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Yu YZ, Ma WT, Wang X, Tcherkez G, Schnyder H, Gong XY. Reconciling water-use efficiency estimates from carbon isotope discrimination of leaf biomass and tree rings: nonphotosynthetic fractionation matters. THE NEW PHYTOLOGIST 2024. [PMID: 39360441 DOI: 10.1111/nph.20170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Accepted: 09/16/2024] [Indexed: 10/04/2024]
Abstract
Carbon isotope discrimination (∆) in leaf biomass (∆BL) and tree rings (∆TR) provides important proxies for plant responses to climate change, specifically in terms of intrinsic water-use efficiency (iWUE). However, the nonphotosynthetic 12C/13C fractionation in plant tissues has rarely been quantified and its influence on iWUE estimation remains uncertain. We derived a comprehensive, ∆ based iWUE model (iWUEcom) which includes nonphotosynthetic fractionations (d) and characterized tissue-specific d-values based on global compilations of data of ∆BL, ∆TR and real-time ∆ in leaf photosynthesis (∆online). iWUEcom was further validated with independent datasets. ∆BL was larger than ∆online by 2.53‰, while ∆BL and ∆TR showed a mean offset of 2.76‰, indicating that ∆TR is quantitatively very similar to ∆online. Applying the tissue-specific d-values (dBL = 2.5‰, dTR = 0‰), iWUE estimated from ∆BL aligned well with those estimated from ∆TR or gas exchange. ∆BL and ∆TR showed a consistent iWUE trend with an average CO2 sensitivity of 0.15 ppm ppm-1 during 1975-2015. Accounting for nonphotosynthetic fractionations improves the estimation of iWUE based on isotope records in leaf biomass and tree rings, which is ultimate for inferring changes in carbon and water cycles under historical and future climate.
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Affiliation(s)
- Yong Zhi Yu
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Wei Ting Ma
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Xuming Wang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Guillaume Tcherkez
- Institut de Recherche en Horticulture et Semences, Université d'Angers, 42 rue Georges Morel, Beaucouzé, 49070, France
- Research School of Biology, ANU College of Sciences, Australian National University, Canberra, ACT, 2601, Australia
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, Freising, 85354, Germany
| | - Xiao Ying Gong
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
- Fujian Provincial Key Laboratory for Plant Eco-physiology, Fuzhou, 350007, China
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2
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Arco Molina JG, Saurer M, Altmanova N, Treydte K, Dolezal J, Song JS, Altman J. Recent warming and increasing CO2 stimulate growth of dominant trees under no water limitation in South Korea. TREE PHYSIOLOGY 2024; 44:tpae103. [PMID: 39151030 DOI: 10.1093/treephys/tpae103] [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: 11/29/2023] [Revised: 07/26/2024] [Accepted: 08/13/2024] [Indexed: 08/18/2024]
Abstract
Increases in temperatures and atmospheric CO2 concentration influence the growth performance of trees worldwide. The direction and intensity of tree growth and physiological responses to changing climate do, however, vary according to environmental conditions. Here we present complex, long-term, tree-physiological responses to unprecedented temperature increase in East Asia. For this purpose, we studied radial growth and isotopic (δ13C and δ18O) variations using tree-ring data for the past 100 yr of dominant Quercus mongolica trees from the cool-temperate forests from Hallasan, South Korea. Overall, we found that tree stem basal area increment, intercellular CO2 concentration and intrinsic water-use efficiency significantly increased over the last century. We observed, however, short-term variability in the trends of these variables among four periods identified by change point analysis. In comparison, δ18O did not show significant changes over time, suggesting no major hydrological changes in this precipitation-rich area. The strength and direction of growth-climate relationships also varied during the past 100 yr. Basal area increment (BAI) did not show significant relationships with the climate over the 1924-1949 and 1975-1999 periods. However, over 1950-1974, BAI was negatively affected by both temperature and precipitation, while after 2000, a temperature stimulus was observed. Finally, over the past two decades, the increase in Q. mongolica tree growth accelerated and was associated with high spring-summer temperatures and atmospheric CO2 concentrations and decreasing intrinsic water-use efficiency, δ18O and vapour pressure deficit, suggesting that the photosynthetic rate continued increasing under no water limitations. Our results indicate that the performance of dominant trees of one of the most widely distributed species in East Asia has benefited from recent global changes, mainly over the past two decades. Such findings are essential for projections of forest dynamics and carbon sequestration under climate change.
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Affiliation(s)
| | - Matthias Saurer
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
| | - Nela Altmanova
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, Třeboň 379 01, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice 37005, Czech Republic
| | - Kerstin Treydte
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Hochschulstrasse 4, Bern 3012, Switzerland
| | - Jiri Dolezal
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, Třeboň 379 01, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice 37005, Czech Republic
| | - Jong-Suk Song
- College of Natural Sciences, Andong National University, Gyeongsangbuk-do, 36729, Andong 760-749, Republic of Korea
| | - Jan Altman
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, Třeboň 379 01, Czech Republic
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 21, Prague 6 - Suchdol, Czech Republic
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3
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Qi X, Treydte K, Saurer M, Fang K, An W, Lehmann M, Liu K, Wu Z, He HS, Du H, Li MH. Contrasting water-use strategies to climate warming in white birch and larch in a boreal permafrost region. TREE PHYSIOLOGY 2024; 44:tpae053. [PMID: 38769900 DOI: 10.1093/treephys/tpae053] [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: 12/19/2023] [Revised: 05/11/2024] [Accepted: 05/18/2024] [Indexed: 05/22/2024]
Abstract
The effects of rising atmospheric CO2 concentrations (Ca) with climate warming on intrinsic water-use efficiency and radial growth in boreal forests are still poorly understood. We measured tree-ring cellulose δ13C, δ18O, and tree-ring width in Larix dahurica (larch) and Betula platyphylla (white birch), and analyzed their relationships with climate variables in a boreal permafrost region of northeast China over past 68 years covering a pre-warming period (1951-1984; base period) and a warm period (1985-2018; warm period). We found that white birch but not larch significantly increased their radial growth over the warm period. The increased intrinsic water-use efficiency in both species was mainly driven by elevated Ca but not climate warming. White birch but not larch showed significantly positive correlations between tree-ring δ13C, δ18O and summer maximum temperature as well as vapor pressure deficit in the warm period, suggesting a strong stomatal response in the broad-leaved birch to temperature changes. The climate warming-induced radial growth enhancement in white birch is primarily associated with a conservative water-use strategy. In contrast, larch exhibits a profligate water-use strategy. It implies an advantage for white birch over larch in the warming permafrost regions.
