Ipucas da planície do Araguaia, estado do Tocantins: ambiente físico de ocorrência, solos e uso da terra

• Autor(a) principal: Martins, Alan Kardec Elias
• Data de Publicação: 2004
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/539
• topic: Manejo; Preservação; Geoprocessamento; Pedo-Geomorfológia; Ipucas; Solo; Monitoramento ambiental; Environmental management; Preservation; Geomorphology; Land use; Ipucas; Environmental monitoring; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::CONSERVACAO DA NATUREZA::RECUPERACAO DE AREAS DEGRADADAS

This work was carried out in hte municipality of Lagoa da Confusão in the State of Tocantins, Brazil. The objective was to find out about the soil use and the geologic, geomorphologic and soil features in the ipucas areas. An area of 8,232 ha was used of which 1,762 ha belong to a hydroagricultural project with access roads. Ipucas are natural forest fragments that occur around the Bananal Isle, in an ecotone region between the Cerrado and the Amazon Forest. Methodogically spoken, mappings were using ETM+Landsat-7 images, 3, 4, 5 and 8 bands, obtained in August 22nd 2002. The land use map generated nine classes which later were confirmed in field surveys. By means of this classification, the dominance of extensive plains (cleared and uncleared land: 3,003 ha) was shown upon the other features on the landscape composition. Among the other features of natural occurrence, by decreasing order, there are cerrado (1,218 ha), the ipucas (1,107 ha), the riparian forest (622 ha) and the rock outcrops (376 ha), besides water collections (144 ha). Also geologic, geomorphologic and soil maps were generated. According to the results, the variation among and within the foodable ecosystems are mainly shown in changes in the floristic composition and structure of the plant communities, forming true mosaics. The soils in the area are classified as: Gleisoil, sandy-clay Plinthsoil and clayish-sand Plinthsoil. The results indicate that all the Gleisoils under ipucas (53 and 54) are acidic and extremely poor in nutrients such as Ca, Mg and K, while the aluminum content is very higl. When the geologic map was generated in detail it was possible to identify two geologic units: Sedimentary cover of Bananal and Residual of the Tocantins Group. In the geomorphologic in detail it was possible to identify five geomorphologic units: Closed Depression with ipuca, Accumulation Plain, Alluvial Plain, Dissected Plain and Rock Emergence. The combination of these elements results in the various earth landscapes, that is, in various relief forms and vegetation typs, which are organized in an arrangement or mosaic, that result in an unique cluster of interactive ecosystems. The conclusion is that the ipucas need to be understood, preserved and maintained because of their soil and geomorphologic features as well as other ecologic factors.