| 研究領域 | デジタルバイオスフェア：地球環境を守るための統合生物圏科学 |
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| 研究課題/領域番号 |
22H05725
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| 研究機関 | 京都大学 |
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研究代表者 |
EPRON Daniel 京都大学, 農学研究科, 教授 (60844305)
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| 研究期間 (年度) |
2022-06-16 – 2024-03-31
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| キーワード | tree ring / cellulose / isotopes / climate change |
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| 研究実績の概要 |
During the fiscal year R4, we successfully sampled wood cores from 14 trees in November in the Kiryu experimental watershed when tree growth and cellulose deposit have ceased. Annual tree rings were cut and cellulose were extracted in February and March. Duplicate samples (1592) were weighed in silver capsules and were analysed by isotope ratio mass spectrometry from July 2023 to February 2024.
During the fiscal year R4, we have also reanalysed the 20-year series of canopy CO2 and H2O fluxes measured by eddy covariance and calculated evapotranspiration, canopy photosynthesis and stand-level water use efficiency. We started to collect samples of sap wood in March to ascertain the relation between xylem water and source water (soil and rainwater).
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
Because the delivery of experimental consumables was delayed due to reduced supply, we were not able to start measuring the isotope composition of the tree ring cellulose during the fiscal year R4. We were able to do it in the next fiscal year (R5) and we successfully completed the work.
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| 今後の研究の推進方策 |
Tree ring isotope composition will be measured on all rings cut from wood cores collected on 14 trees in the Kiryu experimental watershed. We will collect samples of sap wood monthly to ascertain the relation between xylem water and source water (soil and rainwater). Water samples will be analysed for 18O and 2H with a cavity ring-down spectrometer. From May to August (growing season) we will sample leaves and branches and extracted their water monthly. We will also sample atmospheric water and soil water at the same time. We will characterise leaf water enrichment above source water and test several models able to predict the observed enrichment.
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