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Affiliation(s)
- Xi Qi
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Renmin Street, Nanguan District, Changchun 130024, China
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
| | - Kerstin Treydte
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
| | - Keyan Fang
- Key Laboratory of Humid Subtropical Eco-Geographical Process, Ministry of Education, College of Geographical Sciences, Fujian Normal University, Shangsan Road, Cangshan District, Fuzhou 350007, China
| | - Wenling An
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beitucheng West Road, Chaoyang District, Beijing 100029, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China
| | - Marco Lehmann
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
| | - Kunyuan Liu
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Renmin Street, Nanguan District, Changchun 130024, China
| | - Zhengfang Wu
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Renmin Street, Nanguan District, Changchun 130024, China
| | - Hong S He
- School of Natural Resources, University of Missouri, 230 Jesse Hall, Columbia, MO 65211, USA
| | - Haibo Du
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Renmin Street, Nanguan District, Changchun 130024, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Renmin Street, Nanguan District, Changchun 130024, China
| | - Mai-He Li
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Renmin Street, Nanguan District, Changchun 130024, China
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf CH-8903, Switzerland
- School of Life Sciences, Hebei University, Wusi East Road, Lianchi District, Baoding 071000, China
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Li J, Zhang SB, Li YP. Photosynthetic response dynamics in the invasive species Tithonia diversifolia and two co-occurring native shrub species under fluctuating light conditions. PLANT DIVERSITY 2024; 46:265-273. [PMID: 38807905 PMCID: PMC11128914 DOI: 10.1016/j.pld.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/15/2023] [Accepted: 04/15/2023] [Indexed: 05/30/2024]
Abstract
To determine the invasiveness of invasive plants, many studies have compared photosynthetic traits or strategies between invasive and native species. However, few studies have compared the photosynthetic dynamics between invasive and native species during light fluctuations. We compared photosynthetic induction, relaxation dynamics and leaf traits between the invasive species, Tithonia diversifolia and two native species, Clerodendrum bungei and Blumea balsamifera, in full-sun and shady habitats. The photosynthetic dynamics and leaf traits differed among species. T. diversifolia showed a slower induction speed and stomatal opening response but had higher average intrinsic water-use efficiency than the two native species in full-sun habitats. Thus, the slow induction response may be attributed to the longer stomatal length in T. diversifolia. Habitat had a significant effect on photosynthetic dynamics in T. diversifolia and B. balsamifera but not in C. bungei. In shady habitat, T. diversifolia had a faster photosynthetic induction response than in full-sun habitat, leading to a higher average stomatal conductance during photosynthetic induction in T. diversifolia than in the two native species. In contrast, B. balsamifera had a larger stomatal length and slower photosynthetic induction and relaxation response in shady habitat than in full-sun habitat, resulting in higher carbon gain during photosynthetic relaxation. Nevertheless, in both habitats, T. diversifolia had an overall higher carbon gain during light fluctuations than the two native species. Our results indicated that T. diversifolia can adopt more effective response strategies under fluctuating light environments to maximize carbon gain, which may contribute to its successful invasion.
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Affiliation(s)
- Ju Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Yang-Ping Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
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5
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Sanchez-Lucas R, Mayoral C, Raw M, Mousouraki MA, Luna E. Elevated CO2 alters photosynthesis, growth and susceptibility to powdery mildew of oak seedlings. Biochem J 2023; 480:1429-1443. [PMID: 37497606 PMCID: PMC10586781 DOI: 10.1042/bcj20230002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 07/18/2023] [Accepted: 07/27/2023] [Indexed: 07/28/2023]
Abstract
Elevated CO2 (eCO2) is a determinant factor of climate change and is known to alter plant processes such as physiology, growth and resistance to pathogens. Quercus robur, a tree species integrated in most forest regeneration strategies, shows high vulnerability to powdery mildew (PM) disease at the seedling stage. PM is present in most oak forests and it is considered a bottleneck for oak woodland regeneration. Our study aims to decipher the effect of eCO2 on plant responses to PM. Oak seedlings were grown in controlled environment at ambient (aCO2, ∼400 ppm) and eCO2 (∼1000 ppm), and infected with Erysiphe alphitoides, the causal agent of oak PM. Plant growth, physiological parameters and disease progression were monitored. In addition, to evaluate the effect of eCO2 on induced resistance (IR), these parameters were assessed after treatments with IR elicitor β-aminobutyric acid (BABA). Our results show that eCO2 increases photosynthetic rates and aerial growth but in contrast, reduces root length. Importantly, under eCO2 seedlings were more susceptible to PM. Treatments with BABA protected seedlings against PM and this protection was maintained under eCO2. Moreover, irrespectively of the concentration of CO2, BABA did not significantly change aerial growth but resulted in longer radicular systems, thus mitigating the effect of eCO2 in root shortening. Our results demonstrate the impact of eCO2 in plant physiology, growth and defence, and warrant further biomolecular studies to unravel the mechanisms by which eCO2 increases oak seedling susceptibility to PM.
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Affiliation(s)
- Rosa Sanchez-Lucas
- Birmingham Institute of Forest Research, School of Biosciences, University of Birmingham, Birmingham B15 2TT, U.K
| | - Carolina Mayoral
- Birmingham Institute of Forest Research, School of Biosciences, University of Birmingham, Birmingham B15 2TT, U.K
| | - Mark Raw
- Birmingham Institute of Forest Research, School of Biosciences, University of Birmingham, Birmingham B15 2TT, U.K
| | - Maria-Anna Mousouraki
- Birmingham Institute of Forest Research, School of Biosciences, University of Birmingham, Birmingham B15 2TT, U.K
- School of Life Sciences, University of Warwick, Gibber Hill Campus, Coventry CV4 7AL, U.K
| | - Estrella Luna
- Birmingham Institute of Forest Research, School of Biosciences, University of Birmingham, Birmingham B15 2TT, U.K
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6
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Singh R. Spectral reflectance and fluorescence is a rapid, non-destructive tool for drought tolerance monitoring in Withania somnifera (L.) Dunal. PROTOPLASMA 2023; 260:1421-1435. [PMID: 37119439 DOI: 10.1007/s00709-023-01859-1] [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: 02/26/2023] [Accepted: 04/15/2023] [Indexed: 06/19/2023]
Abstract
Withania somnifera plants were exposed to drought stress for 23 days. Relative water content (RWC), gaseous exchange, fluorescence parameters, and spectral reflectance changes were monitored under drought stress. Assimilation rate and RWC decreased by 81% and 65%, respectively, during drought exposure of 23 days. Photosynthetic reflectance index (PRI) and water index (WI) showed a decreasing pattern under drought stress and correlated with Amax and RWC. Anthocyanin reflectance index and anthocyanin content increased with drought stress. Similarly, rational among R727, R696, R770, and R731 reflects chlorophyll content and Chl a/b ratio and copes with actual chlorophyll content. Fluorescence changes showed the opening and closing of PSII reaction centers, while absorbance change at 830/875 nm showed activity and energy balance of PSI. Non-photochemical quenching increased under drought, which showed depoxydation of xanthine cycle pigment. Energy balance at the acceptor and donor side of PSI adjusted under drought stress by increasing electron carrying limitation at donor side. Energy balance between PSI and PSII is maintained by increasing cyclic electron flux under mild drought stress. Both protective mechanism depoxydation of xanthine cycle pigment and enhancement of cyclic electron flux reduced or diminished under severe drought stress. Decrease in leaf area and stomatal closure may cause a reduction in transpiration that results into loss of RWC and altered physiological processes. Since fluorescence, absorbance change and spectral reflectance are non-invasive measurements that may be used as indicators for assessing drought tolerance in medicinal plants.
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Affiliation(s)
- Ruchi Singh
- Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India, 226015.
