EFFECTS OF IONIZING RADIATION ON ECOSYSTEMS

Technical Report · Tue Jan 01 04:00:00 EST 1963

DOI:https://doi.org/10.2172/4141086· OSTI ID:4141086

Woodwell, G. M.

The nature of changes that might be induced in ecosystems by ionizing radiation is discussed. Effects of ionizing radiation were studied in two ecosystems at opposite extremes of the temporal sequence characteristic of the Aeciduous Forest: an old field and a near-climax forest. The same general plan of irradiation was used in both systems. A centrally located gamma source produced exposure rates ranging from several thousand r/day within a few meters to about 2 r/day at 130 meters. Highest exposures, continued chronically throughout the winter and spring of 1961-62, caused devastation of both ecosystems, The old-field plant community was intact at daily exposures below about 300 r/day, but the forest suffered loss of the principal plant species contributing to its structure at exposures in excess of 60 r/day. It is evident that there is great variation in radiosensitivity among the plant species of the two ecosystems. The forest ecosystem, considered as a unit, was much more sensitive than the oldfield, the difference spanning a factor of 5-10 in exposure necessary to produce equivalent change in structure. This difference is most likely attributable to differences in stage of succession of the two systems. An hypothesis derived and evaluated from the age/sensitivity relation was that organisms capable of surviving in harsh environments are more radioresistant than organisms of more equable regimes. Factors contributing to the radiosensitivity of various components of the two ecosystems are discussed. (H.M.G.)

• Research Organization: Brookhaven National Lab., Upton, N. Y.
• DOE Contract Number: AT(30-2)-GEN-16
• NSA Number: NSA-18-003476
• OSTI ID: 4141086
• Report Number(s): BNL-6869
• Country of Publication: United States
• Language: English

Related Subjects

AGE
BIOLOGY AND MEDICINE
ENVIRONMENT
FORESTS
GAMMA SOURCES
PLANTS
RADIATION DOSES
RADIATION EFFECTS
RADIOSENSITIVITY
VARIATIONS