Hydrological consequences of land-use change from forest to pasture in the Atlantic rain forest region

  • Luiz Felippe Salemi Centro de Energia Nuclear na Agricultura - Universidade de São Paulo
  • Juliano Daniel Groppo Centro de Energia Nuclear na Agricultura - Universidade de São Paulo
  • Rodrigo Trevisan Centro de Energia Nuclear na Agricultura - Universidade de São Paulo
  • Gustavo Bicci Seghesi Centro de Energia Nuclear na Agricultura - Universidade de São Paulo
  • Jorge Marcos de Moraes Centro de Energia Nuclear na Agricultura - Universidade de São Paulo
  • Silvio Fronsini de Barros Ferraz Escola Superior de Agricultura "Luiz de Queiroz" - Universidade de São Paulo
  • Luiz Antonio Martinelli Centro de Energia Nuclear na Agricultura - Universidade de São Paulo
Keywords: Atlantic Forest, water, soil, water resources

Abstract

The Atlantic rain forest is the most endangered ecosystem in Brazil. Its degradation has started since 1500 when the European settlers arrived. Despite of all land use changes that have occurred, hydrological studies carried out in this biome have been limited to hydrological functioning of rain forests only. In order to understand the hydrological consequences of land-use change from forest to pasture, we described the hydrological functioning of a pasture catchment that was previously covered by tropical rain forest. To reach this goal we measured the precipitation, soil matric potential, discharge, surface runoff and water table levels during one year. The results indicated that there is a decrease in surface soil saturated hydraulic conductivity. However, as low intensity rainfall prevails, the lower water conductivity does not necessarily leads to a substantially higher surface runoff generation. Regarding soil water matric potential, the pasture presented higher moisture levels than forest during the dry season. This increase in soil moisture implies in higher water table recharge that, in turn, explain the higher runoff ratio. This way, land-use change conversion from forest to pasture implies a higher annual streamflow in pasture catchments. Nonetheless, this increase in runoff due to forest conversion to pasture implies in losses of biological diversity as well as lower soil protection.
Published
26/12/2012
Section
Papers