Radiation ecology pdf

But systems ecology has many other connotations as well, as appear for example in the definition of two other system ecologists: 'Systems ecology is a robust hybrid of engi- neering, mathematics, operations research, cybernetics, and ecology. A few years after systems ecology came into existence, systems ecological projects con- stituted the bulk of the American contribution to the International Biologi- cal Programme , and a separate programme for systems ecology was set up at the National Science Foundation that equalled or surpassed the one existing NSF programme for the rest of ecology.?

The ecological pro- grammes at the University of Georgia and Oak Ridge National Laboratory were among its most important beneficiaries.

One might say that the history of these two institutions coincide to a large extent with the early history of systems ecology, i. US ecology around mid-century In the ecological programmes at the UGa and ORNL occupied periph- eral positions within the discipline of ecology, and not only because they were newly built.

The UGa was a small land-grant university of modest 4 G. Auerbach and N. Milleman, eds. Van Dyne, 'Reflections and projections', in Grasslands, systems analysis and man A. Breymeyer and Van Dyne, eds. Shugart and R. O'Neill, eds. Kwa, 'Representations of nature mediating between ecology and science policy: The case of the International Biological Programme', Social studies of science, 17, pp.

Radiation ecology and systems ecology [ 2 15 ] reputation and without a long-standing programme in ecology. ORNL was primarily a physics laboratory and its endeavors into other realms were of marginal interest by necessity.

A second shared feature is that they were strongly limited to applied ecological problems, and this seemed enough to prevent them from taking a place in mainstream ecology.

Both the UGa and ORNL were entirely or almost entirely dependent on funding by the Atomic Energy Commission, and this draws attention to the extraordinary fact that, prior to , the AEC was the most important patron of American ecology. The early work was as solidly de- scriptive as the work being done at the intellectual centers of ecology such as the University of Chicago and Yale University. The effects of radiation on the environment opened, as it were, a new territory for pre-existing ecologi- cal approaches and practices.

Its practitioners regarded radiation ecology as a subdiscipline of ecology in its own right. In most American universities, if not all, ecology was and still is usually represented by one or more faculty members at Departments of Biology, Zoology, Botany, Forestry, etc. They had widely diverging backgrounds, reflecting the many sources that feed into ecology: zoology and botany, mathematical and field methods, taxonomic and physiological approaches.

Furthermore, different foci can be discerned such as the familiar division between terrestrial and aquatic ecology, and, most importantly, the defini- tion of the object of ecology as the population groups of individuals of any one kind of organism , the community all the populations occupying a given area or the 'ecosystem', i.

The University of Chicago was among the most important. Its tradition in ecology dates from the beginning of the century, and includes ecologists such as Henry Cowles, his student Victor Shelford and W.

Apart from Allee, the group S The definitions are taken from E. Odum, Fundamentals ofecology, 2nd ed. Tansley, 'The use and abuse of vegetational concepts and terms', Ecology, 16, pp. Worster, Nature's economy: A history ofecological ideas. Cambridge, , pp. Allee and A. Emerson', Journal of the history of biology, , 2 I, pp. The group at Chicago the ecologists at the Botany Department not included was rela- tively large compared to most universities.

Eugene Odum and the Oak Ridge ecologist Stanley Auerbach received at least part of their education from Chicago or Chicago-related ecologists. At the end of the s, Yale occupied a similar position. Evelyn Hutchinson, who was at Yale from until his retirement in , is perhaps the single most influential American ecologist of this century, through his own work and that of his graduate students. A high proportion of these students rank among the most important ecologists in the US.

At the time, three of his former graduate students were on the staff at Yale, too, and they were sometimes designated as the 'Hutchinson School'. According to one of them, Gordon Riley, it was 'a loosely knit, informal group' that later on disbanded. Much of the research was done in the context of education, and both Hutchinson and the Chicago ecologists wrote widely used textbooks. Thus their importance for American ecology far exceeded their numerical size, an importance which can also be inferred from the fact that for instance, the Chicago ecologists Emerson and Park held key positions such as the editorship of Ecology.

I I As indicated by the enumeration of its various sources, ecology is an extremely heterogeneous field, with many subfields developing quite inde- pendently of one another. It has been commented recently that this situation probably precludes for ever any theoretical unification.

