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New critical levels for ozone effects on young trees based on AOT 40 and simulated leaf uptake of ozone
2004
Karlsson, Pererik | Uddling, Johan | Braun, Sabine | Broadmeadow, Mark | Elvira, Susana | Gimeno, Benjamin | Le Thiec, Didier, | Oksanen, Elina | Vandermeiren, Karine | Wilkinson, Matthew | Emberson, Lisa
New critical levels for ozone effects on young trees based on AOT 40 and simulated leaf uptake of ozone
2004
Karlsson, Pererik | Uddling, Johan | Braun, Sabine | Broadmeadow, Mark | Elvira, Susana | Gimeno, Benjamin | Le Thiec, Didier | Oksanen, Elina | Vandermeiren, Karine | Wilkinson, Matthew | Emberson, Lisa | Swedish Environmental Research Institute (IVL) | Department of Plant and Environmental Sciences ; Göteborgs Universitet = University of Gothenburg (GU) | Institute for Applied Plant Biology ; Partenaires INRAE | Forest Research [Great Britain] | Ecotoxicidad de la Contaminacion Atmosferica ; Partenaires INRAE | Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | University of Joensuu | Sciensano [Bruxelles] ; Réseau International des Instituts Pasteur (RIIP) | Stockholm Environment Institute at York (SEI-YORK) ; University of York [York, UK]
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Show more [+] Less [-]Toxic effect of air pollution on plants : characterization of ozone fluxes and analysis and modelling of ozone impact on photosynthesis
2004
Le Thiec, Didier, | Dizengremel, Pierre, | Bethenod, Olivier, | Castell, Jean-François, | Biolley, J.P. | Leitão, Luís | Cellier, Pierre
Formation and Deposition of Ozone in a Red Pine Forest
2004
Utiyama, Masahiro | Fukuyama, Tsutomu | Yamada Maruo, Yasuko | Ichino, Toshihiro | Izumi, Katsuyuki | Hara, Hiroshi | Takano, Kenichi | Suzuki, Haruko | Aoki, Masatoshi
Concentrations of ozone and nitrogen oxides, together with air temperature and solar radiation intensity, were measured at several heights on a tower standing through the canopy of a red pine forest in summer and in autumn. In the summer observation, the diurnal variation patterns of ozone concentration both above and below the canopy were all similar and parallel to the solar radiation intensity. Using the data collected immediately above the canopy, deviation from the Leighton relationship and variations of concentration sums [O₃] + [NO] and [NO₂] + [NO] were examined, and as a result, it was supposedthat ozone was photochemically formed there in the daytime, probably because hydrocarbons emitted from pine trees broke the photostationary state among ozone and nitrogen oxides. The vertical temperature profile exhibited an inversion at the leaf-layer, which must have hindered vertical mixing of the air and made the trunk space more or less isolated from the upper atmosphere. These observations led to an idea that the similarity of the ozone variation pattern at every height was caused by the photochemical formation that proceeded simultaneously above and below the canopy rather than by vertical transport. Such situations of ozone formation were supported by observation of two maximums in the ozone vertical profile, one immediately above the canopy and another in the trunk space. Another feature of the ozone profile was a deep minimum in the leaf layer, which indicated ozone deposition onto leaf surfaces. This study thus revealed concurrence of ozone formation and deposition, and left two potentially important implications worthy of further investigation: (1) a forest is not always a sink but can be a source of ozone in sunlit conditions, and (2) deposition of ozone to trees can take place not only from outside but also from inside of a forest. In the autumn observation, however, the ozone formation was barely recognizable above the canopy and no longer found in the trunk space; in addition, the ozone concentration minimum in the leaf layer disappeared, suggesting that the deposition or removal was dependent on temperature.
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