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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/4119

Title: Chronic ozone exposure affects leaf senescence of adult beech trees: a chlorophyll fluorescence approach
Authors: GIELEN, Birgit
Loew, Markus
Deckmyn, Gaby
Metzger, Ursula
Franck, Fabrice
Heerdt, Christian
Matyssek, Rainer
VALCKE, Roland
Ceulemans, Reinhart
Issue Date: 2007
Citation: JOURNAL OF EXPERIMENTAL BOTANY, 58(4). p. 785-795
Abstract: Accelerated leaf senescence is one of the harmful effects of elevated tropospheric ozone concentrations ([O-3]) on plants. The number of studies dealing with mature forest trees is scarce however. Therefore, five 66-year-old beech trees (Fagus sylvatica L.) have been exposed to twice-ambient (2xambient) [O-3] levels by means of a free-air canopy O-3 exposure system. During the sixth year of exposure, the hypothesis of accelerated leaf senescence in 2xambient [O-3] compared with ambient [O-3] trees was tested for both sun and shade leaves. Chlorophyll (chl) fluorescence was used to assess the photosynthetic quantum yield, and chl fluorescence images were processed to compare functional leaf homogeneity and the proportion of O-3-injured leaf area (stipples) under ambient and 2xambient [O-3] regimes. Based on the analysis of chl fluorescence images, sun leaves of both ambient and 2xambient [O-3] trees had apparently developed typical necrotic O-3 stipples during high O-3 episodes in summer, while accelerated senescence was only observed with sun leaves of 2xambient [O-3] trees. This latter effect was indicated along with a faster decrease of photosynthetic quantum yield, but without evidence of changes in non-photochemical quenching. Overall, treatment effects were small and varied among trees. Therefore, compared with ambient [O-3], the consequence of the observed O-3-induced accelerated leaf senescence for the carbon budget is likely limited.
Notes: Univ Antwerp, Dept Biol, Res Grp Plant & Vegetat Ecol, B-2610 Antwerp, Belgium. Tech Univ Munich, D-85354 Freising Weihenstephan, Germany. Univ Liege, Dept Sci Biochim Vegetale, B-4000 Liege, Belgium. Tech Univ Munich, Lehrstuhl Okoklimatol, D-85354 Freising Weihenstephan, Germany. Hasselt Univ, Ctr Environm Sci, Dept SBG, Lab Mol & Phys Plant Physiol, B-3590 Diepenbeek, Belgium.Gielen, B, Univ Antwerp, Dept Biol, Res Grp Plant & Vegetat Ecol, Campus Drie Eiken,Univ Pl 1, B-2610 Antwerp, Belgium.birgit.gielen@ua.ac.be
URI: http://hdl.handle.net/1942/4119
DOI: 10.1093/jxb/erl222
ISI #: 000244659200007
ISSN: 0022-0957
Category: A1
Type: Journal Contribution
Validation: ecoom, 2008
Appears in Collections: Research publications

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