378 



REINERS 



TABLE 1 



ORGANIC CARBON AND ITS RATES OF PRODUCTION* 



(Living and Dead, Excluding Incipient Fossil Deposits) 



*Resistant humus and other material with decay rates of 0.001 per year or 

 less have been omitted. Production is "net primary production," i.e., 

 production from photosynthesis minus plant respiration; it represents the 

 yield to animals and decomposers. 



tThe numbers shown here are intermediate values from the several sources 

 listed in the text. Although these sources present similar estimates, their 

 combined accuracy is not regarded as high; procedures for obtaining global 

 estimates for characteristics of vegetation are still primitive. 



inputs and outputs. Inputs are controlled by the quantity of primary production 

 reaching the detritus pools; outputs are basically controlled by decay rates 

 together with pool size. 



A series of estimates for inputs into terrestrial detritus pools is presented by 

 Reiners in this volume. These estimates are probably reasonable for many types 

 of more-or-less undisturbed systems. Certain types are poorly represented, 

 however. These are dry or monsoon tropical forests; temperate and tropical 

 savannas; dry, grazed grasslands; various types of arctic tundra; and extreme 

 deserts. Field data would be very useful for these types. Further information of 

 this sort should be forthcoming from the International Biological Programme. 

 Estimates of input are also needed for agricultural systems of the world, together 

 with an analysis of diversion, and rate of change of diversion, of detritus inputs 

 by such human-related activities as forest ground fires, intense grazing, and 

 forestry practice. 



Normal decay rates can be determined in apparently steady-state systems by 

 assuming they equal inputs. These rates can be used as reference points for 



