRUCIAL. If I am wrong in this, I look forward to being corrected with persuasive logic and evidence. WT ----- Original Message ----- From: "Kristin Mercer" <[email protected]> To: <[email protected]> Sent: Wednesday, February 04, 2009 2:35 PM Subject: Re: [ECOLOG-L] Ecosystems and agronomy Definition of agroecosystem Re: [ECOLO G-L] The Role of Ecos > Dear Wayne, > > The definition you received from another ecologger is a good > one. Given your concern about the term agroecosystems, I think the > best way to understand agroecosystems is to see that they are > connected to, but distinct from, the natural or urban or managed > ecosystems around them. Just as savana may be surrounded by forests, > agroecosystems can exist within a matrix of other kinds of > ecosystems. So although parts of agroecology does study the effects > of agriculture on natural ecosystems, it is certainly not limited to > that perspectives. Studies of weed community dynamics, insect pest > population genetics, nutrient cycling under various management > practices (i.e., studies within the agroecosystem) all fall within > agroecology. > > I would think that few agroecologists see themselves as promoting the > "business as usual" agriculture or "destruction and degredation". In > fact, within the context of needing to grow food on our landscapes, I > think most ESA members would be cheering agroecologists along. In > that vein, the agroecology section of ESA is alive and well. > > Cheers, > Kristin > > > At 06:03 PM 2/3/2009, Wayne Tyson wrote: >>Ecolog: >> >>I received the following off-list response to my enquiry about the >>definition of agroecosystem: >> >>"Agroecosystems are best understood as the unit of study of >>agroecology, which looks at agricultural production systems in terms >>of ecosystem prosperities: e.g. stability, resilience, disturbance >>regime, stocks and flows of nutrients and energy, and niche >>dynamics, etc. Look to Miguel Altieri for a thorough, scientifically >>based discussion of agroecology. Additionally, the wikipedia article >>on agroecology is more substantial and less vague than the one agroecosystems." >> >>I agree with the respondent that "the wikipedia article on >>agroecology is more substantial and less vague than the one >>agroecosystems." Agro-ecology seems somewhat less of an oxymoron >>than agro-ecosystem. Certainly the study of ecosystems and the >>effects of agriculture upon them is legitimate, but it seems to me >>that the use of the term agro-ecosystem implies that the two are >>somehow interdependent or that agriculture is just a part of the >>ecosystem in which it stands. On the one hand, there seem to be two >>opposite impulses at work within the field, one trying to minimize >>the adverse effects of agriculture upon ecosystems and recognize the >>positive effects of ecosystem preservation, conservation, and >>restoration upon their integration with agricultural practice, and >>on the other the various hyphenated "dash" ecosystem terms seem to >>be, intentionally or unintentionally, a front for business as usual >>and a cover for continued expediency as the primary driver of >>ecosystem destruction and degradation. >> >>Am I missing something here, or should ESA perhaps take a scientific >>position on this issue? If so, "ecologgers" might be a good place to >>begin drafting a more unified, or at least less vague definition? >>Even if they just buy into one or more of the existing ones? Or >>throw them all out? >> >>I should imagine that the ecological economists would be "all over" >>this. Are they? >> >>WT > > Kristin Mercer > Assistant Professor > The Ohio State University > Department of Horticulture and Crop Science > 310F Kottman Hall > 2021 Coffey Road > Columbus, OH 43210 > > Office: (614) 247-6394 > Lab: (614) 247-8626 (341 Kottman) > Fax: (614) 292-7162 > > email: [email protected] ---------------------------------------------------------------------------- ---- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database: 270.11.1/1960 - Release Date: 02/19/09 10:48:00
