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espanolLos suelos de los oasis antarcticos, en las areas libres de hielo tanto en la costa como tierra adentro rodeadas por los glaciares terrestres o plataformas de hielo, atraen la atencion como uno de los componentes de los ecosistemas mas extremos de la Tierra. El conocimiento sobre las etapas iniciales de edafogenesis, formacion y estabilizacion del solum, interaccion entre los componentes organicos y minerales en estos suelos es todavia limitado. Hemos realizado un estudio micromorfologico de algunos perfiles de suelos superficiales, desarrollados en los sedimentos recientes no consolidados, bajo musgos y liquenes en el Oasis Schirmacher. El material mineral esta dominado por particulas de arena, de minerales primarios (cuarzo, feldespatos K-Na y micas). Los granos de cuarzo demuestran estructuras superficiales indicativas de la fragmentacion criogenica, mientras que la biotita tiene signos de alteracion quimica: intemperizacion a lo largo del clivaje, deformacion de las laminillas, perdida de los colores de interferencia y del pleocroismo. A pesar de las condiciones ambientales severas, el intemperismo incipiente genera minerales arcillosos y oxidos de hierro que se incorporan al material fino. Este ultimo forma recubrimientos discontinuos sobre los granos gruesos generando un modelo de distribucion c/f quitonico. La distribucion de los componentes finos en forma de recubrimientos sobre los granos gruesos proporciona una interaccion maxima con la humedad del suelo y la materia organica y con la generacion de micro-habitats para microorganismos. La caracteristica micromorfologica comun de los suelos estudiados consiste en una matriz compleja que combina tejidos bien conservados de musgos y liquenes y particulas minerales distribuidas entre ellos. Se concluye que los cuerpos edaficos estudiados son sin-sedimentarios: el deposito del material mineral ocurre simultaneamente con el crecimiento de las plantas primitivas. Los granos minerales estan atrapados entre los tejidos vegetales que forman el “armazon” de la matriz del suelo. Esta interaccion permite tambien la conservacion de la materia organica en la cubierta del suelo. Los suelos estudiados demuestran similitudes a las costras biologicas de otros ambientes terrestres extremos del presente y del pasado. EnglishThe soils of Antarctic oases - coastal as well as inland ice-free areas limited by ice sheet or ice shelves attract attention as a block of one of the most extreme terrestrial ecosystems of the Earth. The knowledge about early stages of pedogenesis, solum formation and stabilization, interaction between organic and mineral components in these soils is still limited. We performed micromorphological investigation of several thin soil profiles developed under mosses and lichens on the sediments deposited by meltwater in a lake depression of Schirmacher Oasis. Mineral components are dominated by sand particles of primary minerals (mostly quartz, K-Na feldspars and micas) derived from gneiss bedrock. Quartz grains exhibit surface structures indicative of cryogenic fragmentation, whereas biotite has signs of chemical alteration: exfoliation along cleavage planes, deformation of laminae, loss of interference colours and pleochroism. Despite severe environmental conditions, incipient weathering occurs that contribute clay minerals and iron oxides to the fine material. The latter forms discontinuous coatings on the coarse grains providing a chitonic c/f related distribution pattern. Arrangement of the fine components in form of coatings on coarse grains provides their maximal interaction with soil moisture and organic matter and generation of microhabitats for the microorganisms. Common micromorphological features of the studied soils is a complex groundmass which combines well preserved organic tissues of mosses and lichens and mineral particles spread among them. We conclude that the studied soil bodies are synsedimentary: fluvial (and possibly eolian) deposition of mineral material that occurs simultaneously with the growth of primitive plants. The mineral grains are trapped between plant tissues which form a framework of the soil matrix. This interlacing provides also conservation of organic material within the soil layer. Studied soils demonstrate similarities with the biological crusts of other present and past extreme terrestrial environments.

This chapter describes the soils of Queen Maud Land (QML). This is the part of Antarctica between longitudes 20° W and 45° E. QML is the fourth largest ice-free territory of Antarctica, comprising 3,400 km2 (6.9 % of total ice-free area). The most studied areas of QML in terms of soils include the Sor Rondane Mountains and Schirmacher Oasis (35 km2). QML is underlain by continuous permafrost. The mountains are underlain by thick permafrost; and active layer ranges from 8 to 40 cm in depth to from 30 to 120 cm in depth in the Schirmacher Oasis. The dominant soil taxa include Typic Haploturbels-Haplorthels and Lithic Haploturbels-Haplorthels under moss cover, Typic Aquorthels Haplorthels in soils along lake margins and those influenced by algae, Typic Haploturbels in areas of patterned ground, Typic Haplorthels in dry areas, and Typic and Lithic Anhyorthels-Anhyturbels in the mountains. Soils of Queen Maud Land are less developed than those elsewhere in East Antarctica because they are more distant from the coast and have not been influenced by penguins and other birds.