Re: Ecology Logic Fuzzy* I was never much good at statistics, to put it mildly (two or three courses put a real drag on my GPA and my intuition).
It seems (intuitively) to me that Bayes and Zadaeh both had good ideas that were aimed at the direction of the best fit POSSIBLE, the former seeming to be more elegantly conforming to hypotheses, the latter embracing uncertainty more certainly--maybe. I am grateful for those laboring in the fields of numerical research; without them observers of the interplay of organisms and their environments might tumble down some warren of fantasy and never to return. Yet, looking in the looking-glass never hurt anybody. On the other hand, it seems that the Sword of Certainty, especially in the form of irrelevant decimal points and other attempts to reduce complex and constantly-changing phenomena to quantities that fit neat boxes carved out for them, hangs threateningly over jiggly and evasive phenomena, threatening to freeze it all in place for all time. Still, provided analyses don't stray too far from the actual data manipulated and are not treated as license for (ironically?) unbridled conjecture amongst self-ordained emperors, those numbers can open up insights as well as interfere with them. I have no firm answer for this conundrum. What are the Great Questions in ecology? What are the answers? What answers have actually changed rather than just been re-clothed or bumped off the mountain in, say, the last century or so? What new questions have been added? WT *Sorry, Bill, in a lame attempt to please everybody I didn't fuss with the subject line (what a wuss, eh?), I was going to ask Eric off-list but the reply-to-all button didn't have his email address in it, so I just deleted one of the apparently duplicate list addresses--gad, this is getting complicated! Back to square one . . . ----- Original Message ----- From: "William Silvert" <[email protected]> To: <[email protected]> Sent: Thursday, August 06, 2009 8:13 AM Subject: [ECOLOG-L] Fuzzy Logic in Ecology I missed Wayne's posting since the subject line had nothing to do with fuzzy logic, and although I know that I will raise a chorus of outrage I am changing the subject line. Quite a few papers on fuzzy logic aplications have been published, many in Ecological Modelling (including a couple of my own). I also have some PowerPoint presentations on my website, http://ciencia.silvert.org, and there are many in related fields such as soil science. I think that one of my first efforts was in niche theory, obviously the "multi-dimensional manifold" that Hutchinson defined must have fuzzy boundaries. Unfortunately a lot of work in the field seems to consist of lots of mathematics with little biological content. I like to think in terms of fuzzy rules like IF the weather is warm AND nutrient levels are high THEN there is a serious risk of bottom anoxia (which is similar to a rule composed for aquaculture siting) but many authors seem more concerned with whether the membership function is triangular or trapezoidal. As with any new field or approach, fuzzy ecology is experiencing growing pains. There was an international conference on the topic in Kiel many years ago, perhaps 15, but progress has been slow. Bill Silvert ----- Original Message ----- From: "Jonathan Nelson" <[email protected]> To: <[email protected]> Sent: Thursday, August 06, 2009 3:00 PM Subject: Re: [ECOLOG-L] Bayesian analysis in population ecology workshop, early registration deadline 10 August 2009 > On Wed, Aug 5, 2009 at 7:25 PM, Wayne Tyson <[email protected]> wrote: >> >> Do you know if anyone has investigated the possible application of fuzzy >> logic theory to ecology/population ecology and why or why not? > > Re the first part of the question: > > Results 1 - 10 of about 12,300 for fuzzy logic ecology. > http://scholar.google.com/scholar?q=fuzzy%20logic%20ecology&oe=utf-8 > > The results include the 2002 overview paper by Regan, Colyvan, Burgman > (Ecological Applications, 12(2), 2002, pp. 618–628) as the 3rd result, > available as PDF. I had not seen this before but I'll be reading it > this evening, as it looks fascinating: > > "Abstract. Uncertainty is pervasive in ecology where the difficulties > of dealing with > sources of uncertainty are exacerbated by variation in the system > itself. Attempts at clas- > sifying uncertainty in ecology have, for the most part, focused > exclusively on epistemic > uncertainty. In this paper we classify uncertainty into two main > categories: epistemic un- > certainty (uncertainty in determinate facts) and linguistic > uncertainty (uncertainty in lan- > guage). We provide a classification of sources of uncertainty under the > two main categories > and demonstrate how each impacts on applications in ecology and > conservation biology. > In particular, we demonstrate the importance of recognizing the effect > of linguistic uncer- > tainty, in addition to epistemic uncertainty, in ecological > applications. The significance to > ecology and conservation biology of developing a clear understanding > of the various types > of uncertainty, how they arise and how they might best be dealt with > is highlighted. Finally, > we discuss the various general strategies for dealing with each type > of uncertainty and offer > suggestions for treating compounding uncertainty from a range of sources." > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database: 270.13.44/2283 - Release Date: 08/05/09 05:57:00
