Publicações

The study of the phytosociological structures and sizes in secondary forest fragments allows to
make inferences on the original composition and structures at the beginning of the secondary succession. The
importance of gallery or riparian forest studies increases with the increasing concerns on the impacts caused by
water courses and their borders, specially the building of power plant dams. The objectives of this work were to
describe the structure of a secondary gallery forest to identify an arboreous species population which participated
at the beginning of the successional process in this forest and based on these data, to study the genetic structure
and to assess the biology of the species which probably started the successional process. A survey of all the trees

with a 1.3 m stem circumference from the ground greater than or equal to 10 cm was carried out. Out of the
48 tree species already included, 87.5% are endozoochoric and 12.5% are anemochoric. Out of the latter those
with the smallest propagules presented greater density in this forest, which is isolated from others by pastures.
The most important species (VI) presented by this gallery forest were: Talauma ovata, Erythrina falcata and
Euterpe edulis. Ficus species from the subgenus Urostigma presented a great biomass in spite of its low density.
Erythrina falcata was considered one of the species of greater importance, probably associated to the Ficus
species at the beginning of the secondary succession, due to the structure of the stem diameters presented. In
Erythrina falcata, the isoenzymatic systems of Isocitrate Dehydrogenase, Peroxidase, Phosphoglyco Mutase and
Xiquimate Dehydrogenase were analyzed by means of zimograms. The population of 27 individuals of Erythrina
falcata was found in Hardy-Weinberg balance, presenting a relatively high allelic diversity. The population of
Erythrina falcata was found to be under biological and ecological conditions to start the secondary succession.
The high genetic diversity of the Erythrina falcata population could be one of the determinant factors for the
success of the colonization of the area. The association of Erythrina falcata with trees of the Ficus genus could
have been determinant for the successful beginning of this process of colonization, and the initial association
may have functioned as a low diversity system of species, comparable to other flooded forests of Southeastern
Brazil.