ABSTRACT
Environmental disturbance can be assessed through the behavior of the microorganism population in the soil. Many methods can be used to assess the environmental impact in the soil. Some groups, such as rhizobia symbiotic microorganisms (Tao et al., 1992; Lakzian et al., 2002) and mycorrhizal fungi (Requena et al., 1997), are widely used as bioindicators. However, the soil is a microcosm where all groups of microorganisms interact directly or indirectly with each other, with the plants and/or the soil. In this sense, the present chapter deals with functional groups of microorganisms as bioindicators to assess soil disturbances or biotic fertility.
