Structure and dynamics of floodplain forest in the amazonian estuary in the Amapa state

Abstract

The present study was developed aiming to evaluate the structure and the dynamics of Amazonian estuarine floodplain forest, in the district of Mazagão, Amapá state and in nearby area with which it keeps intense partner-economic relationship. In 2000 three permanent sample plots were installed with size 100 x 100 m, divided in ten sub-plots with 20 x 50 m, each one. In 2005, a new measurement was done in the sample plots, when it was evaluated the changes in the horizontal structure, in the growth in diameter at DBH of all trees with circunference above 15cm (CBH), the ingrowth and the mortality. In the Mazagão, alterations in relation to the number of species (52) and families (27) in the period from 2000 to 2005 had not occurred. The absolute density increased in 78 trees per hectare and the basal area increased 4,01 m²/ha. In the Maniva river in 2000 they had 48 species of 24 families; in 2005 it appeared one new species and one family. The absolute density increased in 119 trees per hectare. The basal area increased in 4,96 m²/ha. In the Mutuacá River in 2000 they had 76 species of 32 families; in 2005 appeared five new species, two disappeared and the number of families kept the same. The basal area diminished in 3,05 m²/ha.