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7
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Strange BM, Monson RK, Szejner P, Ehleringer J, Hu J. The North American Monsoon buffers forests against the ongoing megadrought in the Southwestern United States. GLOBAL CHANGE BIOLOGY 2023; 29:4354-4367. [PMID: 37283085 DOI: 10.1111/gcb.16762] [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: 11/09/2022] [Revised: 04/05/2023] [Accepted: 04/08/2023] [Indexed: 06/08/2023]
Abstract
The US Southwest has been entrenched in a two-decade-long megadrought (MD), the most severe since 800 CE, which threatens the long-term vitality and persistence of regional montane forests. Here, we report that in the face of record low winter precipitation and increasing atmospheric aridity, seasonal activity of the North American Monsoon (NAM) climate system brings sufficient precipitation during the height of the summer to alleviate extreme tree water stress. We studied seasonally resolved, tree-ring stable carbon isotope ratios across a 57-year time series (1960-2017) in 17 Ponderosa pine forests distributed across the NAM geographic domain. Our study focused on the isotope dynamics of latewood (LW), which is produced in association with NAM rains. During the MD, populations growing within the core region of the NAM operated at lower intrinsic and higher evaporative water-use efficiencies (WUEi and WUEE , respectively), compared to populations growing in the periphery of the NAM domain, indicating less physiological water stress in those populations with access to NAM moisture. The disparities in water-use efficiencies in periphery populations are due to a higher atmospheric vapor pressure deficit (VPD) and reduced access to summer soil moisture. The buffering advantage of the NAM, however, is weakening. We observed that since the MD, the relationship between WUEi and WUEE in forests within the core NAM domain is shifting toward a drought response similar to forests on the periphery of the NAM. After correcting for past increases in the atmospheric CO2 concentration, we were able to isolate the LW time-series responses to climate alone. This showed that the shift in the relation between WUEi and WUEE was driven by the extreme increases in MD-associated VPD, with little advantageous influence on stomatal conductance from increases in atmospheric CO2 concentration.
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Affiliation(s)
- Brandon M Strange
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, USA
- Laboratory of Tree Ring Research, University of Arizona, Tucson, Arizona, USA
| | - Russell K Monson
- Laboratory of Tree Ring Research, University of Arizona, Tucson, Arizona, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA
| | - Paul Szejner
- Laboratory of Tree Ring Research, University of Arizona, Tucson, Arizona, USA
- Instituto de Geología, Universidad Nacional Autónoma de México, México City, Mexico
| | - Jim Ehleringer
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Jia Hu
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, USA
- Laboratory of Tree Ring Research, University of Arizona, Tucson, Arizona, USA
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Hong Y, Liu X, Camarero JJ, Xu G, Zhang L, Zeng X, Aritsara ANA, Zhang Y, Wang W, Xing X, Lu Q. The effects of intrinsic water-use efficiency and climate on wood anatomy. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2023:10.1007/s00484-023-02475-7. [PMID: 37072578 DOI: 10.1007/s00484-023-02475-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Climate warming may induce growth decline in warm-temperate areas subjected to seasonal soil moisture deficit, whereas increasing atmospheric CO2 concentration (Ca) is expected to enhance tree growth. An accurate understanding of tree growth and physiological processes responding to climate warming and increasing Ca is critical. Here, we analyzed tree-ring stable carbon isotope and wood anatomical traits of Pinus tabuliformis from Qinling Mountains in China to understand how lumen diameter (LD) determining potential hydraulic conductivity and cell-wall thickness (CWT) determining carbon storage responded to climate and Ca. The effects of climate and Ca on intrinsic water-use efficiency (iWUE) were isolated, and iWUE values due to only-climate (iWUEClim) and only-CO2 effects (iWUECO2) were obtained. During a low-iWUE period, the influences of climate on earlywood (EW) LD and latewood (LW) CWT prevailed. During a high-iWUE period, CO2 fertilization promoted cell enlargement and carbon storage but this was counteracted by a negative influence of climate warming. The limiting direct effects of iWUEClim and indirect effects of climate on EW LD were greater than on LW CWT. P. tabuliformis in temperate forests will face a decline of growth and carbon fixation, but will produce embolism-resistant tracheids with narrow lumen responding to future hotter droughts.
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Affiliation(s)
- Yixue Hong
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Shenzhen, 518107, China
| | - Xiaohong Liu
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China.
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
| | - J Julio Camarero
- Instituto Pirenaico de Ecología (IPE-CSIC), Zaragoza, 50092, Spain
| | - Guobao Xu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Lingnan Zhang
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
| | - Xiaomin Zeng
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
| | - Amy Ny Aina Aritsara
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China
| | - Yu Zhang
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
| | - Wenzhi Wang
- The Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Xiaoyu Xing
- Qinling National Botanical Garden, Xi'an, 710061, China
| | - Qiangqiang Lu
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
- Xi'an Botanical Garden of Shaanxi Province (Institute of Botany of Shaanxi Province), Xi'an, 710061, China
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Wang S, Han Y, Jia Y, Chen Z, Wang G. Addressing the Relationship between Leaf Nitrogen and Carbon Isotope Discrimination from the Three Levels of Community, Population and Individual. PLANTS (BASEL, SWITZERLAND) 2023; 12:1551. [PMID: 37050177 PMCID: PMC10097192 DOI: 10.3390/plants12071551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/30/2023] [Accepted: 03/30/2023] [Indexed: 06/19/2023]
Abstract
The carbon, nitrogen and water cycles of terrestrial ecosystems are important biogeochemical cycles. Addressing the relationship of leaf nitrogen (N) and carbon isotope discrimination (Δ) will enhance the understanding of the links between these three cycles in plant leaves because Δ can reflect time-integrated leaf-level water-use efficiency (WUE) over the period when the leaf material is produced. Previous studies have paid considerable attention to the relationship. However, these studies have not effectively eliminated the interference of environmental factors, inter-species, and inter-individual differences in this relationship, so new research is necessary. To minimize these interferences, the present work explored the relationship at the three levels of community, population, and plant individual. Three patterns of positive, negative and no relationship were observed across communities, populations, and individuals, which is dependent on environmental conditions, species, and plant individuals. The results strongly suggested that there is no general pattern for the relationship between leaf N and Δ. Furthermore, the results indicated that there is often no coupling between leaf-level long-term WUE and leaf N in the metabolic process of carbon, N and water in leaves. The main reason for the lack of this relationship is that most plants do not invest large amounts of nitrogen into photosynthesis. In addition, the present study also observed that, for most plant species, leaf N was not related to photosynthetic rate, and that variations in photosynthetic rates are mainly driven by stomatal conductance.
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Affiliation(s)
- Shuhan Wang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
- Department of Biotechonology, College of Biotechonology and Pharmceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Yaowen Han
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Yufu Jia
- Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
| | - Zixun Chen
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Guoan Wang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
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10
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Treml V, Tumajer J, Jandová K, Oulehle F, Rydval M, Čada V, Treydte K, Mašek J, Vondrovicová L, Lhotáková Z, Svoboda M. Increasing water-use efficiency mediates effects of atmospheric carbon, sulfur, and nitrogen on growth variability of central European conifers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156483. [PMID: 35675888 DOI: 10.1016/j.scitotenv.2022.156483] [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: 03/01/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Climate controls forest biomass production through direct effects on cambial activity and indirectly through interactions with CO2, air pollution, and nutrient availability. The atmospheric concentration of CO2, sulfur and nitrogen deposition can also exert a significant indirect control on wood formation since these factors influence the stomatal regulation of transpiration and carbon uptake, that is, intrinsic water use efficiency (iWUE). Here we provide 120-year long tree-ring time series of iWUE, stem growth, climatic and combined sulfur and nitrogen (SN) deposition trends for two common tree species, Pinus sylvestris (PISY) and Picea abies (PCAB), at their lower and upper distribution margins in Central Europe. The main goals were to explain iWUE trends using theoretical scenarios including climatic and SN deposition data, and to assess the contribution of climate and iWUE to the observed growth trends. Our results showed that after a notable increase in iWUE between the 1950s and 1980s, this positive trend subsequently slowed down. The substantial rise of iWUE since the 1950s resulted from a combination of an accelerated increase in atmospheric CO2 concentrations (Ca) and a stable level of leaf intercellular CO2 (Ci). The offset of observed iWUE values above the trajectory of a constant Ci/Ca scenario was explained by trends in SN deposition (all sites) together with the variation of drought conditions (low-elevation sites only). Increasing iWUE over the 20th and 21st centuries improved tree growth at low-elevation drought-sensitive sites. In contrast, at high-elevation PCAB sites, growth was mainly stimulated by recent warming. We propose that SN pollution should be considered in order to explain the steep increase in iWUE of conifers in the 20th century throughout Central Europe and other regions with a significant SN deposition history.
