1
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Morgner E, Holloway-Phillips M, Basler D, Nelson DB, Kahmen A. Effects of increasing atmospheric CO 2 on leaf water δ 18O values are small and are attenuated in grasses and amplified in dicotyledonous herbs and legumes when transferred to cellulose δ 18O values. THE NEW PHYTOLOGIST 2024. [PMID: 38575849 DOI: 10.1111/nph.19713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 03/08/2024] [Indexed: 04/06/2024]
Abstract
The oxygen isotope composition of cellulose (δ18O values) has been suggested to contain information on stomatal conductance (gs) responses to rising pCO2. The extent by which pCO2 affects leaf water and cellulose δ18O values (δ18OLW and δ18OC) and the isotope processes that determine pCO2 effects on δ18OLW and δ18OC are, however, unknown. We tested the effects of pCO2 on gs, δ18OLW and δ18OC in a glasshouse experiment, where six plant species were grown under pCO2 ranging from 200 to 500 ppm. Increasing pCO2 caused a decline in gs and an increase in δ18OLW, as expected. Importantly, the effects of pCO2 on gs and δ18OLW were small and pCO2 effects on δ18OLW were not directly transferred to δ18OC but were attenuated in grasses and amplified in dicotyledonous herbs and legumes. This is likely because of functional group-specific pCO2 effects on the model parameter pxpex. Our study highlights important uncertainties when using δ18OC as a proxy for gs. Specifically, pCO2-triggered gs effects on δ18OLW and δ18OC are possibly too small to be detected in natural settings and a pCO2 effect on pxpex may render the commonly assumed negative linkage between δ18OC and gs to be incorrect, potentially confounding δ18OC based gs reconstructions.
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Affiliation(s)
- Eva Morgner
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
| | | | - David Basler
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
| | - Daniel B Nelson
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
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2
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Martínez-Sancho E, Cernusak LA, Fonti P, Gregori A, Ullrich B, Pannatier EG, Gessler A, Lehmann MM, Saurer M, Treydte K. Unenriched xylem water contribution during cellulose synthesis influenced by atmospheric demand governs the intra-annual tree-ring δ 18 O signature. THE NEW PHYTOLOGIST 2023; 240:1743-1757. [PMID: 37753542 DOI: 10.1111/nph.19278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/16/2023] [Indexed: 09/28/2023]
Abstract
The oxygen isotope composition (δ18 O) of tree-ring cellulose is used to evaluate tree physiological responses to climate, but their interpretation is still limited due to the complexity of the isotope fractionation pathways. We assessed the relative contribution of seasonal needle and xylem water δ18 O variations to the intra-annual tree-ring cellulose δ18 O signature of larch trees at two sites with contrasting soil water availability in the Swiss Alps. We combined biweekly δ18 O measurements of soil water, needle water, and twig xylem water with intra-annual δ18 O measurements of tree-ring cellulose, xylogenesis analysis, and mechanistic and structural equation modeling. Intra-annual cellulose δ18 O values resembled source water δ18 O mean levels better than needle water δ18 O. Large parts of the rings were formed under high proportional exchange with unenriched xylem water (pex ). Maximum pex values were achieved in August and imprinted on sections at 50-75% of the ring. High pex values were associated with periods of high atmospheric evaporative demand (VPD). While VPD governed needle water δ18 O variability, we estimated a limited Péclet effect at both sites. Due to a variable pex , source water has a strong influence over large parts of the intra-annual tree-ring cellulose δ18 O variations, potentially masking signals coming from needle-level processes.
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Affiliation(s)
- Elisabet Martínez-Sancho
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
- Department of Biological Evolution, Ecology and Environmental Sciences, University of Barcelona, Diagonal 643, Barcelona, 08028, Spain
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, QLD, 4878, Australia
| | - Patrick Fonti
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Alessandro Gregori
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Bastian Ullrich
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Elisabeth Graf Pannatier
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Arthur Gessler
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Marco M Lehmann
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Matthias Saurer
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Kerstin Treydte
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
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3
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Yan Q, Zhao Y, Ma R, Wang B, Zhu Z, Li T, He D, Hocart CH, Zhou Y. Capping the hydroxyl groups (-OH) of α-cellulose to reduce Hy-groscopicity for accurate 18O/ 16O measurement by EA/Py/IRMS. Talanta 2023; 262:124698. [PMID: 37244243 DOI: 10.1016/j.talanta.2023.124698] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/18/2023] [Accepted: 05/21/2023] [Indexed: 05/29/2023]
Abstract
Obtaining an accurate measurement of 18O/16O at natural abundance level for land plants-derived α-cellulose with the currently popular EA/Py/IRMS (elemental analysis/pyrolysis/isotope ratio mass spectrometry) method is a challenge due to the hygroscopic nature of the exposed hydroxyl groups, as the 18O/16O of adsorbed moisture is usually different from that of the α-cellulose and the relative amount of adsorbed moisture is sample- and relative humidity-dependent. To minimize the hygroscopicity-related measurement error, we capped the hydroxyl groups of α-cellulose by benzylation to various degrees and found that the 18O/16O ratio of α-cellulose increased with the degree of benzyl substitution (DS), consistent with the theoretical prediction that a reduced presence of exposed hydroxyl groups should lead to a more accurate (and therefore more reliable) α-cellulose 18O/16O measurement. We propose the establishment of a moisture adsorption-degree of substitution or percentage of oxygen-18O/16O ratio equation, based on the measurement of C%, O% and δ18O of variably capped α-cellulose, so that a robust correction can be made in a plant species- and laboratory conditions-specific manner. Failure to do so will lead to an average underestimate of α-cellulose δ18O by 3.5 mUr under "average" laboratory conditions.
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Affiliation(s)
- Qiulin Yan
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Yu Zhao
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Ran Ma
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Bo Wang
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Zhenyu Zhu
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Ting Li
- College of Science and Engineering, ARC Centre of Excellence for Australian Biodiversity and Heritage, Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, 4878, Australia
| | - Ding He
- Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Hong Kong SAR, China; State Key Laboratory of Marine Pollution, Hong Kong, China
| | - Charles H Hocart
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China; Research School of Biology, Australian National University, Acton, 2601, ACT, Australia
| | - Youping Zhou
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China; Isotopomics in Chemical & Biological Oceanography (ICBO), Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
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4
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Göhring A, Hölzl S, Mayr C, Strauss H. Identification and quantification of the sea spray effect on isotopic systems in α-cellulose (δ 13C, δ 18O), total sulfur (δ 34S), and 87Sr/ 86Sr of European beach grass (Ammophila arenaria, L.) in a greenhouse experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:158840. [PMID: 36122729 DOI: 10.1016/j.scitotenv.2022.158840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/06/2022] [Accepted: 09/14/2022] [Indexed: 06/15/2023]
Abstract
The sea spray effect can severely influence the isotopic signature of terrestrial individuals in coastal regions. To further specify this effect, beach grass was grown in a greenhouse under controlled environmental conditions and sprayed with mineral salt solution containing different mineral salts but only traces of NaCl (group 1). Another group of plants was sprayed with salty water from the Schlei inlet and the Baltic Sea, respectively (group 2). Control plants were only sprayed with tap water. Isotope analyses were conducted on the unwashed and washed plants (δ13Ccellulose, δ18Ocellulose, δ34Stotal S, 87Sr/86Sr), soil (δ18Osulfate, δ34Ssulfate, 87Sr/86Sr), and spray as well as irrigation water (δ18Osulfate, δ34Ssulfate, 87Sr/86Sr). Moreover, elemental analyses were performed on the water samples. The sea spray effect was visible in all isotopic systems under study. The uptake of SO42-, HCO3-, and Sr2+ directly affected plants of group 1, while plants of group 2, sprayed with salty water, additionally showed salinity stress in the case of α-cellulose and total sulfur due to biochemical reactions of the plants. Very high concentrations in HCO3- or SO42- also affected the plants' isotopic signatures. The impact of the sea spray and additional stress reactions were quantified. Our study is the first experiment creating an artificial sea spray effect in a greenhouse. This experiment for the first time enables the identification and quantification of the sea spray effect in environmental samples. The marine signature taken up by the plants and recorded by the investigated isotopic systems is apparently high and should have an impact on the isotopic fingerprints of animal consumers at the coast, as evidenced for archaeological animals from the Viking Haithabu and the early medieval Schleswig sites located close to the Baltic Sea. This result demonstrates the potential of greenhouse experiments as an isotopic predictor of the past local sea spray effect.
