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Oxygen isotope ratios between soil water and stem water of trees in pot experiments
Author(s) -
Takahashi Kazushi
Publication year - 1998
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1046/j.1440-1703.1998.00240.x
Subject(s) - transpiration , soil water , isotopes of oxygen , oxygen isotope ratio cycle , evaporation , chemistry , environmental chemistry , isotope , isotopic signature , stable isotope ratio , water content , environmental science , isotope analysis , soil science , ecology , geology , biology , photosynthesis , biochemistry , physics , geotechnical engineering , quantum mechanics , nuclear chemistry , thermodynamics
Since the oxygen isotopic ratio of water extracted from stems reflects that of water taken up by roots, the stem water isotope ratio can be used to analyze the source of water for plant growth. However, it is known that the fractionation of isotopes during evaporation from the surface soil increases the isotope ratio in soil water drastically. In this study, it was experimentally confirmed that the stem water of Elaeocarpus sylvestris vs. ellipticus Hara seedlings is not isotopically similar to the water source in the case where evaporation from the soil occurs actively. However, since water in these plant bodies was replaced in about 2 days in the pot experiments, the 2‐day‐averaged values of the soil water isotope ratio approached the stem water isotope ratio. Thus, time‐course samplings of the soil and stems, and measurements of the replacement time of water in the plant body (water volume in plant/transpiration rate) are recommended for correct interpretation of the isotopic signature of soil water and stem water.