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Affiliation(s)
- Václav Treml
- Faculty of Science, Charles University, Prague, Czechia.
| | - Jan Tumajer
- Faculty of Science, Charles University, Prague, Czechia
| | | | | | - Miloš Rydval
- Faculty of Forestry and Wood Science, Czech University of Life Science, Prague, Czechia
| | - Vojtěch Čada
- Faculty of Forestry and Wood Science, Czech University of Life Science, Prague, Czechia
| | - Kerstin Treydte
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Jiří Mašek
- Faculty of Science, Charles University, Prague, Czechia
| | | | | | - Miroslav Svoboda
- Faculty of Forestry and Wood Science, Czech University of Life Science, Prague, Czechia
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11
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Gong XY, Ma WT, Yu YZ, Fang K, Yang Y, Tcherkez G, Adams MA. Overestimated gains in water-use efficiency by global forests. GLOBAL CHANGE BIOLOGY 2022; 28:4923-4934. [PMID: 35490304 DOI: 10.1111/gcb.16221] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/09/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
Increases in terrestrial water-use efficiency (WUE) have been reported in many studies, pointing to potential changes in physiological forcing of global carbon and hydrological cycles. However, gains in WUE are of uncertain magnitude over longer (i.e. >10 years) periods of time largely owing to difficulties in accounting for structural and physiological acclimation. 13 C signatures (i.e. δ13 C) of plant organic matter have long been used to estimate WUE at temporal scales ranging from days to centuries. Mesophyll conductance is a key uncertainty in estimated WUE owing to its influence on diffusion of CO2 to sites of carboxylation. Here we apply new knowledge of mesophyll conductance to 464 δ13 C chronologies in tree-rings of 143 species spanning global biomes. Adjusted for mesophyll conductance, gains in WUE during the 20th century (0.15 ppm year-1 ) were considerably smaller than those estimated from conventional modelling (0.26 ppm year-1 ). Across the globe, mean sensitivity of WUE to atmospheric CO2 was 0.15 ppm ppm-1 . Ratios of internal-to-atmospheric CO2 (on a mole fraction basis; ci /ca ) in leaves were mostly constant over time but differed among biomes and plant taxa-highlighting the significance of both plant structure and physiology. Together with synchronized responses in stomatal and mesophyll conductance, our results suggest that ratios of chloroplastic-to-atmospheric CO2 (cc /ca ) are constrained over time. We conclude that forest WUE may have not increased as much as previously suggested and that projections of future climate forcing via CO2 fertilization may need to be adjusted accordingly.
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Affiliation(s)
- Xiao Ying Gong
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Wei Ting Ma
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yong Zhi Yu
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Keyan Fang
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yusheng Yang
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Guillaume Tcherkez
- Research School of Biology, ANU College of Medicine, Biology and Environment, Australian National University, Canberra, Australia
- Institut de Recherche en Horticulture et Semences, INRAe, Université d'Angers, Beaucouzé, France
| | - Mark A Adams
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria, Australia
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12
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Ehleringer JR, Driscoll AW. Intrinsic water-use efficiency influences establishment in Encelia farinosa. Oecologia 2022; 199:563-578. [PMID: 35819533 DOI: 10.1007/s00442-022-05217-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/21/2022] [Indexed: 11/25/2022]
Abstract
We describe establishment of Encelia farinosa, a drought-deciduous shrub common to the Mojave and Sonoran Deserts, based on annual observations of two populations between 1980 and 2020. Only 11 establishment events of 50 + yearlings (0.02-0.03 individuals m-2) occurred during this monitoring period; in 68% of the years fewer than 10 yearlings were established. Yearling survival to adulthood (age 4) ranged from 88 to 5% and was significantly related to cumulative precipitation. Juvenile survival rates were lowest during the current megadrought period. We calculated intrinsic water-use efficiency (iWUE) and observed the widest variations in iWUE values among the youngest plants. Among juveniles, surviving yearlings with the lowest iWUE values exhibited upward ontogenetic shifts in iWUE values, whereas those yearlings with the highest initial iWUE values exhibited little if any change. Juvenile size, higher iWUE values, and greater likelihood of surviving were all positively related with each other over the past several decades. Furthermore, iWUE and photosynthetic capacity were positively related to each other, providing a mechanistic explanation for why increased iWUE values among juveniles could lead to greater survival rates and to larger plants under water-deficit conditions. We posit that there is bi-directional selection for genotypic variations in iWUE values among E. farinosa and that this variation is selected for because of interannual environmental heterogeneity in precipitation and VPD associated with both high- and low-frequency climate cycles. Extreme drought cycles may favor plants with higher iWUE values, whereas more mesic periods may allow for greater persistence of lower iWUE genotypes.
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Affiliation(s)
- James R Ehleringer
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA.
| | - Avery W Driscoll
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA
- Present Address: Department of Soil and Crop Sciences, Colorado State University, 301 University Avenue, Fort Collins, CO, 80523, USA
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13
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Strongly Active Responses of Pinus tabuliformis Carr. and Sophora viciifolia Hance to CO2 Enrichment and Drought Revealed by Tree-Ring Isotopes on the Central China Loess Plateau. FORESTS 2022. [DOI: 10.3390/f13070986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Understanding the water-use strategy of human-planted species used in response to climate change is essential to optimize afforestation programs in dry regions. Since 2000, trees on the central Loess Plateau have experienced a shift from strengthening drought to weakening drought. In this study, we combined tree-ring δ13C and δ18O records from Pinus tabuliformis (syn. tabulaeformis) Carr. (a tree) and Sophora viciifolia Hance (a shrub) on the central Loess Plateau to investigate species-specific responses to rising atmospheric CO2 (Ca) and drought. We found summer relative humidity controlled the fractionation of tree-ring δ18O, but the magnitude of the climate influence on δ13C differed between the species. The intrinsic water-use efficiency (iWUE) trends of both species suggested a strongly active response to maintain constant intercellular CO2 concentrations as Ca rose. The tree-ring δ13C and δ18O of both species using first-difference data were significantly and positively correlated, with stronger relationships for the shrub. This indicated the dominant regulation of iWUE by stomatal conductance in both species, but with greater stomatal control for the shrub. Moreover, the higher mean iWUE value of S. viciifolia indicated a more conservative water-use strategy than P. tabuliformis. Based on our commonality analysis, the main driver of the increased iWUE was the joint effect of Ca and vapor-pressure deficit (25.51%) for the tree, while it was the joint effect of Ca and the self-calibrated Palmer drought severity index (39.13%) for the shrub. These results suggest S. viciifolia will be more drought-tolerant than P. tabuliformis and as Ca continually rises, we should focus more on the effects of soil drought than atmospheric drought on the water-use strategy of S. viciifolia.
