When H.T. Odum returned to the University of Florida in 1970, the systems approach that had developed through studies of ecosystems began to expand rapidly. Ecological systems remained important, but the boundaries of the systems being studied increasingly included human activities, economies, technologies, land use, and environmental management. At the same time, Odum began building a research and teaching program in which systems concepts could develop through the interaction of students, faculty, research projects, modeling, and continuing discussion.<\/p>\n\n\n\n
The Systems Ecology program in the Department of Environmental Engineering Sciences became an important setting for this work. Graduate students worked together in shared space, developing systems diagrams, models, and analyses while exchanging ideas across individual research projects. Weekly Systems Seminars provided a particularly important forum. Students presented developing research rather than simply completed results, and extended discussion often led to new questions, calculations, models, and interpretations. Systems Ecology was therefore developing not only through publications, but through a continuing process of research, discussion, modeling, and revision.<\/p>\n\n\n\n
One of the first major research projects of this period concerned the effects of herbicides used during the war in South Vietnam. The original problem focused on the effects of herbicides on mangrove ecosystems, but the boundaries of the investigation expanded. Mangrove destruction was part of a larger system involving military activity, agriculture, forests, people, resources, and the economy of a country at war. Models were developed at several scales, including a systems model of South Vietnam itself. The resulting work eventually appeared as Models of Herbicide Mangroves and War in Vietnam<\/em>, reflecting how an initially ecological question had expanded into an analysis of interacting ecological and human systems.<\/p>\n\n\n\n A second major research effort began in 1973 with the Cypress Wetlands Project<\/strong>, supported jointly by the National Science Foundation through its Research Applied to National Needs program and by the Rockefeller Foundation through its Quality of the Environment program. The project investigated whether treated municipal wastewater could be recycled through cypress wetlands, allowing ecological processes to contribute to water treatment, nutrient recycling, and water conservation. Research encompassed hydrology, soils, vegetation, animals, nutrients, heavy metals, microorganisms, and viruses, examining both the processing of wastewater and the response of the wetland ecosystem. The project brought faculty and graduate students from different disciplines together around a common experimental system and helped establish the Center for Wetlands at the University of Florida. It provided another setting in which understanding how an ecosystem functioned was directly connected with understanding how ecological processes might be coupled with human activities. Early results were reported in Recycling Treated Sewage through Cypress Wetlands in Florida<\/em>. <\/p>\n\n\n\n At an even larger scale, the controversy surrounding the proposed Miami Dade jetport in the Big Cypress Swamp created a very different systems problem. Construction began in 1968 only a few miles north of Everglades National Park. Concern soon extended beyond the direct effects of the airport to the roads, drainage, housing, industry, and other development expected to accompany it. A 1969 Department of the Interior investigation headed by Luna Leopold concluded that the associated development posed a serious threat to the South Florida ecosystem and Everglades National Park.<\/p>\n\n\n\n The controversy led to a much broader scientific investigation. Numerous studies examined different components of the South Florida environment and their relationship to Everglades National Park. Scientists from many disciplines generated a large body of information, but the separate studies had to be synthesized to understand the consequences of the proposed jetport and its associated development for the Everglades system. Odum and his group were brought into the effort to provide that synthesis. Models for Planning and Research for the South Florida Environmental Study <\/em>appeared in 1971, and the work eventually developed into the much larger Carrying Capacity for Man and Nature in South Florida<\/em>, completed in 1975.<\/p>\n\n\n\n The South Florida work required ecosystems, water, land use, agriculture, urban development, resources, economic activity, and people to be represented as interacting components of a regional system. Historical aerial photographs and other records were also used to reconstruct changes in land use and land cover, placing the contemporary regional system within a longer history of development. Systems diagrams and models provided a means of bringing otherwise separate bodies of information together and examining their relationships at the scale of the region.