THEORETICAL-ANALYSIS OF MICROBIAL BIOMASS DYNAMICS IN SOILS

Microbial biomass can serve as a rapid indicator of state and change of soil properties. We have extended a published theory in order to incorporate the dynamics of microbial biomass in the soil. The extension adds a requirement of information about microbial mortality. Theoretical predictions are given for the ratio between carbon in living microbial biomass and carbon in the substrate in decomposing litter cohorts, in the soil at steady state and in chronosequences of forests and agricultural systems. These predictions compare well with empirical studies. The extended theory allows a new interpretation to the dispersion function, which relates to processes in the food chain of the microbial community. Effects of soil texture are also discussed.