Solos de Lions Rump, Antártica Marítima: Processos de Formação, Classificação, Mapeamento e monitoramento da camada ativa

• Ano de defesa: 2012
• Autor(a) principal: Almeida, Ivan Carlos Carreiro
• Orientador(a): Fernandes, Raphael Bragança Alves
• Banca de defesa: Costa, Liovando Marciano da , Oliveira, Fábio Soares de , Mendonça, Eduardo de Sá , Simas, Felipe Nogueira Bello
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Solos e Nutrição de Plantas
• Departamento: Fertilidade do solo e nutrição de plantas; Gênese, Morfologia e Classificação, Mineralogia, Química,
• País: BR
• Palavras-chave em Português: Criossolos; Temperatura do solo; Permafrost; Camada ativa
• Palavras-chave em Inglês: Criossolos; Soil temperature; Permafrost; Active layer
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO
• Link de acesso: http://locus.ufv.br/handle/123456789/1660

In this context, the present study is structured within a wide network of Brazilian scientific cooperation for the Antarctic region, with a special focus in the area known as Lions Rump, located in the King George Bay, Maritime Antarctica. The objective of this study was to evaluate the processes of soil formation in the area, its main physical, chemical, mineralogical and micromorphological characteristics, the hydrothermal regime, geomorphological formations present, ending with the classification and mapping of soils according to the WRB and USDA classification systems. Twenty-six soil profiles from Lions Rump (LR), King George Bay, Maritime Antarctica were described, sampled and analyzed for their physical, chemical and mineralogical properties, as a result, a soil map was made. Results showed that soils in LR are most formed from weathered basalt-andesitic rocks, having apatite as accessory mineral, with high P background. For this purpose, the area was covered and twenty-six soil profiles were described, sampled and analyzed. The results indicated that soil chemical properties, mineralogy and vegetation type were strongly influenced by the duration of the occupation by penguins and soil drainage. The main vegetation formations within the area were instrumental in the water-thermal regime of the active layer of soil. The results grouped Lions Rump soils into three groups, depending on the ornithogenic influence. Acidic pH Ornithogenic soils predominate in the oldest and most stable of positions the landscape, where the occupation of the birds was longer lasting. They have dense vegetation with higher plants, low pH and base saturation, high levels of P, Al3+, total organic carbon (TOC) and total nitrogen. Neutral pH ornithogenic soils, similar to previous ones, have high levels of P and dense vegetation; however, have high base saturation and pH close to neutral. These are present in areas recently occupied by the ornithogenic influence, especially in the Quaternary moraines and uplifted terraces. The main difference between the two groups of ornithogenic soils was the exposure time under the influence of the bird and the amount of guano depositions. In ornithogenic soils, phosphatization is the main process of soil formation, in which the phosphate minerals are formed from the interaction of guano with the primary minerals of the soil. Non- ornithogenic soils have basic pH, high base saturation, low TOC and almost devoid of vegetation. Typic Dystrogelepts ornithic and Typic Gelorthents ornithic are the main soils in LR, which possibly represents one of the first ice-free areas colonized by penguins in Maritime Antarctica. Typic Dystrogelepts ornithic from LR represent the deepest, most structured and reddish soils so far described in the area. Typic Haplogelepts ornithic are the main soils on first and second moraine levels from the White Eagle Glacier. Typic Haplorthels and Lithic Haplorthels are present just above 80 m a.s.l., especially on the top areas and paraglacial spots, and represent LR Gelisols, with gelic materials within 100 cm of the soil surface and permafrost within 200 cm of the soil surface. Despite their occurrence only at higher altitudes, they represent the greatest soil cover in the studied area. Turbic Haplogelepts and Typic Haplorthents are situated between 40 and 80 m a.s.l., without bird nesting influence and absent of permafrost within 200 cm in the profile. Vitrandic Cryopsamments and Oxyaquic Cryopsamments dominated the first level of terraces and former beaches along the coastal area. Other soils classified are present in very limited areas: Lithic Cryorthents ornithic, present on the sea stacks rock outcrops (basaltic plugs) close to the beach, and Typic Gelifluvents ornithic represent a small area on glacial alluvial fans. Overall, the distribution and classification of local soils allowed the separation of two main soil domains in LR: (1) Ornithogenic soils (without permafrost) and the Gelisols (above 80 m a.s.l.). The monitoring of active layer thermal regime at Lions Rump was realized in two shallow boreholes, geographic closed, at proximally altitude and same soil class but under different vegetation. The ground temperature series were collected at 1-hour intervals, recorded of two years from March 2009 to February 2011. In both boreholes, a network of three soil temperatures sensors were installed at 10, 30 and 80 cm depths, one moisture sensor at 80 cm and one air temperature sensor 100 cm height. The two sites show significant differences of the mean annual ground temperature for all depths. The moss site show lower soil temperature amplitude than Usnea site. The soil temperature at Usnea site followed most the variability of air temperate. Moss site show more soil humid throughout the years because of his position on the landscape (water track). The buffer effect on moss site happens because of the high content of water available associated with the moss vegetation. The active layer in both sites of Lions Rump is thick and the both boreholes did not reach the permafrost table, but probable it is between one meter depth.