SMALL-DISTANCE VARIATION OF CARBON AND NITROGEN STORAGE IN MINERAL ANTARCTIC CRYOSOLS NEAR CASEY STATION (WILKES LAND)

In the antarctic summer 1996 top soils and whole profiles were collect ed systematically near the Australian Casey Station (Wilkes Land).in o rder to specify the carbon and nitrogen storage in permafrost-affected mineral soils (Cryosols) of coastal areas of Antarctica. Cryorthents, Cryaquepts and Haplocryods are the main soil units observed. The orga nic matter accumulation in mineral soils of the ice-free coastal Antar ctic region is similar to that of comparable Arctic regions. A Small-d istance storage variation is mainly due to the patch pattern of topogr aphy, geomorphology and especially soil geography. Haplocryods are imp ortant sinks of carbon and nitrogen, whereas the storage in the Cryaqu epts is of minor importance. In addition, large parts of the landscape are characterized by Lithic Cryorthents, which store nearly 50% of th e organic carbon and 40% of the nitrogen. A high variability in the C and N concentration and storage complicates a calculation of soil C an d N storage of the total landscape necessary for developing ecosystem models. However, the survey on landscape level suggests that in 75% of the landscape sites the soil carbon and nitrogen stock is very simila r, but a wide-spread podzolization and/or extraordinary organic matter accumulation increases the stocks to a great extent. For this reason a storage estimation could be improved by a proper soil survey.