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14
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Brienen R, Helle G, Pons T, Boom A, Gloor M, Groenendijk P, Clerici S, Leng M, Jones C. Paired analysis of tree ring width and carbon isotopes indicates when controls on tropical tree growth change from light to water limitations. TREE PHYSIOLOGY 2022; 42:1131-1148. [PMID: 34718816 PMCID: PMC9190751 DOI: 10.1093/treephys/tpab142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Light and water availability are likely to vary over the lifespan of closed-canopy forest trees, with understory trees experiencing greater limitations to growth by light and canopy trees greater limitation due to drought. As drought and shade have opposing effects on isotope discrimination (Δ13C), paired measurement of ring width and Δ13C can potentially be used to differentiate between water and light limitations on tree growth. We tested this approach for Cedrela trees from three tropical forests in Bolivia and Mexico that differ in rainfall and canopy structure. Using lifetime ring width and Δ13C data for trees of up to and over 200 years old, we assessed how controls on tree growth changed from understory to the canopy. Growth and Δ13C are mostly anti-correlated in the understory, but this anti-correlation disappeared or weakened when trees reached the canopy, especially at the wettest site. This indicates that understory growth variation is controlled by photosynthetic carbon assimilation due to variation in light levels. Once trees reached the canopy, inter-annual variation in growth and Δ13C at one of the dry sites showed positive correlations, indicating that inter-annual variation in growth is driven by variation in water stress affecting stomatal conductance. Paired analysis of ring widths and carbon isotopes provides significant insight in what environmental factors control growth over a tree's life; strong light limitations for understory trees in closed-canopy moist forests switched to drought stress for (sub)canopy trees in dry forests. We show that combined isotope and ring width measurements can significantly improve our insights in tree functioning and be used to disentangle limitations due to shade from those due to drought.
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Affiliation(s)
| | - Gerhard Helle
- GFZ—German Research Centre for Geosciences, Section 4.3 Climate Dynamics and Landscape Evolution, 14473 Potsdam, Germany
| | - Thijs Pons
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3512 Utrecht, The Netherlands
| | - Arnoud Boom
- School of Geography, University of Leicester, Leicester LE1 7RH, UK
| | - Manuel Gloor
- School of Geography, University of Leeds, Leeds LS2 9JT, UK
| | - Peter Groenendijk
- Department of Plant Biology, Institute of Biology, PO Box: 6109, University of Campinas, UNICAMP, Campinas 13083-970, Brazil
- Ecology and Biodiversity, Institute of Environmental Biology, Utrecht University, 3584 Utrecht, The Netherlands
| | | | - Melanie Leng
- National Environmental Isotope Facility, British Geological Survey, Nottingham NG12 5GG, UK
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15
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Jia G, Chen L, Yu X, Liu Z. Soil water stress overrides the benefit of water-use efficiency from rising CO 2 and temperature in a cold semi-arid poplar plantation. PLANT, CELL & ENVIRONMENT 2022; 45:1172-1186. [PMID: 35037279 DOI: 10.1111/pce.14260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 09/15/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
The counteractive effect of atmospheric CO2 (ca ) enrichment and drought stress on tree growth results in great uncertainty in the growth patterns of forest plantations in cold semi-arid regions. We analysed tree ring chronologies and carbon isotopes in Populus simonii plantations in cold semi-arid areas in northern China over the past four decades. We hypothesized that the hydraulic stress from drought would override the stimulating effect of increasing ca and temperature (T) on stem growth (basal area increment [BAI]). We found the stimulating effect of rising ca and T on the growth, indicated by continuous increase of intrinsic water-use efficiency in all stands and a positive correlation between T and BAI. However, these effects failed to alleviate the negative impacts of drought on tree growth. Concurrent acceleration of BAI reversed during the intensive drought episodes. Water stress resulted from inaccessibility of roots to deep soil water rather than from lack of precipitation, suggested by the decoupling of BAI from precipitation and vapour pressure deficit. Local soil water limitation might also cause greater stomatal regulation in declining trees, indicated by lower intercellular CO2 concentration. Thus, site-specific soil moisture conditions growth sensitivity to global warming resulting in site-specific decline episodes in drought-prone areas.
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Affiliation(s)
- Guodong Jia
- Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Lixin Chen
- Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xinxiao Yu
- Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Ziqiang Liu
- School of Forestry, Nanjing Forestry University, Nanjing, China
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16
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Liu Q, Sterck FJ, Zhang JL, Scheire A, Konings E, Cao M, Sha LQ, Poorter L. Traits, strategies, and niches of liana species in a tropical seasonal rainforest. Oecologia 2021; 196:499-514. [PMID: 34023971 PMCID: PMC8241640 DOI: 10.1007/s00442-021-04937-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 05/05/2021] [Indexed: 11/27/2022]
Abstract
Plant functional traits and strategies hold the promise to explain species distribution, but few studies have linked multiple traits to multiple niche dimensions (i.e., light, water, and nutrients). Here, we analyzed for 29 liana species in a Chinese tropical seasonal rainforest how: (1) trait associations and trade-offs lead to different plant strategies; and (2) how these traits shape species' niche dimensions. Eighteen functional traits related to light, water, and nutrient use were measured and species niche dimensions were quantified using species distribution in a 20-ha plot combined with data on canopy gaps, topographic water availability, and soil nutrients. We found a tissue toughness spectrum ranging from soft to hard tissues along which species also varied from acquisitive to conservative water use, and a resource acquisition spectrum ranging from low to high light capture and nutrient use. Intriguingly, each spectrum partly reflected the conservative-acquisitive paradigm, but at the same time, the tissue toughness and the resource acquisition spectrum were uncoupled. Resource niche dimensions were better predicted by individual traits than by multivariate plant strategies. This suggests that trait components that underlie multivariate strategy axes, rather than the plant strategies themselves determine species distributions. Different traits were important for different niche dimensions. In conclusion, plant functional traits and strategies can indeed explain species distributions, but not in a simple and straight forward way. Although the identification of global plant strategies has significantly advanced the field, this research shows that global, multivariate generalizations are difficult to translate to local conditions, as different components of these strategies are important under different local conditions.
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Affiliation(s)
- Qi Liu
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan, 666303, China
| | - Frank J Sterck
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan, 666303, China.
