A Model to Evaluate the Impact of Cyclically Recurring Hazards on Selected Populations

  • John Calkins
Part of the NATO Conference Series book series (NATOCS, volume 7)


It has been observed that solar ultraviolet radiation, particularly the portion of wavelengths below 320 nm (the UV-B), is quite lethal for a variety of microorganisms (Harm 1969, Gameson and Saxon 1967, Resnick 1970, Calkins 1974). In addition to the lethal action, the short wavelength component of solar UV demonstrates a considerable potential for delaying the growth of irradiated organisms (Jagger 1975, Calkins 1975). Growth delay obviously reduces the competitive ability of organisms in the natural environment. Various authors have proposed that the lethal (Harm 1969, Gameson and Saxon 1967) and the growth delaying action (Jagger 1975, Calkins 1974) of solar UV are significant ecological factors. It is, however, quite difficult to translate the reasonable but intuitive feeling that solar radiation has an important impact on various ecosystems into quantitative measurements of the amount of injury for assessment of such an ecological action. It is especially important at present to make quantitative determinations of the ecological effects of solar UV radiation because there is growing awareness that human activities may modify the global environment and could result in disastrous injuries to critical ecosystems.


Maximum Tolerable Dose Growth Delay Coliform Bacterium Marine Diatom Solar Ultraviolet Radiation 
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Copyright information

© Plenum Press, New York 1982

Authors and Affiliations

  • John Calkins
    • 1
    • 2
  1. 1.Department of Radiation MedicineUniversity of KentuckyLexingtonUSA
  2. 2.School of Biological SciencesUniversity of KentuckyLexingtonUSA

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