Sediment accumulation and mineralization in mangrove forests, Jiulongjiang Estuary, China

Rates of sediment accumulation and microbial mineralisation were examined at 3 Kandelia candel forests.Within each forest, measurements for species (6)identification, basal area, and diameter at breast height were taken. All sediment samples were taken within the same 100-200m2 plots. Root (live and dead) biomass was estimated. Triplicate surface samples were taken for percent sand, silt and clay, and water content. Soild-phase concentrations of TOC, TN, Fe and S (all % dry weights), Mn and TP (ug g-1), and C:N (molar) were determined from 2-3 cores from each site. Salinity was measured on filtered water.Mass sediment accumulation rates were determined from gamma spectrometric measurements of 210Pb, 226Ra and 137Cs.Sediment samples were taken in summer (July 2002) and autumn (September 2003).Gas fluxes (CO2 and O2) were measured across the sediment-air interface. Rates of net dissolved Fe, Mn and ammonium releases from sediments and denitrification, nitrogen fixation, methane and nitrous oxide fluxes were also measured. To measure rates of sediment accumulation and microbial mineralisation in Kandeli candel mangrove forests of southern China