ABSTRACT
The exact ratio between living and dead organic matter in terrestrial ecosystems varies, depending on the ecosystem. The amount of carbon stored in soil is determined by the balance of two biotic processes—the productivity of terrestrial vegetation and the decomposition of organic matter. Each of these processes has strong physical and biological controlling factors. Interactions among these controlling factors are of particular importance. These biological and physical factors are the same as the ones that influence the above ground structure and composition of terrestrial ecosystems, so there are strong correspondences between soil organic matter content and ecosystem type.
