The influence of climate change on stomatal ozone flux to a mountain Norway spruce forest

Daily stomatal ozone flux to a mountain Norway spruce forest stand at the Bily Kriz experimental site in the Beskydy Mts. (Czech Republic) was modelled using a multiplicative model during the 2009 growing season. The multiplicative model was run with meteorological data for the growing season 2009 and ALADIN-CLIMATE/CZ model data for the 2030 growing season. The exceedance of the flux-based critical level of O3 (Phytotoxic Ozone Dose) might be lower for Norway spruce at the Bily Kriz experimental site in a future climate (around 2030), due to increased stomatal closure induced by climate change, even when taking into account increased tropospheric background O3 concentration. In contrast, exceedance of the concentration-based critical level (AOT40) of O3 will increase with the projected increase in background O3 concentration. Ozone concentration and stomatal flux of ozone significantly decreased NEP under both present and future climatic conditions, especially under high intensities of solar radiation.

► We estimated stomatal ozone flux in a Norway spruce forest using a multiplicative model.
► The model was run with meteorological data for the 2009 and 2030 growing seasons.
► The exceedance of the flux-based critical level of O3 will decrease in a predicted future climate.
► The exceedance of AOT40 will increase. Stomatal flux significantly negatively affected NEP values.