title: Wood properties of trembling aspen and paper birch after 5 years of exposure to elevated concentrations of CO(2) and O(3).
abstract: We investigated the interactive effects of elevated concentrations of carbon dioxide ([CO(2)]) and ozone ([O(3)]) on radial growth, wood chemistry and structure of five 5-year-old trembling aspen (Populus tremuloides Michx.) clones and the wood chemistry of paper birch (Betula papyrifera Marsh.). Material for the study was collected from the Aspen FACE (free-air CO(2) enrichment) experiment in Rhinelander, WI, where the saplings had been exposed to four treatments: control, elevated [CO(2)] (560 ppm), elevated [O(3)] (1.5 x ambient) and their combination for five growing seasons. Wood properties of both species were altered in response to exposure to the treatments. In aspen, elevated [CO(2)] decreased uronic acids (constituents of, e.g., hemicellulose) and tended to increase stem diameter. In response to elevated [O(3)] exposure, acid-soluble lignin concentration decreased and vessel lumen diameter tended to decrease. Elevated [O(3)] increased the concentration of acetone-soluble extractives in paper birch, but tended to decrease the concentration of these compounds in aspen. In paper birch, elevated [CO(2)] decreased and elevated [O(3)] increased starch concentration. The responses of wood properties to 5 years of fumigation differed from those previously reported after 3 years of fumigation.
authors.affiliation: Finnish Forest Research Institute, Suonenjoki Research Unit, Suonenjoki, Finland.
authors.forename: Katri
authors.initials: K
authors.lastname: Kostiainen
authors.forename: Seija
authors.initials: S
authors.lastname: Kaakinen
authors.forename: Elina
authors.initials: E
authors.lastname: Warsta
authors.forename: Mark E
authors.initials: ME
authors.lastname: Kubiske
authors.forename: Neil D
authors.initials: ND
authors.lastname: Nelson
authors.forename: Jaak
authors.initials: J
authors.lastname: Sober
authors.forename: David F
authors.initials: DF
authors.lastname: Karnosky
authors.forename: Pekka
authors.initials: P
authors.lastname: Saranpää
authors.forename: Elina
authors.initials: E
authors.lastname: Vapaavuori
mesh_terms: D029662:Betula / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D002245:Carbon Dioxide / Q000494:pharmacology*; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D010126:Ozone / Q000494:pharmacology*; D032107:Populus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D014574:Uronic Acids / Q000378:metabolism
chemical_list: D014574:Uronic Acids; D002245:Carbon Dioxide; D010126:Ozone