Stem girdling affects the quantity of CO2 transported in xylem as well as CO2 efflux from soil. Issue 3 (1st November 2013)

• Record Type: Journal Article
• Authors: Bloemen, Jasper; Agneessens, Laura; Van, Lieven; Aubrey, Doug P.; McGuire, Mary Anne; Teskey, Robert O.; Steppe, Kathy
• Is Part Of: New phytologist. Volume 201:Issue 3(2014)
• Page Start: 897
• Page End: 907
• Publication Date: 2013-11-01
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12568
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12568-abs-0001"> <title>Summary</title> <p> <list id="nph12568-list-0001" list-type="bullet"> <list-item> <p>There is recent clear evidence that an important fraction of root‐respired CO<sub>2</sub> is transported upward in the transpiration stream in tree stems rather than fluxing to the soil. In this study, we aimed to quantify the contribution of root‐respired CO<sub>2</sub> to both soil CO<sub>2</sub> efflux and xylem CO<sub>2</sub> transport by manipulating the autotrophic component of belowground respiration.</p> </list-item> <list-item> <p>We compared soil CO<sub>2</sub> efflux and the flux of root‐respired CO<sub>2</sub> transported in the transpiration stream in girdled and nongirdled 9‐yr‐old oak trees (<italic>Quercus robur</italic>) to assess the impact of a change in the autotrophic component of belowground respiration on both CO<sub>2</sub> fluxes.</p> </list-item> <list-item> <p>Stem girdling decreased xylem CO<sub>2</sub> concentration, indicating that belowground respiration contributes to the aboveground transport of internal CO<sub>2</sub>. Girdling also decreased soil CO<sub>2</sub> efflux.</p> </list-item> <list-item> <p>These results confirmed that root respiration contributes to xylem CO<sub>2</sub> transport and that failure to account for this flux results in inaccurate estimates of belowground respiration when efflux‐based methods are used. This research adds to the growing body of evidence that efflux‐based measurements of belowground respiration underestimate autotrophic contributions.</p> </list-item> </list> </p> </abstract>