title: Downward flux of water through roots (i.e. inverse hydraulic lift) in dry Kalahari sands.
abstract: Downward transport of water in roots, in the following termed "inverse hydraulic lift," has previously been shown with heat flux techniques. But water flow into deeper soil layers was demonstrated in this study for the first time when investigating several perennial grass species of the Kalahari Desert under field conditions. Deuterium labelling was used to show that water acquired by roots from moist sand in the upper profile was transported through the root system to roots deeper in the profile and released into the dry sand at these depths. Inverse hydraulic lift may serve as an important mechanism to facilitate root growth through the dry soil layers underlaying the upper profile where precipitation penetrates. This may allow roots to reach deep sources of moisture in water-limited ecosystems such as the Kalahari Desert.
authors.affiliation: Max-Planck-Institut for Biogeochemistry, PO Box 100164, D-07401 Jena, Germany, , , , , , DE.
authors.forename: E-D
authors.initials: ED
authors.lastname: Schulze
authors.affiliation: Ecology Center, Utah State University, Logan, UT 84322-5230, USA, , , , , , US.
authors.forename: M M
authors.initials: MM
authors.lastname: Caldwell
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA, , , , , , US.
authors.forename: J
authors.initials: J
authors.lastname: Canadell
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA, , , , , , US.
authors.forename: H A
authors.initials: HA
authors.lastname: Mooney
authors.affiliation: Department of Botany, University of Texas, Austin, TX 78713, USA, , , , , , US.
authors.forename: R B
authors.initials: RB
authors.lastname: Jackson
authors.affiliation: CSIRO Division of Forest Science and Technology, P Box 395, Pretoria, South Africa, , , , , , ZA.
authors.forename: D
authors.initials: D
authors.lastname: Parson
authors.affiliation: CSIRO Division of Forest Science and Technology, P Box 395, Pretoria, South Africa, , , , , , ZA.
authors.forename: R
authors.initials: R
authors.lastname: Scholes
authors.affiliation: Department of Ecology, University of Buenos Aires, Av. San Martin 4453, Buenos Aires 1417, Argentina, , , , , , AR.
authors.forename: O E
authors.initials: OE
authors.lastname: Sala
authors.affiliation: Institut für Hydrologie, GSF Neuherberg, Ingolstädter Landstrasse 1, D-81377 München, Germany, , , , , , DE.
authors.forename: P
authors.initials: P
authors.lastname: Trimborn
keywords: Deserts; Grass roots; Hydraulic lift; Key words Water transport