Organic matter decomposition in intertidal sediments, Hinchinbrook Channel, North Queensland

Four sites (in 2 mud flats and 2 mangrove forests) were sampled in August 1997 (winter) and February 1998 (summer).Data was collected for analyses of sediments, porewater, and solid-phase elements (TOC, total C, total N, etc). Sediment temperature, redox potential and pH were measured.Metal reduction (Fe and Mn) was estimated by using the core incubation method.Sulphate reduction was measured and a two-step distillation procedure was used to determine the fractions of reduced radiolabel in the acid volitile sulphide (AVS=free sulphides, FeS) and chromium-reducible sulphur (CRS=S, FeS2).Denitrification rates were calculated.Fluxes of dissolved oxygen, total CO2, DOC, Fe and Mn were measured. To examine rates and pathways of organic matter decomposition in sediments during winter and summer.

本研究于1997年8月（南半球冬季）与1998年2月（南半球夏季），在2处潮间带泥滩与2处红树林湿地的4个采样位点开展沉积物采样。研究采集相关样品用于沉积物、孔隙水以及固相元素（总有机碳（TOC）、总碳、总氮等）的分析测试；测定了沉积物温度、氧化还原电位（redox potential）与pH值；采用柱培养法估算了铁（Fe）与锰（Mn）的金属还原过程；测定了硫酸盐还原速率，并通过两步蒸馏法分别测定了酸挥发性硫化物（acid volatile sulphide, AVS=游离硫化物、FeS）与铬还原态硫（chromium-reducible sulphur, CRS=单质硫、FeS₂）中的还原态放射性标记物占比；计算了反硝化速率；测定了溶解氧、总二氧化碳（total CO₂）、溶解有机碳（dissolved organic carbon, DOC）、铁与锰的界面通量。本研究旨在探究冬夏两季沉积物中有机质的分解速率与途径。