Phytosociological structure of mangrove in Roteiro Lagoon, Alagoas state, Northeastern Brazil

Abstract

This study aimed to characterize the phytosociological structure of the mangrove in Roteiro Lagoon in the state of Alagoas, through phytosociological parameters. For that purpose, six transects were traced, divided into three 400 m² plots each, 10 meters apart each other. To check the abiotic factors, a thermometer (temperature) and a refractometer (salinity) were used. Three sediment samples were also collected, at a depth of 20 cm, for the granulometry and organic matter analyses. A total of 449 trees were measured, showing trees Rhizophora mangle, Laguncularia racemosa and Avicennia schaueriana. The average density of the arboreal vegetation was 624 ind.ha^-1, with the Rhizophora mangle species showing the highest phytosociological indexes, with a value of 220.59%. The values of the phytosociological parameters showed great amplitude in the analyzed plots, occurring from seedlings to adult trees. The temperature values did not show significant differences between the average of the fringe, intermediate and interior portion, however, the salinity stood out, showing an increase in relation to the interior of the forest. There was a predominance of sandy silt in the studied mangrove forest. Thus, the phytosociological analysis revealed high structural diversity, in an environment where the abiotic factors contribute to the establishment of tree species and a high contribution of the Rhizophora mangle species in all phytosociological parameters assessed in the ecosystem.

Keywords:
Mangrove forest; Phytosociology; Abiotic parameters