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Affiliation(s)
- Andrea Göhring
- Ludwig-Maximilians-Universität München, Faculty of Biology, Department of Biology I, Anthropology and Human Genomics, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany.
| | - Stefan Hölzl
- RiesKraterMuseum Nördlingen, Eugene-Shoemaker-Platz 1, 86720 Nördlingen, Germany
| | - Christoph Mayr
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Geography, Wetterkreuz 15, 91058 Erlangen, Germany; Ludwig-Maximilians-Universität München, Faculty of Geosciences, Department of Earth and Environmental Studies and GeoBio-Center, Richard-Wagner-Straße 10, 80333 Munich, Germany
| | - Harald Strauss
- Westfälische Wilhelms-Universität Münster, Institute of Geology and Palaeontology, Corrensstr. 24, 48149 Münster, Germany
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5
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Kagawa A. Foliar water uptake as a source of hydrogen and oxygen in plant biomass. TREE PHYSIOLOGY 2022; 42:2153-2173. [PMID: 35554604 DOI: 10.1101/2020.08.20.260372] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/08/2022] [Indexed: 05/25/2023]
Abstract
Introductory biology lessons around the world typically teach that plants absorb water through their roots, but, unfortunately, absorption of water through leaves and subsequent transport and use of this water for biomass formation remains a field limited mostly to specialists. Recent studies have identified foliar water uptake as a significant net water source for terrestrial plants. The growing interest in the development of a new model that includes both foliar water uptake (in liquid form) and root water uptake to explain hydrogen and oxygen isotope ratios in leaf water and tree rings demands a method for distinguishing between these two water sources. Therefore, in this study, I have devised a new labelling method that utilizes two different water sources, one enriched in deuterium (HDO + D2O; δD = 7.0 × 10 4‰, δ18O = 4.1‰) and one enriched in oxygen-18 (H218O; δD = -85‰, δ18O = 1.1 × 104‰), to simultaneously label both foliar-absorbed and root-absorbed water and quantify their relative contributions to plant biomass. Using this new method, I here present evidence that, in the case of well-watered Cryptomeria japonica D. Don, hydrogen and oxygen incorporated into new leaf cellulose in the rainy season derives mostly from foliar-absorbed water (69% from foliar-absorbed water and 31% from root-absorbed water), while that of new root cellulose derives mostly from root-absorbed water (20% from foliar-absorbed water and 80% from root-absorbed water), and new branch xylem is somewhere in between (55% from foliar-absorbed water and 45% from root-absorbed water). The dual-labelling method first implemented in this study enables separate and simultaneous labelling of foliar-absorbed and root-absorbed water and offers a new tool to study the uptake, transport and assimilation processes of these waters in terrestrial plants.
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Affiliation(s)
- Akira Kagawa
- Forestry and Forest Products Research Institute, Wood Anatomy and Quality Laboratory, Tsukuba 305-8687, Japan
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6
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Cueni F, Nelson DB, Lehmann MM, Boner M, Kahmen A. Constraining parameter uncertainty for predicting oxygen and hydrogen isotope values in fruit. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5016-5032. [PMID: 35512408 DOI: 10.1093/jxb/erac180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 05/04/2022] [Indexed: 06/14/2023]
Abstract
Understanding δ18O and δ2H values of agricultural products like fruit is of particular scientific interest in plant physiology, ecology, and forensic studies. Applications of mechanistic stable isotope models to predict δ18O and δ2H values of water and organic compounds in fruit, however, are hindered by a lack of empirical parameterizations and validations. We addressed this lack of data by experimentally evaluating model parameter values required to model δ18O and δ2H values of water and organic compounds in berries and leaves from strawberry and raspberry plants grown at different relative humidities. Our study revealed substantial differences between leaf and berry isotope values, consistent across the different relative humidity treatments. We demonstrated that existing isotope models can reproduce water and organic δ18O and δ2H values for leaves and berries. Yet, these simulations require organ-specific model parameterization to accurately predict δ18O and δ2H values of leaf and berry tissue and water pools. We quantified these organ-specific model parameters for both species and relative humidity conditions. Depending on the required model accuracy, species- and environment-specific model parameters may be justified. The parameter values determined in this study thus facilitate applications of stable isotope models where understanding δ18O and δ2H values of fruit is of scientific interest.
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Affiliation(s)
- Florian Cueni
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056 Basel, Switzerland
- Agroisolab GmbH, Professor-Rehm-Strasse 6, 52428 Jülich, Germany
| | - Daniel B Nelson
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056 Basel, Switzerland
| | - Marco M Lehmann
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Markus Boner
- Agroisolab GmbH, Professor-Rehm-Strasse 6, 52428 Jülich, Germany
| | - Ansgar Kahmen
- University of Basel, Department of Environmental Sciences - Botany, Schönbeinstrasse 6, 4056 Basel, Switzerland
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7
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Effects of climate factors on spatiotemporal variation in carbon and oxygen isotope ratios in Korean rice. J Food Compost Anal 2022. [DOI: 10.1016/j.jfca.2022.104416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Miranda JC, Lehmann MM, Saurer M, Altman J, Treydte K. Insight into Canary Island pine physiology provided by stable isotope patterns of water and plant tissues along an altitudinal gradient. TREE PHYSIOLOGY 2021; 41:1611-1626. [PMID: 33824979 DOI: 10.1093/treephys/tpab046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
The Canary Islands, an archipelago east of Morocco's Atlantic coast, present steep altitudinal gradients covering various climatic zones from hot deserts to subalpine Mediterranean, passing through fog-influenced cloud forests. Unlike the majority of the Canarian flora, Pinus canariensis C. Sm. ex DC. in Buch grow along most of these gradients, allowing the study of plant functioning in contrasting ecosystems. Here we assess the water sources (precipitation, fog) of P. canariensis and its physiological behavior in its different natural environments. We analyzed carbon and oxygen isotope ratios of water and organics from atmosphere, soil and different plant organs and tissues (including 10-year annual time series of tree-ring cellulose) of six sites from 480 to 1990 m above sea level on the Canary Island La Palma. We found a decreasing δ18O trend in source water that was overridden by an increasing δ18O trend in needle water, leaf assimilates and tree-ring cellulose with increasing altitude, suggesting site-specific tree physiological responses to relative humidity. Fog-influenced and fog-free sites showed similar δ13C values, suggesting photosynthetic activity to be limited by stomatal closure and irradiance at certain periods. In addition, we observed an 18O-depletion (fog-free and timberline sites) and 13C-depletion (fog-influenced and fog-free sites) in latewood compared with earlywood caused by seasonal differences in: (i) water uptake (i.e., deeper ground water during summer drought, fog water frequency and interception) and (ii) meteorological conditions (stem radial growth and latewood δ18O correlated with winter precipitation). In addition, we found evidence for foliar water uptake and strong isotopic gradients along the pine needle axis in water and assimilates. These gradients are likely the reason for an unexpected underestimation of pine needle water δ18O when applying standard leaf water δ18O models. Our results indicate that soil water availability and air humidity conditions are the main drivers of the physiological behavior of pine along the Canary Island's altitudinal gradients.
