The fate of photosynthetically-fixed carbon in Lolium perenne grassland as modified by elevated CO2 and sward management
Hill, P.W.; Marshall, C.; Williams, G.G.; Blum, H.; Harmens, H.; Jones, D.L.; Farrar, J.F.. 2007 The fate of photosynthetically-fixed carbon in Lolium perenne grassland as modified by elevated CO2 and sward management. New Phytologist, 173 (3). 766-777. 10.1111/j.1469-8137.2007.01966.xFull text not available from this repository.
Prediction of the impact of climate change requires the response of carbon (C) flow in plant–soil systems to increased CO2 to be understood. A mechanism by which grassland C sequestration might be altered was investigated by pulse-labelling Lolium perenne swards, which had been subject to CO2 enrichment and two levels of nitrogen (N) fertilization for 10 yr, with 14CO2. Over a 6-d period 40–80% of the 14C pulse was exported from mature leaves, 1–2% remained in roots, 2–7% was lost as below-ground respiration, 0.1% was recovered in soil solution, and 0.2–1.5% in soil. Swards under elevated CO2 with the lower N supply fixed more 14C than swards grown in ambient CO2, exported more fixed 14C below ground and respired less than their high-N counterparts. Sward cutting reduced root 14C, but plants in elevated CO2 still retained 80% more 14C below ground than those in ambient CO2. The potential for below-ground C sequestration in grasslands is enhanced under elevated CO2, but any increase is likely to be small and dependent upon grassland management.
|Programmes:||CEH Programmes pre-2009 publications > Biogeochemistry|
|Additional Keywords:||carbon cycle, carbon partitioning, carbon sequestration, climate change, defoliation, free air carbon dioxide enrichment (FACE), nitrogen, rhizodeposition.|
|NORA Subject Terms:||Meteorology and Climatology
Agriculture and Soil Science
|Date made live:||04 Jan 2008 13:54|
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