314 



REINERS 



TABLE 4 (Continued) 



*Based on Whittaker and Likens' estimates of land area occupied by ecosystem types, 40 

 plus averages of total detritus input by representative ecosystems tabulated by Rodin and 

 Bazilevich. 49 Carbon has been assumed to be one-half of litter dry weight. 



tProduction value from Whittaker and Likens. 40 The 50% detritus value is author's own 

 estimate. 



may also be high for savannas in which there are only two examples and a large 

 area of land surface. 



Comparison of Detritus-Input Estimates 



All four approximations represent different aspects of flux through 

 terrestrial detritus pools. The first represents carbon input that will be released 

 to the atmosphere by decomposition in a world without man. This total is 85% 

 of Whittaker and Likens' estimate of annual terrestrial primary production. 



The second and third approximations represent total carbon return from 

 plants minus some respiratory losses through grazing from principally steady- 

 state systems. Both totals exceed Whittaker and Likens' estimate 40 of terrestrial 

 production (64 and 62 vs. 54 X 10 9 tons C/year). 



The fourth approximation most closely represents carbon input that will be 

 returned to the atmosphere by decomposition alone under current conditions of 

 land use. This input is 69% of Whittaker and Likens' primary production 



40 



estimate. 



