A COMPARATIVE-STUDY OF CERRADO (SENSU-STRICTO) VEGETATION IN CENTRAL BRAZIL

Floristic and structural comparisons and a numerical classification were performed to identify the priority areas for conservation of genetic resources in central Brazil. The main type of woody vegetation, cerrado sensu stricto (savanna woodland with 10-60% tree cover), was sampled under a uniform methodology in six selected sites (total sample of 6 ha) scattered in a physiographic unit called the Pratinha Plateau located between 15-20-degrees-S and 46-49-degrees-W. A total of 6971 trees belonging to 139 species and 42 families was measured. Each site had a combination of 50-80 species and approximately 30 families but only 22 species from 14 families were common to all sites. Similarity decreased with distance, indicating the existence of geographical gradients as the physical characteristics were relatively uniform and the soils were dystrophic at all sites. The most dissimilar sites, in the localities of Patrocinio-MG and Paracatu-MG were recommended for the establishment of conservation units. The already existent conservation units are all clumped in the Federal District and are not enough to protect the genetic heritage of the plateau. Floristics and phytosociological surveys based on land system zoning were recommended as useful tools in planning conservation areas at a regional level to preserve the maximum biodiversity.