ABSTRACT
From the moment a seed genninates, it comes into contact with soil microorganisms and the two-way plant-microbe interactions that follow have profound effects on the growth and development of both the plant and the soil microbial communities. These processes can be modified strongly by inter actions with soil micro-, meso-, and macrofauna and may, over extended periods of time, significantly affect the floral and faunal diversity both above and below ground (Brown 1995), as well as the productivity of the ecosystem in which they occur. The intensity of the spatial and functional interactions in subterranean food webs (Anderson 1988) (depicted in Figure 1) is influenced strongly by the daily, seasonal, and annual patterns of rainfall and temperature. These interac tions occur in a number of key biological locations which are foci of intense microbial activity associated with the decomposition of organic residues. These include the rhizosphere (roots), the detritusphere (surface detritus), the drilosphere (earthworms), and the termitosphere (termites) (bavelle et al. 1992; Beare et al. 1995).
