Soil priorities for Antarctica

Abstract

While most of Antarctica is covered by ice sheets, a small part of the continent is permanently ice-free, sometimes for millions of years, where soils developed. Ice-free regions represent about 0.44% of the total area of Antarctica (~54, 000 km², although a precise estimate is still lacking), and are small ‘islands’ dotted along the coast, mountain ranges, and nunataks (Figure 1, Brooks et al., 2019). There, environmental conditions result in a diverse range of soils. The largest expanse of ice-free areas, the McMurdo Dry Valleys, is an arid, cold desert , with very low and fluctuating temperatures, almost no liquid water, often very high soil salinity, and typically slow rates of soil formation. Despite the small area they represent, Antarctic soils are scientifically remarkable: they harbour life, including arthropods, nematodes, rotifers and tardigrades, and a surprisingly high diversity of soil microbes, therefore representing the major part of the biomass of all Antarctica terrestrial systems (Convey et al., 2014). Ice-free areas also form essential breeding grounds for macrofauna, such as seals and seabirds. The trophic simplicity of those ecosystems make Antarctic soils a great model for studying broader ecosystem functioning. Some of the highest elevation ice-free areas and their dry permafrost conditions represent the closest Mars analogue on Earth.