I2 To the extent that the most highly esteemed work in ecology was and to some extent still is descriptive, this hardly mattered. The journal Ecology refused theoretical papers with few exceptions until , when the Board of Editors changed its policy.

I3 Traditional virtues such as a good background in taxonomy thus remained strong prerequisites for academic recognition. So much for appearances during the S. By the late s the ORNL and the UGa had gained national prominence as centers of ecological re- search, and the factors that helped them to win that position were the very same factors that initially seemed to constrain them to the marginal position of the peculiar form of applied ecology known as radiation ecology.

Seen 10 G. Riley, 'Introduction', Limnology and oceanography, 16, pp. Egerton, ed. Radiation ecology and systems ecology [2 I 7] retrospectively, the Atomic Energy Commission provided a context in which elements of what was later to emerge as systems ecology could be combined.

The problems and perspectives of radiation ecology were broad- ened in a specific way so as to give rise to systems ecology. In this way, Eugene Odum and Stanley Auerbach, typical naturalists and outdoors ecologists lacking a mathematical background, were the founders of a subdiscipline of ecology that was strongly mathematical. The role of the AEC and the institutional context it provided to the nascent science of radiation ecology can hardly be overestimated.

In various ways, the particular setting of radiation ecology helped to select and shape its research directions. The importance of the problems of health directed the attention of the AEC-hired ecologists at an early stage to the food chain. Radiation ecology, which was initially developed as research on the direct effects of radiation on organisms and their environment, thus provided important methodologies for the study of the food chain and led ultimately to systems ecology.

Another element pertinent to the development of systems ecology were certain mathematical techniques. Their possibilities and constraints, in par- ticular with respect to computers, shaped some of the essential presupposi- tions of systems ecology. Computers became available to ecologists during the s. They soon raised high expectations, not least with respect to the possibility of a scientific management of ecosystems through the production of simulation models of ecosystems.

The institutional setting of radiation ecology, within AEC-directed pro- grammes, provided an important impetus to fuse these elements together. Yet the development from radiation ecology to systems ecology was by no means wholly determined by the institutional context provided by the AEC.

Such a view would leave little room for the innovative actions of several of the key actors whose work is described here. Rather we could say, somewhat paradoxically, that this particular institutional context was instru- mental in creating an atmosphere in which a confidence to bring about a 'new ecology' could flourish.

What I hope to demonstrate in the following pages is that the practical orientation of radiation ecology was retained in systems ecology on a more 14 Interview with Eugene Odum 11 October Radioactive isotopes had caused environmental problems that were addressed by radiation ecology in their specificity. Systems ecology transformed this practical orientation into a generalized managerial ap- proach to the natural environment.

The first programmes of radioecology After the end of World War Il, the Atomic Energy Commission refused during many years to take problems of radioactive waste and fallout seri- ously!

The con- tamination of the Marshall Islands, their inhabitants, and in particular of a Japanese fishing boat, caused world wide concern and it forced the AEC to engage in biological research on a relatively large scale.

By the end of the S, 'radioecology' was being practiced at several National Laboratories and at up to fifty universi- ties, sponsored by the AEC. Almost everywhere, radioecological research was directed to the ecological effects of specific isotopes, or the dose- response relationships between levels of radiation and organisms. Yet, radioecological studies had preceded Bikini, even though there had been no central policy of engaging in ecological research.

If ecolo- gists were in effect hired or given an opportunity to do research, it was the 15 S. Both focussed on dose-effect relationships. See Stannard, op. The first radiation studies were done at this university in , on tne effects of radiation on salmon and trout. These studies were largely physiological. From on, environmental surveys were undertaken in the Pacific and Columbia River, now also by scientists hired on the staff of General Electric, tne operator of Hanford N.

See Radioecology, op. Foster, and J. Davis, 'The accumulation of radioactive substances in aquatic forms', Pro- ceedings of the International Conference on the Peaceful Uses of Atomic Energy, 13, pp. Radiation ecology and systems ecology [ 2 19] result of ad hoc decisions by the directors of the individual National Labo- ratories, sometimes responding only to initiatives taken by lower officials.

The programmes at Hanford and Oak Ridge both found their origin in the toxic waste problems that the atomic installations had created for themselves: at Hanford significant amounts of radioactive isotopes were being released into the Columbia river; at Oak Ridge a small lake, the White Oak Lake, had been turned into a heavily contaminated waste depository during World War n.

