One of my favorite authors once suggested that trees and soil are not so different; they both “consist of living, dying and dead matter”. In trees, this represents living meristems (biologically dynamic), dying sapwood (partially biologically dynamic), and dead heartwood (non biologically dynamic). In soils, we have all kinds of living, dying and dead things; fungi, bacteria, amebas, rootlets and earthworms in addition to the “dirt” itself that serves as the medium for this unique and cryptic biome.
One of the most important components of a healthy soil is nothing at all (empty space). That is to say, air. Without free air space and exchange with the outside atmosphere there can be little if any biological activity, “life”. This includes healthy plant roots, as they require oxygen to respire. Unfortunately, many of our soils are lacking in important components such as oxygen and mycorrhizal fungi (a beneficial, plant symbiotic fungi) due to the original construction activity required to build our homes that resulted in unhealthy and susceptible trees and plants.