<\/p>\n\n\n\n These projects also exposed a fundamental difficulty in systems analysis. The different forms of energy driving a region could not simply be added. Sunlight, water, fuels, electricity, environmental processes, and economic activity differed greatly in their ability to perform work within the system. During the South Florida research, different forms of energy were converted to Fossil Fuel Work Equivalents<\/strong>, providing an early means of placing otherwise different contributions on a comparable basis. The effort to understand and quantify differences in energy quality would become increasingly important in the development of Energy Analysis and, eventually, emergy.<\/p>\n\n\n\n The research projects of this period were therefore more than applications of an already established Systems Ecology. They were among the principal means through which it developed. Systems diagrams came first. Constructing the diagram required the system boundary, major components, sources, storages, pathways, and interactions to be identified. The diagram exposed what was known and, equally important, what was not known. It raised questions and helped determine what needed to be measured. Measurements and calculations then provided values for the pathways and relationships represented in the diagram, while models required assumptions to be made explicit and allowed their consequences to be explored. Results returned to the diagrams, models, seminars, and discussions for further examination and revision. Ideas were repeatedly proposed, tested, modified, and sometimes abandoned. Concepts that later appeared as established parts of Systems Ecology emerged through this iterative interaction among diagramming, measurement, calculation, modeling, and discussion.<\/p>\n\n\n\n At the same time, the systems language itself was becoming more general. Environment, Power and Society<\/em>, published in 1971, extended the systems perspective explicitly into relationships among environment, resources, society, and economic activity. Its diagrams ranged from ecosystems and agriculture to economic and political systems. In 1972 Odum formalized much of the developing methodology in An Energy Circuit Language for Ecological and Social Systems: Its Physical Basis<\/em>, explicitly extending the language across ecological and human systems. The methods that had grown from studies of ecosystems were becoming a general framework for investigating systems in which human and environmental processes were inseparably coupled.<\/p>\n\n\n\n Milestones and Key References<\/strong><\/p>\n\n\n\n 1970 \u2014 Systems Ecology Program established at the University of Florida<\/strong><\/p>\n\n\n\n Odum established the Systems Ecology program in the Department of Environmental Engineering Sciences, creating a setting in which graduate research, systems modeling, funded research projects, and weekly Systems Seminars continually interacted. The program became an important center for the development of Systems Ecology and the ideas and methods that followed.<\/p>\n\n\n\n 1971 \u2014 Systems thinking extended to environment and society<\/strong> Odum, H.T. 1971. Environment, Power and Society<\/em>. John Wiley, NY. 336 pp.<\/p>\n\n\n\n 1971- 1974 \u2014 Vietnam Project<\/strong> <\/p>\n\n\n\n Research initiated to investigate the effects of wartime herbicide use on mangrove ecosystems expanded its boundaries from an ecological problem to a coupled ecological, social, economic, and wartime system. <\/p>\n\n\n\n Odum, H.T., M. Sell, M. Brown, J. Zucchetto, C. Swallows, J. Browder, T. Ahlstrom and L. Peterson. 1974. Models of herbicide mangroves and war in Vietnam. The effects of herbicides in South Vietnam, Part B: working papers<\/em>. National Academy of Sciences. 302 pp.<\/p>\n\n\n\n 1971\u20131975 \u2014 South Florida as a regional system<\/strong> Lugo, A.E., S.C. Snedaker, S. Bayley and H.T. Odum. 1971. Models for Planning and Research for the South Florida Environmental Study<\/em>. Report on Contract 14-10-9-900-363, National Park Service, U.S. Dept. of the Interior and Center for Aquatic Sciences, Univ. of Florida. 141 pp.<\/p>\n\n\n\n Odum, H.T. and M.T. Brown, eds. 1975. Carrying Capacity for Man and Nature in South Florida. <\/em> Final report to National Park Service, U.S. Dept. of Interior and State of Florida, Division of State Planning. Center for Wetlands, Univ. of Florida. 886 pp.<\/p>\n\n\n\n
Environment, Power and Society<\/em> extended the developing systems framework beyond ecosystems to resources, economics, society, and human organization. The book also marked a major expansion in Odum’s use of energy circuit diagrams. <\/p>\n\n\n\n
Research initiated in response to the environmental consequences of the proposed jetport and its associated development. The research resulted in a synthesis of many disciplinary studies into a regional systems analysis and the development of energy quality and Fossil Fuel Work Equivalents.<\/p>\n\n\n\n