Effect of soil drought on evapotranspiration of a young spruce forest
F. Matejka, J. Rožnovský, T. Hurtalová, D. Janoušhttps://doi.org/10.17221/11871-JFSCitation:Matejka F., Rožnovský J., Hurtalová T., Janouš D. (2002): Effect of soil drought on evapotranspiration of a young spruce forest. J. For. Sci., 48: 166-172.
Daily courses of the actual transpiration of a forest stand were determined by an experimentally verified mathematical Soil – Vegetation – Atmosphere Transfer model. The results refer to the Norway spruce (Picea abies [L.] Karst.) monoculture situated in the highest locations of the Beskids Mts. Drought-free transpiration was estimated as a model simulation run for nonlimiting soil moisture exceeding the level of decreased availability of water. Drought-induced reduction in transpiration was quantified as a difference between actual transpiration and simulated transpiration for moist soil. The results led to conclusions that dry soil causes a significant reduction in actual evapotranspiration and its components in comparison with moist soil. Simultaneously, the effect of soil desiccation was compensated by extremely high evaporative demands of the atmosphere, so that the daily totals of evapotranspiration and its components remained sufficiently high. The high values of global radiation and saturation deficit in the air favourably influenced the water regime of the analysed forest stand in the dry period.
evapotranspiration; transpiration; evaporation; soil drought; saturation deficit; Norway spruce