Journal of Experimental Botany, Vol. 52, No. 355, pp. 257-264,
February 2001
© 2001 Oxford University Press
Original Papers |
Hydraulic properties of individual xylem vessels of Fraxinus americana
Department of Organismic and Evolutionary Biology, Biological Laboratories, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA
Studies of the hydraulic properties of xylem vessels have been limited to measurements of whole plant or whole stem segments. This approach allows the longitudinal transport properties of the ensemble of vessels within a stem to be determined, but provides little information on radial transport. Here the xylem of Fraxinus americana L. has been examined using a new method that allows the transport properties of individual vessels to be examined. One goal of this study was to quantify transport parameters relevant to embolism repair. The longitudinal conductivity of vessel segments open at both ends (i.e. no end walls) agreed with values predicted by the Poiseuille equation. Radial specific conductance (conductance per unit area) was approximately six orders of magnitude lower than the longitudinal conductance of the vessel segment normalized by the cross-sectional area of the vessel lumen. There was a step increase in the radial specific conductance of previously gas-filled vessels when the delivery pressure exceeded 0.4 MPa. This is consistent with the idea that positive pressure, required for embolism repair, can be compartmentalized within a vessel if the bordered pit chambers are gas-filled. The diffusion coefficient for the movement of gas from a pressurized air-filled vessel was of the same order of magnitude as that for air diffusing through water (1.95 e-9 m2 s-1). Estimates of the time needed to displace all of the gas from an air-filled vessel were in the order of 20 min, suggesting that gas removal may not be a major limitation in embolism repair.
Key words: Hydraulic conductivity, xylem vessel, Fraxinus americana L., Poiseuille equation, embolism.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
J. S. Sperry, U. G. Hacke, and J. Pittermann Size and function in conifer tracheids and angiosperm vessels Am. J. Botany, October 1, 2006; 93(10): 1490 - 1500. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Pittermann, J. S. Sperry, U. G. Hacke, J. K. Wheeler, and E. H. Sikkema Inter-tracheid pitting and the hydraulic efficiency of conifer wood: the role of tracheid allometry and cavitation protection Am. J. Botany, September 1, 2006; 93(9): 1265 - 1273. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Choat, T. W. Brodie, A. R. Cobb, M. A. Zwieniecki, and N. M. Holbrook Direct measurements of intervessel pit membrane hydraulic resistance in two angiosperm tree species Am. J. Botany, July 1, 2006; 93(7): 993 - 1000. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Choat, S. Jansen, M. A. Zwieniecki, E. Smets, and N. M. Holbrook Changes in pit membrane porosity due to deflection and stretching: the role of vestured pits J. Exp. Bot., July 1, 2004; 55(402): 1569 - 1575. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. B. Kitin, T. Fujii, H. Abe, and R. Funada Anatomy of the vessel network within and between tree rings of Fraxinus lanuginosa (Oleaceae) Am. J. Botany, June 1, 2004; 91(6): 779 - 788. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Sperry and U. G. Hacke Analysis of circular bordered pit function I. Angiosperm vessels with homogenous pit membranes Am. J. Botany, March 1, 2004; 91(3): 369 - 385. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. VESALA, T. HOLTTA, M. PERAMAKI, and E. NIKINMAA Refilling of a Hydraulically Isolated Embolized Xylem Vessel: Model Calculations Ann. Bot., March 1, 2003; 91(4): 419 - 428. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Van Ieperen, V. S. Volkov, and U. Van Meeteren Distribution of xylem hydraulic resistance in fruiting truss of tomato influenced by water stress J. Exp. Bot., January 2, 2003; 54(381): 317 - 324. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.R. Lancashire and A.R. Ennos Modelling the hydrodynamic resistance of bordered pits J. Exp. Bot., June 1, 2002; 53(373): 1485 - 1493. [Abstract] [Full Text] [PDF] |
||||