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Affiliation(s)
- José Carlos Miranda
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, 28034 Madrid, Spain
| | - Marco M Lehmann
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Jan Altman
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
- Institute of Botany, Czech Academy of Science, 25243 Průhonice, Czech Republic
| | - Kerstin Treydte
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
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9
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Mejia-Chang M, Reyes-Garcia C, Seibt U, Royles J, Meyer MT, Jones GD, Winter K, Arnedo M, Griffiths H. Leaf water δ 18O reflects water vapour exchange and uptake by C 3 and CAM epiphytic bromeliads in Panama. FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:732-742. [PMID: 34099101 DOI: 10.1071/fp21087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 04/20/2021] [Indexed: 05/27/2023]
Abstract
The distributions of CAM and C3 epiphytic bromeliads across an altitudinal gradient in western Panama were identified from carbon isotope (δ13C) signals, and epiphyte water balance was investigated via oxygen isotopes (δ18O) across wet and dry seasons. There were significant seasonal differences in leaf water (δ18Olw), precipitation, stored 'tank' water and water vapour. Values of δ18Olw were evaporatively enriched at low altitude in the dry season for the C3 epiphytes, associated with low relative humidity (RH) during the day. Crassulacean acid metabolism (CAM) δ18Olw values were relatively depleted, consistent with water vapour uptake during gas exchange under high RH at night. At high altitude, cloudforest locations, C3 δ18Olw also reflected water vapour uptake by day. A mesocosm experiment with Tillandsia fasciculata (CAM) and Werauhia sanguinolenta (C3) was combined with simulations using a non-steady-state oxygen isotope leaf water model. For both C3 and CAM bromeliads, δ18Olw became progressively depleted under saturating water vapour by day and night, although evaporative enrichment was restored in the C3 W. sanguinolenta under low humidity by day. Source water in the overlapping leaf base 'tank' was also modified by evaporative δ18O exchanges. The results demonstrate how stable isotopes in leaf water provide insights for atmospheric water vapour exchanges for both C3 and CAM systems.
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Affiliation(s)
- Monica Mejia-Chang
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Casandra Reyes-Garcia
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK; and Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, Calle 43 Num. 130 Churburná de Hidalgo, Mérida, 97200, México
| | - Ulli Seibt
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK; and Department of Atmospheric and Oceanic Sciences, UCLA, Los Angeles, CA, USA
| | - Jessica Royles
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Moritz T Meyer
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Glyn D Jones
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Republic of Panama
| | - Miquel Arnedo
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Fac. Biologia, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain
| | - Howard Griffiths
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK; and Corresponding author.
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10
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Rees-Owen RL, Newton RJ, Ivanovic RF, Francis JE, Riding JB, Marca AD. A calibration of cellulose isotopes in modern prostrate Nothofagus and its application to fossil material from Antarctica. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142247. [PMID: 33254952 DOI: 10.1016/j.scitotenv.2020.142247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 08/21/2020] [Accepted: 09/04/2020] [Indexed: 06/12/2023]
Abstract
Carbon and oxygen isotopes (δ13C and δ18O) in tree rings are widely used to reconstruct palaeoclimate variables such as temperature during the Holocene (12 thousand years ago - present), and are used increasingly in deeper time. However, their use is largely restricted to arboreal trees, which excludes potentially important data from prostrate trees and shrubs, which grow in high latitude and altitude end-member environments. Here, we calibrate the use of δ13C and δ18O as climatic archives in two modern species of southern beech (Nothofagus) from Tierra del Fuego, Chile, at the southern limit of their current range. We show that prostrate trees are potentially suitable archives for recording climatological means over longer periods (on the order of decades), which opens up these important environments for tree ring isotope analysis. We then apply our new understanding to a remarkable late Neogene (17-2.5 Ma) fossil Nothofagus assemblage from the Transantarctic Mountains, Antarctica, representative of a prostrate tundra shrub growing during a period of significant ice sheet retreat. The δ13C of the fossil cellulose was found to be ~4‰ enriched relative to that of the modern tress. This is likely to be due to a combination of a more positive δ13C of contemporaneous atmospheric CO2 and enhanced water use efficiency at the fossil site. Using the cellulose-δ18O in the fossil wood, we are able to reconstruct precipitation oxygen isotopes over the Antarctic interior for the first time for this time period. The results show that δ18Oprecip over Antarctica was -16.0 ± 4.2‰, around 12‰ enriched relative to today, suggesting changes in the hydrological cycle linked to warmer temperatures and a smaller ice sheet.
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Affiliation(s)
| | - Robert J Newton
- School of Earth and Environment, University of Leeds, Leeds, UK.
| | - Ruza F Ivanovic
- School of Earth and Environment, University of Leeds, Leeds, UK
| | | | | | - Alina D Marca
- School of Environmental Sciences, University of East Anglia, Norwich, UK
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11
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Adsorption separation of heavier isotope gases in subnanometer carbon pores. Nat Commun 2021; 12:546. [PMID: 33483513 PMCID: PMC7822881 DOI: 10.1038/s41467-020-20744-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 12/16/2020] [Indexed: 11/08/2022] Open
Abstract
Isotopes of heavier gases including carbon (13C/14C), nitrogen (13N), and oxygen (18O) are highly important because they can be substituted for naturally occurring atoms without significantly perturbing the biochemical properties of the radiolabelled parent molecules. These labelled molecules are employed in clinical radiopharmaceuticals, in studies of brain disease and as imaging probes for advanced medical imaging techniques such as positron-emission tomography (PET). Established distillation-based isotope gas separation methods have a separation factor (S) below 1.05 and incur very high operating costs due to high energy consumption and long processing times, highlighting the need for new separation technologies. Here, we show a rapid and highly selective adsorption-based separation of 18O2 from 16O2 with S above 60 using nanoporous adsorbents operating near the boiling point of methane (112 K), which is accessible through cryogenic liquefied-natural-gas technology. A collective-nuclear-quantum effect difference between the ordered 18O2 and 16O2 molecular assemblies confined in subnanometer pores can explain the observed equilibrium separation and is applicable to other isotopic gases.
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12
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Ma R, Zhao Y, Liu L, Zhu Z, Wang B, Wang Y, Yin X, Su J, Zhou Y. Novel Position-Specific 18O/ 16O Measurement of Carbohydrates. II. The Complete Intramolecular 18O/ 16O Profile of the Glucose Unit in a Starch of C4 Origin. Anal Chem 2020; 92:7462-7470. [PMID: 32365292 DOI: 10.1021/acs.analchem.9b05314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Information about plant photosynthetic carbon assimilation, physiology, and biochemistry is locked in the 18O/16O ratios of the individual positions of higher plants carbohydrates but is under-utilized, because of the difficulty of making these determinations. We report the extension of the wet chemistry approach we used to access the 18O/16O ratio of O-3 of glucose with a novel GC/Pyrolysis/IRMS-based method, to determine the 18O/16O ratios of O-4, O-5, and O-6. The O atoms (OH groups) at positions 1, 2, 5, and 6 of glucose were protected by acetonation (converting to 1,2;5,6-di-O-isopropylidene-glucofuranose, DAGF). The DAGF was then converted to 6-bromo-6-deoxy-1,2;3,5-di-O-isopropylidene-glucofuranose (6-bromoDAGF) with the simultaneous removal of O-6 with N-bromosuccinimide and triphenylphosphine. The DAGF was also methylated at O-3 with CH3I under the catalysis of NaH to 3-methylDAGF, which was then deacetonated to 1,2-O-isopropylidene-3-O-methyl-glucofuranose (3-methylMAGF). O-5 and O-6 were then removed as a whole from 3-methylMAGF by I2 oxidization under the catalysis of Ph3P and imidazole. Isotope mass balance was then applied to calculate the 18O/16O of O-5 and O-6 as a whole and O-6, respectively. Sampling at different stages of substrate conversion to product and applying a Rayleigh-type fractionation model were employed, when quantitative conversion of substrate was unachievable to calculate the δ18O of the converted substrate. Quantitative conversion of glucose with phenylhydrazine to phenylglucosazone also allowed for the calculation of δ18O2 by applying isotope mass balance between the two. A C4 starch-derived glucose intramolecular δ18O profile is now determined: O-3 is relatively enriched (by 12.16 mUr), O-4 is relatively depleted (by 20.40-31.11 mUr), and O-2 is marginally enriched (by 2.40 mUr) against the molecular average.
