ISSN:
1573-5117
Keywords:
radionuclides
;
leaf litter
;
microbes
;
detritus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We used decomposition of elm leaf discs as a model system to determine the uptake of 60Co, 85Sr, 95m Tc, 131I and 134Cs from freshwater by detritus and the role of microbes in this process. Two treatments were used: a microbially enhanced (ME) treatment and a microbially inhibited (MI) treatment. The ME treatment involved the addition of a microbial inoculum, collected from a beaver pond, and nutrients (5 mg P l−1 as K2HPO4 and 20 mg N l−1 as (NH4)2SO4) to the water to enhance microbial growth. The MI treatment involved sterlizing the leaf discs and water with gamma irradiation (1.7 Gy s−1 for 4 h) and the addition of a fungicide (100 mg l−1 of nystatin) and bactericide (3.0 mg l−1 each of streptomycin and penicillin) to the water. The 60Co, 95m Tc, 131I and 134Cs concentrations of the elm leaf discs were greater (P〈0.05) in the ME treatment than the MI treatment, whereas the 85Sr concentration was higher in the MI treatment. The increase in the 95m Tc, 131I and 134Cs concentration of leaf discs with time in the ME treatment suggests microbes played an important role in uptake. Uptake of these radionuclides by the leaf discs points to the potential importance of detritus in the accumulation of radionuclides. This could subsequently result in the transfer of radionuclides to higher trophic levels by the detritus-food web.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00020964
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