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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. Additional keywords: Sphagnum, [sup.13]C nuclear magnetic resonance, humified peat., Introduction Peat is an organic soil formed where the combination of climate and topography results in a higher rate of organic matter production than decay. This accumulation of organic matter [...]

Three hundred and six soil samples were classified for sodicity on the basis of exchangeable sodium percentage (ESP), and for spontaneous or mechanical dispersion on the basis of a dispersion test (Emerson 1991). Each sample was analysed for pH, electrical conductivity (EC), concentrations of exchangeable and soluble cations ([Ca.sup.2+], [Mg.sup.2+], [Na.sup.+], [K.sup.+]), and concentration of organic carbon (OC). These variables were used to explain the sodicity and dispersive classifications of the 306 samples. Concentrations of exchangeable and soluble [Ca.sup.2+], [Mg.sup.2+], and [Na.sup.+] along with EC and total cation concentration (TCC) significantly affected the sodicity and dispersion classification of the soil. A sodic soil was expected to disperse spontaneously, a non-sodic soil was not expected to disperse spontaneously. From this hypothesis the expected and observed dispersion class was compared with sodicity class. The expected result corresponded to the observed result 77% of the time and the hypothesis was accepted (P < 0.001). Additional keywords: dispersion, sodic soils, Red-Brown Earth., Introduction To manage cropping soils in northern Victoria and southern New South Wales it is advantageous to know whether the soil is liable to disperse. Does the soil disperse spontaneously [...]