| | - Arne Scheire
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Evelien Konings
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Min Cao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan, 666303, China
| | - Li-Qing Sha
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan, 666303, China
| | - Lourens Poorter
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
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17
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Beaulne J, Boucher É, Garneau M, Magnan G. Paludification reduces black spruce growth rate but does not alter tree water use efficiency in Canadian boreal forested peatlands. FOREST ECOSYSTEMS 2021; 8:28. [PMID: 34721933 PMCID: PMC8550502 DOI: 10.1186/s40663-021-00307-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 04/15/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Black spruce (Picea mariana (Mill.) BSP)-forested peatlands are widespread ecosystems in boreal North America in which peat accumulation, known as the paludification process, has been shown to induce forest growth decline. The continuously evolving environmental conditions (e.g., water table rise, increasing peat thickness) in paludified forests may require tree growth mechanism adjustments over time. In this study, we investigate tree ecophysiological mechanisms along a paludification gradient in a boreal forested peatland of eastern Canada by combining peat-based and tree-ring analyses. Carbon and oxygen stable isotopes in tree rings are used to document changes in carbon assimilation rates, stomatal conductance, and water use efficiency. In addition, paleohydrological analyses are performed to evaluate the dynamical ecophysiological adjustments of black spruce trees to site-specific water table variations. RESULTS Increasing peat accumulation considerably impacts forest growth, but no significant differences in tree water use efficiency (iWUE) are found between the study sites. Tree-ring isotopic analysis indicates no iWUE decrease over the last 100 years, but rather an important increase at each site up to the 1980s, before iWUE stabilized. Surprisingly, inferred basal area increments do not reflect such trends. Therefore, iWUE variations do not reflect tree ecophysiological adjustments required by changes in growing conditions. Local water table variations induce no changes in ecophysiological mechanisms, but a synchronous shift in iWUE is observed at all sites in the mid-1980s. CONCLUSIONS Our study shows that paludification induces black spruce growth decline without altering tree water use efficiency in boreal forested peatlands. These findings highlight that failing to account for paludification-related carbon use and allocation could result in the overestimation of aboveground biomass production in paludified sites. Further research on carbon allocation strategies is of utmost importance to understand the carbon sink capacity of these widespread ecosystems in the context of climate change, and to make appropriate forest management decisions in the boreal biome. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s40663-021-00307-x.
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Affiliation(s)
- Joannie Beaulne
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- GRIL-UQAM, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
| | - Étienne Boucher
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Centre d’études nordiques, Université Laval, Montréal, Québec G1V 0A6 Canada
| | - Michelle Garneau
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- GRIL-UQAM, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Centre d’études nordiques, Université Laval, Montréal, Québec G1V 0A6 Canada
| | - Gabriel Magnan
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- GRIL-UQAM, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
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Belmecheri S, Maxwell RS, Taylor AH, Davis KJ, Guerrieri R, Moore DJP, Rayback SA. Precipitation alters the CO 2 effect on water-use efficiency of temperate forests. GLOBAL CHANGE BIOLOGY 2021; 27:1560-1571. [PMID: 33464665 DOI: 10.1111/gcb.15491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 05/08/2023]
Abstract
Increasing water-use efficiency (WUE), the ratio of carbon gain to water loss, is a key mechanism that enhances carbon uptake by terrestrial vegetation under rising atmospheric CO2 (ca ). Existing theory and empirical evidence suggest a proportional WUE increase in response to rising ca as plants maintain a relatively constant ratio between the leaf intercellular (ci ) and ambient (ca ) partial CO2 pressure (ci /ca ). This has been hypothesized as the main driver of the strengthening of the terrestrial carbon sink over the recent decades. However, proportionality may not characterize CO2 effects on WUE on longer time-scales and the role of climate in modulating these effects is uncertain. Here, we evaluate long-term WUE responses to ca and climate from 1901 to 2012 CE by reconstructing intrinsic WUE (iWUE, the ratio of photosynthesis to stomatal conductance) using carbon isotopes in tree rings across temperate forests in the northeastern USA. We show that iWUE increased steadily from 1901 to 1975 CE but remained constant thereafter despite continuously rising ca . This finding is consistent with a passive physiological response to ca and coincides with a shift to significantly wetter conditions across the region. Tree physiology was driven by summer moisture at multi-decadal time-scales and did not maintain a constant ci /ca in response to rising ca indicating that a point was reached where rising CO2 had a diminishing effect on tree iWUE. Our results challenge the mechanism, magnitude, and persistence of CO2 's effect on iWUE with significant implications for projections of terrestrial productivity under a changing climate.
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Affiliation(s)
- Soumaya Belmecheri
- Laboratory of Tree Ring Research, University of Arizona, Tucson, AZ, USA
| | | | - Alan H Taylor
- Department of Geography and Earth and Environmental Systems Institute, The Pennsylvania State University, University Park, PA, USA
| | - Kenneth J Davis
- Department of Meteorology and Atmospheric Science and Earth and Environmental Systems Institute, The Pennsylvania State University, University Park, PA, USA
| | - Rossella Guerrieri
- Department of Agricultural and Food Sciences (DISTAL), University of Bologna, Bologna, Italy
| | - David J P Moore
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA
| | - Shelly A Rayback
- Department of Geography, University of Vermont, Burlington, VT, USA
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Rayback SA, Belmecheri S, Gagen MH, Lini A, Gregory R, Jenkins C. North American temperate conifer (Tsuga canadensis) reveals a complex physiological response to climatic and anthropogenic stressors. THE NEW PHYTOLOGIST 2020; 228:1781-1795. [PMID: 33439504 DOI: 10.1111/nph.16811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/03/2020] [Indexed: 05/08/2023]
Abstract
Rising atmospheric CO2 (ca) is expected to promote tree growth and lower water loss via changes in leaf gas exchange. However, uncertainties remain if gas-exchange regulation strategies are homeostatic or dynamical in response to increasing ca, as well as evolving climate and pollution inputs. Using a suite of tree ring-based δ13C-derived physiological parameters (Δ13C, ci, iWUE) and tree growth from a mesic, low elevation stand of canopy-dominant Tsuga canadensis in north-eastern USA, we investigated the influence of rising ca, climate and pollution on, and characterised the dynamical regulation strategy of, leaf gas exchange at multidecadal scales. Isotopic and growth time series revealed an evolving physiological response in which the species shifted its leaf gas-exchange strategy dynamically (constant ci; constant ci/ca; constant ca - ci) in response to rising ca, moisture availability and site conditions over 111 yr. Tree iWUE plateaued after 1975, driven by greater moisture availability and a changing soil biogeochemistry that may have impaired a stomatal response. Results suggested that trees may exhibit more complex physiological responses to the changing environmental conditions over multidecadal periods, and complicating the parameterisation of Earth system models and the estimation of future carbon sink capacity and water balance in midlatitude forests and elsewhere.
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Affiliation(s)
- Shelly A Rayback
- Department of Geography, University of Vermont, 207 Old Mill Building, 94 University Place, Burlington, VT, 05405, USA
| | - Soumaya Belmecheri
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, 85721, USA
| | - Mary H Gagen
- Department of Geography, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Andrea Lini
- Department of Geology, University of Vermont, 319 Delehanty Hall, 180 Colchester Avenue, Burlington, VT, 05405, USA
| | - Rachel Gregory
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK
| | - Catherine Jenkins
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK
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20
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Choi SH, Manousiouthakis VI. On the carbon cycle impact of combustion of harvested plant biomass vs. fossil carbon resources. Comput Chem Eng 2020. [DOI: 10.1016/j.compchemeng.2020.106942] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Driscoll AW, Bitter NQ, Sandquist DR, Ehleringer JR. Multidecadal records of intrinsic water-use efficiency in the desert shrub Encelia farinosa reveal strong responses to climate change. Proc Natl Acad Sci U S A 2020; 117:18161-18168. [PMID: 32719142 PMCID: PMC7414048 DOI: 10.1073/pnas.2008345117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
While tree rings have enabled interannual examination of the influence of climate on trees, this is not possible for most shrubs. Here, we leverage a multidecadal record of annual foliar carbon isotope ratio collections coupled with 39 y of survey data from two populations of the drought-deciduous desert shrub Encelia farinosa to provide insight into water-use dynamics and climate. This carbon isotope record provides a unique opportunity to examine the response of desert shrubs to increasing temperature and water stress in a region where climate is changing rapidly. Population mean carbon isotope ratios fluctuated predictably in response to interannual variations in temperature, vapor pressure deficit, and precipitation, and responses were similar among individuals. We leveraged the well-established relationships between leaf carbon isotope ratios and the ratio of intracellular to ambient CO2 concentrations to calculate intrinsic water-use efficiency (iWUE) of the plants and to quantify plant responses to long-term environmental change. The population mean iWUE value increased by 53 to 58% over the study period, much more than the 20 to 30% increase that has been measured in forests [J. Peñuelas, J. G. Canadell, R. Ogaya, Glob. Ecol. Biogeogr. 20, 597-608 (2011)]. Changes were associated with both increased CO2 concentration and increased water stress. Individuals whose lifetimes spanned the entire study period exhibited increases in iWUE that were very similar to the population mean, suggesting that there was significant plasticity within individuals rather than selection at the population scale.
