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Howard Thomas Odum | |
|---|---|
| Born | (1924-09-01)September 1, 1924 |
| Died | September 11, 2002(2002-09-11) (aged 78) |
| Alma mater | University of North Carolina at Chapel Hill;Yale University |
| Known for | Ecological economics,ecological engineering,emergy,maximum power principle, systems ecology |
| Awards | Crafoord Prize(1987) |
| Scientific career | |
| Fields | Zoology,meteorology,ecology andsystems ecology |
Howard Thomas Odum (September 1, 1924 – September 11, 2002), usually cited asH. T. Odum, was an Americanecologist. He is known for his pioneering work onecosystem ecology, and for his provocative proposals for additional laws of thermodynamics, informed by his work ongeneral systems theory.
Odum was the third child ofHoward W. Odum, an Americansociologist, and his wife, Anna Louise (née Kranz) Odum (1888–1965). He was the younger brother ofEugene Odum. Their father "encouraged his sons to go into science and to develop new techniques to contribute tosocial progress". Howard learned his early scientific lessons about (a) birds from his brother, (b) fish and thephilosophy of biology while working after school formarine zoologist Robert Coker, and (c) electrical circuits fromThe Boy Electrician (1929) byAlfred Powell Morgan.[1]
Howard Thomas studiedbiology at theUniversity of North Carolina at Chapel Hill, where he published his first paper while still an undergraduate. His education was interrupted for three years by hisWorld War II service with theArmy Air Force inPuerto Rico and thePanama Canal Zone, where he worked as a tropicalmeteorologist. After the war, he returned to the University of North Carolina and completed hisB.S. in zoology (Phi Beta Kappa) in 1947.
In 1947, Odum married Virginia Wood, and they later had two children. After Wood's death in 1973, he married Elisabeth C. Odum (who had four children from her previous marriage) in 1974. Odum's advice on how to manage a blended family wasto be sure to keep talking[clarify]; Elisabeth's was to hold back on discipline and new rules.[2]
In 1950, Odum earned his Ph.D. in zoology atYale University, under the guidance ofG. Evelyn Hutchinson. His dissertation was titledThe Biogeochemistry of Strontium: With Discussion on the Ecological Integration of Elements, which brought him into the emerging field ofsystems ecology. He made a meteorological "analysis of the global circulation of strontium, [and] anticipated in the late 1940s the view of the earth as one greatecosystem".[3]
While at Yale, Howard began his lifelong collaborations with his brother Eugene. In 1953, they published the first English-language textbook on systems ecology,Fundamentals of Ecology. Howard wrote the chapter onenergetics, which introduced hisenergy circuit language. They continued to collaborate in research as well as writing for the rest of their lives. For Howard, his energy systems language (which he called "energese") was itself a collaborative tool.[4]
From 1956 to 1963, Odum worked as the director of theMarine Institute of the University of Texas. During this time, he became aware of the interplay of ecological-energetic and economic forces. He taught in the Department of Zoology at the University of North Carolina at Chapel Hill, and was one of the professors in the new curriculum of Marine Sciences until 1970.
That year he moved to the University of Florida, where he taught in the Environmental Engineering Sciences Department, founded and directed the Center for Environmental Policy, and founded the university's Center for Wetlands in 1973; it was the first center of its kind in the world that is still in operation today. Odum continued this work for 26 years until his retirement in 1996.
In the 1960s and 1970s, Odum was also chairman of theInternational Biological Program's Tropical Biome planning committee. He was supported by large contracts with theUnited States Atomic Energy Commission, resulting in participation by nearly 100 scientists, who conducted radiation studies of a tropical rainforest.[5] His featured project at University of Florida in the 1970s was on recycling treated sewage into cypress swamps. This was one of the first projects to explore the now widespread approach of using wetlands as water quality improvement ecosystems. This is one of his most important contributions to the beginnings of the field of ecological engineering.
In his last years, Odum was Graduate Research Professor Emeritus and Director of the Center for Environmental Policy.[6] He was an avidbirdwatcher in both his professional and personal life.
