Tags

Type your tag names separated by a space and hit enter

Leaf photosynthetic characteristics of silver birch during three years of exposure to elevated concentrations of CO2 and O3 in the field.
Tree Physiol 2005; 25(5):621-32TP

Abstract

Effects of elevated concentrations of carbon dioxide ([CO2]) and ozone ([O3]) on photosynthesis and related biochemistry of two European silver birch (Betula pendula Roth) clones were studied under field conditions during 1999-2001. Seven-year-old trees of Clones 4 and 80 were exposed for 3 years to the following treatments in an open-top chamber experiment: outside control (OC), chamber control (CC), 2x ambient [CO2] (EC), 2x ambient [O3] (EO) and 2x ambient [CO2] + 2x ambient [O3] (EC+EO). During the experiment, gas exchange, chlorophyll fluorescence, amount and activity of Rubisco, concentrations of chlorophyll, soluble protein, soluble sugars, starch, nitrogen (N) and carbon:nitrogen (C:N) ratio were determined in short- and long-shoot leaves. Elevated [CO2] increased photosynthetic rate by around 30% when measurements were made at the growth [CO2]. When measured at ambient [CO2], photosynthesis was around 15% lower in EC trees than in CC trees. This was related to a approximately 10% decrease in total leaf N, to 26 and 20% decreases in the amount and activity of Rubisco, respectively, and to a 49% increase in starch concentration in elevated [CO2]. Elevated [O3] had no significant effect on gas exchange parameters and its effect on biochemistry was small in both clones. However, elevated [O3] decreased the proportion of Rubisco in total soluble proteins and the apparent quantum yield of photosystem II (PSII) photochemistry in light and increased non-photochemical quenching in 2000. The interactive effect of CO2 and O3 was variable. Elevated [O3] decreased chlorophyll concentration only in EO trees, and the EC+EO treatment decreased the total activity of Rubisco and increased the C:N ratio more than the EO treatment alone. The small effect of elevated [O3] on photosynthesis indicates that these young silver birches were fairly tolerant to annual [O3] exposures that were 2-3 times higher than the AOT40 value of 10 ppm.h. set as a critical dose for forest trees.

Authors+Show Affiliations

Department of Ecology and Environmental Science, University of Kuopio, P.O. Box 1627, 70211 Kuopio, Finland.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15741148

Citation

Riikonen, Johanna, et al. "Leaf Photosynthetic Characteristics of Silver Birch During Three Years of Exposure to Elevated Concentrations of CO2 and O3 in the Field." Tree Physiology, vol. 25, no. 5, 2005, pp. 621-32.
Riikonen J, Holopainen T, Oksanen E, et al. Leaf photosynthetic characteristics of silver birch during three years of exposure to elevated concentrations of CO2 and O3 in the field. Tree Physiol. 2005;25(5):621-32.
Riikonen, J., Holopainen, T., Oksanen, E., & Vapaavuori, E. (2005). Leaf photosynthetic characteristics of silver birch during three years of exposure to elevated concentrations of CO2 and O3 in the field. Tree Physiology, 25(5), pp. 621-32.
Riikonen J, et al. Leaf Photosynthetic Characteristics of Silver Birch During Three Years of Exposure to Elevated Concentrations of CO2 and O3 in the Field. Tree Physiol. 2005;25(5):621-32. PubMed PMID: 15741148.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Leaf photosynthetic characteristics of silver birch during three years of exposure to elevated concentrations of CO2 and O3 in the field. AU - Riikonen,Johanna, AU - Holopainen,Toini, AU - Oksanen,Elina, AU - Vapaavuori,Elina, PY - 2005/3/3/pubmed PY - 2007/3/21/medline PY - 2005/3/3/entrez SP - 621 EP - 32 JF - Tree physiology JO - Tree Physiol. VL - 25 IS - 5 N2 - Effects of elevated concentrations of carbon dioxide ([CO2]) and ozone ([O3]) on photosynthesis and related biochemistry of two European silver birch (Betula pendula Roth) clones were studied under field conditions during 1999-2001. Seven-year-old trees of Clones 4 and 80 were exposed for 3 years to the following treatments in an open-top chamber experiment: outside control (OC), chamber control (CC), 2x ambient [CO2] (EC), 2x ambient [O3] (EO) and 2x ambient [CO2] + 2x ambient [O3] (EC+EO). During the experiment, gas exchange, chlorophyll fluorescence, amount and activity of Rubisco, concentrations of chlorophyll, soluble protein, soluble sugars, starch, nitrogen (N) and carbon:nitrogen (C:N) ratio were determined in short- and long-shoot leaves. Elevated [CO2] increased photosynthetic rate by around 30% when measurements were made at the growth [CO2]. When measured at ambient [CO2], photosynthesis was around 15% lower in EC trees than in CC trees. This was related to a approximately 10% decrease in total leaf N, to 26 and 20% decreases in the amount and activity of Rubisco, respectively, and to a 49% increase in starch concentration in elevated [CO2]. Elevated [O3] had no significant effect on gas exchange parameters and its effect on biochemistry was small in both clones. However, elevated [O3] decreased the proportion of Rubisco in total soluble proteins and the apparent quantum yield of photosystem II (PSII) photochemistry in light and increased non-photochemical quenching in 2000. The interactive effect of CO2 and O3 was variable. Elevated [O3] decreased chlorophyll concentration only in EO trees, and the EC+EO treatment decreased the total activity of Rubisco and increased the C:N ratio more than the EO treatment alone. The small effect of elevated [O3] on photosynthesis indicates that these young silver birches were fairly tolerant to annual [O3] exposures that were 2-3 times higher than the AOT40 value of 10 ppm.h. set as a critical dose for forest trees. SN - 0829-318X UR - https://www.unboundmedicine.com/medline/citation/15741148/Leaf_photosynthetic_characteristics_of_silver_birch_during_three_years_of_exposure_to_elevated_concentrations_of_CO2_and_O3_in_the_field_ L2 - https://academic.oup.com/treephys/article-lookup/doi/10.1093/treephys/25.5.621 DB - PRIME DP - Unbound Medicine ER -