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Affiliation(s)
- Ran Ma
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021
| | - Yu Zhao
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021
| | - Lan Liu
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China, 519082
| | - Zhenyu Zhu
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021
| | - Bo Wang
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021
| | - Ying Wang
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021
| | - Xijie Yin
- MNR Third Institute of Oceanology, Xiamen, China, 361005
| | - Jing Su
- MNR Third Institute of Oceanology, Xiamen, China, 361005
| | - Youping Zhou
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, China, 710021.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China, 519082
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Strobel P, Haberzettl T, Bliedtner M, Struck J, Glaser B, Zech M, Zech R. The potential of δ 2H n-alkanes and δ 18O sugar for paleoclimate reconstruction - A regional calibration study for South Africa. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 716:137045. [PMID: 32059328 DOI: 10.1016/j.scitotenv.2020.137045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
The hydrogen isotopic composition of leaf wax-derived n-alkanes (δ2Hn-alkanes) is a widely applied proxy for (paleo)climatic changes. It has been suggested that the coupling with the oxygen isotopic composition of hemicellulose-derived sugars (δ18Osugar) - an approach dubbed 'paleohygrometer' - might allow more robust and quantitative (paleo)hydrological reconstructions. However, the paleohygrometer remains to be evaluated and tested regionally. In this study, topsoil samples from South Africa, covering extensive environmental gradients, are analysed. δ2Hn-alkanes correlates significantly with the isotopic composition of precipitation (δ2Hp), whereas no significant correlation exists between δ18Osugar and δ18Op. The apparent fractionation (εapp) is the difference between δ2Hn-alkanes and δ2Hp (εapp 2H) and δ18Osugar and δ18Op (εapp 18O), respectively, and integrates i) isotopic enrichment due to soil water evaporation, ii) leaf (and xylem) water transpiration and iii) biosynthetic fractionation. We find no correlation of εapp 18O nor for εapp 2H with temperature, and no correlation of εapp 2H with potential evapotranspiration and an aridity index. By contrast, εapp 18O correlates significantly with both potential evapotranspiration and the aridity index. This highlights the strong effect of evapotranspirative enrichment on δ18Osugar. In study areas without plant predominance using Crassulacean Acid Metabolism (CAM), coupling δ18Osugar and δ2Hn-alkanes enables to reconstruct δ2Hp and δ18Op with an offset of Δδ2H = 6 ± 27‰ and Δδ18O = 0.8 ± 3.7‰, respectively, as well as relative humidity (RH) with an offset of ΔRH = 6 ± 17%. The paleohygrometer does, however, not work well for our study areas where CAM plants prevail (reconstructed δ18Op, δ2Hp and RH are off by 3.1‰, 27.2‰ and 31.7%). This probably reflects plant-specific (phenological) adaptations and/or post-photosynthetic exchange reactions related to CAM metabolism. Overall, our findings corroborate that δ2Hn-alkanes and δ18Osugar are valuable proxies, and the paleohygrometer is a promising approach for paleoclimate reconstructions in southern Africa.
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Affiliation(s)
- P Strobel
- Physical Geography, Institute of Geography, Friedrich Schiller University Jena, Jena, Germany.
| | - T Haberzettl
- Physical Geography, Institute of Geography and Geology, University of Greifswald, Germany
| | - M Bliedtner
- Physical Geography, Institute of Geography, Friedrich Schiller University Jena, Jena, Germany
| | - J Struck
- Physical Geography, Institute of Geography, Friedrich Schiller University Jena, Jena, Germany
| | - B Glaser
- Institute of Agronomy and Nutritional Sciences, Soil Biogeochemistry, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - M Zech
- Physical Geography with focus on Paleoenvironmental Research, Institute of Geography, Dresden University of Technology, Dresden, Germany
| | - R Zech
- Physical Geography, Institute of Geography, Friedrich Schiller University Jena, Jena, Germany
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14
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Barçante Ladvocat Cintra B, Gloor M, Boom A, Schöngart J, Locosselli GM, Brienen R. Contrasting controls on tree ring isotope variation for Amazon floodplain and terra firme trees. TREE PHYSIOLOGY 2019; 39:845-860. [PMID: 30824929 PMCID: PMC6594573 DOI: 10.1093/treephys/tpz009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/10/2018] [Accepted: 01/15/2019] [Indexed: 05/04/2023]
Abstract
Isotopes in tropical trees rings can improve our understanding of tree responses to climate. We assessed how climate and growing conditions affect tree-ring oxygen and carbon isotopes (δ18OTR and δ13CTR) in four Amazon trees. We analysed within-ring isotope variation for two terra firme (non-flooded) and two floodplain trees growing at sites with varying seasonality. We find distinct intra-annual patterns of δ18OTR and δ13CTR driven mostly by seasonal variation in weather and source water δ18O. Seasonal variation in isotopes was lowest for the tree growing under the wettest conditions. Tree ring cellulose isotope models based on existing theory reproduced well observed within-ring variation with possible contributions of both stomatal and mesophyll conductance to variation in δ13CTR. Climate analysis reveal that terra firme δ18OTR signals were related to basin-wide precipitation, indicating a source water δ18O influence, while floodplain trees recorded leaf enrichment effects related to local climate. Thus, intrinsically different processes (source water vs leaf enrichment) affect δ18OTR in the two different species analysed. These differences are likely a result of both species-specific traits and of the contrasting growing conditions in the floodplains and terra firme environments. Simultaneous analysis of δ13CTR and δ18OTR supports this interpretation as it shows strongly similar intra-annual patterns for both isotopes in the floodplain trees arising from a common control by leaf stomatal conductance, while terra firme trees showed less covariation between the two isotopes. Our results are interesting from a plant physiological perspective and have implications for climate reconstructions as trees record intrinsically different processes.
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Affiliation(s)
| | - Manuel Gloor
- School of Geography, University of Leeds, Leeds, Garstang North
| | - Arnoud Boom
- School of Geology, Geography and the Environment, Bennett Building, University Road, University of Leicester, Leicester, UK
| | - Jochen Schöngart
- National Institute for Amazon Research, Av. André Araújo, 2.936, Petrópolis, CEP 69.067-375, Manaus, Amazonas Brazil
| | - Giuliano Maselli Locosselli
- Institute of Biosciences, University of São Paulo, Rua do Matão, 14, Butantã, São Paulo, CEP 05508-090, Brazil
| | - Roel Brienen
- School of Geography, University of Leeds, Leeds, Garstang North
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15
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Belmecheri S, Wright WE, Szejner P, Morino KA, Monson RK. Carbon and oxygen isotope fractionations in tree rings reveal interactions between cambial phenology and seasonal climate. PLANT, CELL & ENVIRONMENT 2018; 41:2758-2772. [PMID: 29995977 DOI: 10.1111/pce.13401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 06/23/2018] [Accepted: 07/02/2018] [Indexed: 06/08/2023]
Abstract
We developed novel approaches for using the isotope composition of tree-ring subdivisions to study seasonal dynamics in tree-climate relations. Across a 30-year time series, the δ13 C and δ18 O values of the earlywood (EW) cellulose in the annual rings of Pinus ponderosa reflected relatively high intrinsic water-use efficiencies and high evaporative fractionation of 18 O/16 O, respectively, compared with the false latewood (FLW), summerwood (SW), and latewood (LW) subdivisions. This result is counterintuitive, given the spring origins of the EW source water and midsummer origins of the FLW, SW, and LW. With the use of the Craig-Gordon (CG), isotope-climate model revealed that the isotope ratios in all of the ring subdivision are explained by the existence of seasonal lags, lasting several weeks, between the initial formation of tracheids and the production of cellulosic secondary cell walls during maturation. In contrast to some past studies, modification of the CG model according to conventional methods to account for mixing of needle water between fractionated and nonfractionated sources did not improve the accuracy of predictions. Our results reveal new potential in the use of tree-ring isotopes to reconstruct past intra-annual tree-climate relations if lags in cambial phenology are reconciled with isotope ratio observations and included in theoretical treatments.
