TY - JOUR
T1 - Effects of chronic elevated ozone exposure on gas exchange responses of adult beech trees (Fagus sylvatica) as related to the within-canopy light gradient
AU - Kitao, Mitsutoshi
AU - Löw, Markus
AU - Heerdt, Christian
AU - Grams, Thorsten E.E.
AU - Häberle, Karl Heinz
AU - Matyssek, Rainer
N1 - Funding Information:
This work has been funded within the interdisciplinary research program “Growth and Parasite Defense” (SFB 607;TP B4) by Deutsche Forschungsgemeinschaft. We thank T. Feuerbach and P. Kuba for their skilful technical assistance, and H. Lohner and P. Klemm for leaf N and stable isotope analyses. We gratefully acknowledge Dr. I. Reiter for his helpful suggestions.
PY - 2009/2
Y1 - 2009/2
N2 - The effects of elevated O3 on photosynthetic properties in adult beech trees (Fagus sylvatica) were investigated in relation to leaf mass per area as a measure of the gradually changing, within-canopy light availability. Leaves under elevated O3 showed decreased stomatal conductance at unchanged carboxylation capacity of Rubisco, which was consistent with enhanced δ13C of leaf organic matter, regardless of the light environment during growth. In parallel, increased energy demand for O3 detoxification and repair was suggested under elevated O3 owing to enhanced dark respiration. Only in shade-grown leaves, light-limited photosynthesis was reduced under elevated O3, this effect being accompanied by lowered Fv/Fm. These results suggest that chronic O3 exposure primarily caused stomatal closure to adult beech trees in the field regardless of the within-canopy light gradient. However, light limitation apparently raised the O3 sensitivity of photosynthesis and accelerated senescence in shade leaves.
AB - The effects of elevated O3 on photosynthetic properties in adult beech trees (Fagus sylvatica) were investigated in relation to leaf mass per area as a measure of the gradually changing, within-canopy light availability. Leaves under elevated O3 showed decreased stomatal conductance at unchanged carboxylation capacity of Rubisco, which was consistent with enhanced δ13C of leaf organic matter, regardless of the light environment during growth. In parallel, increased energy demand for O3 detoxification and repair was suggested under elevated O3 owing to enhanced dark respiration. Only in shade-grown leaves, light-limited photosynthesis was reduced under elevated O3, this effect being accompanied by lowered Fv/Fm. These results suggest that chronic O3 exposure primarily caused stomatal closure to adult beech trees in the field regardless of the within-canopy light gradient. However, light limitation apparently raised the O3 sensitivity of photosynthesis and accelerated senescence in shade leaves.
KW - Adult trees
KW - Chronic free-air O fumigation
KW - Fagus sylvatica
KW - Leaf differentiation
KW - Light gradient
KW - Photosynthetic capacity
KW - Stomatal conductance
UR - http://www.scopus.com/inward/record.url?scp=57049173920&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2008.09.016
DO - 10.1016/j.envpol.2008.09.016
M3 - Article
C2 - 18976843
AN - SCOPUS:57049173920
SN - 0269-7491
VL - 157
SP - 537
EP - 544
JO - Environmental Pollution
JF - Environmental Pollution
IS - 2
ER -