TERRESTRIAL DETRITUS AND THE CARBON CYCLE 



323 



50 



10 



50 



10 



1500 



Human 

 population 



Detritus pool 



(b) 



10.0 



0.0 



1700 



1900 



2100 



TIME, years 



Fig. 1 (a) Human-population increase up to a limit of 10 billion with 

 proportional increase in decay rate of detritus pools; turnover time is 

 calculated as pool size/input, (b) Change in detritus input in proportion to 

 human-population increase; change in output is calculated as a product of 

 decay rate and pool size; change in detritus-pool size is calculated as the 

 difference between input and output. 