It ranked among the most contaminated areas in the world. There was no National Laboratory involved here and the research was com- missioned to the University of Georgia. The ecologists at Hanford achieved the first real breakthrough in radiation ecology. At the International Conference for the Peaceful Uses of Atomic Energy held in Geneva in , two papers reported 21 that several species accumulated radioactive isotopes in surprisingly high quantities.

Even if under normal operating conditions no spills occurred, radioisotopes were formed through neutron activation of solids present in the cooling water. Moreover, the exchange surfaces became activated and radioactive material was released through corrosion.

Radioactive levels of the effluent into the Columbia River, however, did not exceed the then permissible levels. But there was a potential environmental problem, since the water of the Colum- bia River was used as drinking water, and there were also salmon fisheries.

Foster and Davis, op. Hanson and H. Kornberg, 'Radioactivity in terrestrial animals near an atomic energy site', Proceedings of the International Conference on Peaceful Uses of Atomic Energy, 13, pp.

Z2 The discovery of this concentration phenomenon along the food chain seems to have preceded the discovery of the very similar phenomenon of concentration of pesticides such as DOT and ODD. That DOT was passed on from one level of the food chain to another was noted as early as in However, the fact that these chemicals were concentrated in, for instance, the fatty tissues of birds, and that this was the cause of bird deaths, was not noted until the late fifties and published in the early sixties.

See R. Rudd, Pesticides and the living landscape, Madison, Wisconsin, , pp. Foster and J. Davis found high concentration factors of this isotope in various forms of aquatic life, e. Apparently the levels were still such that no effect on the reproductive capability of the waterfowl was noted.

The idea to use radionuclides in an experimental manner would be taken up by the ecologists at Oak Ridge and at Savannah River. But the team of Hanford and the neighbouring University of Washington at Seattle re- mained confined to doing environmental surveys. A possible reason is that the Hanford ecologists were financed from operating rather than research funds, the Hanford management conducted by General Electric for the AEC on a contract basis apparently unwilling to change this.

Thus the Hanford ecologists remained oriented toward the needs of their plant, whereas the ecologists at Oak Ridge increasingly broadened their scope while striving for recognition by the academic ecological community. Davis et al. Davis and R. Foster, 'Bioaccumulation of radioactive isotopes through aquatic food chains', Ecology, 39, pp.

Radiation ecology and systems ecology [ 22 1 ] At his retirement in , Odum was still at the Department. He was also Director of the Institute of Ecology at the University of Georgia, with about faculty members, graduate students, and 50 support staff. The Insti- tute has a world-wide reputation as a center of ecosystem ecology.

Since Od urn can be considered its chief architect, it seems justified to start the history of the development of ecology at the University of Georgia with a look at Odum's career. Eugene Pleasants Odum was born on 17 September He wanted to pursue his graduate studies with Victor Shelford at the University of Illinois at ChampaignY Charles Kendeigh, a former student and collaborator ofShelford, became the advisor of his doctoral thesis, on geographical and physiological aspects of the ecol- ogy of birds.

He came to know Shelford well, and, along with sharing his naturalist's enthusiasm, sympathised also with Shelford's intellectual project, which was to combine plant and animal ecol- ogy in order to understand the functioning of ecosystems or biomes, as they were called in his terminology.

Shelford and Frederic Clements tried to accomplish this goal in their joint publication of , Bio-ecologyY In the eyes of contemporaries, the book remained largely classificatory, however, and was by many, including Odum, considered a failure. Through him Odum was asked to give a seminar. At the time Raymond Lindeman's paper on trophic-dynamics was one of the most talked-about topics.

Odum acquainted himself also with Hutchinson's writings, much of which reflected the same interest. Eugene Od urn's inter- ests were clearly similar to those of Hutchinson's students who were prima- rily concerned with the movement of nutrients and biogeochemical cycles.

Odum's Fundamentals of ecology, published in , can be seen as an attempt to integrate these various intellectual influences, around the central concept of the ecosystem.

The book was written primarily to secure ecology a place among the so-called core curricula of his own Department at the 0 E. Odum, Fundamentals of ecology, 1St edn. Odum, interview. Hutchinson in his review of Bio-ecology, Ecology, 21, The next year, it went through two more printings. It has continued to be re- printed, as well as translated into many languages. A new edition appeared in , followed by a third edition in For several generations of students, 'the Odum' was the textbook.