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Affiliation(s)
- Soumaya Belmecheri
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - William E Wright
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - Paul Szejner
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona
| | - Kiyomi A Morino
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - Russell K Monson
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona
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16
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Ma R, Zhu Z, Wang B, Zhao Y, Yin X, Lu F, Wang Y, Su J, Hocart CH, Zhou Y. Novel Position-Specific 18O/16O Measurement of Carbohydrates. I. O-3 of Glucose and Confirmation of 18O/16O Heterogeneity at Natural Abundance Levels in Glucose from Starch in a C4 Plant. Anal Chem 2018; 90:10293-10301. [DOI: 10.1021/acs.analchem.8b02022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ran Ma
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Zhenyu Zhu
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Bo Wang
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Yu Zhao
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Xijie Yin
- SOA Third Institute of Oceanography, Xiamen 361005, China
| | - Fengyan Lu
- Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
| | - Ying Wang
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Jing Su
- SOA Third Institute of Oceanography, Xiamen 361005, China
| | - Charles H. Hocart
- Research School of Biology, Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Youping Zhou
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
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17
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Cheesman AW, Cernusak LA. Infidelity in the outback: climate signal recorded in Δ18O of leaf but not branch cellulose of eucalypts across an Australian aridity gradient. TREE PHYSIOLOGY 2017; 37:554-564. [PMID: 28008083 DOI: 10.1093/treephys/tpw121] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
The isotopic composition of leaf water in terrestrial plants is highly dependent upon a plant's environment. This isotopic signature can become integrated into organic molecules, allowing the isotopic composition of biomarkers such as cellulose to be used as sensitive paleo and climatic proxies. However, the mechanisms by which cellulose isotopic composition reflect environmental conditions are complex, and may vary between leaf and woody tissues. To date few empirical tests have been made on the relative roles of leaf-water enrichment and source water on the isotopic composition of leaf and wood cellulose within the same plant. Here, we study both leaf and branch wood cellulose, as well as xylem/source water of eucalypts across a 900 km aridity gradient in NE Australia. Across 11 sites, spanning average annual precipitation of 235-1400 mm and average relative humidity of 33-70%, we found a strong and consistent trend in leaf cellulose. However, once the effect of altered source water was considered we found wood cellulose to show no trend across this environmental gradient. We consider potential mechanisms that could explain the 'damping' of a climatic signal within wood cellulose and consider the implication and limitations on the use of tree-ring cellulose as a climate proxy.
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Affiliation(s)
- Alexander W Cheesman
- Terrestrial Ecology Group, College of Science & Engineering, James Cook University, Cairns, QLD 4878, Australia
| | - Lucas A Cernusak
- Terrestrial Ecology Group, College of Science & Engineering, James Cook University, Cairns, QLD 4878, Australia
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18
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Royles J, Griffiths H. Invited review: climate change impacts in polar regions: lessons from Antarctic moss bank archives. GLOBAL CHANGE BIOLOGY 2015; 21:1041-57. [PMID: 25336089 DOI: 10.1111/gcb.12774] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/24/2014] [Accepted: 10/08/2014] [Indexed: 05/13/2023]
Abstract
Mosses are the dominant plants in polar and boreal regions, areas which are experiencing rapid impacts of regional warming. Long-term monitoring programmes provide some records of the rate of recent climate change, but moss peat banks contain an unrivalled temporal record of past climate change on terrestrial plant Antarctic systems. We summarise the current understanding of climatic proxies and determinants of moss growth for contrasting continental and maritime Antarctic regions, as informed by 13C and 18O signals in organic material. Rates of moss accumulation are more than three times higher in the maritime Antarctic than continental Antarctica with growing season length being a critical determinant of growth rate, and high carbon isotope discrimination values reflecting optimal hydration conditions. Correlation plots of 13C and 18O values show that species (Chorisodontium aciphyllum / Polytrichum strictum) and growth form (hummock / bank) are the major determinants of measured isotope ratios. The interplay between moss growth form, photosynthetic physiology, water status and isotope composition are compared with developments of secondary proxies, such as chlorophyll fluorescence. These approaches provide a framework to consider the potential impact of climate change on terrestrial Antarctic habitats as well as having implications for future studies of temperate, boreal and Arctic peatlands. There are many urgent ecological and environmental problems in the Arctic related to mosses in a changing climate, but the geographical ranges of species and life-forms are difficult to track individually. Our goal was to translate what we have learned from the more simple systems in Antarctica, for application to Arctic habitats.
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Affiliation(s)
- Jessica Royles
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK; Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
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19
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Greule M, Rossmann A, Schmidt HL, Mosandl A, Keppler F. A stable isotope approach to assessing water loss in fruits and vegetables during storage. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:1974-1981. [PMID: 25674668 DOI: 10.1021/jf505192p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Plant tissue water is the source of oxygen and hydrogen in organic biomatter. Recently, we demonstrated that the stable hydrogen isotope value (δ(2)H) of plant methoxyl groups is a very reliable and easily available archive for the δ(2)H value of this tissue water. Here we show in a model experiment that the δ(2)H values of methoxyl groups remain unchanged after water loss during storage of fruits and vegetables under controlled conditions, while δ(2)H and δ(18)O values of tissue water increase. This enhancement is plant-dependent, and the correlation differs from the meteoric water line. The δ(18)O value is better correlated to the weight decrease of the samples. Therefore, we postulate that the δ(2)H value of methoxyl groups and the δ(18)O value of tissue water are suitable parameters for checking postharvest alterations of tissue water, either addition or loss.
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Affiliation(s)
- Markus Greule
- Institute of Earth Sciences, Ruprecht Karls University Heidelberg , Im Neuenheimer Feld 234-236, D-69120 Heidelberg, Germany
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20
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Potentials and caveats with oxygen and sulfur stable isotope analyses in authenticity and origin checks of food and food commodities. Food Control 2015. [DOI: 10.1016/j.foodcont.2014.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Schmidt HL, Robins RJ, Werner RA. Multi-factorial in vivo stable isotope fractionation: causes, correlations, consequences and applications. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2015; 51:155-199. [PMID: 25894429 DOI: 10.1080/10256016.2015.1014355] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many physical and chemical processes in living systems are accompanied by isotope fractionation on H, C, N, O and S. Although kinetic or thermodynamic isotope effects are always the basis, their in vivo manifestation is often modulated by secondary influences. These include metabolic branching events or metabolite channeling, metabolite pool sizes, reaction mechanisms, anatomical properties and compartmentation of plants and animals, and climatological or environmental conditions. In the present contribution, the fundamentals of isotope effects and their manifestation under in vivo conditions are outlined. The knowledge about and the understanding of these interferences provide a potent tool for the reconstruction of physiological events in plants and animals, their geographical origin, the history of bulk biomass and the biosynthesis of defined representatives. It allows the use of isotope characteristics of biomass for the elucidation of biochemical pathways and reaction mechanisms and for the reconstruction of climatic, physiological, ecological and environmental conditions during biosynthesis. Thus, it can be used for the origin and authenticity control of food, the study of ecosystems and animal physiology, the reconstruction of present and prehistoric nutrition chains and paleaoclimatological conditions. This is demonstrated by the outline of fundamental and application-orientated examples for all bio-elements. The aim of the review is to inform (advanced) students from various disciplines about the whole potential and the scope of stable isotope characteristics and fractionations and to provide them with a comprehensive introduction to the literature on fundamental aspects and applications.
