Geoambientes, pedogênese e uso da terra no setor norte do Parque Nacional da Serra do Divisor, Acre / Geo-environments, pedogenesis and land use in north sector of the National Park of Serra do Divisor

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The Serra do Divisor National Park , in the Upper Jurua River, west of the State of Acre, with 784.077 hectares, is covered by primary forest vegetation, with high biodiversity. In this study, we caracterized and mapped the geoenvironmental units and the land use of the northern sector of the Park (319.373 ha), and we also studied the pedogenetics aspects of a topossequence in Serra do Divisor and aluvial soils of Moa River, in northwest of Acre. For identification, characterization and mapping of the geoenvironmental units, we used pedological, geomorpholgical and vegetation data obtained by The Ecologic-Economical Zoning of Acre (2006), elevation data by SRTM (Shuttle Radar Topographic Mission), digital semi-controled mosaic of vertical aerophotographics, soils profiles and fields observations. The land use was mapped and quantifed, using a Landsat 5 TM image from 2005,, vertical aerophotographs and field observations. In the pedological study, we analized physical, chemical, mineralogical and micromorphological attributes, of the Serra do Divisor and Moa river foodplain soils, explaining the factors and processes of soil formation in the northwestern part of the Acre State. We identified nine geoenvironmental units: (i) Deep valley and hillside with forests and young soils in Serra do Divisor; (ii) Highlands with Ceja Forest in sandy soils; (iii) Valleys and hillsides with forest and eutrofic soils; (iv) Upper Moa river floodplain with eutrofic soils; (v) Upper Moa river valleys with Bamboo Forest in eutrofic soils; (vi) Dissecated hills and plateaus with forest in eutrofic soils of the upper Moa and Azul rivers; (vii) Hills and plateau with forest in aluminic soils; (viii) Upper Moa river and tributaries foodplains with aluminic soils and; (ix) Sandy deposits with Buriti forests in distrofic soils. The land use was classified in farming areas and regeneration areas, representing 1.15 % and 0.43 %, respectively, of the northern sector. In general, the northwestern of Acre have typical environments of the Andean region;specially the highlands with Ceja Forest in Serra do Divisor. This area consists of important ecossystems with high biodiversity, representing a good attraction for research and ecoturism in this region. The land uses prevail in the border of most important Rivers, indicating activities with low impacts. More studies are necessary for the zonation of the Park, because of low impacts in the land use. The Serra do Divisor soils have an expressive acumulation of organic material in the surface horizons, because of the low nutrients, high Al levels and association with vegetation of difficult decomposition. The sandy texture, with high soil porosity, associated with high precipitation in this region, favor the migration of organic compounds bound to poorly crystalline Fe and Al forms. Sediment discontinuity represents the dominant factor in soil genesis at the Moa river foodplain. Those soils have evidences of 2:1 clays with hidroxy-Al interlayers in subsurface horizons.

ASSUNTO(S)

geo-environments land use uso da terra pedogenesis geoambientes pedzolizados ciencia do solo

ACESSO AO ARTIGO

Documentos Relacionados