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Affiliation(s)
- Avery W Driscoll
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Nicholas Q Bitter
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Darren R Sandquist
- Department of Biological Science, California State University, Fullerton, CA 92834
| | - James R Ehleringer
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112;
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22
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Marchand W, Girardin MP, Hartmann H, Depardieu C, Isabel N, Gauthier S, Boucher É, Bergeron Y. Strong overestimation of water-use efficiency responses to rising CO 2 in tree-ring studies. GLOBAL CHANGE BIOLOGY 2020; 26:4538-4558. [PMID: 32421921 DOI: 10.1111/gcb.15166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/25/2020] [Indexed: 06/11/2023]
Abstract
The carbon isotope ratio (δ13 C) in tree rings is commonly used to derive estimates of the assimilation-to-stomatal conductance rate of trees, that is, intrinsic water-use efficiency (iWUE). Recent studies have observed increased iWUE in response to rising atmospheric CO2 concentrations (Ca ), in many different species, genera and biomes. However, increasing rates of iWUE vary widely from one study to another, likely because numerous covarying factors are involved. Here, we quantified changes in iWUE of two widely distributed boreal conifers using tree samples from a forest inventory network that were collected across a wide range of growing conditions (assessed using the site index, SI), developmental stages and stand histories. Using tree-ring isotopes analysis, we assessed the magnitude of increase in iWUE after accounting for the effects of tree size, stand age, nitrogen deposition, climate and SI. We also estimated how growth conditions have modulated tree physiological responses to rising Ca . We found that increases in tree size and stand age greatly influenced iWUE. The effect of Ca on iWUE was strongly reduced after accounting for these two variables. iWUE increased in response to Ca , mostly in trees growing on fertile stands, whereas iWUE remained almost unchanged on poor sites. Our results suggest that past studies could have overestimated the CO2 effect on iWUE, potentially leading to biased inferences about the future net carbon balance of the boreal forest. We also observed that this CO2 effect is weakening, which could affect the future capacity of trees to resist and recover from drought episodes.
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Affiliation(s)
- William Marchand
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn Noranda, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Martin P Girardin
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn Noranda, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Henrik Hartmann
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Claire Depardieu
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
- Chaire de recherche du Canada en génomique forestière, Université Laval, Sainte-Foy, QC, Canada
| | - Nathalie Isabel
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
- Chaire de recherche du Canada en génomique forestière, Université Laval, Sainte-Foy, QC, Canada
| | - Sylvie Gauthier
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Étienne Boucher
- GEOTOP, Université du Québec à Montréal, Montreal, QC, Canada
- Department of Geography, Université du Québec à Montréal, Montreal, QC, Canada
- Centre d'Études Nordiques, Université Laval, Quebec City, QC, Canada
| | - Yves Bergeron
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn Noranda, QC, Canada
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Li X, Piao S, Wang K, Wang X, Wang T, Ciais P, Chen A, Lian X, Peng S, Peñuelas J. Temporal trade-off between gymnosperm resistance and resilience increases forest sensitivity to extreme drought. Nat Ecol Evol 2020; 4:1075-1083. [DOI: 10.1038/s41559-020-1217-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 05/05/2020] [Indexed: 01/15/2023]
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Savard MM, Bégin C, Marion J. Response strategies of boreal spruce trees to anthropogenic changes in air quality and rising pCO 2. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114209. [PMID: 32220752 DOI: 10.1016/j.envpol.2020.114209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/12/2020] [Accepted: 02/16/2020] [Indexed: 06/10/2023]
Abstract
Little is known about how forests adjust their gas-exchange mode while atmospheric CO2 rises globally and air quality changes regionally. The present study aims at addressing this research gap for boreal spruce trees growing in three different regions of Canada, submitted to distinct levels of atmospheric emissions, by examining the amount of carbon gained per unit of water lost in trees, i.e., the intrinsic water use efficiency (iWUE). Under pristine air quality conditions, middle-to long-term trends passed from no-reaction mode to passive strategies due to atmospheric CO2, and short-term iWUE variations mostly ensue from year-to-year climatic conditions. In contrast, in trees exposed to pollutants from a copper smelter and an oil-sands mining region, air quality deterioration generated swift, long-term iWUE rises immediately at the onset of operations. In this case, the very active foliar strategy sharply reduced the intra-foliar CO2 (Ci) pressure. Statistical modeling allowed identifying emissions as the main trigger for the iWUE swift shifts; subsequent combined effects of emissions and rising CO2 led to passive foliar modes in the recent decades, and short-term variations due to climatic conditions appeared all along the series. Overall, boreal trees under different regional conditions modified their foliar strategies mostly without changing their stem growth. These findings underline the potential of acidifying emissions for prompting major iWUE increases due to lowering the stomatal apertures in leaves, and the combined influence of rising CO2 in modulating other foliar responses. A fallout of this research is that degrading air quality may create true divergences in the relationship between tree-ring isotopes and climatic conditions, an impact to consider prior to using isotopic series for paleo-climatic modeling.
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Affiliation(s)
- Martine M Savard
- Natural Resources Canada, Geological Survey of Canada, 490 de La Couronne, Québec (QC), G1K 9A9, Canada.
| | - Christian Bégin
- Natural Resources Canada, Geological Survey of Canada, 490 de La Couronne, Québec (QC), G1K 9A9, Canada
| | - Joëlle Marion
- Natural Resources Canada, Geological Survey of Canada, 490 de La Couronne, Québec (QC), G1K 9A9, Canada
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25
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Vadeboncoeur MA, Jennings KA, Ouimette AP, Asbjornsen H. Correcting tree-ring δ13C time series for tree-size effects in eight temperate tree species. TREE PHYSIOLOGY 2020; 40:333-349. [PMID: 31976526 DOI: 10.1093/treephys/tpz138] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/16/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
Stable carbon isotope ratios (δ13C) in tree rings have been widely used to study changes in intrinsic water-use efficiency (iWUE), sometimes with limited consideration of how C-isotope discrimination is affected by tree height and canopy position. Our goals were to quantify the relationships between tree size or tree microenvironment and wood δ13C for eight functionally diverse temperate tree species in northern New England and to better understand the physical and physiological mechanisms underlying these differences. We collected short increment cores in closed-canopy stands and analyzed δ13C in the most recent 5 years of growth. We also sampled saplings in both shaded and sun-exposed environments. In closed-canopy stands, we found strong tree-size effects on δ13C, with 3.7-7.2‰ of difference explained by linear regression vs height (0.11-0.28‰ m-1), which in some cases is substantially stronger than the effect reported in previous studies. However, open-grown saplings were often isotopically more similar to large codominant trees than to shade-grown saplings, indicating that light exposure contributes more to the physiological and isotopic differences between small and large trees than does height. We found that in closed-canopy forests, δ13C correlations with diameter at breast height were nonlinear but also strong, allowing a straightforward procedure to correct tree- or stand-scale δ13C-based iWUE chronologies for changing tree size. We demonstrate how to use such data to correct and interpret multi-decadal composite isotope chronologies in both shade-regenerated and open-grown tree cohorts, and we highlight the importance of understanding site history when interpreting δ13C time series.
