title: Risk assessments for forest trees: the performance of the ozone flux versus the AOT concepts.
abstract: Published ozone exposure-response relationships from experimental studies with young trees performed at different sites across Europe were re-analysed in order to test the performance of ozone exposure indices based on AOTX (Accumulated exposure Over a Threshold of X nmol mol(-1)) and AF(st)Y (Accumulated Stomatal Flux above a threshold of Y nmol m(-2) s(-1)). AF(st)1.6 was superior, as compared to AOT40, for explaining biomass reductions, when ozone sensitive species with differing leaf morphology were included in the analysis, while this was not the case for less sensitive species. A re-analysis of data with young black cherry trees, subject to different irrigation regimes, indicated that leaf visible injuries were more strongly related to the estimated stomatal ozone uptake, as compared to the ozone concentration in the air. Experimental data with different clones of silver birch indicated that leaf thickness was also an important factor influencing the development of ozone induced leaf visible injury.
authors.affiliation: Swedish Environmental Research Institute (IVL), PO Box 5302, S-400 14, Göteborg, Sweden. pererik.karlsson@ivl.se
authors.forename: P E
authors.initials: PE
authors.lastname: Karlsson
authors.forename: S
authors.initials: S
authors.lastname: Braun
authors.forename: M
authors.initials: M
authors.lastname: Broadmeadow
authors.forename: S
authors.initials: S
authors.lastname: Elvira
authors.forename: L
authors.initials: L
authors.lastname: Emberson
authors.forename: B S
authors.initials: BS
authors.lastname: Gimeno
authors.forename: D
authors.initials: D
authors.lastname: Le Thiec
authors.forename: K
authors.initials: K
authors.lastname: Novak
authors.forename: E
authors.initials: E
authors.lastname: Oksanen
authors.forename: M
authors.initials: M
authors.lastname: Schaub
authors.forename: J
authors.initials: J
authors.lastname: Uddling
authors.forename: M
authors.initials: M
authors.lastname: Wilkinson
mesh_terms: D029662:Betula / Q000187:drug effects / Q000378:metabolism; D018533:Biomass; D004781:Environmental Exposure / Q000009:adverse effects; D004784:Environmental Monitoring / Q000379:methods; D010083:Oxidants, Photochemical / Q000493:pharmacokinetics / Q000633:toxicity*; D010126:Ozone / Q000493:pharmacokinetics / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D027861:Prunus / Q000187:drug effects / Q000378:metabolism; D018570:Risk Assessment / Q000379:methods; D014197:Trees / Q000187:drug effects* / Q000378:metabolism
chemical_list: D010083:Oxidants, Photochemical; D010126:Ozone