DYNAMICS OF THE NATURAL REGENERATION IN THE GAMA GALLERY FOREST IN CENTRAL BRAZIL

Permanent plots were studied over 6 years in approximately 64 ha of un disturbed gallery forest alongside the Gama stream in the Federal Dist rict, Brazil. Trees from 31 cm with at breast height (gbh) (ca. 10 cm diameter at breast height (dbh)) were measured every 3 years from 1985 in 151 (10 m X 20 m) permanent plots. Natural regeneration (individua ls under 31 cm gbh) was measured in 1986, 1989 and 1991 in subplots wi thin the 200 m(2) plots. The total tree flora (gbh greater than or equ al to 31 cm) consisted of 93 species, 81 genera and 44 families in 198 5. Almost all species, present as trees, had seedlings and saplings at some time during the measurement period: but for most species one of these phases was missing on some occasions. Regeneration of about 80% of the species occurred in the establishment phase (poles). The densit y structure of trees and natural regeneration was similar to each othe r with more than 80% of the species occurring at low densities. The ra te of decrease between successive height classes was around 50%, indic ating the typical low level of establishment for juveniles in tropical forests. The species most abundant as trees also had abundant regener ation, apart from few exceptions. Therefore, the Gama community seems to be robust enough to maintain a diversity of species and structure i n undisturbed conditions.