HR: 0800h
AN: A51B-0027    [Abstracts]
TI: Leaf Uptake of Nitrogen Dioxide (NO2) Under Different Environmental Conditions.
AU: * Chaparro-Suarez, I
EM: gchaparro@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Thielmann, A
EM: athielm@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Meixner, F X
EM: meixner@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Kesselmeier, J
EM: jks@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AB: The chemical budget of Ozone in the troposphere is largely determined by the concentration of NOx (NO, NO2) within a photostationary equilibrium. It is well known that atmospheric concentration is strongly influenced by the bi-directional exchange of NO2. However, there is some debate about the magnitude of the compensation point. Therefore, we investigated the uptake of atmospheric NO2 by trees in relation to atmospheric NO2 concentrations. Using the dynamic chamber technique and a sensitive and specific NO-analysator (CLD 780, Eco Physics) we measured the uptake of NO2 by four different tree species (Betula pendula, Fagus sylvatica, Quercus ilex und Pinus sylvestris) under field and laboratory conditions. Simultaneous measurements of CO2 exchange and transpiration were performed to track photosynthesis and stomatal conductance. Depending on tree species we found the exchange to be controlled by very low NO2 compensation points sometimes reaching zero values (no emission) under laboratory conditions. In the field a high compensation point for European beech (Fagus sylvatica) was observed, which is understood as a result of complex atmospheric conditions.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere: composition and chemistry
DE: 0426 Biosphere/atmosphere interactions (0315)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005