Transpiration of Anatolian black pine and sessile oak forest stands in a sub-humid region of Turkey

Objectives of this study were to compare transpiration of Anatolian black pine ( Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe) and sessile oak ( Quercus petraea (Matt.) Liebl) tree stands and modelling stand transpiration based on the measured climatic factors. Stand transpirations were calculated from sap flow measurements made by the trunk heat balance method. Mean daily and yearly canopy transpirations (E c ) were 1.05 mm day -1 and 378.3 mm year -1 for the pine stand and 3.52 mm day -1 and 801.7 mm year -1 for the oak stand, respectively. There was a highly positive correlation between daily stand transpiration and wind speed, global radiation, air vapour pressure deficit and air temperature, but a negative correlation with relative humidity for both stands. Soil water potential had little effect on stand transpiration. We conducted an exploratory factor analysis (PCR) to detect effective meteorological factors of stand transpiration and to develop linear regression equations for predicting transpiration of pine and oak stands. The model equations accounted to 81% of the variations in transpiration for pine stand and 85% for oak stand. Transpiration of forest stands should be considered for effective vegetation management practices and the model equations can be used to estimate transpiration of pine and oak stands in the region.