Abstract
Within the scope of quantifying ozone (O3 ) effects on forest tree crowns it is still an open question whether cuvette branches of adult trees are reasonable surrogates for O3 responses of entire tree crowns and whether twigs exhibit autonomy in defense metabolism in addition to carbon autonomy. Therefore, cuvette-enclosed branches of mature beech (Fagus sylvatica) trees were compared with branches exposed to the same and different ozone regimes by a free-air fumigation system under natural stand conditions by means of a vice versa experiment. For this purpose, cuvettes receiving 1 × O3 air were mounted in trees exposed to 2 × O3 and cuvettes receiving 2 × O3 air were mounted in trees exposed to 1 × O3 in the upper sun crown. At the end of the fumigation period in September 2004, leaves were examined for differences in gas exchange parameters, pigments, antioxidants, carbohydrates, and stable isotope ratios. No significant differences in foliar gas exchange, total carbohydrates, stable isotope ratios, pigment, and antioxidant contents were found as a consequence of cuvette enclosure (cuvette versus free-air branches) of the same O3 concentrations besides increase of glucose inside the cuvettes and reduction of the de-epoxidation state of the xanthophyll cycle pigments. No significant ozone effect was found for the investigated gas exchange and most biochemical parameters. The total and oxidized glutathione level of the leaves was increased by the 2 × O3 treatment in the cuvette and the free-air branches, but this effect was significant only for the free-air branches. From these results we conclude that cuvette branches are useful surrogates for examining the response of entire tree crowns to elevated O3 and that the defence metabolism of twigs seems to be at least partially autonomous.
Key words
Branch cuvettes - ozone -
Fagus sylvatica
- free-air fumigation - gas exchange - antioxidants - carbohydrates - stable isotopes
References
Fagus sylvatica L.) and Norway spruce (Picea abies L.) trees in a mixed forest stand.
Plant Biology.
(2007);
9
227-241
Ziziphus mauritiana and Prunus persica trees: water relations, osmotic adjustment and carbon isotope composition.
Australian Journal of Plant Physiology.
(2000);
27
985-996
Fagus sylvatica L.) under chronic free-air O3 fumigation.
Plant Biology.
(2007);
9
207-214
The role of glutathione in plant reaction and adaptation to air pollutants. Significance of Glutathione in Plant Adaptation to the Environment, Kluwer Handbook Series of Plant Ecophysiology. Amsterdam; Kluwer Publishers (2001): 185-208
Light stress and photoprotection related to the xanthophyll cycle. Foyer, C. H. and Mullineaux, P. M., eds. Causes of Photooxidative Stress and Amelioration of Defense Systems in Plants. Boca Raton; CRC Press (1994): 105-126
(Prunus serotina) trees.
Environmental Pollution.
(2000);
108
297-302
Oxygen metabolism and electron transport in photosynthesis. Scandalios, G., ed. Oxidative Stress and the Molecular Biology of Antioxidant Defense. Cold Spring Harbor; Cold Spring Harbor Laboratory Press (1997): 587-621
Fagus sylvatica trees.
Journal of Forest Research.
(2006);
11
69-75
(Betula pendula) under low ozone concentration.
Trees.
(1993);
7
104-114
(Fagus sylvatica) under double ambient O3 concentrations in a free-air exposure system.
Plant Biology.
(2007 a);
9
215-226
15 N and total N in Fagus sylvatica and associated mycorrhizal fungi.
Plant Biology.
(2007 b);
9
242-252
KROCO, Freising, Germany: Canopy research in a temperate mixed forest of Southern Germany. Basset, Y., Horlyck, V., and Wright, S. J., eds. Studying Forest Canopies from Above: The International Canopy Crane Network. Smithsonian Tropical Research Institute and UNEP (2003): 71-78
Fagus sylvatica under experimental free-air ozone exposure.
Environmental Pollution.
(2005);
173
476-482
Fagus sylvatica L. und Picea abies L. im Kranzberger Forst. Diplomarbeit der Studienfakultät für Forstwissenschaft und Ressourcenmanagement der Technischen Universität München. (2005)
Picea abies [L.] Karst.).
Trees.
(1998);
12
482-489
(Betula pendula) .
New Phytologist.
(1997);
37
389-397
2 and/or pO3 on C-, N-, and S-metabolites in the leaves of juvenile beech and spruce differ between trees grown in monoculture and mixed culture.
Plant Physiology and Biochemistry.
(2005);
43
147-154
(Fagus sylvatica) .
Trees.
(2006);
20
539-548
Fagus sylvatica L.) leaves: seasonal variation and responses to changing ozone concentrations in air.
Plant, Cell and Environment.
(1996);
19
321-328
13 C in leaves and stem, and phloem structure of birch (Betula pendula) under low ozone concentrations.
Trees.
(1992);
6
69-76
How sensitive are forest trees to ozone - new research on an old issue. Omasa, K., Nouchi, I., and De Kok, L. J., eds. Plant Responses to Air Pollution and Global Change. Tokyo; Springer-Verlag (2005): 21-28
Fagus sylvatica L. in a changing environment - experimental risk assessment of mitigation by chronic ozone impact.
Plant Biology.
(2007);
9
163-180
Methods for controlled and field ozone exposure of forest tree species in North America. Sandermann Jr., H., Wellburn, A. R., and Heath, R. L., eds. Forest Decline and Ozone: A Comparison of Controlled Chamber and Field Experiments. Berlin, Heidelberg, New York; Springer Verlag (1997): 277-315
(Fagus sylvatica) und Fichten (Picea abies) eines forstlich begründeten Mischbestandes. Dissertation (PhD), Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Technische Universität München. (2004)
Fagus sylvatica L.) in Southern Sweden as related to environmental factors.
Tree Physiology.
(1989);
5
485-495
Photooxidative stress in trees. Foyer, C. H. and Mullineaux, P. M., eds. Causes of Photooxidative Stress and Amelioration of Defense Systems in Plants. Boca Raton; CRC Press (1994): 199-218
Quercus rubra L.
New Phytologist.
(1993);
64
93-106
Pinus ponderosa to ozone in southern Californian forests.
Water, Air, and Soil Pollution.
(1999);
116
249-254
The role of glutathione in plant reaction and adaptation to natural stresses. Grill, D., Tausz, M., and DeKok, L. J., eds. Significance of Glutathione in Plant Adaptation to the Environment. Kluwer Handbook Series of Plant Ecophysiology, Amsterdam; Kluwer Publishers (2001): 101-122
3 fumigation. 2. Comparison between young and adult trees at the branch and tree level. In Proceedings of the Meeting “Forests under changing climate, enhanced UV and air pollution”, August 25 - 30, 2004, Oulu, Finland. (2004): 143-150
Picea abies and Pinus cembra : a synthesis.
Environmental Pollution.
(2000);
110
415-422
Pinus cembra L.) tree growing at the alpine timberline as affected by ozone exposure.
Biologia Plantarum.
(2001);
44
225-232
(Picea abies) susceptibility to ozone uptake: a novel approach relating stress avoidance to defense.
Tree Physiology.
(2002 a);
22
583-590
Picea abies [L.] Karst.) across tree age: implications for the sun- and shade-crown.
Phyton.
(2002 b);
42
245-253
Exchange of trace gases at the tree-atmosphere interface-ozone. Papen, H., Gasche, R., and Rennenberg, H., eds. Trace Gas Exchange in Forest Ecosystems. Dordrecht; Kluwer Academic Publishers (2002): 211-226
Fagus sylvatica L.) against oxidative stress.
Annales of Forest Science.
(2003);
60
131-135
christiane.then@uibk.ac.at
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