A comparison of two different approaches for mapping potential ozone damage to vegetation. A model study

Area of Science:

• Environmental science
• Plant physiology
• Atmospheric chemistry

Background:

• Ozone damage to vegetation poses a significant environmental risk in Europe.
• Current risk assessment methods include ozone concentration-based indices and stomatal flux-based approaches.

Purpose of the Study:

• To compare two distinct indicators of ozone damage risk to vegetation across Europe.
• To map and analyze the spatial patterns of ozone risk using the EMEP chemical transport model.
• To evaluate future risks under emission control scenarios.

Main Methods:

• Utilized the EMEP chemical transport model to simulate ozone damage indicators.
• Assessed two indicators: Accumulated Ozone exposure over a Threshold (AOTX) and Accumulated Stomatal Flux (AFstY).
• Simulated risks for wheat and beech forests under current and future emission scenarios (year 2020).

Main Results:

• Widespread exceedances of critical ozone damage levels were observed across Europe for both indicators.
• The AOTX and AFstY indicators exhibited markedly different spatial patterns of ozone risk.
• Model simulations indicated reduced vegetation damage risks for year 2020 scenarios.

Conclusions:

• Both AOTX and AFstY indicators show widespread ozone risk to European vegetation.
• The choice of indicator significantly influences the perceived spatial distribution of risk.
• The AOT40 index is more sensitive to emission reductions than AFstY, suggesting it may be a more responsive metric for policy evaluation.