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Affiliation(s)
- Hanns-Ludwig Schmidt
- a Lehrstuhl für Biologische Chemie , Technische Universität München , Freising-Weihenstephan, Germany
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22
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Gessler A, Ferrio JP, Hommel R, Treydte K, Werner RA, Monson RK. Stable isotopes in tree rings: towards a mechanistic understanding of isotope fractionation and mixing processes from the leaves to the wood. TREE PHYSIOLOGY 2014; 34:796-818. [PMID: 24907466 DOI: 10.1093/treephys/tpu040] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The mechanistic understanding of isotope fractionation processes is increasing but we still lack detailed knowledge of the processes that determine the isotopic composition of the tree-ring archive over the long term. Especially with regard to the path from leaf photosynthate production to wood formation, post-assimilation fractionations/processes might cause at least a partial decoupling between the leaf isotope signals that record processes such as stomatal conductance, transpiration and photosynthesis, and the wood or cellulose signals that are stored in the paleophysiological record. In this review, we start from the rather well understood processes at the leaf level such as photosynthetic carbon isotope fractionation, leaf water evaporative isotope enrichment and the issue of the isotopic composition of inorganic sources (CO2 and H2O), though we focus on the less explored 'downstream' processes related to metabolism and transport. We further summarize the roles of cellulose and lignin as important chemical constituents of wood, and the processes that determine the transfer of photosynthate (sucrose) and associated isotopic signals to wood production. We cover the broad topics of post-carboxylation carbon isotope fractionation and of the exchange of organic oxygen with water within the tree. In two case studies, we assess the transfer of carbon and oxygen isotopic signals from leaves to tree rings. Finally we address the issue of different temporal scales and link isotope fractionation at the shorter time scale for processes in the leaf to the isotopic ratio as recorded across longer time scales of the tree-ring archive.
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Affiliation(s)
- Arthur Gessler
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany Long-term Forest Ecosystem Research (LWF), Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Juan Pedro Ferrio
- Department of Crop and Forest Science-AGROTECNIO Center, University of Lleida, Avda Rovira Roure 191, 25198 Lleida, Spain
| | - Robert Hommel
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany
| | - Kerstin Treydte
- Research Unit Landscape Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roland A Werner
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland
| | - Russell K Monson
- School of Natural Resources and the Environment and Laboratory for Tree Ring Research, University of Arizona, Tucson, AZ 85721, USA
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23
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Royles J, Ogée J, Wingate L, Hodgson DA, Convey P, Griffiths H. Temporal separation between CO2 assimilation and growth? Experimental and theoretical evidence from the desiccation-tolerant moss Syntrichia ruralis. THE NEW PHYTOLOGIST 2013; 197:1152-1160. [PMID: 23311300 DOI: 10.1111/nph.12114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 11/25/2012] [Indexed: 06/01/2023]
Abstract
The extent of an external water layer around moss tissue influences CO(2) assimilation. Experiments on the desiccation-tolerant moss Syntrichia ruralis assessed the real-time dependence of the carbon and oxygen isotopic compositions of CO(2) and H(2)O in terms of moss water status and integrated isotope signals in cellulose. As external (capillary) water, and then mesophyll water, evaporated from moss tissue, assimilation rate, relative water content and the stable isotope composition of tissue water (δ(18)O(TW)), and the CO(2) and H(2)O fluxes, were analysed. After drying, carbon (δ(13)C(C)) and oxygen (δ(18)O(C)) cellulose compositions were determined. During desiccation, assimilation and (13)CO(2) discrimination increased to a maximum and then declined; δ(18)O(TW) increased progressively by 8‰, indicative of evaporative isotopic enrichment. Experimental and meteorological data were combined to predict tissue hydration dynamics over one growing season. Nonsteady-state model predictions of δ(18)O(TW) were consistent with instantaneous measurements. δ(13)C(C) values suggest that net assimilation occurs at 25% of maximum relative water content, while δ(18)O(C) data suggests that cellulose is synthesized during much higher relative water content conditions. This implies that carbon assimilation and cellulose synthesis (growth) may be temporally separated, with carbon reserves possibly contributing to desiccation tolerance and resumption of metabolism upon rehydration.
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Affiliation(s)
- Jessica Royles
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Jérôme Ogée
- INRA, UR1263 EPHYSE, 71 Avenue Edouard Bourleaux, 33140, Villenave d'Ornon, France
| | - Lisa Wingate
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
- INRA, UR1263 EPHYSE, 71 Avenue Edouard Bourleaux, 33140, Villenave d'Ornon, France
| | - Dominic A Hodgson
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Peter Convey
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Howard Griffiths
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
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Ellsworth PV, Ellsworth PZ, Anderson WT, Sternberg LSL. The role of effective leaf mixing length in the relationship between the δ18 O of stem cellulose and source water across a salinity gradient. PLANT, CELL & ENVIRONMENT 2013; 36:138-148. [PMID: 22716972 DOI: 10.1111/j.1365-3040.2012.02562.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Previous mangrove tree ring studies attempted, unsuccessfully, to relate the δ(18) O of trunk cellulose (δ(18) O(CELL) ) to the δ(18) O of source water (δ(18) O(SW) ). Here, we tested whether biochemical fractionation associated with one of the oxygen in the cellulose glucose moiety or variation in leaf water oxygen isotope fractionation (Δ(LW) ) can interfere with the δ(18) O(SW) signal as it is recorded in the δ(18) O(CELL) of mangrove (saltwater) and hammock (freshwater) plants. We selected two transects experiencing a salinity gradient, located in the Florida Keys, USA. The δ(18) O(CELL) throughout both transects did not show the pattern expected based on that of the δ(18) O(SW) . We found that in one of the transects, biochemical fractionation interfered with the δ(18) O(SW) signal, while in the other transect Δ(LW) differed between mangrove and hammock plants. Observed differences in Δ(LW) between mangroves and hammocks were caused by a longer effective leaf mixing length (L) of the water pathway in mangrove leaves compared to those of hammock leaves. Changes in L could have caused the δ(18) O(CELL) to record not only variations in the δ(18) O(SW) but also in Δ(LW) making it impossible to isolate the δ(18) O(SW) signal.
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Sternberg L, Ellsworth PFV. Divergent biochemical fractionation, not convergent temperature, explains cellulose oxygen isotope enrichment across latitudes. PLoS One 2011; 6:e28040. [PMID: 22132203 PMCID: PMC3221677 DOI: 10.1371/journal.pone.0028040] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 10/31/2011] [Indexed: 11/18/2022] Open
Abstract
Recent findings based on the oxygen isotope ratios of tree trunk cellulose indicate that the temperature of biomass production in biomes ranging from boreal to subtropical forests converge to an average leaf temperature of 21.4°C. The above conclusion has been drawn under the assumption that biochemically related isotopic fractionations during cellulose synthesis are not affected by temperature. Here we test the above assumption by heterotrophically generating cellulose at different temperatures and measuring the proportion of carbohydrate oxygen that exchange with water during cellulose synthesis and the average biochemical fractionation associated with this exchange. We observed no variation in the proportion of oxygen that exchange with different temperatures, which averaged 0.42 as it has been observed in other studies. On the other hand, the biochemical oxygen isotope fractionation during cellulose synthesis is affected by temperature and can be described by a 2(nd) order polynomial equation. The biochemical fractionation changes little between temperatures of 20 and 30°C averaging 26‰ but increases at lower temperatures to values of 31‰. This temperature sensitive biochemical fractionation explains the pattern of cellulose oxygen isotope ratios of aquatic plants encompassing several latitudes. The observed temperature sensitive biochemical fractionation also indicates that divergent biochemical fractionation and not convergent leaf temperature explains the increase in oxygen isotope enrichment of cellulose across several biomes.
