Résumé
Impact of anthropisation and revegetation on soil microbial diversity was studied by characterizing bacterial community structure in a sandpit located in Terga (Algeria). Soil samples were collected from several sites: an undisturbed forest area with pristine vegetation, a site revegetated by the National Forest Services in 1998, a newly revegetated site by the introduction of two tree species (Tetraclinis articulata and Schinus terebinthifolius) associated, or not, with two legume species (Retama monosperma and Lotus creticus). Samples were collected from bulk and rhizospheric soil compartments during an18 month-period. Soil bacterial community structure was characterized by rRNA Intergenic Spacer Analysis (RISA) and statistical analysis. Concerning revegetated sites, soil physicochemical analysis was performed just after plantation and after 18 months. The plant effects on bacterial community structure differed among sites and plant species. In pristine forest, bacterial community structures of bulk and rhizospheric soils are most similar, both in time and whatever the cover plant species. In the recolonized site, no temporal change was observed, but plant, mayimpact bacterial community structure in rhizosphere. ‘T. articulata’ impacted bacterial community structure all along the temporal scale. Opposite, no significant effect of S. terebinthifolius was detected. A correlation between soil parameters and bacterial community structure was observed, suggesting that plant may drive bacterial community structure by providing nutriments and modifying soil physicochemical parameters. These results evidence the dynamics of microbial communities in response to revegetation efforts; registering microbial community evolution in time may help to select plant species with biological soil quality enhancing potential.