Soil Organisms and Their Habitat

Abstract

The edaphonedaphoncomprises all organisms living in the soil. Based on the body diameter of the organisms, the edaphon is divided into the classifications microfloramicroflora, microfaunamicrofauna, mesofaunamesofaunaand macrofaunamacrofauna. The body width of soil organisms largely determines their microhabitats (Fig. 4.1). Microflora (bacteria, archaea, fungi, algae) and microfauna (protozoa, nematodes) form the community of microorganisms in soils. Soil organisms influence soil formation (pedogenesis) directly (e.g. through burrowing activity and decomposition of organic matter) and indirectly (e.g. by feeding on plant roots). Soil microorganisms and soil fauna whose life cycle stages all take place in the soil, belong to the permanent soil organismssoil organismspermanent. Temporary soil faunasoil faunatemporaryspend only part of their life cycle in the soil (e.g. insect larvae), while periodicalsoil organismsperiodicalfauna often leave the soil and then return. Alternating soil faunasoil faunaalternatingalternate between aboveground and underground generations (Fig. 4.2). However, permanent soil organisms can also be spread through the atmosphere in resistant dormant forms (cysts, spores), or sorbed onto dust particles. Active or passive transport of soil organisms within the soil profile can take place as well.