@article{201a91303d1b4c3fbfb7df53216162a5,
title = "Elevated CO2 stimulates soil respiration in a FACE wheat field",
abstract = "Understanding the response of soil carbon (C) dynamics to higher atmospheric CO2 concentrations is critical for evaluating the potential for soil C sequestration on time scales of decades to centuries. Here, we report on changes in soil respiration under Free-Air CO2 Enrichment (FACE) where spring wheat was grown in an open field at two CO2 concentrations (ambient and ambient+200 μmol mol-1), under natural meteorological conditions. FACE increased soil respiration rates by 40-70% during the peak of wheat growth. On the FACE plots, stable C isotopic composition of soil CO2 was used to partition the soil CO2 flux into C from rhizosphere respiration and decomposition of pre-existing C. Decomposition contributed 100% of the soil CO2 flux before crop growth commenced, and only 35-45% of the flux at the peak of the growing season. Decomposition rates were not correlated with soil temperature, but rhizosphere respiration rates were strongly correlated with green leaf area index.",
keywords = "C cycling, C/C, CO fertilization, Free-Air CO Enrichment, Rhizosphere, Soil organic matter, Soil respiration, Stable isotopes",
author = "Elise Pendall and Leavitt, {Steven W.} and Talbot Brooks and Kimball, {Bruce A.} and Pinter, {Paul J.} and Wall, {Gerhard W.} and LaMorte, {Robert L.} and Gabriele Wechsung and Frank Wechsung and Floyd Adamsen and Matthias, {Allan D.} and Thompson, {Thomas L.}",
note = "Funding Information: Acknowledgements. We thank S. Trumbore, E. Holland, P. Tans, and S. Hart for helpful discussions and comments on the manuscript. S. Borges, D. Kane, M. Lenart, N. Ricketts, and S. Schorr assisted in the field and laboratory. F. Nakaya-ma provided early advice on soil respiration methodology. This research was supported by Grant #DE-FG03-95ER-62072 from the Department of Energy Terrestrial Carbon Processes Research Program to the University of Arizona, Tucson and Maricopa, Arizona to S. Leavitt, T. Thompson, A. Matthias, R. Rauschkolb, and H.Y. Cho, and by Interagency Agreement No. IBN-9652614 between the National Science Foundation and the USDA-ARS U.S. Water Conservation Laboratory as part of the NSF/DOE/NASA/USDA Joint Program on Terrestrial Ecology and Global Change (TECO II; G.W. Wall, F.J. Adamsen, B.A. Kimball, and A.N. Webber, principal investigators). Operational support was also provided by the USDA-ARS U.S. Water Conservation Laboratory, Phoenix, Arizona, and by the Potsdam Institute for Climate Impact Research, Potsdam, Germany. We acknowledge the cooperation of R. Rauschkolb and his staff at the Maricopa Agricultural Center. The FACE apparatus was furnished by Brookhaven National Laboratory, and we are grateful to K. Lewin, J. Nagy, and G. Hendrey for installation and consulting. This work contributes to the Global Change Terrestrial Ecosystem (GCTE) Core Research Programme, which is part of the International Geosphere-Biosphere Programme (IGBP).",
year = "2001",
doi = "10.1078/1439-1791-00053",
language = "English (US)",
volume = "2",
pages = "193--201",
journal = "Basic and Applied Ecology",
issn = "1439-1791",
publisher = "Elsevier GmbH",
number = "3",
}