The Ecological Society awarded Odum its Mercer Award to recognize his contributions to the study of the coral reef onEniwetok Atoll.[7] Odum also received the French Prix de Vie, and theCrafoord Prize of the Royal Swedish Academy of Science, considered the Nobel equivalent for bioscience.Charles A. S. Hall described Odum as one of the most innovative and important thinkers of the time.[8] Hall noted that Odum, either alone or with his brother Eugene, received essentially all international prizes awarded to ecologists. The only higher education institute to award honorary degrees to both Odum brothers was Ohio State University, which honored Howard in 1995 and Euene in 1999.
Odum's contributions to ecosystems ecology have been recognized by theMars Society, who named their experimental station the "H. T. Odum Greenhouse" at the suggestion of his former student Patrick Kangas. Kangas and his student, David Blersch, made significant contributions to the design of the waste water recycling system on the station.
Odum's students have furthered his work at institutions around the world, most notably Mark Brown at theUniversity of Florida, David Tilley and Patrick Kangas at theUniversity of Maryland, Daniel Campbell at theUnited States Environmental Protection Agency, Enrique Ortega at theUNICAMP inBrazil, and Sergio Ulgiati at theUniversity of Siena. Work done at these institutions continues to evolve and propagate the Odum's concept ofemergy. His former studentsBill Mitsch,Robert Costanza, andKarin Limburg are some former students who have been recognized internationally for their contributions to ecological engineering, ecological economics, ecosystem science, wetland ecology, estuarine ecology, ecological modeling, and related fields.
Odum left a large legacy in many fields associated with ecology, systems, and energetics.[9] He studied ecosystems all over the world, and pioneered the study of several areas, some of which are now distinct fields of research. According to Hall (1995, p.ix), Odum published one of the first significant papers in each of the following areas:
Odum's contributions to these and other areas are summarized below.
Odum also wrote on radiation ecology,systems ecology, unified science, and themicrocosm. He was one of the first to discuss the use of ecosystems for life-support function in space travel.[10] Some have suggested that Odum was technocratic in orientation,[11] while others believe that he sided with those calling for "new values".
In his 1950 Ph.D. thesis, Odum gave a novel definition of ecology as the study of large entities (ecosystems) at the "natural level of integration".[12] In the traditional role of an ecologist, one of Odum's doctoral aims was to recognize and classify large cyclic entities (ecosystems). However, another one of his aims was to make predictive generalizations about ecosystems, such as the whole world for example. For Odum, as a large entity, the world constituted a revolving cycle with highstability. It was the presence of stability, which Odum believed enabled him to talk about theteleology of suchsystems. While he was writing his thesis, Odum felt that the principle ofnatural selection was more thanempirical, because it had a teleological, "stability over time" component. As an ecologist interested in the behavior and function of large entities over time, Odum sought to give a more general statement of natural selection so that it was equally applicable to large entities as it was to small entities traditionally studied in biology.[13]
Odum also wanted to extend the scope and generality of natural selection to include large entities such as the world. This extension relied on the definition of anentity as a combination of properties that have some stability with time.[14][15] Odum's approach was motivated byLotka's idea's on the energetics of evolution.
Odum used an analog of electrical energy networks to model the energy flow pathways of ecosystems.[16] His analog electrical models had a significant role in the development of his approach to systems and have been recognized as one of the earliest instances of systems ecology.[17]
Electron flow in the electrical network represented the flow of material (e.g. carbon) in the ecosystem, charge in a capacitor was analogous to storage of a material, and the model was scaled to the ecosystem of interest by adjusting the size of electrical component.[18]
In the 1950s Odum introduced his electrical circuit diagrams of ecosystems to theEcological Society of America. He claimed that energy was driven through ecological systems by an "ecoforce" analogous to the role of voltage in electrical circuits.[19]
Odum developed an analogue ofOhm's Law which aimed to be a representation of energy flows through ecosystems.[20] In terms of steady state thermodynamics, Ohm's Law can be considered a special case of a more general flux law, where the flux () "is proportional to the driving thermodynamic force () with conductivity ()", or.[21]
Kangas states that Odum concluded that as thermodynamic systems, ecosystems should also obey theforce-flux law, and that Ohm's law and passive electrical analog circuits can be used to simulate ecosystems.[22] In this simulation, Odum attempted to derive an ecological analog for electrical voltage. Voltage, or driving force, is related to thebiomass in pounds per acre. The analogous concept required is the biomass activity, that is, the thermodynamic thrust, which may be linear. Exactly what this is in nature is still uncertain, as it is a new concept.
