From Description to Process

I started out like many ecologists of my generation interested in natural history, particularly listing birds and pinning insects. My interest in biology was a walk in the woods looking for interesting critters and observations. Ecology seemed to be the modern natural history. In University I slowly came to the realization that ecology and science in general were not necessarily about things but processes. Ecology was a study of some six or seven interactions between primarily organisms and the physical environment. This development of my understanding still goes on. Papers, books, field experience, and people influence the changes in your thinking. You try to keep up with advances or you end up doing things that are derivative or in fields that have been abandoned as unproductive, ill-defined, or blind alleys. Here are some of the papers and books that influenced me. We are always encouraged to read classic papers and books in ecology. When I was an undergraduate at the University of Wisconsin, I was encouraged by John Neess to read Eugen Warming's 1909 book entitled Oecology of Plants. Both Henry Cowles and Frederick Clements had been influenced by the 1897 edition of this text in German, which in turn had been a translation of the 1895 Danish text Plantesanfund. I read this to try to understand the origin of the ideas of succession and communities of Cowles and Clements. Since Cowles and Clements would have read the 1896 German edition, I made a comparison between the German and the 1909 English edition to see if there were any differences. The significant differences between the two texts were that Warming had removed most of the Lamarckian-evolution-like statements from the 1909 edition. It seemed to me that the original ideas of succession and communities were, in fact, meant to be seen as a kind of Lamarckian evolution at the community level. The reason it had been removed in the 1909 edition probably was because of the emerging understanding of genetics and natural selection at the individual level. Most ecologists in 1909 had begun to be more discreet about their original ideas with Lamarckian overtones. Certainly this was the case with Henry Cowles. If you read the difference between his Ph.D. thesis in 1898 and the published paper on sand dune succession in the 1899 Botanical Gazette 27: 95–117, 167–202, 281–308, 361–391, you see the toned-down Lamarckian ideas of adaptation caused by the extreme environment in a generation. However, Frederick Clements seemed to persist in his Lamarckian evolution ideas until his death in 1945. In retrospect, I believe that this discovery made me question many of the contemporary ideas in ecology, which seemed to be derived from similar thinking to Warming's, and led to my interest in organization and mechanisms in ecological processes. Saying you wanted to do this is one thing, but doing it turned out to be considerably harder. Two papers had considerable influence on me in this early part of my development. First was a paper by McNaughton and Wolf in 1970 in Science 167:131–139 on how to quantify niches and their organization. In this paper I learned that niche measures (metrics) were not simply descriptions, but were processes of competition and interactions with the physical environment. However, the niche organization seemed to be simply the correlation between the niche measurements with no real governing equations that specified the organization and interactions of the measures. The second paper, “Geomorphology and forest ecology of a mountain region in Central Appalachians” (USGS Professional Paper 347, 1960) was authored by a very well-known geomorphologist, John Hack, and an ecologist, John Goodlett. This paper is considered a classic in geomorphology because Hack showed largely that the geomorphology of the terrain arose from creep and debris flow processes in this unglaciated landscape. Hack stressed that the landscape could be seen as made up of ridgelines, stream courses, and hill slopes. This was one of the early papers that started the research on landscape development by understanding, with scaling relationships, transport processes that dissected the terrain and shaped hill slopes. This, of course, is the template that determines the moisture and nutrient gradients upon which most vegetation is distributed. But the paper also revealed the deficiency of Goodlett's part of the paper which was simply a description of the plants associated with the different parts of the terrain. Goodlett had a compositional approach to describing ecological communities and did not use ecological processes to couple to the geomorphological processes. Consequently, this paper was both exciting and frustrating. Much has been done to rectify this deficiency in geomorphology by linking to biotic and ecological processes, e.g., K. Yoo, R. Amundson, A. M. Heimsath, and W. E. Dietrich (2005) Process-based model linking pocket gopher (Thomomys bottae) activity to sediment transport and soil thickness. Geology 33:917–920, and many others. The book that most excited me early in my career was David M. Gates' 1962 book entitled Energy Exchange in the Biosphere (Harper and Row Publishers, NY). David Gates was by training a physicist, but was the son of a very well-known early ecologist, Frank Gates, at Yale University. In this book I ran into explicit equations of processes made up of transport laws or fluxes of mass, energy, and momentum in ecology. More interestingly, the transport processes were put together into conservation laws or, as ecologists would say, budgets. Since that time, Gates' student Warren Porter has greatly expanded our understanding of the connection between parts of the physical environment and organisms. The follow-on paper in this endeavor was Porter and Gates' 1969 paper “Thermodynamic equilibria of animals with environment” in Ecological Monographs 39:227–244. Since then, Porter has made substantial contributions, particularly taking advantage of fine-scaled digital elevation models and micrometeorological models, e.g., M. Kearney, R. Shine, W. P. Porter (2009) The potential for behavioral thermoregulation to buffer “cold-blooded” animals against climate warming. PNAS 106:3835–3840. The much later book by R.M. Nisbet and W.S.C. Gurney in 1982, Modeling Fluctuating Populations (John Wiley, New York) helped me understand solving fluxes and conservation equations by nonlinear differential equations using up-to-date numerical methods.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.