Burgess Stephen S O, Adams Mark A, Turner Neil C, White Don A, Ong Chin K
Department of Botany, University of Western Australia, 6907, Nedlands, WA, Australia.
CSIRO Plant Industry, 6014, Private Bag, P.O., Wembley, WA, Australia.
Oecologia. 2001 Jan;126(2):158-165. doi: 10.1007/s004420000501. Epub 2001 Jan 1.
In previous work, we provided evidence from sap flow measurements that when root systems span soil layers of different moisture content, water is redistributed by roots in the direction of the difference in water potential. In addition to the phenomenon termed "hydraulic lift", where water is redistributed from depth to dry topsoil, the process of "hydraulic redistribution" includes downward transfer of water when the surface layers of soils with low permeability become wet after rainfall. In this paper, we support our previous findings with evidence from measurements of soil water and estimate the quantities of water transferred to depth following rain. Amounts of water stored at depth are not likely to be significant for drought avoidance by plants. However, downward transfer of water may be important to plant establishment and the reduction of waterlogging in certain soil types.
在之前的研究中，我们通过液流测量提供了证据，表明当根系跨越不同含水量的土壤层时，水分会沿着水势差的方向由根系重新分配。除了被称为“水力提升”的现象，即水分从深层重新分配到干燥的表层土壤外，“水力再分配”过程还包括降雨后低渗透率土壤表层变湿时水分的向下转移。在本文中，我们通过土壤水分测量的证据支持了之前的研究结果，并估算了降雨后向下转移到深层的水量。深层储存的水量对植物避旱可能意义不大。然而，水分的向下转移对植物定植以及某些土壤类型中涝渍的减轻可能很重要。
