title: Quantification of ozone uptake at the stand level in a Pinus canariensis forest in Tenerife, Canary Islands: an approach based on sap flow measurements.
abstract: Ozone uptake was studied in a pine forest in Tenerife, Canary Islands, an ecotone with strong seasonal changes in climate. Ambient ozone concentration showed a pronounced seasonal course with high concentrations during the dry and warm period and low concentrations during the wet and cold season. Ozone uptake by contrast showed no clear seasonal trend. This is because canopy conductance significantly decreased with soil water availability and vapour pressure deficit. Mean daily ozone uptake averaged 1.9 nmol m(-2) s(-1) during the wet and cold season, and 1.5 nmol m(-2) s(-1) during the warm and dry period. The corresponding daily mean ambient ozone concentrations were 42 and 51 nl l(-1), respectively. Thus we conclude that in Mediterranean type forest ecosystems the flux based approach is more capable for risk assessment than an external, concentration based approach.
authors.affiliation: Division of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Rennweg 1, A-6020 Innsbruck, Austria. gerhard.wieser@uibk.ac.at
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wieser
authors.forename: Vanessa C
authors.initials: VC
authors.lastname: Luis
authors.forename: Emilio
authors.initials: E
authors.lastname: Cuevas
mesh_terms: D001266:Atlantic Islands; D002980:Climate; D004784:Environmental Monitoring / Q000379:methods; D010083:Oxidants, Photochemical / Q000493:pharmacokinetics*; D010126:Ozone / Q000493:pharmacokinetics*; D028223:Pinus / Q000378:metabolism*; D018526:Plant Transpiration / Q000502:physiology; D012621:Seasons; D014197:Trees / Q000378:metabolism
chemical_list: D010083:Oxidants, Photochemical; D010126:Ozone