Coppicing shifts CO2 stimulation of poplar productivity to above-ground pools: a synthesis of leaf to stand level results from the POP/EUROFACE experiment.
A poplar short rotation coppice (SRC) grown for the production of bioenergy can combine carbon (C) storage with fossil fuel substitution. Here, we summarize the responses of a poplar (Populus) plantation to 6 yr of free air CO(2) enrichment (POP/EUROFACE consisting of two rotation cycles). We show that a poplar plantation growing in nonlimiting light, nutrient and water conditions will significantly increase its productivity in elevated CO(2) concentrations ([CO(2)]). Increased biomass yield resulted from an early growth enhancement and photosynthesis did not acclimate to elevated [CO(2)]. Sufficient nutrient availability, increased nitrogen use efficiency (NUE) and the large sink capacity of poplars contributed to the sustained increase in C uptake over 6 yr. Additional C taken up in high [CO(2)] was mainly invested into woody biomass pools. Coppicing increased yield by 66% and partly shifted the extra C uptake in elevated [CO(2)] to above-ground pools, as fine root biomass declined and its [CO(2)] stimulation disappeared. Mineral soil C increased equally in ambient and elevated [CO(2)] during the 6 yr experiment. However, elevated [CO(2)] increased the stabilization of C in the mineral soil. Increased productivity of a poplar SRC in elevated [CO(2)] may allow shorter rotation cycles, enhancing the viability of SRC for biofuel production.
Liberloo
Marion
M
University of Antwerp, Research Group of Plant and Vegetation Ecology, Department of Biology, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Lukac
Martin
M
NERC Centre for Population Biology, Division of Biology, Imperial College London, Silwood Park Campus, Ascot SL5 7PY, UK.
Calfapietra
Carlo
C
University of Tuscia, DISAFRI, Via San Camillo De Lellis, I-01100 Viterbo, Italy.|National Research Council (CNR), Institute of Agro-Environmental & Forest Biology, Via Salaria km 29,300, 00015 Monterotondo Scalo (Roma), Italy.
Hoosbeek
Marcel R
MR
Department of Environmental Sciences, Earth System Science - Climate Change group, Wageningen University, PO Box 47, 6700AA Wageningen, the Netherlands.
Gielen
Birgit
B
University of Antwerp, Research Group of Plant and Vegetation Ecology, Department of Biology, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Miglietta
Franco
F
Institute of Biometeorology - National Research Council (IBIMET-CNR), Via Caproni 8, 50145 Firenze, Italy.
Scarascia-Mugnozza
Giuseppe E
GE
University of Tuscia, DISAFRI, Via San Camillo De Lellis, I-01100 Viterbo, Italy.|National Research Council (CNR), Institute of Agro-Environmental & Forest Biology, Via Salaria km 29,300, 00015 Monterotondo Scalo (Roma), Italy.
Ceulemans
Reinhart
R
University of Antwerp, Research Group of Plant and Vegetation Ecology, Department of Biology, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk, Belgium.
D018533:Biomass; D002244:Carbon / Q000378:metabolism / Q000502:physiology*; D002245:Carbon Dioxide / Q000502:physiology*; D003246:Conservation of Energy Resources / Q000379:methods*; D017752:Greenhouse Effect; D009584:Nitrogen / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology; D032107:Populus / Q000254:growth & development* / Q000502:physiology; D012987:Soil; D014934:Wood
D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen