Floristic and structural characteristics determined in one hectare of caatinga in 2001 were compared to data from 2006. The number of species increased from 27 to 28, one species disappeared and two others arrived. The number of plants increased significantly, from 3142 to 3567 (13.5% increase). Average diameter increased 0.5mm.year-1 and aboveground biomass increased from 41.2 to 43.8 Mg.ha-1, but the difference was not statistically significant. Population dynamics were peculiar to each species, with some increasing and some decreasing in density, possibly due to establishment problems. Jatropha mollissima (Pohl) Baill. and Schinopsis brasiliensis Engl. populations were greatly reduced and that of Mimosa ophthalmocentra Mart. ex Benth. almost tripled, while the dynamics of most species changed little. The vegetation seems to be still developing after clear-cutting 20 years before 2001. This process, possibly affected by low rainfall in two of the five years, may be responsible for the greater structural change reported here than in other, little disturbed tropical vegetation.
Caatinga; community structure; dynamics