Ecosystems can be defined as representing the community of organisms living in its non-living environment. Four broad components can be identified which make up an ecosystem:

• Abiotic (non-living –e.g. minerals)
• Producers (autotrophs – e.g. green plants, cyanobacteria, chemoautotrophic bacteria)
• Consumers (heterotrophs –e.g. bacteria, soil animals)
• Decomposers (mostly bacteria & fungi)

Between the living components there will be overlap in the capability of the organisms e.g.  decomposers can also be considered consumers. The type of organisms and how they interact is governed by the abiotic component. In soil, the prevailing environmental conditions such as water and temperature as well as the latitude and also the history affect the living (biotic) components of the ecosystem. Conversely, the living components have an effect on the abiotic component, for example primary producers growing on rock surfaces effect the breakdown of the rock minerals, the first stage in soil formation.