Schulze E-D, Caldwell M M, Canadell J, Mooney H A, Jackson R B, Parson D, Scholes R, Sala O E, Trimborn P
Max-Planck-Institut for Biogeochemistry, PO Box 100164, D-07401 Jena, Germany, , , , , , DE.
Ecology Center, Utah State University, Logan, UT 84322-5230, USA, , , , , , US.
Oecologia. 1998 Jul;115(4):460-462. doi: 10.1007/s004420050541.
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.
根系中水分的向下运输，以下称为“逆水力提升”，此前已通过热通量技术得到证实。但在本研究中，首次在野外条件下对卡拉哈里沙漠的几种多年生草本植物进行调查时，证明了水分流入更深的土壤层。利用氘标记表明，根系从上部土壤层潮湿沙子中获取的水分通过根系系统运输到更深层的根系，并在这些深度释放到干燥的沙子中。逆水力提升可能是一种重要机制，有助于根系穿过上部土壤层下方的干燥土壤层生长，降水会渗透到该上部土壤层。这可能使根系在诸如卡拉哈里沙漠这样的水分有限的生态系统中获取深层水源。
