351. Coppicing shifts CO2 stimulation of poplar productivity to above-ground pools: a synthesis of leaf to stand level results from the POP/EUROFACE experiment.
- Author
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Liberloo M, Lukac M, Calfapietra C, Hoosbeek MR, Gielen B, Miglietta F, Scarascia-Mugnozza GE, and Ceulemans R
- Subjects
- Carbon metabolism, Greenhouse Effect, Nitrogen metabolism, Photosynthesis physiology, Populus physiology, Soil, Wood, Biomass, Carbon physiology, Carbon Dioxide physiology, Conservation of Energy Resources methods, Populus growth & development
- Abstract
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.
- Published
- 2009
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