Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): J.-C. Domec; A. Noormets; Ge Sun; J. King; Steven McNulty; Michael Gavazzi; Johnny Boggs; Emrys Treasure
    Date: 2009
    Source: Plant, Cell and Environment, Vol. 32: 980-991
    Publication Series: Scientific Journal (JRNL)
    PDF: Download Publication  (628.97 KB)


    The study examined the relationships between whole tree hydraulic conductance (Ktree) and the conductance in roots (Kroot) and leaves (Kleaf) in loblolly pine trees. In addition, the role of seasonal variations in Kroot and Kleaf in mediating stomatal control of transpiration and its response to vapour pressure deficit (D) as soil-dried was studied. Compared to trunk and branches, roots and leaves had the highest loss of conductivity and contributed to more than 75% of the total tree hydraulic resistance. Drought altered the partitioning of the resistance between roots and leaves. As soil moisture dropped below 50%, relative extractable water (REW), Kroot declined faster than Kleaf. Although Ktree depended on soil moisture, its dynamics was tempered by the elongation of current-year needles that significantly increased Kleaf when REW was below 50%.After accounting for the effect of D on gs, the seasonal decline in Ktree caused a 35% decrease in gs and in its sensitivity to D, responses that were mainly driven by Kleaf under high REW and by Kroot under low REW.We conclude that not only water stress but also leaf phenology affects the coordination between Ktree and gs and the acclimation of trees to changing environmental conditions.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Domec, J.-C., A. Noormets, J.S. King, G. Sun, S.G. McNulty, M.J. Gavazzi, J.L. Boggs, and E.A. Treasure. 2009. Decoupling the influence of leaf and root hydraulic conductances on stomatal conductance and its sensitivity to vapour pressure deficit as soil dries in a drained loblolly pine plantation. Plant, Cell & Environment 32:980-991.


    pinus taeda, coastal plain, conductivity, embolism, LAI, leaf phenology, soil moisture, water potential

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page