Distribution and characterization of soils and landform relationships in Byers Peninsula, Livingston Island, Maritime Antarctica

Abstract

This paper presents the spatial distribution of soils from the northern part of Byers Peninsula, Livingston Island, which is the largest ice-free area of the South Shetlands archipelago, Maritime Antarctica. Physical and chemical characteristics are presented for 23 soil profiles. Soil parent materials vary from marine sedimentary to volcanic and volcanoclastic rocks, intruded by igneous bodies. To assess soil–landscape relationships, twenty-three soil profiles were described and sampled. Soil samples of selected horizons were submitted to chemical, physical and mineralogical analyses. Soil mapping was based on the soil profiles, integrated with the existent topographic map (1:25.000 scale), a digital elevation model, the geological map and a satellite image. Twenty different soil units were identified and mapped. According to the World Reference Base for Soil Resources (WRB) system, soils were classified as Fluvisols, Regosols, Leptosols or Cryosols, which correspond mostly to Fluvents, Orthents/Psamments, Inceptsols and Gelisols, respectively, according to the Soil Taxonomy. Soils from northern Byers Peninsula are generally shallow and coarse textured, with low organic matter content. Three soils from the rocky platforms of the northern coastal region possess ornithogenic character, with lower pH, higher P, Al3+ and organic C values when compared to soils not influenced by sea birds. In non-ornithogenic soils, the presence of easily weatherable minerals in the clay fraction indicates that physical weathering occurs with limited chemical alteration of primary minerals. The influence of penguin and other birds on coastal soils alters clay mineralogy, with formation of poorly crystalline P-rich phases. A better understanding of the depth of the permafrost table and the spatial distribution of permafrost is necessary for a more conclusive classification of Cryosols or Gelisols.