Free-air CO2 enrichment (FACE) enhances biomass production in a short-rotation poplar plantation

• Published in: Tree physiology 2003-08, Vol.23 (12), p.805-814
• Main Authors: Calfapietra, C, Gielen, B, Galema, A.N.J, Lukac, M, De Angelis, P, Moscatelli, M.C, Ceulemans, R, Scarascia-Mugnozza, G
• Format: Article
• Language: English
• Subjects: Biomass; branches; carbon dioxide; Carbon Dioxide - physiology; carbon sequestration; carbon-dioxide enrichment; crop rotation; crown architecture; dry matter partitioning; elevated atmospheric co2; elevated atmospheric gases; equations; fine roots; forest plantations; hybrid poplar; light; light use efficiency; mathematical models; net primary production; nitrogen; Photosynthesis - physiology; pinus-sylvestris; Plant Roots - growth & development; Plant Shoots - growth & development; Populus - growth & development; Populus alba; Populus canadensis; Populus nigra; populus-grandidentata; roots; short rotation cultures; simulation models; soil n-availability; soil nutrients; stems; Trees - growth & development; wood density
• ISSN: 0829-318X; 1758-4469
• DOI: 10.1093/treephys/23.12.805

This paper investigates the possible contribution of Short Rotation Cultures (SRC) to carbon sequestration in both current and elevated atmospheric CO2 concentrations ([CO2]). A dense poplar plantation (1 x 1 m) was exposed to a [CO2] of 550 ppm in Central Italy using the free-air CO2 enrichment (FACE) technique. Three species of Populus were examined, namely P. alba L., P. nigra L. and P. x euramericana Dode (Guinier). Aboveground woody biomass of trees exposed to elevated [CO2] for three growing seasons increased by 15 to 27%, depending on species. As a result, light-use efficiency increased. Aboveground biomass allocation was unaffected, and belowground biomass also increased under elevated [CO2] conditions, by 22 to 38%. Populus nigra, with total biomass equal to 62.02 and 72.03 Mg ha-1 in ambient and elevated [CO2], respectively, was the most productive species, although its productivity was stimulated least by atmospheric CO2 enrichment. There was greater depletion of inorganic nitrogen from the soil after three growing seasons in elevated [CO2], but no effect of [CO2] on stem wood density, which differed significantly only among species.