title: Long-term exposure to elevated CO2 and O3 alters aspen foliar chemistry across developmental stages.
abstract: Anthropogenic activities are altering levels of greenhouse gases to the extent that multiple and diverse ecosystem processes are being affected. Two gases that substantially influence forest health are atmospheric carbon dioxide (CO2 ) and tropospheric ozone (O3 ). Plant chemistry will play an important role in regulating ecosystem processes in future environments, but little information exists about the longitudinal effects of elevated CO2 and O3 on phytochemistry, especially for long-lived species such as trees. To address this need, we analysed foliar chemical data from two genotypes of trembling aspen, Populus tremuloides, collected over 10 years of exposure to levels of CO2 and O3 predicted for the year 2050. Elevated CO2 and O3 altered both primary and secondary chemistry, and the magnitude and direction of the responses varied across developmental stages and between aspen genotypes. Our findings suggest that the effects of CO2 and O3 on phytochemical traits that influence forest processes will vary over tree developmental stages, highlighting the need to continue long-term, experimental atmospheric change research.
authors.affiliation: Department of Entomology, University of Wisconsin, 237 Russell Laboratories, 1630 Linden Dr., Madison, WI, 53706, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Couture
authors.forename: L M
authors.initials: LM
authors.lastname: Holeski
authors.forename: R L
authors.initials: RL
authors.lastname: Lindroth
mesh_terms: D002245:Carbon Dioxide / Q000494:pharmacology*; D006027:Glycosides / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010126:Ozone / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects* / Q000254:growth & development*; D032107:Populus / Q000187:drug effects* / Q000254:growth & development*; D044945:Proanthocyanidins / Q000378:metabolism; D013997:Time Factors
chemical_list: D006027:Glycosides; D044945:Proanthocyanidins; D002245:Carbon Dioxide; D010126:Ozone; D009584:Nitrogen
keywords: Aspen FACE; CO2; ontogeny; phytochemistry; secondary metabolism; tropospheric ozone