New flux based dose–response relationships for ozone for European forest tree species.

To derive O 3 dose–response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O 3 doses (POD y ) were related to biomass reductions. POD y was calculated using a stomatal flux model with a range of cut-off thresholds ( y ) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce POD y , mainly due to the short duration of soil water stress periods. This study validates the stomatal O 3 flux concept and represents a step forward in predicting O 3 damage to forests in a spatially and temporally varying climate. [ABSTRACT FROM AUTHOR]