Decomposition of Avicennia marina on an iron-smelting slag substrate

The present study, conducted near Newcastle, Australia, used a blocked anal ysis of variance experimental design to compare initial nutrient concentrat ions and decomposition rates of Avicennia marina (grey mangrove) grown on s and and rock blast furnace slag. There were no significant differences (ANO VA; P > 0.05) in mean initial nutrient concentrations of total C, N and P f or plants grown on the sand and slag substrates. A litterbag technique was used to estimate decomposition rates. After 360 days of incubation, repeate d measures analysis did not identify significant differences between the su bstrates for the interaction term 'substrate x time' or the term 'substrate ' for percentage weight loss or for C, N and P remaining. Avicennia marina on both substrates had nutrient characteristics and decomposition rates com parable to those found in the literature. Results suggest that initial nutr ient concentration and decomposition rates are not dramatically influenced by the presence of slag.