|SREL Reprint #0339|
Structure and Function of Hardwood Litter and Soil
Subsystem after Chronic Gamma Irradiation.
T. Cowley, J. W. Martin and David C. Coleman
The microfungal populations in six experimental and two control plots
were studied before and after irradiation for 113 days with a 9200-Ci 137Cs
source. Experimental plots received
cumulative dosages ranging from 5 million to 4 thousand rads.
The number of detectable propagules was reduced sharply in the three
plots receiving the highest dosages. Recovery
was slow, since reduced populations in the soil were still in evidence 13 months
after termination of irradiation.
Species composition of soil and litter populations was also seriously
altered. Before irradiation,
populations in all plots were predictably similar. However, immediately after irradiation, an abnormally high
percentage of both soil and litter species isolated from the most heavily
irradiated sites was darkly pigmented, and populations displayed little
similarity to those in control and lightly irradiated sites.
Some lightly pigmented or nonpigmented species soon became reestablished.
However, similarities between heavily irradiated plots and nonirradiated
plots remained low and had not returned to preirradiation levels in the soil by
13 months after irradiation. Apparent
recovery of litter populations was more rapid than for soil populations in
regard to both number of detectable propagules and species composition.
SREL Reprint #0339
Cowley, G.T., J.W. Martin, and D.C. Coleman. 1971.
Structure and function of hardwood litter and soil subsystems
after chronic gamma irradiation. II. Microfungi. p. 1229-1236.
In Third National Symposium on Radioecology, edited by D.J.
Nelson. ORNL CONF 710501 P2. Oak Ridge, TN.