Soil research in the Ross Sea region of Antarctica

Abstract

Abstract The Ross Sea sector has been the focal point of most Antarctic soil research, and since the early 1960s widespread chemical weathering, soil-biological, and pedological studies have been carried out. Chemical weathering of soils is slight and occurs at a very slow rate, but there are measurable differences among soils in the amount of iron oxides released, while in some instances clay mineral transformations can be detected. Differences can be related to various environmental factors. The chemical properties of the soils are complicated by additions of soluble salts such as nitrates, chlorides, and sulphates in amounts which vary according to geographic location, age of the soils, and degree of leaching. The biological component of the soil is effectively zero in most situations, although in localised places such as penguin rookeries organic matter has accumulated in the soil. Pedologically the soils are distinctive and have properties that characterise them as cold desert soils. They show small but distinctive morphological differences in colour, particle size, salt content, depth, and disaggregation of surface material, the differences being related to regional climate, age, and parent rock. With knowledge of the predictable differences in soil properties, the soils are used as a means of age correlation in Antarctic glacial chronology studies. The salts in the soils allow a reconstruction of past environmental conditions, with nitrate salts in particular illustrating relationships to global atmospheric circulation patterns. A consideration of polar soil relationships has shown that Antarctic soils are the coldest and driest of a polar soil zonation system, but on a global basis they have many similarities with hot desert soils. Antarctic soils have formed over a very long time (> 5 m.y.) and are part of one of the world's most fragile ecosystems.