title: Net carbon storage in a poplar plantation (POPFACE) after three years of free-air CO2 enrichment.
abstract: A high-density plantation of three genotypes of Populus was exposed to an elevated concentration of carbon dioxide ([CO(2)]; 550 micromol mol(-1)) from planting through canopy closure using a free-air CO(2) enrichment (FACE) technique. The FACE treatment stimulated gross primary productivity by 22 and 11% in the second and third years, respectively. Partitioning of extra carbon (C) among C pools of different turnover rates is of critical interest; thus, we calculated net ecosystem productivity (NEP) to determine whether elevated atmospheric [CO(2)] will enhance net plantation C storage capacity. Free-air CO(2) enrichment increased net primary productivity (NPP) of all genotypes by 21% in the second year and by 26% in the third year, mainly because of an increase in the size of C pools with relatively slow turnover rates (i.e., wood). In all genotypes in the FACE treatment, more new soil C was added to the total soil C pool compared with the control treatment. However, more old soil C loss was observed in the FACE treatment compared with the control treatment, possibly due to a priming effect from newly incorporated root litter. FACE did not significantly increase NEP, probably as a result of this priming effect.
authors.affiliation: University of Antwerpen, Campus Drie Eiken, Dept. of Biology, Research Group of Plant and Vegetation Ecology, Wilrijk, Belgium. birgit.gielen@ua.ac.be
authors.forename: B
authors.initials: B
authors.lastname: Gielen
authors.forename: C
authors.initials: C
authors.lastname: Calfapietra
authors.forename: M
authors.initials: M
authors.lastname: Lukac
authors.forename: V E
authors.initials: VE
authors.lastname: Wittig
authors.forename: P
authors.initials: P
authors.lastname: De Angelis
authors.forename: I A
authors.initials: IA
authors.lastname: Janssens
authors.forename: M C
authors.initials: MC
authors.lastname: Moscatelli
authors.forename: S
authors.initials: S
authors.lastname: Grego
authors.forename: M F
authors.initials: MF
authors.lastname: Cotrufo
authors.forename: D L
authors.initials: DL
authors.lastname: Godbold
authors.forename: M R
authors.initials: MR
authors.lastname: Hoosbeek
authors.forename: S P
authors.initials: SP
authors.lastname: Long
authors.forename: F
authors.initials: F
authors.lastname: Miglietta
authors.forename: A
authors.initials: A
authors.lastname: Polle
authors.forename: C J
authors.initials: CJ
authors.lastname: Bernacchi
authors.forename: P A
authors.initials: PA
authors.lastname: Davey
authors.forename: R
authors.initials: R
authors.lastname: Ceulemans
authors.forename: G E
authors.initials: GE
authors.lastname: Scarascia-Mugnozza
mesh_terms: D018533:Biomass; D002245:Carbon Dioxide; D018517:Plant Roots / Q000502:physiology; D032107:Populus / Q000502:physiology*; D012987:Soil; D014197:Trees / Q000502:physiology*
chemical_list: D012987:Soil; D002245:Carbon Dioxide