Article révisé par les pairs
Résumé : Mangrove structure and distribution is conditioned by geomorphic processes. This paper describes the response of mangroves to sedimentary processes at the Cananéia-Iguape Coastal System on the south coast of São Paulo State (Brazil), between latitudes 24° 40'S and 25° 20'S. Within six study areas 41 plots were established along 14 transects. Plot size varied according to stem density from 2m×2m to 20m×20m. Here mangroves are strongly coupled to sedimentary processes, forming discrete architectural elements within particular depositional environments or topographic settings. These sedimentary structures and progradation environments are colonized by Laguncularia racemosa, associated with the smooth cordgrass Spartina alterniflora. Rhizophora mangle occurs typically near creeklets where tidal flooding is more frequent. Where tidal influence is restricted Avicennia schaueriana becomes dominant. Erosive margins are dominated by A. schaueriana or R. mangle. Single linkage cluster analysis yields three groups (A, B and C), with high levels of similarity, providing support to the classification of the data into two broad landform categories: depositional and erosive. Group A includes plots with the least structural development (nominal stem diameter dn between 1.05 and 4.61cm). Group B is composed of stems of intermediate diameter (4.99 cm ≤ dn ≤ 5.63cm). Group C plots have the largest structural development (5.50 cm ≤ dn ≤ 11.10cm). The structure of mangroves (dominance and structural development) reflects responses to geomorphology and habitat change.

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