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Birds nesting activity during the short antarctic summer promotes intense localized sea-land transference of nutrients and organic matter, originating the ornithogenic soils. This study presents chemical, physical and mineralogical data as well as some micropedological and submicroscopical characteristics of ornithogenic and non-ornithogenic soils from the western coast of the Admiralty Bay, King George Island. Chemical analyses of selected soil properties show P and N enrichment in ornithogenic soils. Vegetation growth is enhanced and results in high soil organic C contents. A granular, sub-rounded structure composed by silt particles surrounded by illuvial phosphates is typical at ornithogenic horizons. These illuviation features characterize a distinct process of phosphatization, with P mobility and neoformation of secondary phosphates, such as taranakite, minyulite and leucophosphite. Ornithogenic sites are extremely important and constitute the most important locci of C sequestration in antarctic terrestrial ecosystems. A classification scheme for ornithogenic soils is proposed within the Soil Taxonomy and WRB classification systems.

This paper investigates the natural and anthropogenic processes controlling sediment chemistry in Admiralty Bay, King George Island, Antarctica, emphasizing the area affected by the Brazilian Antarctic Station Comandante Ferraz (Ferraz). Total and bioavailable concentrations of sixteen elements were determined in 32 sediment and 14 soils samples. Factor analysis allowed us to distinguish three groups of samples: (1) Ferraz sediments, with higher content of total trace metals and organic matter; (2) control sediments, with intermediate characteristics; (3) Ferraz soils, with higher bioavailability of most metals due to its oxidizing condition and low organic matter content. Major elements such as Fe, Al, Ca and Ti presented similar levels in all three groups. Enrichment factor calculations showed that paints, sewage and petroleum contamination enhanced metal concentrations in Ferraz surface sediments as follows: B, Mo, and Pb (>90%); V and Zn (70-80%); Ni, Cu, Mg, and Mn (30-40%). Despite evidence of contamination in these sediments, the low bioavailability, probably caused by iron-sulfide, indicates small environmental risks.

-(Soils associated with rock outcrops in the Brazilian mountain ranges Mantiqueira and Espinhaço). Espinhaço and Mantiqueira are two mountain ranges of great importance in Brazil. In the uppermost parts of these areas, unique ecosystems occur, generally associated with rock outcrops, they are collectively called High Altitude Rocky Complexes. These environments show distinct soil and biota characteristics in relation to the surrounding biome. The soils are generally shallow, coarse textured, with high Al 3+ and varying amounts of organic matter. Entisols, Inceptsols and Histosols are dominant, directly associated with the rock outcrops, and forming a complex mosaic of soils. Some of these soils are endemic, based on peculiar conditions of parent materials, topography and vegetation, and this pedodiversity is important for detecting unique and endangered soils. In these soils, organic matter is highly humified, with a great amount of soluble forms and conspicuous presence of charcoal. Spodic horizons and dark water rivers are typically associated with quartzite and quartzite outcrops, formed by illuviation of organic compounds, being less common in granitic rocks. The very low nutrient content of these soils and other environmental limitations required the development of specific physiological and morphological plant adaptations. Most high altitude environments are unstable under current climatic conditions, and anthropic interventions may be accelerating this process. Detailed soil surveys are necessary for a better understanding of the role of these soils in ecological processes and for the development of adequate conservation policies.Key words -high altitude rocky complexes, lithosols, organic soils RESUMO -(Solos associados aos afloramentos rochosos das Serras do Espinhaço e da Mantiqueira). A Serra do Espinhaço e a Serra da Mantiqueira são duas cadeias de grande importância para o Brasil. Nas partes mais altas destas serras encontram-se ecossistemas com características singulares, associados aos afloramentos rochosos, denominados Complexos Rupestres de Altitude. Esses ambientes apresentam características do solo e da vegetação distintas das áreas adjacentes. Os solos são em geral rasos, arenosos, com alta saturação de alumínio e teores variados de matéria orgânica. Neossolos Litólicos, Cambissolos e Organossolos são as classes de solo dominantes, diretamente associadas aos afloramentos, formando um mosaico de solos. Alguns solos encontrados nestes ambientes são endêmicos, em função das características peculiares da rocha matriz, da topografia e da vegetação, e sua preservação é estratégica por se tratar de solos raros e ameaçados de extinção. A matéria orgânica desses solos apresenta alto grau de humificação, com grande quantidade de frações solúveis, e a presença generalizada de fragmentos de carvão. Horizontes espódicos e rios negros estão tipicamente associados às áreas de afloramento de arenito e quartzito, sendo formados pela iluviação de compostos orgânicos, e sendo menos comuns nas áreas de ...

Results obtained during the International Polar Year (IPY) on the thermal state of permafrost and the active layer in the Antarctic are presented, forming part of ANTPAS ('Antarctic Permafrost and Soils'), which was one of the key projects developed by the International Permafrost Association and the Scientific Committee for Antarctic Research for the IPY. The number of boreholes for permafrost and active-layer monitoring was increased from 21 to 73 during the IPY, while CALM-S sites to monitor the active layer were increased from 18 to 28. Permafrost temperatures during the IPY were slightly below 08C in the South Shetlands near sea-level, showing that this area is near the climatic boundary of permafrost and has the highest sensitivity to climate change in the region. Permafrost temperatures were much lower in continental Antarctica: from the coast to the interior and with increasing elevation they ranged between À13.38C and À18.68C in Northern Victoria Land, from À17.48C to À22. during the IPY shows that the range of ground temperatures in the Antarctic is greater than in the Arctic.