Microbial processes occur at the scale of microns but they manifest themselves at the scales of centimeters to meters. To effectively assimilate information from the micron scale (microbial community composition, enzyme concentrations, soil physics) to the macro-scale requires understanding the balance of biological, biochemical, and physical processes that control microbial processes. How do physical processes regulating substrate supply balance against biotic factos that regulate substrate use? We will discuss how this balance affects soil carbon dynamics, with a particular focus on the influences of varying moisture (dry-wet cycling). We will discuss how to begin integrating such micro-scale informaiton into models that provide insight and predictive power at the macro-scale.