TRANSURANIC ELEMENTS IN ARCTIC TUNDRA ECOSYSTEMS 453 



0.7 



0.6 



0.5 



CM 0.4 



E 

 o 



c 



^ 0.3 



0.2 



0.1 



0.07 



0.06 



— 0.05 



— 0.04 - 



CN 



E 



o 



c 



— 0.03 3 



Q- 

 00 

 n 



CN 



0.02 



— 0.01 



1968 



1970 



1972 

 YEAR 



1974 



1976 



Fig. 3 Inventories of ^ ^ *Pu and ^ 3' '^ 4o p^ -^^ ^^i^ Cladonia-Cetraria lichen carpet at 

 Anaktuvuk Pass, Alaska, during the period 1968-1976. 



TABLE 7 " ^ Pu and 2 ' "^ -^ ^ ^ Pu Concentrations in 



Northern Alaskan Lichen Communities 



During 1971-1976 



Alaska; however, that mechanism did not appear to be of major significance in this study, 

 or possibly it was masked by other parameters. 



Correlations between radionuclide isotopic ratios obtained from soil and lichen 

 samples (Table 10) indicated that Unear relationships between ^^^Pu/^^^Pu and 

 2 3 9 p^j^i 3 7 (->g \fjQXQ more constant in Alaskan samples than in Greenland samples and that 

 ratios in lichen samples were more strongly related than ratios in soil samples. There was 



