Carbon flux and growth in mature deciduous forest trees exposed to elevated CO2.
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.
Körner
Christian
C
Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056 Basel, Switzerland. ch.koerner@unibas.ch
Asshoff
Roman
R
Bignucolo
Olivier
O
Hättenschwiler
Stephan
S
Keel
Sonja G
SG
Peláez-Riedl
Susanna
S
Pepin
Steeve
S
Siegwolf
Rolf T W
RT
Zotz
Gerhard
G
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
D002247:Carbon Isotopes; D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon; D008031:Lignin; D009584:Nitrogen