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Soil [N] modulates soil C cycling in CO2‐fumigated tree stands: a meta‐analysis |
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| Authors: | W. I. J. DIELEMAN S. LUYSSAERT A. REY P. DE ANGELIS C. V. M. BARTON M. S. J. BROADMEADOW S. B. BROADMEADOW K. S. CHIGWEREWE M. CROOKSHANKS E. DUFRÊNE P. G. JARVIS A. KASURINEN S. KELLOMÄKI V. LE DANTEC M. LIBERLOO M. MAREK B. MEDLYN R. POKORNÝ G. SCARASCIA‐MUGNOZZA V. M. TEMPERTON D. TINGEY O. URBAN R. CEULEMANS I. A. JANSSENS |
| Affiliation: | 1. Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp (UA), Universiteitsplein 1, B‐2610 Wilrijk, Belgium;2. LSCE IPSL, CEA CNRS UVSQ, Orme des Merisiers, 91191, Gif‐sur‐Yvette, France;3. Estacion Experimental de Zonas Aridas, Consejo Superior de Investigaciones Cientificas, General Segura n. 1, Almeria, Spain;4. Department of Forest Environment and Resources, University of Tuscia, Via S. Camillo de Lellis, I‐01100 Viterbo, Italy;5. Forest Research and Development Division, State Forests of New South Wales, Beecroft, NSW 2119, Australia;6. Forestry Commission (England), Southeast England Regional Office, Alice Holt, Farnham, Surrey, GU10?4LF, UK;7. Department of Life Sciences, Aalborg University, Sohngaardholmsvej 49, DK‐9000 Aalborg, Denmark;8. CNRS, Orsay, F‐91405;9. Laboratoire Ecologie Systématique et Evolution, UMR 8079, Univ. Paris‐Sud, Orsay, F‐91405;10. AgroParisTech, Paris, F‐75231 France;11. School of GeoSciences, University of Edinburgh, Crew Building, The King's Buildings, Edinburgh, EH9?3JU, Scotland, UK;12. Department of Environmental Science, University of Eastern Finland, FI‐70211 Kuopio, Finland;13. Faculty of Forestry, University of Joensuu, Joensuu, Finland;14. Centre Etudes Spatiales de la BIOsphere, 31401 Toulouse Cedex 4, France;15. CzechGlobe, Center for Global Climate Change Impact Studies, Po?í?í 3b, 603 00 Brno, Czech Republic;16. Department of Biological Science, Macquarie University, North Ryde NSW 2109, Australia;17. Forschungszentrum Jülich GmbH, Institute of Chemistry and Dynamics of the Geosphere (ICG‐3), 52425 Jülich, Germany;18. US Environmental Protection Agency, Corvallis, OR 97333, USA |
| Abstract: | Under elevated atmospheric CO2 concentrations, soil carbon (C) inputs are typically enhanced, suggesting larger soil C sequestration potential. However, soil C losses also increase and progressive nitrogen (N) limitation to plant growth may reduce the CO2 effect on soil C inputs with time. We compiled a data set from 131 manipulation experiments, and used meta‐analysis to test the hypotheses that: (1) elevated atmospheric CO2 stimulates soil C inputs more than C losses, resulting in increasing soil C stocks; and (2) that these responses are modulated by N. Our results confirm that elevated CO2 induces a C allocation shift towards below‐ground biomass compartments. However, the increased soil C inputs were offset by increased heterotrophic respiration (Rh), such that soil C content was not affected by elevated CO2. Soil N concentration strongly interacted with CO2 fumigation: the effect of elevated CO2 on fine root biomass and –production and on microbial activity increased with increasing soil N concentration, while the effect on soil C content decreased with increasing soil N concentration. These results suggest that both plant growth and microbial activity responses to elevated CO2 are modulated by N availability, and that it is essential to account for soil N concentration in C cycling analyses. |
| Keywords: | [CO2] enrichment C sequestration fine root production microbial respiration N fertilization root biomass |