title: Carbon flux and growth in mature deciduous forest trees exposed to elevated CO2.
abstract: Whether rising atmospheric carbon dioxide (CO2) concentrations will cause forests to grow faster and store more carbon is an open question. Using free air CO2 release in combination with a canopy crane, we found an immediate and sustained enhancement of carbon flux through 35-meter-tall temperate forest trees when exposed to elevated CO2. However, there was no overall stimulation in stem growth and leaf litter production after 4 years. Photosynthetic capacity was not reduced, leaf chemistry changes were minor, and tree species differed in their responses. Although growing vigorously, these trees did not accrete more biomass carbon in stems in response to elevated CO2, thus challenging projections of growth responses derived from tests with smaller trees.
authors.affiliation: Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056 Basel, Switzerland. ch.koerner@unibas.ch
authors.forename: Christian
authors.initials: C
authors.lastname: Körner
authors.forename: Roman
authors.initials: R
authors.lastname: Asshoff
authors.forename: Olivier
authors.initials: O
authors.lastname: Bignucolo
authors.forename: Stephan
authors.initials: S
authors.lastname: Hättenschwiler
authors.forename: Sonja G
authors.initials: SG
authors.lastname: Keel
authors.forename: Susanna
authors.initials: S
authors.lastname: Peláez-Riedl
authors.forename: Steeve
authors.initials: S
authors.lastname: Pepin
authors.forename: Rolf T W
authors.initials: RT
authors.lastname: Siegwolf
authors.forename: Gerhard
authors.initials: G
authors.lastname: Zotz
mesh_terms: D001272:Atmosphere; D029401:Betulaceae / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D002244:Carbon / Q000032:analysis / Q000378:metabolism*; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes; D017753:Ecosystem; D029964:Fagus / Q000254:growth & development / Q000378:metabolism; D008031:Lignin / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010788:Photosynthesis; D018515:Plant Leaves / Q000378:metabolism; D018520:Plant Shoots / Q000254:growth & development; D018547:Plant Stems / Q000254:growth & development; D029963:Quercus / Q000254:growth & development / Q000378:metabolism; D012987:Soil / Q000032:analysis; D013557:Switzerland; D014197:Trees / Q000254:growth & development* / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon; D008031:Lignin; D009584:Nitrogen