A theoretical investigation of the organic carbon-microbial biomass relation in muddy sediments

A population/diagenetic model is developed to describe the behavior/dynamics of the microbial biomass in aquatic sediments. This model is analyzed in order to establish the dominant terms, i.e, processes, in that balance. The result of this analysis shows that production-removal processes, i.e, growth, death, grazing, transformation to inactive or active, etc., are essentially in balance to the best (lowest order) approximation, while all varieties of transport processes, i.e. motility, chemotaxis, bioturbation, burial, etc., contribute only higher order corrections to this balance. The balance between production-removal processes is shown to imply a linear relation between the size of the microbial biomass and the concentration of organic substrate, as advanced by Rublee (1982; Estuarine comparisons, Academic Press, p. 159-182), based on empirical evidence.