Salinity and flooding frequency as determinant of mangrove forest structure in Babitonga Bay, Santa Catarina state, southern Brazil

Abstract

This work aimed to evaluate the effects of salinity and flooding frequency on structure of mangrove forests in Babitonga Bay, State of Santa Catarina (southern Brazil). Eight sites were selected along a salinity gradient. Into each site, 100m2 plots were positioned along the flooding frequency gradient, 50m from each other, from water edge to landwards. All the trees into the plot was identified and measured to estimate structural parameters of the forest. Data were compared using cluster and canonical correspondence analyses. was dominant in oligohaline plots with high flooding frequencies, which showed lower densities and higher diameters and biomass. Euhaline and mesohaline plots with high flooding frequencies were clustered due to lower total densities, high diameter and tree height and high biomass. Low flooding frequencies plots presented high tree densities and low biomass, and were separated in two clusters: euhaline and mesohaline forests. In euhaline forests with low flooding frequencies was the dominant species, with higher densities and biomass. In mesohaline forests with low flooding frequencies was largely dominant in density, but biomass was very similar among species. In Babitonga Bay, mangrove structure is primarily related to flooding frequencies, but it is also dependent on salinity.