Such a consideration led Odum to ask two important methodological questions:
For example, what is a diode in nature? One needs a diode to allow biomass to accumulate after the voltage of the sun has gone down, or else the circuit reverses. Higher organisms like fish are diodes.
Silver Springs is a common type of spring-fed stream inFlorida with a constant temperature and chemical composition.[citation needed] The study Odum conducted here was the first complete analysis of a naturalecosystem.[3]
Odum started with an overall model and in his early work used a diagramming methodology very similar to theSankey diagrams used in chemical process engineering.[24]
Starting from that overall model, Odum "mapped in detail all the flow routes to and from the stream. He measured the energy input of sun and rain, and of all organic matter - even those of the bread the tourists threw to the ducks and fish - and then measured the energy that gradually left the spring. In this way he was able to establish the stream's energy budget."[3]
Around 1955 Odum directed studies intoradioecology,[25] which included the effects of radiation on the tropical rainforest in El Verde, Puerto Rico (Odum and Pidgeon), and the coral reefs and ocean ecology at Eniwetok atoll.[26] The Odum brothers were approached by the Atomic Energy Commission to undertake a detailed study of the atoll after nuclear testing; the atoll was sufficiently radioactive that upon their arrival the Odums were able to produce anautoradiographic image of a coral head by placing it on photographic paper.[27] These studies were early applications of energy concepts to ecological systems, and explored the implications of the laws of thermodynamics when used in these new settings.[28]
From this view,biogeochemical cycles are driven byradiant energy.[29] Odum expressed the balance between energy input and output as the ratio of production (P) torespiration (R):P-R. He classified water bodies based on theirP-R ratios, which separatedautotrophic fromheterotrophic ecosystems: "[Odum's] measurements of flowing water metabolism were measurements of whole systems. Odum was measuring the community as a system, not adding up the metabolism of the components as Lindeman and many others had done".[30] This reasoning appears to have followed that of Odum's doctoral supervisor, G. E. Hutchinson, who thought that if a community were an organism then it must have a form of metabolism.[31] However, Golley notes that Odum attempted to go beyond the reporting of mere ratios, a move which resulted in the first serious disagreement in systems energetics.
In a controversial move, Odum and Richard Pinkerton (at the time physicist at the University of Florida) were motivated byAlfred J. Lotka's articles on the energetics of evolution, and subsequently proposed the theory that natural systems tend to operate at an efficiency that produces themaximum power output, not the maximum efficiency.[32]
By the end of the 1960s, Odum's electronic circuit ecological simulation models were replaced by a more general set of energy symbols. When combined to form systems diagrams, these symbols were considered by Odum and others to be the language of the macroscope which could portray generalized patterns of energy flow: "Describing such patterns and reducing ecosystem complexities to flows of energy, Odum believed, would permit discovery of general ecosystem principles."[33] Some have attempted to link it with theuniversal scientific language projects which have appeared throughout the history of natural philosophy.[34][35]
Kitching claimed that the language was a direct result of working with analogue computers, and reflected an electrical engineer's approach to the problem of system representation: "Because of its electrical analogy, the Odum system is relatively easy to turn into mathematical equations ... If one is building a model of energy flow then certainly the Odum system should be given serious consideration... "[36]
In the 1990s in the latter part of his career, Odum andDavid M. Scienceman developed the idea of emergy as a specific use of the termembodied energy. Some consider the concept of "emergy", sometimes briefly defined as "energy memory", as one of Odum's more significant contributions, but the concept is neither free from controversy nor without its critics. Odum looked at natural systems as being formed by the use of various forms of energy in the past: "emergy is a measure of energy used in the past and thus is different from a measure of energy now. The unit of emergy (past available energy use) is the emjoule, as distinguished from joules used for available energy remaining now." This was conceived as a principle ofmaximum empower, which might explain theevolution of self-organising open systems. However, the principle has only been demonstrated in a few experiments[37] and is not widely recognized in the scientific community.
