Details

Autor(en) / Beteiligte

• Emberson, Lisa D.
• Büker, Patrick
• Ashmore, Mike R.

Titel

Assessing the risk caused by ground level ozone to European forest trees: A case study in pine, beech and oak across different climate regions

Ist Teil von

• Environmental pollution (1987), 2007-06, Vol.147 (3), p.454-466

Ort / Verlag

Oxford: Elsevier Ltd

Erscheinungsjahr

2007

Quelle

MEDLINE

Beschreibungen/Notizen

• Two different indices have been proposed for estimation of the risk caused to forest trees across Europe by ground-level ozone, (i) the concentration based AOT40 index (Accumulated Over a Threshold of 40 ppb) and (ii) the recently developed flux based AFst Y index (Accumulated stomatal Flux above a flux threshold Y). This paper compares the AOT40 and AFst Y indices for three forest trees species at different locations in Europe. The AFst Y index is estimated using the DO 3SE (Deposition of Ozone and Stomatal Exchange) model parameterized for Scots pine ( Pinus sylvestris), beech ( Fagus sylvatica) and holm oak ( Quercus ilex). The results show a large difference in the perceived O 3 risk when using AOT40 and AFst Y indices both between species and regions. The AOT40 index shows a strong north-south gradient across Europe, whereas there is little difference between regions in the modelled values of AFst Y. There are significant differences in modelled AFst Y between species, which are predominantly determined by differences in the timing and length of the growing season, the periods during which soil moisture deficit limits stomatal conductance, and adaptation to soil moisture stress. This emphasizes the importance of defining species-specific flux response variables to obtain a more accurate quantification of O 3 risk. A new flux-based model provides a revised assessment of risks of ozone impacts to European forests.