Trophic-dynamics is essentially a reinterpreta- tion of the feeding relationships and the cycling of elements such as phos- phorus and nitrogen that they involve existing in a given ecosystem. Food chains, in terms of the species involved, can be extremely complex.

I , in which it is shown that the number of animals in small size classes is much greater than the number of animals in larger size classes that may feed upon them , and these in turn significantly greater than the still bigger animals that may prey upon these, and so onY Lindeman performed a reduction operation on these pyramids of numbers, transforming them into pyramids of biomass corresponding to discrete trophic levels producers, primary and secondary consumers, and so on.

Thus 'the principle of the Eltonian Pyramid was redefined in terms of productivity. Odum dismissed the original Eltonian pyramid of numbers out of hand to entirely embrace the pyramids of biomass and energy Fig. Odum, 'The emergence of ecology as an integrative discipline', Science, t , , 9. Burgess, 'United States', in Handbook of contemporary developments in wodd ecology 0. Kormondy and J. McCormick, eds.

Orians, 'A diversity of textbooks: Ecology comes of age', Science, 18 I, pp. See D. Elton, Animal ecology, London, See also Cox, op. Lindeman, 'The trophic-dynamic aspect of ecology', Ecology, [ 23, pp. Lindeman attributed this to Hutchinson. See also R. Cook, 'Raymond Lindeman and the trophic-dynamic concept in ecology', Science, , pp. Hutchinson, 'Addendum' [to Lindeman's paper], Ecology, 23, p.

The pyramid of biomass is of more fundamental interest. Radiation ecology and systems ecology.. I: Elconian pyramid of numbers according CO animal size as drawn by Eliot Williams, 'An ecological study of the floor fauna of the Panama rain forest', Bulletin of the Chicago Academy of Sciences, 6, pp.

Odum, Fundamentals of ecology, 1st edn. Odum reflected Hutchinson's influence in other respects as well. Clements and Shelford had regarded communities or ecosystems as supraorganisms. Odum's thought is informed by the metaphor of the homeostatic machine, by cyberneticsY Hutchinson had most clearly expressed his thoughts about the cybernetic nature of ecosystems in his paper 'Circular causal systems in ecology',4 2 where he undertook to demonstrate the validity of Norbert Wiener's cyber- netic conceptions for the study of ecosystems.

It is, therefore, usual to find in natural p. Elton was understandably not very happy about these remarks, as he made he clear in his review of Odum; see Cox, op. Chunglin Kwa circular systems various mechanisms acting to damp oscillations He now conferred on these cycles the property of being regulatory mechanisms, ensuring the stability of the ecological systems for which they were relevant.

Odum, Hutchinson's student, would complete his PhD thesis in on the biogeochemical cycling of strontium. But the book conveyed much more than a naturalist's enthusiasm. We may see this textbook as a careful assimilation of the major new trends in the ecology of the S. As such, it was not only a powerful textbook, but became the manifesto of a movement to modernize research as well. This summarizes its two achieve- ments: I the book motivated the research programme at the UGa and also at ORNL to which Odum was asked to be a consultant; and 2 it created a larger audience for the ecosystem approach, ecosystem management and preservation, albeit on a programmaticallevel.

The second edition of incorporated many of the radio-ecological results, and articulated the sys- tems approach to ecosystems more clearly. The 'stability principle' One of the principles of ecosystems that Odum proposed tentatively, and that literally inspired several generations of students of ecology, was the relationship between diversity and stability of ecosystems. The research on food chains at Savannah River, and the tagging of plants and animals that it involved, would also serve to make possible investigations on this relation- 43 Hurchinson, op.

Odum, 'The biogeochemistry of strontium', PhD thesis, Yale University, ; idem, 'The stability of the world strontium cycle', Science, I , pp. Taylor, 'Technocratic optimism, H. Odum and the partial transformation of ecological metaphor after World War 11', Journal of the history of biology, 21, pp. Odum would call the strontium cycling an ecosystem itself, a hypostasis that is apparently lacking with either Hutchinson or Eugene Odum.

Radiation ecology and systems ecology [ ] ship. In a word: the more species present, the more possible negative feed backs will be established. However, by elucidating food webs in all their intricacy, in a quantitative way, one would be able to 'deal with diversity in terms of network variables rather than merely in terms of number of species and individuals present' ' Although Odum clearly included in his relation- ship population interactions such as predation and competition, its outlook was definitively synchronic and functional, rather than evolutionary and long-term.

