Northern Environment Predisposes Birches to Ozone Damage

Abstract

Ozone sensitivity of silver birch (Betula pendula Roth) has been thoroughly investigated since early 1990′s in Finland. In our long-term open-field experiments the annual percentage reduction in basal diameter and stem volume increment were the best non-destructive growth indicators for ozone impact when plotted against AOTX. Remarkable differences in defence strategies, stomatal conductance, and defence compounds (phenolics), clearly indicate that external exposure indices are ineffective for accurate risk assessment for birch. For flux-based approaches, site-specific values for g _max and g _dark are necessary, and determinants for detoxification capacity, ageing of leaves, and cumulative ozone impact would be needed for further model development. Increasing CO₂ seems to counteract negative ozone responses in birch, whereas exposure to springtime frost may seriously exacerbate ozone damage in northern conditions. Therefore, we need to proceed towards incorporating the most important climate change factors in any attempts for ozone risk assessment.

Key words

Ozone - birch - open-field experiment - northern Europe - risk assessment - AOT40 - AfstY.

References

• 1 Ashmore M. R.. Assessing the future global impacts of ozone on vegetation.  Plant, Cell and Environment. (2005);  28 949-964
• 2 Fowler D., Cape J. N., Coyle M., Flechard C., Kuylenstierna J., Hicks K., Derwent D., Johnson C., Stevenson D.. The global exposure of forests to air pollutants.  Water, Air and Soil Pollution. (1999);  116 5-32
• 3 Foyer C. F., Noctor G.. Oxidant and antioxidant signalling in plants: a re-evaluation of the concept of the oxidative stress in a physiological context.  Plant, Cell and Environment. (2005);  28 1056-1071
• 4 Goulden M., Munger J. L., Fan S.. et al. . Exchange of carbon dioxide by a deciduous forest: response to interannual climate variability.  Science. (1996);  271 1576-1578
• 5 Herric J. D., Thomas R. B.. Leaf senescence and late-season net photosynthesis of sun and shade leaves of overstory sweetgum (Liquidambar styraciflua) grown in elevated and ambient carbon dioxide concentrations.  Tree Physiology. (2003);  23 109-118
• 6 IPCC .Climate Change 2001. The Scientific Basis. Report of Working Group I of the Intergovernmental Panel on Climate Change. http://www.grida.no/climate/ipcc_tar/wg1 and wg2. 
• 7 Karlsson P. E., Uddling J., Braun S., Broadmeadow M., Elvira S., Gimeno B. S., Le Thiec D., Oksanen E., Vandermeiren K., Wilkinson M., Emberson L.. New critical levels for ozone effects on young trees based on AOT40 and simulated cumulative leaf uptake of ozone.  Atmospheric Environment. (2004);  38 2283-2294
• 8 Millard P., Wendler R., Hepburn A., Smith A.. Variations in the amino acid composition of xylem sap of Betula pendula Roth trees due to remobilization of stored N in the spring.  Plant, Cell and Environment. (1998);  21 715-722
• 9 Oksanen E.. Responses of selected birch (Betula pendula) clones to ozone change over time.  Plant, Cell and Environment. (2003 a);  26 875-886
• 10 Oksanen E.. Physiological ozone responses of birch (Betula pendula Roth) differ between soil-grown trees in a multi-year exposure and potted saplings in a single-season exposure.  Tree Physiology. (2003 b);  23 603-614
• 11 Oksanen E., Freiwald V., Prozherina N., Rousi M.. Photosynthesis of birch (Betula pendula Roth) is sensitive to spring-time frost and ozone.  Canadian Journal of Forest Research. (2005 a);  35 703-712
• 12 Oksanen E., Riikonen J., Kaakinen S., Holopainen T., Vapaavuori E.. Structural characteristics and chemical composition of birch (Betula pendula Roth) leaves are modified by increasing CO₂ and ozone.  Global Change Biology. (2005 b);  11 732-748
• 13 Padu E., Kollist H., Tulva I., Oksanen E., Moldau H.. Components of apoplastic ascorbate use in Betula pendula leaves exposed to CO₂ and O₃ enrichment.  New Phytologist. (2005);  165 131-142
• 14 Peltonen P. A., Vapaavuori E., Julkunen-Tiitto R.. Accumulation of phenolic compounds in birch leaves is changed by elevated carbon dioxide and ozone.  Global Change Biology. (2005);  11 1305-1324
• 15 Percy K. E., Awmack C. S., Lindroth R. L.. et al. . Altered performance of forest pests under atmospheres enriched by CO₂ and O₃.  Nature. (2002);  420 403-407
• 16 Percy K. E., Ferretti M.. Air pollution and forest health: toward new monitoring concepts.  Environmental Pollution. (2004);  130 113-126
• 17 Prozherina N., Freiwald V., Rousi M., Oksanen E.. Effects of spring-time frost and elevated ozone on early growth, foliar injuries and leaf structure of birch (Betula pendula Roth) genotypes.  New Phytologist. (2003);  159 623-636
• 18 Pääkkönen E., Günthardt-Goerg M., Holopainen T.. Responses of leaf processes in a sensitive birch (Betula pendula Roth) clone to ozone combined with drought.  Annals of Botany. (1998 a);  82 49-59
• 19 Pääkkönen E., Vahala J., Pohjola M., Holopainen T., Kärenlampi L.. Physiological, stomatal and ultrastructural ozone responses in birch (Betula pendula Roth) are modified by water stress.  Plant, Cell and Environment. (1998 b);  21 671-684
• 20 Riikonen J., Lindsberg M.-M., Holopainen T., Oksanen E., Peltonen P., Lappi J., Vapaavuori E.. Silver birch and climate change: variable growth and carbon allocation responses to elevated concentrations of carbon dioxide and ozone.  Tree Physiology. (2004);  24 1227-1237
• 21 Riikonen J., Holopainen T., Oksanen E., Vapaavuori E.. Leaf photosynthetic characteristics of silver birch during three years of exposure to elevated CO₂ and O₃ in the field.  Tree Physiology. (2005);  25 621-632
• 22 Root T. J., Price J. T., Hall K. R., Schneider S. H., Rosenzweig C., Pounds J. A.. Fingerprints of global warming on wild animals and plants.  Nature. (2003);  421 57-60
• 23 Rousi M., Pusenius J.. Variations in phenology and growth of European white birch (Betula pendula) clones.  Tree Physiology. (2005);  25 201-210
• 24 Saleem A., Loponen J., Pihlaja K., Oksanen E.. Effects of long-term open-field ozone exposure on leaf phenolics of European silver birch (Betula pendula Roth).  Journal of Chemical Ecology. (2001);  27 1049-1062
• 25 Uddling J., Günthardt-Goerg M. S., Matyssek R., Oksanen E., Pleijel H., Selldén G., Karlsson P. E.. Biomass reductions of juvenile birch were more strongly related to stomatal uptake of ozone than to ozone indices based on external exposure.  Atmospheric Environment. (2004);  38 4709-4719
• 26 Uddling J., Karlsson P. E., Glorvigen A., Selldén G.. Ozone impairs autumnal resorption of nitrogen from birch (Betula pendula) leaves, causing an increase in whole-tree nitrogen loss through litter fall.  Tree Physiology. (2005);  26 113-120
• 27 Yamaji K., Julkunen-Tiitto R., Rousi M., Freiwald V., Oksanen E.. Ozone exposure over two growing seasons alters root to shoot ratio and chemical composition of birch (Betula pendula Roth).  Global Change Biology. (2003);  9 1363-1377

Guest Editor: R. Matyssek