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Affiliation(s)
- Leonel Sternberg
- Department of Biology, University of Miami, Coral Gables, Florida, United States of America.
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Tanz N, Werner RA, Eisenreich W, Schmidt HL. Assessment of enzymatic methods in the δ18O value determination of the L-tyrosine p-hydroxy group for proof of illegal meat and bone meal feeding to cattle. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:9475-9483. [PMID: 21740012 DOI: 10.1021/jf201217r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The δ(18)O value of the p-hydroxy group of L-tyrosine depends on the biosynthesis by plants or animals, respectively. In animal proteins it reflects the diet and is therefore an absolute indicator for illegal feeding with meat and bone meal. The aim of this investigation was to perform the positional (18)O determination on L-tyrosine via a one-step enzymatic degradation. Proteins from plants, herbivores, omnivores, and carnivores were characterized by their δ(13)C, δ(15)N, and δ(18)O values, the latter for normalizing the positional δ(18)O values. Their L-tyrosine was degraded by tyrosine phenol lyase to phenol, analyzed as (2,4,6)-tribromophenol. Degradation by tyrosine decarboxylase yielded tyramine. The δ(18)O values of both analytes corresponded to the trophic levels of their sources but were not identical, probably due to an isotope effect on the tyrosine phenol lyase reaction. Availability of the enzyme, easy control of the reaction, and isolation of the analyte are in favor of tyrosine decarboxylase degradation as a routine method.
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Affiliation(s)
- Nicole Tanz
- isolab GmbH, Woelkestrasse 9/I, D-85301 Schweitenkirchen, Germany
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Gagen M, McCarroll D, Loader NJ, Robertson I. Stable Isotopes in Dendroclimatology: Moving Beyond ‘Potential’. DENDROCLIMATOLOGY 2011. [DOI: 10.1007/978-1-4020-5725-0_6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Hagopian WM, Jahren AH. Minimization of sample requirement for delta18O in benzoic acid. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2010; 24:2542-2546. [PMID: 20740528 DOI: 10.1002/rcm.4669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The measurement of the oxygen stable isotope content in organic compounds has applications in many fields, ranging from paleoclimate reconstruction to forensics. Conventional High-Temperature Conversion (HTC) techniques require >20 microg of O for a single delta(18)O measurement. Here we describe a system that converts the CO produced by HTC into CO(2) via reduction within a Ni-furnace. This CO(2) is then concentrated cryogenically, and 'focused' into the isotope ratio mass spectrometry (IRMS) source using a low-flow He carrier gas (6-8 mL/min). We report analyses of benzoic acid (C(7)H(6)O(2)) reference materials that yielded precise delta(18)O measurement down to 1.3 microg of O, suggesting that our system could be used to decrease sample requirement for delta(18)O by more than an order of magnitude.
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Affiliation(s)
- William M Hagopian
- Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822, USA
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29
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Hilasvuori E, Berninger F. Dependence of tree ring stable isotope abundances and ring width on climate in Finnish oak. TREE PHYSIOLOGY 2010; 30:636-647. [PMID: 20357343 DOI: 10.1093/treephys/tpq019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We measured ring widths and isotopic abundances of carbon, oxygen and hydrogen (delta(13)C, delta(18)O and delta(2)H) from the latewood of tree rings of pedunculate oak (Quercus robur L.) in its distributional northern limit in Southern Finland. Ring width was observed to be related to precipitation and relative humidity but not significantly to temperature. delta(13)C and delta(18)O were significantly related to all studied climatic variables, most strongly to cloud cover. Variations in delta(2)H were discovered to be complex combinations of signals from biochemical and physical processes. The results suggest that oaks in Finland can be used as a source of climate information. delta(18)O was discovered to be especially promising as it showed the strongest climate signal and highest common signal between trees. The relationship between climate and ring width indicates that water availability is the main control of ring radial growth. This is supported by the isotope data. High correlation between delta(13)C and delta(18)O time series indicates that photosynthetic carbon assimilation is limited by stomatal control. Therefore, in contrast to the expected temperature limitation, our data indicate that drought limits oak growth more than cold temperatures on the border of its northernmost distribution range.
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Affiliation(s)
- Emmi Hilasvuori
- Dating Laboratory, Finnish Museum of Natural History, University of Helsinki, POB 64, FI-00014 Helsinki, Finland.
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Ogée J, Barbour MM, Wingate L, Bert D, Bosc A, Stievenard M, Lambrot C, Pierre M, Bariac T, Loustau D, Dewar RC. A single-substrate model to interpret intra-annual stable isotope signals in tree-ring cellulose. PLANT, CELL & ENVIRONMENT 2009; 32:1071-1090. [PMID: 19422614 DOI: 10.1111/j.1365-3040.2009.01989.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The carbon and oxygen stable isotope composition of wood cellulose (delta(13)C(cellulose) and delta(18)O(cellulose), respectively) reveal well-defined seasonal variations that contain valuable records of past climate, leaf gas exchange and carbon allocation dynamics within the trees. Here, we present a single-substrate model for wood growth to interpret seasonal isotopic signals collected in an even-aged maritime pine plantation growing in South-west France, where climate, soil and flux variables were also monitored. Observed seasonal patterns in delta(13)C(cellulose) and delta(18)O(cellulose) were different between years and individuals, and mostly captured by the model, suggesting that the single-substrate hypothesis is a good approximation for tree ring studies on Pinus pinaster, at least for the environmental conditions covered by this study. A sensitivity analysis revealed that the model was mostly affected by five isotopic discrimination factors and two leaf gas-exchange parameters. Modelled early wood signals were also very sensitive to the date when cell wall thickening begins (t(wt)). Our model could therefore be used to reconstruct t(wt) time series and improve our understanding of how climate influences this key parameter of xylogenesis.
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Affiliation(s)
- J Ogée
- Ephyse, Inra, Bordeaux, BP81, 33883 Villenave d'Ornon, France.
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Brand WA, Coplen TB, Aerts-Bijma AT, Böhlke JK, Gehre M, Geilmann H, Gröning M, Jansen HG, Meijer HAJ, Mroczkowski SJ, Qi H, Soergel K, Stuart-Williams H, Weise SM, Werner RA. Comprehensive inter-laboratory calibration of reference materials for delta18O versus VSMOW using various on-line high-temperature conversion techniques. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:999-1019. [PMID: 19263478 DOI: 10.1002/rcm.3958] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high-temperature conversion techniques (HTC)a in an evaluation sponsored by the International Union of Pure and Applied Chemistry (IUPAC). To aid in the calibration of these reference materials, which span more than 125 per thousand, an artificially enriched reference water (delta(18)O of +78.91 per thousand) and two barium sulfates (one depleted and one enriched in (18)O) were prepared and calibrated relative to VSMOW2b and SLAP reference waters. These materials were used to calibrate the other isotopic reference materials in this study, which yielded: Reference material delta(18)O and estimated combined uncertainty IAEA-602 benzoic acid+71.28 +/- 0.36 per thousand USGS 35 sodium nitrate+56.81 +/- 0.31 per thousand IAEA-NO-3 potassium nitrate+25.32 +/- 0.29 per thousand IAEA-601 benzoic acid+23.14 +/- 0.19 per thousand IAEA-SO-5 barium sulfate+12.13 +/- 0.33 per thousand NBS 127 barium sulfate+8.59 +/- 0.26 per thousand VSMOW2 water 0 per thousand IAEA-600 caffeine-3.48 +/- 0.53 per thousand IAEA-SO-6 barium sulfate-11.35 +/- 0.31 per thousand USGS 34 potassium nitrate-27.78 +/- 0.37 per thousand SLAP water-55.5 per thousand The seemingly large estimated combined uncertainties arise from differences in instrumentation and methodology and difficulty in accounting for all measurement bias. They are composed of the 3-fold standard errors directly calculated from the measurements and provision for systematic errors discussed in this paper. A primary conclusion of this study is that nitrate samples analyzed for delta(18)O should be analyzed with internationally distributed isotopic nitrates, and likewise for sulfates and organics. Authors reporting relative differences of oxygen-isotope ratios (delta(18)O) of nitrates, sulfates, or organic material should explicitly state in their reports the delta(18)O values of two or more internationally distributed nitrates (USGS 34, IAEA-NO-3, and USGS 35), sulfates (IAEA-SO-5, IAEA-SO-6, and NBS 127), or organic material (IAEA-601 benzoic acid, IAEA-602 benzoic acid, and IAEA-600 caffeine), as appropriate to the material being analyzed, had these reference materials been analyzed with unknowns. This procedure ensures that readers will be able to normalize the delta(18)O values at a later time should it become necessary.The high-temperature reduction technique for analyzing delta(18)O and delta(2)H is not as widely applicable as the well-established combustion technique for carbon and nitrogen stable isotope determination. To obtain the most reliable stable isotope data, materials should be treated in an identical fashion; within the same sequence of analyses, samples should be compared with working reference materials that are as similar in nature and in isotopic composition as feasible.
