Water balance output components are distinctly regulated by precipitation and evapotranspiration in Pinus taeda L. plantations in Southern Brazil

The knowledge about the impact of climate variables on estimated water balance hold significant promise for the estimation of critical periods of soil water deficit or surplus. Here we establish the functional relations between water deficit, water surplus and soil water storage with precipitation and evapotranspiration for Pinus, in Southern Brazil. For that purpose a 31-years daily data series of precipitation (P) and reference evapotranspiration (ETo) were used as input components of the modified Thornthwaite and Mather water balance model. Principal component analysis was performed as an exploratory analysis of the water balance components related to P and ETo. The water deficit was mostly affected by the seasonality of evapotranspiration depending on soil water availability. The sole effect of P on water surplus (WS) determined its variability and showed the possible use of P to estimate WS. Soil water storage was not directly influenced by P or ETo.