Effect of Short-term Water Stress on Leaf Gas Exchange Processes and Plant Water Potential in Schefflera

Increasing water stress situations were imposed on Schefflera arboricola Hayata ‘Compacta’ for up to 7 days under controlled growth chamber conditions. Net CO 2 exchange and transpiration rates, stomatal conductance to water vapor and xylem water potential were measured at constant temperature, photosynthetic photon flux density (PPFD), and atmospheric humidity. A strong relationship was found for transpiration and CO 2 exchange process. When the water content of the substrate decreased as a result of transpiration and soil surface evaporation, both transpiration and CO 2 exchange rates decreased drastically. Xylem water potential remained fairly constant during this soil moisture deficit. Following the drying cycle, efficient and fast recovery of the plants was observed.