Particular climatic conditions (irregular rainfall and long dry period) in addition to the anthropogenic impact (clearing, tillage, cultivation and harvesting) have increased desertification in large areas of arid and semiarid environments (Matson et al., 1997). This degradation results from deterioration of soil quality (soil structure, plant nutrient availability, organic matter content, microbial activity) and of vegetal cover (Barea and Jeffries, 1995). The successful re-establishment of plants in arid and semi-arid ecosystems may be limited by the low density of mycorrhizal propagules (Marx et al., 1985; Requena et al., 2001). Mycorrhizal fungi play critical roles in the growth and survival of host plants in these severe environments. Mycorrhizal symbiosis has been found to be essential components of sustainable soil-plant systems (Smith and Read, 1997; van der Hejden et al., 1998; Schreiner et al., 2003) as this symbiotic process mobilizes and transports nutrients to the roots (Smith and Read, 1997), improves soil aggregation in eroded soils (Querejeta et al., 1998; Caravaca et al., 2002) and reduces water stress (Guehl and Garbaye, 1990; Guehl et al., 1992; Augé, 2001). It appears that ectomycorrhizal inoculation could be of great relevance to improve reafforestation processes of degraded areas with legumes fast growing trees. This mycorrhizal effect on the plant growth has been generally investigated in controlled conditions but data on the efficiency of controlled mycorrhization in field conditions remained very scarce. From the present review, the positive impact of mycorrhizal inoculation was demonstrated in a dry tropical environment. In addition, recent studies have shown that the establishment of mycorrhizal symbiosis greatly interact with soil microflora at physical, metabolic and functional levels. Biological components of this symbiotic association (plant and symbiont) select bacterial strains beneficial for the symbiosis and for the plant. Hence my