Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1073/pnas.2014422117 |
Stem water cryogenic extraction biases estimation in deuterium isotope composition of plant source water | |
Yongle Chen; Brent R. Helliker; Xianhui Tang; Fang Li; Youping Zhou; Xin Song | |
2020-12-14 | |
发表期刊 | Proceedings of the National Academy of Science |
出版年 | 2020 |
英文摘要 | The hydrogen isotope ratio of water cryogenically extracted from plant stem samples (δ2Hstem_CVD) is routinely used to aid isotope applications that span hydrological, ecological, and paleoclimatological research. However, an increasing number of studies have shown that a key assumption of these applications—that δ2Hstem_CVD is equal to the δ2H of plant source water (δ2Hsource)—is not necessarily met in plants from various habitats. To examine this assumption, we purposedly designed an experimental system to allow independent measurements of δ2Hstem_CVD, δ2Hsource, and δ2H of water transported in xylem conduits (δ2Hxylem) under controlled conditions. Our measurements performed on nine woody plant species from diverse habitats revealed a consistent and significant depletion in δ2Hstem_CVD compared with both δ2Hsource and δ2Hxylem. Meanwhile, no significant discrepancy was observed between δ2Hsource and δ2Hxylem in any of the plants investigated. These results cast significant doubt on the long-standing view that deuterium fractionation occurs during root water uptake and, alternatively, suggest that measurement bias inherent in the cryogenic extraction method is the root cause of δ2Hstem_CVD depletion. We used a rehydration experiment to show that the stem water cryogenic extraction error could originate from a dynamic exchange between organically bound deuterium and liquid water during water extraction. In light of our finding, we suggest caution when partitioning plant water sources and reconstructing past climates using hydrogen isotopes, and carefully propose that the paradigm-shifting phenomenon of ecohydrological separation (“two water worlds”) is underpinned by an extraction artifact. |
领域 | 地球科学 |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/308275 |
专题 | 地球科学 |
推荐引用方式 GB/T 7714 | Yongle Chen,Brent R. Helliker,Xianhui Tang,et al. Stem water cryogenic extraction biases estimation in deuterium isotope composition of plant source water[J]. Proceedings of the National Academy of Science,2020. |
APA | Yongle Chen,Brent R. Helliker,Xianhui Tang,Fang Li,Youping Zhou,&Xin Song.(2020).Stem water cryogenic extraction biases estimation in deuterium isotope composition of plant source water.Proceedings of the National Academy of Science. |
MLA | Yongle Chen,et al."Stem water cryogenic extraction biases estimation in deuterium isotope composition of plant source water".Proceedings of the National Academy of Science (2020). |
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