title: Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches.
abstract: We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O(3)) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O(3), i.e. O(3) levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O(3) and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels.
authors.affiliation: Botany Division, Department of Biology, P.O. Box 3000, FIN-90014, University of Oulu, Finland. sirkku.manninen@helsinki.fi
authors.forename: S
authors.initials: S
authors.lastname: Manninen
authors.forename: S
authors.initials: S
authors.lastname: Huttunen
authors.forename: M
authors.initials: M
authors.lastname: Vanhatalo
authors.forename: T
authors.initials: T
authors.lastname: Pakonen
authors.forename: A
authors.initials: A
authors.lastname: Hämäläinen
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D029662:Betula / Q000737:chemistry / Q000254:growth & development*; D018533:Biomass; D002244:Carbon / Q000032:analysis; D002980:Climate; D004463:Ecology / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods; D005387:Finland; D009584:Nitrogen / Q000032:analysis; D010083:Oxidants, Photochemical / Q000032:analysis / Q000633:toxicity*; D010126:Ozone / Q000032:analysis / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D010083:Oxidants, Photochemical; D010126:Ozone; D002244:Carbon; D009584:Nitrogen