Soil architecture and distribution of organic matter

The biological component of soil structure varies greatly in quality and quantity, occurs on different scales, and varies throughout the year. It is far less predictable than the physical part and human impact. The occurrence and distribution of organic matter depends on several processes, related to heterogeneous environmental distributions. Heterogeneous distributions are not the main controlling factors of decomposition rates or carbon retention in soils. It is the accessibility, rather than the location, of organic input to decomposing bacteria and fungi, predators, water, gases and solutes which is of primary importance. New concepts and methods for analysing, interpreting and quantifying distribution patterns of features are needed.