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Extraction and Analysis of Plant Water for Deuterium Isotope Measurement and Application to Field Experiments

2001; Springer Nature (Netherlands); Linguagem: Inglês

10.1007/978-94-015-9841-5_3

0924-1949

Jeffrey V. Turner, P. Farrington, V. Gailitis,

Isotope Analysis in Ecology

Analysis of stable isotopes in water is well established as a powerful tool for investigating processes in plant-water relations such as water use efficiency and determining the source of water uptake in the soil zone. Deuterium and oxygen-18 have been used to determine the source of water taken up by plants and to study the functioning of deep root systems (White et al. 1985, Dawson and Ehleringer 1991, Ehleringer and Dawson 1992, Thorburn and Walker 1993 and Thorburn et al. 1993a and b). Provided there is sufficient difference in isotopic composition between water in the soil profile and groundwater, the stable isotopic composition of water in the xylem sap of the plant can be used to define the mixing ratio of these sources of water for the plant (see Dawson and Pate 1996). The method is based on the finding that the isotopic composition of both hydrogen and oxygen in water is not altered when taken up by roots and transported from roots to the leaves (Zimmerman et al. 1967, White et al. 1985 and Turner et al. 1987).