Water use of a bioenergy plantation increases in a future high CO₂ world

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• 作者：Penny J. Tricker ; Marco Pecchiari ; Steve M. Bunn ; Francesco P. Vaccari ; Aless ; ro Peressotti ; Franco Miglietta ; Gail Taylor
• 关键词：Sap flow ; FACE ; Leaf area ; Biomass crop ; Stomatal conductance
• 刊名：Biomass and Bioenergy
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：33
• 期：2
• 页码：200-208
• 全文大小：369 K

文摘

Fast-growing poplar trees may in future be used as a source of renewable energy for heat, electricity and biofuels such as bioethanol. Water use in Populus x euramericana (clone I214), following long-term exposure to elevated CO₂ in the POPFACE (poplar free-air carbon dioxide enrichment) experiment, is quantified here.<p>Stomatal conductance was measured and, during two measurement campaigns made before and after coppicing, whole-tree water use was determined using heat-balance sap-flow gauges, first validated using eddy covariance measurements of latent heat flux.<p>Water use was determined by the balance between leaf-level reductions in stomatal conductance and tree-level stimulations in transpiration. Reductions in stomatal conductance were found that varied between 16 and 39 % relative to ambient air. Whole-tree sap flow was increased in plants growing under elevated CO₂, on average, by 12 and 23 % , respectively, in the first and in the second measurement campaigns.<p>These results suggest that future CO₂ concentrations may result in an increase in seasonal water use in fast-growing, short-rotation Populus plantations.