Processos hidrológicos em um fragmento de Floresta Estacional Semidecidual no município de Viçosa, MG

• Autor(a) principal: Lorenzon, Alexandre Simões
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3081
• topic: Hidrologia Florestal; Precipitação efetiva; Escoamento superficial; Mata Atlântica; Forest hydrology; Effective precipitation; Runoff; Mata Atlântica; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::CONSERVACAO DA NATUREZA

The Mata Atlântica was one of the biomes that suffered most from the human action over the years. That led to the fragmentation of this biome, which is now at the stage of secondary succession, altered and impoverished in its original floristic composition. However, although fragmented and altered, these woodlands are a valuable source for studying the relationships between forest and water. This study aimed to evaluate the net precipitation and interception of rainfall in a forest fragment in early and advanced stages of regeneration, measure the stemflow of forest species and measure the runoff in the area of initial regeneration. This work was led in the Station of Research, Training and Environmental Education Mata do Paraíso, located in Viçosa, Zona da Mata de Minas Gerais during the period 2009 to 2011. The area has 194 ha and is located in the area of Semideciduous Seasonal Forest, composing a mosaic of different successional stages. To evaluate the net precipitation, interception, were allocated at each stage of regeneration, three plots of 20 x 20 m with throughfall pluviometer. Within each plot of internal precipitation was allocated a plot of 10 x 10 m, which were installed in stemflow collectors in all trees with a circumference ≥ 15 cm at 1.30 m above the ground (CBH). The runoff was obtained by averaging three installments, allocated in the area of initial regeneration. In this same area, we tested the compaction and infiltration capacity of soil water. The net precipitation and interception were 1284.64 and 225.32 mm respectively for the initial stage and 1131.45 and 378.51 mm respectively for the advanced stage of regeneration, corresponding, respectively, 85.08, 14.92, 74, 93 and 25.07 % of the precipitation in open, which was equal to 1510 mm. The plots of stemflow were sampled 126 individuals in 29 families and 59 species. The species with the highest stemflow was the Euterpe edulis, scoring a total of 637 liters throughout the study period. The runoff was equal to 29.69 mm, corresponding to 2.08 % of the precipitation that was open to 1425.51 mm. The compaction in the layer of 0-10 cm deep in soil and infiltration capacity were equal to 0.45 MPa, and 1509 mm/h, respectively. The stage of regeneration of the Mata do Paraíso influence on the dynamics of rainwater in the forest, the precipitation inside the variable that most contributes to soil water. Although stemflow represents a small percentage of precipitation in the open, for some species to stemflow water is significant water near the roots. The runoff was high for the soil conditions encountered, indicating the existence of other influential factors not analyzed in this study. The adjusted equations were consistent, showing that the amount of precipitation is the major influence on hydrological processes studied here.