Soil organic matter of suggested spodic horizons in relic ornithogenic soils of coastal continental Antarctica (Casey Station, Wilkes Land) in comparison with that of spodic soil horizons in Germany

In Antarctica, ornithogenic soils from penguin guano play an important role in nutrient cycles in the ecosystem, Soil organic matter (SOM) degradation and translocation are the main determinants of these dynamics, of which podzolization is probably one, in ornithogenic soil, The purpose of this study is to describe the SOM in the older ornithogenic soils of Coastal Continental Antarctica in order to learn more about the organic matter of these soils, The SOM investigations were carried out by means of wet chemical SOM analyses and carbon-13 and nitrogen-15 nuclear magnetic resonance (NMR) spectroscopy, The purpose is to compare these data with those obtained from spodic horizons formed under temperate climate conditions, This comparison should provide the first information concerning the possibility of podzolization in Antarctica, In contrast to the spodic horizons in Germany, the SOM of the antarctic soils is characterized by a high percentage of amino derivates from proteins, polysaccharides, urates, and chitin, resulting in a mean C-to-N ratio of 10 and a high content of carboxyl carbon units, which probably derived from amino and other organic acids, The N-15-NMR spectrum of penguin guano suggests the presence of uric acid (2, 6,8-trioxypurine), Our data suggest that migration of organic acids, not-humified carbohydrates, and N-containing moieties from the topsoil moving into the spodic horizons of the ornithogenic soils affect the podzolization process, In the SOM of the German Podzols, N-compounds and not-humified carbohydrates were of minor importance within the SOM translocation processes.