Chemical characterisation of bog peat and dried peat of the Australian Alps

The importance of bogs in the catchment hydrology of the Australian Alps has been long recognised but little studied. Damaged bogs are thought to be the source of dried peats now common throughout the Alps. We described the characteristics of a bog peat and a dried peat, to better understand the relationship between the two. Standard chemical properties of peat were measured: pH, loss on ignition, gravimetric contents of carbon and nitrogen, and electrical conductivity. We also measured the concentrations of total and plant-available elements, and the chemical composition of the organic carbon, leading to a measure of the extent of decomposition. The results suggest that this is a typical Sphagnum bog peat - low pH, high carbon content - and the distribution of carbon groups and other elements reflect the stable water source of this groundwater-fed Sphagnum bog. The properties of the dried peat were most similar to the catotelm (lower layer) of the bog peat. This resemblance, combined with decades of field observations, indicates that dried peat may form from the catotelm of bog peat, after the acrotelm (upper layer) dries and erodes. These results have implications for the management of Alps catchments, and further studies are needed to ascertain the hydrologic and carbon cycling roles of organic soils in the Australian Alps.