The energy and water balance of a Eucalyptus plantation in southeast Brazil

The eddy covariance method was used to measure energy and water balance of a plantation of Eucalyptus (grandis × urophylla) hybrids over a 2 year period. The average daily evaporation rates were 5.4 (±2.0) mm day−1 in summer, but fell to 1.2 (±0.3) mm day−1 in winter. In contrast, the sensible heat flux was relatively low in summer but dominated the energy balance in winter. Evaporation accounted for 80% and 26% of the available energy, in summer and winter respectively. The annual evaporation was 82% (1124 mm) and 96% (1235 mm) of the annual rainfall recorded during the first and second year, respectively. Daily average canopy and aerodynamic conductance to water vapour were in the summer 51.9 (±38.4) mm s−1 and 84.1 (±25.6) mm s−1, respectively; and in the winter 6.0 (±10.5) mm s−1 and 111.6 (±24.6) mm s−1, respectively.