6) Structural variation in mangrove forests of the estuary of the River Itabapoana, ES-RJ

Abstract

We analyzed the structure of 13 sites of mangrove vegetation in the Itabapoana estuary by use of the methodology of permanent plots. Considering all individuals >1m within the plots, the average height of forests ranged from 4.0 to 10.1m, the average DBH (diameter at breast height) ranged from 3.7 to 13.5cm, the basal area of living individuals was 13.5 to 48.3m2.ha-1, and the density of trunks was 1,475 to 21,000 trunks.ha-1. Overall, there was a greater contribution of the live basal area in relation to diameter >10.0cm (59%). Forests with better structural development exhibited a dominance of Avicennia germinans (L.) Stearn, while Laguncularia racemosa (L.) Gaertn. f. was dominant in less-developed forests. Our results showed that environmental features and biotic factors contribute to mangrove differentiation among sites. Such differences highlight the peculiarities of each mangrove and emphasize the need of specific management plans for ecosystem maintenance.

Keywords

• Avicennia germinans
• Laguncularia racemosa
• mangrove
• phytosociology
• Rhizophora mangle