For J. B. Hagen, the maximum power principle, and the stability principle could be easily translated into the language ofhomeostasis andcybernetics systems. Hagen claims that the feedback loops in ecosystems were, for Odum, analogous to the kinds of feedback loops diagrammed in electronic circuits and cybernetic systems. This approach represented the migration of cybernetic ideas into ecology and led to the formulation of systems ecology. In Odum's work these concepts form part of what Hagen called an, "ambitious and idiosyncratic attempt to create a universal science of systems".[38]
Hagen identified the systems, thinking of Odum as a form of holistic thinking,[39] who contrasted the holistic thinking of systems science with reductionistic microscopic thinking, and used the termmacroscope to refer to the holistic view, which was a kind of "detail eliminator" allowing a simple diagram to be created.[40]
Odum was a pioneer in his use of small closed and open ecosystems in classroom teaching, which were often constructed from fish tanks or bottles and have been calledmicrocosms.[41] His microcosm studies influenced the design ofBiosphere 2.[42]
Ecological economics is an active field betweeneconomics and ecology with annual conferences, international societies, and an international journal. From 1956 to 1963, Odum worked as Director of the Marine Institute of the University of Texas. During this time Odum became aware of the interplay of ecological-energetic and economic forces. He therefore funded the research into the use of conventional economic approaches to quantify dollar values of ecological resources for recreational, treatment and other uses. This research calculated the potential value of primary production per bay surface area.[43]
For Hall[44] the importance of Odum's work came through his integration of systems, ecology, and energy with economics, together with Odum's view that economics can be evaluated on objective terms such as energy rather than on a subjective, willingness to pay basis.
Ecological engineering is an emerging field of study between ecology andengineering concerned with the designing, monitoring and constructing ofecosystems. The term ecological engineering was first coined by Odum in 1962,[45] before he worked at the University of Florida. Ecological engineering, he wrote, is "those cases where the energy supplied by man is small relative to the natural sources but sufficient to produce large effects in the resulting patterns and processes."[46] Ecological engineering as a practical field was developed by his former graduate studentBill Mitsch, who started and continues to edit the standard journal in the field and helped to start both international and U.S. societies devoted to ecological engineering, and has written two textbooks on the subject[45][47] One of Odum's last papers was his assessment of ecological engineering that was published in the journal Ecological Engineering in 2003, a year after Odum died.[48]
In 1991, Odum was elected the 30th president of the International Society for the Systems Sciences, formerly named the International Society for General Systems Research. He presented many papers on the general systems theory at its annual conferences, and edited the last published General Systems Yearbook. The second, revised edition of his major lifework was retitledEcological and General Systems: An Introduction to Systems Ecology (1994). Some of his energy models and simulations contained general systems components. Odum has been described as a "technocratic optimist",[49] and his approach was significantly influenced by his father, who was also an advocate of viewing the social world through the various lenses of physical science.[50] Within the processes on earth, Odum (1989) believed humans play a central role: he said that the "human is the biosphere's programmatic and pragmatic information processor for maximum performance".
Odum wrote around 15 books and 300 papers, and aFestschrift volume (Maximum Power: The Ideas and Applications of H. T. Odum, 1995) was published in honor of his work.[51]
Odum was also honored by the journalEcological Engineering[52] for his contributions to the field of ecological engineering and general ecology in recognition of his 70th birthday. The publication included over 25 letters from distinguished scientists from all over the world including Mitsch (lead editorial), John Allen, Robert Ulanowitcz, Robert Beyers, Ariel Lugo, Marth Gilliland, Sandra Brown, Ramon Margalef,Paul Risser, Eugene Odum, Kathy Ewel, Kenneth Watt, Pat Kangas, Sven Jørgensen, Bob Knight, Rusong Wang, John Teal, Frank Golley,AnnMari and Bengt-Owe Jansson, Joan Browder, Carl Folke, Richard Wiegert,Scott Nixon, Gene Turner, John Todd, and James Zuchetto.