Odum's relationship between diversity and stability provided a hypo- thetical mechanism to what he had named 'the stability principle', the idea that, obeying the second law of thermodynamics, every natural system would evolve to a state of stable adjustment.

Odum set out to solve on a 'systems level', a problem that had been posed within the ecology of populations. The central question had been: how are populations regulated? Wiegert, E. Odum, and J.

SchneJl, 'Forb-arthropod food chains in a one-year experimental field', Ecology, 48, pp. Margalef's earliest theoretical work on the subject is 'La teoria de la informacion en ecologia', Memorias de la Real Academia de Ciencias y Artes, Barcelona, 32, pp.

This reference in Spanish is cited several times by the Odum brothers. Odum, Ecology, New York, In the 2nd edn of he expressed his reservation in the relationship even more strongly. Coli ins, 'Evolutionary ecology and the use of natural selection in ecological theory', Journal ofthe history ofbiology, 19, pp.

Kingsland, Modeling nature, Chicago, , pp. In one camp, the importance was defended of density dependent mechanisms in the regulation of population size, i. This would make factors such as competition and predation the most relevant. Others argued for the predominant importance of density independent factors, primarily climatic factors that would check population growth and size irrespective of its then prevalent values.

Thus the question can also be put as: is the abundance of a certain population of animals checked by depletion of resources and by other animals or by the weather? As one of the adherants of the latter position observed, the disciples of the density-dependent posi- tion 'vastly oumumber ed ' those of other theories, which were 'rejected by common consent',57 American ecologists were strongly involved in this in- ternational controversy, and usually took the 'orthodox' position.

Before the controversy really developed, Allee and his collaborators had held it. Smith and L. Slobodkin, in a joint paper with Nelson Hairston, expressed their conviction that 'the hypothesis of control by the weather leads to false or untenable implications', and they upheld the theory 54 A.

Nicholson, 'The self-adjustment of populations to change', Cold Spring Harbor symposia on quantitative biology, 22, pp. Birch, 'The role of weather in determining the distribution and abundance of animals', ibid. Milne, 'Theories of natural control of insect populations', Cold Spring Harbor symposia, 22, pp. He proposed a to 11 -year cycle, corresponding to the sunspot cycle. We might infer from this a single causal chain, leading from the sunspots to vegetational growth, and further to the prey species and finally to the predator species.

On this account, fluctuations in the number of predators would be caused by fluctuations in the number of prey, but not vice versa see Cox, op. However, when Elton had aquainted himself with the idea of the generation of oscillations through internal causes, he adopted it see Kingsland, op.

Allee et al. Radiation ecology and systems ecology of resource-limitation in the 'classical density-dependent fashion' 9 The paper was written in an authoritative fashion. It received much favorable attention and may have contributed to the affirmation of orthodoxy, at least for a time. It was argued some time later by ecologist Gordon Orians that this debate revolved not so much about an issue to be decided solely on empirical grounds, but depended rather upon one's perspective: an evolutionary approach would incline more to the density-dependent, a functional one more to the density-independent perspective.

At the heart of the controversy were the different concepts of causation implied in these two perspectives. The dominance of the 'density-depend- ent' position could then be interpreted as the dominance of the evolutionary perspective in ecology, with the corresponding relative unimportance of a functionally oriented, synchronic approach.

Eugene Odum put the density-dependent and density-independent mechanisms in conjunction. The latter, he proposed, could 'cause a shifting of upper asymptotic or carrying capacity levels'. An ecosystem thus appears as a machine, full of stabilizing mechanisms and driven by the climate. Succession studies at Savannah River In it became clear to the AEC that the new atomic weapons plant to be built on the Savannah River in South Carolina would become an even bigger operation than was first thought.

Costs for the entire project were estimated at more than a billion dollars. The whole area along the river below Augusta, Georgia, would be transformed.

Hairston, F. Smith, and L. Slobodkin, 'Community structure, population control, and competition', American naturalist, [ , 94, pp.

See McImosh, op. Hewlett and F. Duncan, Atomic shield, ! In the spring of , the Uni- versities of South Carolina and Georgia were invited to submit proposals for 'pre-installation' inventories. Georgia and South Carolina were asked to divide up inventories of terrestrial flora and fauna and the general ecology of the area among themselves. Odum would congratulate himself ever after for the way he made use of that original offer.

