This paper presents a new set of ozone flux based dose–response relationships for European trees. The model-based study takes into account soil water effects on stomatal flux. Different statistically derived ozone flux thresholds were applied in the model. The study found that climate region specific parameterisation often outperformed simplified parameterisation. These findings could help redefining critical levels for ozone effects on trees.
To derive O3 dose–response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy 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 PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate.
Read the article (external link to journal)
Design and development by Soapbox.