Changes in the structure and composition of a fragment of dry deciduous forest in southeastern Brazil were described for 4-year period (1994-1998). This fragment was quite disturbed by human activities up to 1993, but it has been protected since 1994. A survey of woody plants ( > or = 3.2 cm dbh) was conducted in 26 transects of 50 x 6 m (0.78 ha) in 1994. Four years later (1998), all the transects were revaluated. In 1994, a total of 114 tree species from 46 families were identified. Species richness was almost identical in 1998. The values of the Shannon index (3.72) and the equability (0.79) did not differ significantly during the studied period (t test, p > 0.1). The species richness was greater than Neotropical dry forests due probably to the building sucessional phase of this fragment. Although tree density had declined by about 10.2%, total basal area had a small change, increasing 1.5%. Those alterations were reflected in the size class distribution, which had significant differences between 1994 and 1998 (Chi-square test, p < 0.01). Although overall forest composition showed little change, several species showed significant imbalance between recruitment and mortality rates. The decline of pioneer species (Chi-square test, p < 0.001) and the growth in total basal area of the canopy species caused the changes observed during the four years. The preservation of the studied fragment has been important for its recovery in the last years.
Forest dynamics; floristics; structure; fragment; dry deciduous forest