The University of South Carolina 'wasted' the grant by using it for the summer salaries of their own staff, and dropped out of the project at the termination of the initial contract period. Odum decided it was solely to be spent on graduate students who could be given research assistantships. The University of Georgia had approved a PhD programme in biology a few years before. Odum already had one graduate student, and he could thus considerably enlarge the graduate programme through the arrangement with the AEC.

Odum established a temporary field laboratory in one of the country houses that were left vacant. The major study that Odum assigned to his students was to follow the development of old field succession or secondary succession. Since crop fields of various kinds and on various soils were left bare, a gradual but ongoing change of vegetation with corresponding fauna would take place - theoretically until a so-called climax stage would be reached.

Six hundred fields were designated study areas, and these were exempted from reforestation with pine. To map the successional changes, in vegetation as well as in bird populations, training as a naturalist was a prerequisite. Odum 6j E. Odum, 'Brief history of the University of Georgia's ecological studies at the Savan- nah River Plant prior to establishment of the On-Site Savannah River Ecology Laboratory, ', unpublished manuscript, ,22 p. Kuenzler graduated at the University of Florida, where H.

Odum was Assistant Professor. In , a fourth graduate student, Roben Pearson, a bird biologist, was added to this first 'crew'. He had taken his Master's degree with Kendeigh at the University of Illinois. Radiation ecology and systems ecology [] had selected his students partly on this basis.

After three years, they were replaced by a new team of five graduate students, who continued the meas- urements. Previous studies of secondary succession had focussed completely on species change in vegetation.

The results as reported were admittedly incom- plete, and were confined to measurements of the productivity of the stand- ing crop through seven consecutive years.

Its main finding was that following the abandonment of agriculture, a relatively quick steady state in terms of primary production was achieved, though the process of change in species composition and species dominance had by no means come to an end.

Radioecological studies at Savannah River From on, the DBM increased the budgets for ecological research at the Savannah River site significantly. Odum hired Robert A. Norris, a former student of his to be a full time 'resident' at the Savannah River research site. The AEC also assigned Odum a more professional laboratory. Support at the AEC headquarters in Washington for ecological research continued to increase. John Wolfe, head of the new Environmental Sciences Branch, was very supportive of the ecological research at Savannah River.

He was keen on developing radiation ecology programmes at universities, and, in com- parison, seems to have been more supportive of Odum's programme than of Auerbach's at Oak Ridge. In , the AEC approved, and the next year the laboratory was made available.? Odum, 'Organic production and turnover in old field succession', Ecology, 41, pp. Oosting during the S, cited in Odum, op. See also E.

Odum, 'The strategy of ecosystem development', Science, , pp. But they had no expertise in these methods, and the first grant did not give them room to develop it.

Norris and a graduate student started the first radiation effects studies in In , the first radioactive tracer experiments were carried out, initiating a second major research line on food chains. He was by then already thoroughly familiar with the Oak Ridge programme, having been asked to serve on its advisory board by Stanley Auerbach. He spent another four months at the Hanford Works. Odum, in comparison, was much more free to make his own research choices and steered radio-ecological methods in the direction of food chain analysis earlier than Auerbach did.

They had to sort out for themselves many problems related to the radioactive tagging of plants and animals, even though other researchers had preceded them. Hutchinson had simply administered a sample of radiophosphorus to a lake by dumping a small quantity into the water, and with the help of Geiger counters and a graduate student traced its uptake by the vegetation and plankton. Tagging techniques proved most useful by injecting the stems of plants with P-p.

Measuring of the uptake of radioisotopes was performed with Geiger counters. By plotting radioactive uptake against time, Odum and his col- leagues were able to show the place that various insects occupied in the food chain, such as the predatory activities of certain spiders who fed on 74 Odum, op.

Hutchinson and V. Bowen, 'A direct demonstration of the phosphorus cycle in a small lake', Proceedings of the National Academy of Sciences, 33, pp. According to McImosh, op. Radiation ecology and systems ecology [ ] leafhoppers and beetles which in turn obtained their radioactivity from plants. The application of radioactive tags to plants was standard- ized in , and a new method, applicable on a larger scale, was introduced in In , on the occasion of the International Conference of Peaceful Uses of Atomic Energy, he had pointed out that studies of the effects of radiation should not be directed merely to individual organisms.

