The present study was conducted with the aim of analyzing the physiognomy and structure of major forest types found at UMA. To achieve this study, 40 floristic inventories plots (of 0.25 ha each) were considered and all individuals with dbh ≥10 cm were identified. A total of 3882 trees were identified: 696 (348 trees/ha) for trees stand at Limbali on white sand, 657 (325.5 trees/ha) for trees stand at Limbali on ground hydromorphe, 731(365.5 trees/ha) for monodominant settlement of transition on sandy soil, 887 (443.5 trees/ha) for the heterogeneous population disturbed on clay soil and 991 (455.5 trees/ha) for the heterogeneous population on soil shallow and rocky. They represent a basal area of 32.85 m²/ha, 25.08 m²/ha, 25.56 m²/ha, 30.86 m²/ha and 31.67 m²/ha respectively. The difference in density and basal area was significant between tree stands in all compartments. Statistical analysis indicated a significant difference between populations for species diversity, and Shannon index (stratum A2), Simpson index, Fisher index (Alpha) and equitability (strata E+A1 and A2) but there was not any difference in (E + A1) stratum according to these biodiversity indices. There was floristic similarity between monodominant and heterogeneous stands transitions but no floristic similarity between heterogeneous tree stands and disturbed stands monodominant trees. So these two stands of trees are different. The heterogeneous transition stands is therefore only monodominant forest Julbernardia seretii the interior of what Gilbertiodendron dewevrei (Fabaceae) came to replace Julbernardia seretii (Fabaceae) in the stratum (E + A1).