Successful Ecologists Biography Schedule Organismal Ecology, William Murdoch - Tim Assal group - Oct 7 Population Ecology, Thomas W. Schoener – Adam Dillon group - Oct 14 Community Ecology, Joseph Wright – Jeremy Sueltenfuss group - Oct 21 Ecosystems Ecology, Dave Schimel – Kevin Wilcox group - Oct 28 Nov 9, 11 Dan Simberloff – Jared Stabach group Unknown Ecosystem Ecologist – Ed Gage group William Schlesinger – Nell Campbell group Gene Likens – Ben Gannon group The classic Clements vs. Gleason debate… None of you agreed with all aspects of their arguments. I'm glad that I read these two papers/book excerpts because I think that the way these two theories have been presented to me in the past has been greatly simplified, tending towards the extreme points from either theory. I don't take either of these works to be entire representations of their ideas. But, which way to you lean? As Clementsians or Gleasonians? Why? Clements vs. Gleason – a contrast in style… Clements was an early modeler, and Gleason was an early perfectionist. Ecological patterns, about which we construct theories, are only interesting if they are repeated. They may be repeated in space or in time, and they may be repeated from species to species. A pattern which has all of these kinds of repetition is of special interest because of its generality, and yet these very general events are only seen by ecologists with rather blurred vision. The very sharp-sighted always find discrepancies and are able to say that there is no generality, only a spectrum of special cases. R.H. MacArthur (1968). The Theory of the Niche. I think what I found most interesting about these articles was just the style that they were written in and how different that style is from modern papers. Neither paper provides any concrete evidence. Clements makes sweeping generalizations about the "universal application" of his conception of succession. It's difficult to think of any finding in modern ecology that one could claim as universally applicable. Gleason also makes his assertions based largely on thought- experiments and anecdotal evidence. He provides no actual data, and many of his examples do not even specify a specific location (i.e. "a lake"). I thought it was particularly entertaining when he writes "I have personal records...and can assure you..." He doesn't even specify what system his personal records are for. It's interesting how much things have changed. Both differed markedly from their predecessors in their quantitative approach to community ecology…(species lists, verbal descriptions…) The Clementsian influence… The quadrat, too, was a term (and tool) invented by Clements. It is a basic tool for ecologists, even today. It is impossible to tally up all the plants in a forest or grassland. Some sort of sampling regime is necessary. The quadrat allows that. It is essentially a square in which all of the vegetation is identified and numerically tabulated in some way. Its size, often one meter by one meter, is set to what is appropriate in the judgment of the investigator. Similarly, how many and where the quadrats are placed is a matter for some statistical sophistication. Statistics, in turn, can warm a scientist’s heart. They represent rigor…. Magnificent Failure Frank Egler and the Greening of American Ecology An Epistolary Biography William Drtschilo http://www.atonforest.org/index2.htm I do think this offers a very interesting example of the power of paradigms to limit ideas. It seems to me that Gleason’s ideas were not received simple because most ecologists at the time were just not ready for it. They dismissed it and only after some change of perspective could it be rediscovered. Gleason, Henry Allan (United States 1882- 1975) Gleason’s ideas did not go over well with other ecologists. They called him an "outlaw" and a "good man, gone wrong." According to him, critics "pulverized" his ideas when they were first presented in 1917. Gleason republished them, essentially unchanged, in 1927 and 1939. Critics did not take issue with Gleason’s data, his methods, or his logic. They simply ignored him. They just could not accept his conclusion. Plant communities were real to them, whether they believed in Clements’s superorganisms or not. There were such things as oak-hickory forests, prairies, and swamps. Before 1949, almost no ecology texts cited any of Gleason’s three articles, even though each had been published in highly visible journals. Frank Egler (who also took issue with Clements) sarcastically enjoyed sharing a rather ignoble distinction with Gleason. "Gleason and I used to vie with each other for being the most unquoted ecologists extant," according to Egler, "and we always said we would write ecology texts, if for no better reason than that we could quote ourselves.“ However, to Gleason, being ignored by ecologists had to be less painful than to Egler. Some eighty-five percent of Gleason’s publications were in botany, in which he was quite respected. I really loved the discussion among Gleason, Emerson and MacGinitie, Steiger and Spieth at the end of Gleason's piece. I also enjoyed the often off-topic discussion section in the back of Gleason's paper. I liked that the field was small enough that the reader is expected to know who these contributors are and the fact that the discussion was published despite the fact the discussion was at times totally off-topic. The discussion section at the end is interesting. Gleason's response to Emerson (Discussion/Paragraph 8) clears up Gleason's objective of the paper, in that each particular grouping of plan can not found duplicated elsewhere. Gleason's response to Steiger's first comment is interesting, as he agrees that a classification system of communities is necessary for effective communication between people. “Contributed Paper Sessions” at meetings… How do we do this today? “Balance of Nature” vs. “Non-equilibrium view” In Chemistry – what is the difference between a compound and a mixture? Q. Are natural ecosystems/communities more like compounds or mixtures? • The properties of compounds are different from those of their constituent elements. This is one of the main criteria for distinguishing a compound from a mixture. What is the term for this phenomenon? An Emergent Property of a system. Emergent properties in ecological systems can be defined by three main characteristics: (1) they do not exist on the level of isolated subsystems; (2) they emerge on higher levels as a result of interactions of the subsystems; (3) new properties appear at one level of a system and are not deducible from the observation of the lower levels units or compartments of the system. - Nielsen and Muller (2000) Swarming behavior in animals, social behavior in colonial species are oft cited examples of emergent properties… …the authors are engaging in a debate which has gone on since the days of Gleason and Clements: Is the community (or ecosystem) an entity in the real world, or is it an abstraction which exists only in the minds of ecologists'? The concept of emergent properties appears to provide ecologists with an operational method for deciding these questions. If these ecological entities have an existence in the real world,… then they should exhibit emergent properties in addition to the collective properties derived from their component units. Salt 1979 (Am. Nat.) Do communities have emergent properties? Or simply collective properties? Clement's ideas still are very widely practiced, if not in all the minute details. I think this reflects a need to be able to simplify patterns at broader spatial scales. Whether it is a land manager's ability to map vegetation for management purposes, or a wetland regulator's need to define boundaries on the landscape for regulatory purposes, there would seem to be clear value in a conceptual framework for higher order classification of landscape - here the Gleasonian perspective fails to provide much of practical use. Clements: I found this deterministic viewpoint very appealing. If I was a prospective ecology grad student in 1916, I probably would have begged to become his student. Not that I think his ideas are absolutely correct or that I much care for his writing style, but I am easily taken by grand unifying explanations of seemingly disparate natural phenomena. If Clements is deterministic – what is Gleason? Who would be the “better” natural resource manager? How would their management goals/styles differ?