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Affiliation(s)
- Willi A Brand
- MPI-BGC, Max-Planck-Institute for Biogeochemistry, Beutenberg Campus, P.O. Box 100164, 07701 Jena, Germany.
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O'Reilly Sternberg LDSL. Oxygen stable isotope ratios of tree-ring cellulose: the next phase of understanding. THE NEW PHYTOLOGIST 2009; 181:553-562. [PMID: 19154318 DOI: 10.1111/j.1469-8137.2008.02661.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Analysis of the oxygen isotope ratio of tree-ring cellulose is a valuable tool that can be used as a paleoclimate proxy. Our ability to use this tool has gone through different phases. The first began in the 1970s with the demonstration of empirical relationships between the oxygen isotope ratio of tree-ring cellulose and climate. These empirical relationships, however, did not provide us with the confidence that they are robust through time, across taxa and across geographical locations. The second phase began with a rudimentary understanding of the physiological and biochemical mechanisms responsible for the oxygen isotope ratios of cellulose, which is necessary to increase the power of this tool. This phase culminated in a mechanistic tree-ring model integrating concepts of physiology and biochemistry in a whole-plant system. This model made several assumptions about leaf water isotopic enrichment and biochemistry which, in the nascent third phase, are now being challenged, with surprising results. These third-phase results suggest that, contrary to the model assumption, leaf temperature across a large latitudinal gradient is remarkably constant and does not follow ambient temperature. Recent findings also indicate that the biochemistry responsible for the incorporation of the cellulose oxygen isotopic signature is not as simple as has been assumed. Interestingly, the results of these challenges have strengthened the tree-ring model. There are several other assumptions that can be investigated which will improve the utility of the tree-ring model.
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Reyes-García C, Mejia-Chang M, Jones GD, Griffiths H. Water vapour isotopic exchange by epiphytic bromeliads in tropical dry forests reflects niche differentiation and climatic signals. PLANT, CELL & ENVIRONMENT 2008; 31:828-841. [PMID: 18266906 DOI: 10.1111/j.1365-3040.2008.01789.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The 18O signals in leaf water (delta18O(lw)) and organic material were dominated by atmospheric water vapour 18O signals (delta18O(vap)) in tank and atmospheric life forms of epiphytic bromeliads with crassulacean acid metabolism (CAM), from a seasonally dry forest in Mexico. Under field conditions, the mean delta18O(lw) for all species was constant during the course of the day and systematically increased from wet to dry seasons (from 0 to +6 per thousand), when relative water content (RWC) diminished from 70 to 30%. In the greenhouse, progressive enrichment from base to leaf tip was observed at low night-time humidity; under high humidity, the leaf tip equilibrated faster with delta18O(vap) than the other leaf sections. Laboratory manipulations using an isotopically depleted water source showed that delta18O(vap) was more rapidly incorporated than liquid water. Our data were consistent with a Craig-Gordon (C-G) model as modified by Helliker and Griffiths predicting that the influx and exchange of delta18O(vap) control delta18O(lw) in certain epiphytic life forms, despite progressive tissue water loss. We use delta18O(lw) signals to define water-use strategies for the coexisting species which are consistent with habitat preference under natural conditions and life form. Bulk organic matter (delta18O(org)) is used to predict the deltaO18(vap) signal at the time of leaf expansion.
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Affiliation(s)
- Casandra Reyes-García
- Physiological Ecology Group, Department of Plant Sciences, University of Cambridge, Cambridge CB23EA, UK.
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34
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Barnard RL, Salmon Y, Kodama N, Sörgel K, Holst J, Rennenberg H, Gessler A, Buchmann N. Evaporative enrichment and time lags between delta18O of leaf water and organic pools in a pine stand. PLANT, CELL & ENVIRONMENT 2007; 30:539-50. [PMID: 17407532 DOI: 10.1111/j.1365-3040.2007.01654.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Understanding ecosystem water fluxes has gained increasing attention, as climate scenarios predict a drier environment for many parts of the world. Evaporative enrichment of (18)O (Delta(18)O) of leaf water and subsequent enrichment of plant organic matter can be used to characterize environmental and physiological factors that control evaporation, based on a recently established mechanistic model. In a Pinus sylvestris forest, we measured the dynamics of oxygen isotopic composition (delta(18)O) every 6 h for 4 d in atmospheric water vapour, xylem sap, leaf water and water-soluble organic matter in current (N) and previous year (N-1) needles, phloem sap, together with leaf gas exchange for pooled N and N-1 needles, and relevant micrometeorological variables. Leaf water delta(18)O showed strong diel periodicity, while delta(18)O in atmospheric water vapour and in xylem sap showed little variation. The Delta(18)O was consistently lower for N than for N-1 needles, possibly related to phenological stage. Modelled leaf water Delta(18)O showed good agreement with measured values when applying a non-steady state evaporative enrichment model including a Péclet effect. We determined the time lags between delta(18)O signals from leaf water to water-soluble foliar organic matter and to phloem sap at different locations down the trunk, which clearly demonstrated the relevance of considering these time-lag effects for carbon transport, source-sink and carbon flux partitioning studies.
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Affiliation(s)
- Romain L Barnard
- Institute of Plant Sciences, ETH Zurich, 8092 Zurich, Switzerland.
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35
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Barbour MM. Stable oxygen isotope composition of plant tissue: a review. FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:83-94. [PMID: 32689335 DOI: 10.1071/fp06228] [Citation(s) in RCA: 269] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 11/20/2006] [Indexed: 05/14/2023]
Abstract
With the development of rapid measurement techniques, stable oxygen isotope analysis of plant tissue is poised to become an important tool in plant physiological, ecological, paleoclimatic and forensic studies. Recent advances in mechanistic understanding have led to the improvement of process-based models that accurately predict variability in the oxygen isotope composition of plant organic material (δ18Op). δ18Op has been shown to reflect the isotope composition of soil water, evaporative enrichment in transpiring leaves, and isotopic exchange between oxygen atoms in organic molecules and local water in the cells in which organic molecules are formed. This review presents current theoretical models describing the influences on δ18Op, using recently published experimental work to outline strengths and weaknesses in the models. The potential and realised applications of the technique are described.
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Affiliation(s)
- Margaret M Barbour
- Landcare Research, PO Box 40, Gerald St, Lincoln 7640, New Zealand.Email
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Affiliation(s)
- Angela Augusti
- Department of Medical Biochemistry & Biophysics and UPSC,Umeå University, S-90187 Umeå, Sweden
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