1. Net carbon storage in a popular plantation (POPFACE) after three years of free-air CO2 enrichment
- Author
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Gielen, B., Calfapietra, C., Lukac, M., Wittig, V.E., de Angelis, P., Janssens, I.A., Moscatelli, M.C., Grego, S., Cotrufo, M.F., Godbold, D., Hoosbeek, M.R., Long, S., Miglietta, F., Polle, A., Bernacchi, C., Davey, P.A., Ceulemans, R., Scarascia-Mugnozza, G., Gielen, B., Calfapietra, C., Lukac, M., Wittig, V.E., de Angelis, P., Janssens, I.A., Moscatelli, M.C., Grego, S., Cotrufo, M.F., Godbold, D., Hoosbeek, M.R., Long, S., Miglietta, F., Polle, A., Bernacchi, C., Davey, P.A., Ceulemans, R., and Scarascia-Mugnozza, G.
- Abstract
A high-density plantation of three genotypes of Populus was exposed to an elevated concentration of carbon dioxide ([CO2]; 550 µmol mol¿1) from planting through canopy closure using a free-air CO2 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 [CO2] will enhance net plantation C storage capacity. Free-air CO2 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.
- Published
- 2005