The impact on the 'total' system should also be assayed, and tolerance levels for entire ecological systems determined. In order to reach that goal, he distinguished three approaches to finding 'methods for the measurement of total community structure and function': measurement of productivity, trophic structure and species structure.

Occasionally, Odum was rather quick to claim the existence of homeostatic mechanisms. Odum and E. Kuenzler, 'Experimental isolation of food chains in an old-field ecosystem with the use of phosphorus- 32', in Radioecology: Proceedings of the first national symposium on radioecology held at Colorado State University, September , V.

Schultz and A. Klement, eds. Wiegert and R. Lindeborg, 'A "stem well" method of introducing radioisotopes into plants to study food chains', Ecology, 45, pp. Monk, 'Radioisotope tagging through seed soaking', Bulletin of the Georgian Academy of Sciences, 25, pp.

Rose, C. Monk and R. Wiegert, 'Accumulation and transfer of 45Ca by the biota of a tagged cornfield,', in Proceedings of the second national symposium on radioecology, May 17, D. Nelson and F. Evans, eds. Crossley, 'Movement and accumulation of radiostrontium and radiocesium in insects', in Radioecology, op.

Odum and F. Golley, 'Radioactive tracers as an aid to the measurement of energy flow at the population level in nature', Radioecology, op. Yet it is interesting to note that research at the University of Georgia diverged in a number of directions, not least toward physiological studies of individual organisms and populations.

In a sense, these originated from an extension of the research on energy transmittal from one trophic level to another. The physiological studies are still being pursued.

One relatively early example of these studies, carried out in the late S, was the investi- gation of excretion rates of various radioactive tracers. The tracers were examined with regard to their appropriateness for the measurement of meta- bolic rates of animals such as arthropods and fish.

It was now possible to quantify the extent to which the energy contained in food consumed by the species in a particular trophic level was 'lost' through processes such as respiration, so that only a limited amount of the energy was assimilated and in turn became available for higher trophic levels.

The effects of various environmental factors on these physiological processes were also exam- ined. It should be pointed out that Odum had a very liberal attitude with regard to the research that his fellow workers originated.

His style of directing the programme consisted, in his own words, in pointing to some opportunities and leaving the rest to the newly hired person. But Odum more than made up for this divergence by his way of conferring his enthusiasm for discovering the principles on which the functioning of ecosystems were founded.

In a way, his style of directing the programme was that of a charismatic role model rather than that of a manager-entrepreneur. On the institutional level the creation of the Institute of Ecology pre- vented Odum's activities from falling victim to the vicissitudes of the univer- sity's departmental organisation. Odum and his colleagues with faculty positions at the University of Georgia lobbied successfully for an Institute, independent from any department. The following year, slows down, another may speed up in a compensatory manner.

A researcher with a way of thinking different from Odum might nave ascribed this pnenomenon to the law of great numbers operating in an aggregate, rather than assuming some system property.

Radiation ecology and systems ecology [] the name was changed to Institute of Ecology. In the University provided funds to employ an executive director and secretary. In the same year, the Institute obtained an NIH training grant in ecology, which was used to attract new graduate students and to hire more members of the staff.

Odum and his fellow ecologists could bring in a new person without the necessary approval of one of the departments. Results Citations. Citation Type. Has PDF. Publication Type. More Filters. Ecology and the origin of species. Conservation: Losing Biodiversity by Reverse Speciation. Current Biology. Integrating ecology and genetics in speciation research. The origin of species is one of the most complex processes in evolution, and unraveling its mechanisms requires integrating across key biological disciplines.

Ecological Speciation's stated goal is … Expand. Ecology: Speciation affects ecosystems. Evidence that speciation and adaptive radiation can change the properties of an ecosystem is a reminder of the pressing need to integrate ecosystems science and evolutionary biology. View 1 excerpt, cites background. Ecological constraints on diversification in a model adaptive radiation. The role of competition in adaptive radiation: a field study on sequentially ovipositing host-specific seed predators.

We propose an alternative model to the host-shifting model of sympatric speciation in plant-insect systems. The role of competition in driving ecological adaptive radiation was evaluated in a se … Expand.

View 2 excerpts, cites background. Phylogenetic Insights on Adaptive Radiation. Ecological Opportunity and Adaptive Radiation. Highly Influenced.