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Affiliation(s)
- Matthew A Vadeboncoeur
- Earth Systems Research Center, University of New Hampshire, 8 College Road, Durham, NH 03824, USA
| | - Katie A Jennings
- Earth Systems Research Center, University of New Hampshire, 8 College Road, Durham, NH 03824, USA
| | - Andrew P Ouimette
- Earth Systems Research Center, University of New Hampshire, 8 College Road, Durham, NH 03824, USA
| | - Heidi Asbjornsen
- Earth Systems Research Center, University of New Hampshire, 8 College Road, Durham, NH 03824, USA
- Department of Natural Resources and the Environment, University of New Hampshire, 56 College Road, Durham, NH 03824, USA
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26
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Lavergne A, Voelker S, Csank A, Graven H, de Boer HJ, Daux V, Robertson I, Dorado-Liñán I, Martínez-Sancho E, Battipaglia G, Bloomfield KJ, Still CJ, Meinzer FC, Dawson TE, Julio Camarero J, Clisby R, Fang Y, Menzel A, Keen RM, Roden JS, Prentice IC. Historical changes in the stomatal limitation of photosynthesis: empirical support for an optimality principle. THE NEW PHYTOLOGIST 2020; 225:2484-2497. [PMID: 31696932 DOI: 10.1111/nph.16314] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 10/31/2019] [Indexed: 05/08/2023]
Abstract
The ratio of leaf internal (ci ) to ambient (ca ) partial pressure of CO2 , defined here as χ, is an index of adjustments in both leaf stomatal conductance and photosynthetic rate to environmental conditions. Measurements and proxies of this ratio can be used to constrain vegetation model uncertainties for predicting terrestrial carbon uptake and water use. We test a theory based on the least-cost optimality hypothesis for modelling historical changes in χ over the 1951-2014 period, across different tree species and environmental conditions, as reconstructed from stable carbon isotopic measurements across a global network of 103 absolutely dated tree-ring chronologies. The theory predicts optimal χ as a function of air temperature, vapour pressure deficit, ca and atmospheric pressure. The theoretical model predicts 39% of the variance in χ values across sites and years, but underestimates the intersite variability in the reconstructed χ trends, resulting in only 8% of the variance in χ trends across years explained by the model. Overall, our results support theoretical predictions that variations in χ are tightly regulated by the four environmental drivers. They also suggest that explicitly accounting for the effects of plant-available soil water and other site-specific characteristics might improve the predictions.
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Affiliation(s)
- Aliénor Lavergne
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- Department of Physics, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Steve Voelker
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY, 13210, USA
| | - Adam Csank
- Department of Geography, University of Nevada-Reno, 1664 N. Virginia St, Reno, NV, 89557, USA
| | - Heather Graven
- Department of Physics, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
- Grantham Institute - Climate Change and the Environment, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Hugo J de Boer
- Department of Environmental Sciences, Utrecht University, 3584 CB, Utrecht, the Netherlands
| | - Valérie Daux
- Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, 91191, Gif-sur-Yvette, France
| | - Iain Robertson
- Department of Geography, Swansea University, Swansea, SA2 8PP, UK
| | - Isabel Dorado-Liñán
- Forest Genetics and Ecophysiology Research Group, Technical University of Madrid, Madrid, 28040, Spain
| | - Elisabet Martínez-Sancho
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania "L. Vanvitelli", Via Vivaldi, 81100, Caserta, Italy
| | - Keith J Bloomfield
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Christopher J Still
- Department of Forest Ecosystems & Society, Oregon State University, Corvallis, OR, 97331-5704, USA
| | - Frederick C Meinzer
- USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, 97331-8550, USA
| | - Todd E Dawson
- Department of Integrative Biology, University of California - Berkeley, Berkeley, CA, 94720-3200, USA
| | - J Julio Camarero
- Instituto Pirenaico de Ecología (IPE-CSIC), E-50192, Zaragoza, Spain
| | - Rory Clisby
- Department of Geography, Swansea University, Swansea, SA2 8PP, UK
| | - Yunting Fang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Annette Menzel
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technical University of Munich, 85354, Freising, Germany
| | - Rachel M Keen
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - John S Roden
- Department of Biology, Southern Oregon University, Ashland, OR, 97520, USA
| | - I Colin Prentice
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- Grantham Institute - Climate Change and the Environment, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
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27
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Sperry JS, Venturas MD, Todd HN, Trugman AT, Anderegg WRL, Wang Y, Tai X. The impact of rising CO 2 and acclimation on the response of US forests to global warming. Proc Natl Acad Sci U S A 2019; 116:25734-25744. [PMID: 31767760 PMCID: PMC6926066 DOI: 10.1073/pnas.1913072116] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The response of forests to climate change depends in part on whether the photosynthetic benefit from increased atmospheric CO2 (∆Ca = future minus historic CO2) compensates for increased physiological stresses from higher temperature (∆T). We predicted the outcome of these competing responses by using optimization theory and a mechanistic model of tree water transport and photosynthesis. We simulated current and future productivity, stress, and mortality in mature monospecific stands with soil, species, and climate sampled from 20 continental US locations. We modeled stands with and without acclimation to ∆Ca and ∆T, where acclimated forests adjusted leaf area, photosynthetic capacity, and stand density to maximize productivity while avoiding stress. Without acclimation, the ∆Ca-driven boost in net primary productivity (NPP) was compromised by ∆T-driven stress and mortality associated with vascular failure. With acclimation, the ∆Ca-driven boost in NPP and stand biomass (C storage) was accentuated for cooler futures but negated for warmer futures by a ∆T-driven reduction in NPP and biomass. Thus, hotter futures reduced forest biomass through either mortality or acclimation. Forest outcomes depended on whether projected climatic ∆Ca/∆T ratios were above or below physiological thresholds that neutralized the negative impacts of warming. Critically, if forests do not acclimate, the ∆Ca/∆T must be above ca 89 ppm⋅°C-1 to avoid chronic stress, a threshold met by 55% of climate projections. If forests do acclimate, the ∆Ca/∆T must rise above ca 67 ppm⋅°C-1 for NPP and biomass to increase, a lower threshold met by 71% of projections.
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Affiliation(s)
- John S Sperry
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112;
| | - Henry N Todd
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Anna T Trugman
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
- Department of Geography, University of California, Santa Barbara, CA 93106
| | | | - Yujie Wang
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Xiaonan Tai
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112
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28
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Impact of Climate, Stand Growth Parameters, and Management on Isotopic Composition of Tree Rings in Chestnut Coppices. FORESTS 2019. [DOI: 10.3390/f10121148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Research Highlights: Chestnut trees’ (Castanea sativa Mill.) growth and their responses to climate are influenced by stand-characteristics and managements. This study highlighted that chestnut tree-ring growth is not particularly influenced by climate, while minimum temperature showed a positive relation with both intrinsic water-use efficiency (WUEi) and δ¹8O. Background and Objectives: The aim is to check the responses of chestnut trees to climate conditions and the role of stand structure and management. Materials and Methods: Stands with 12–14-year-old shoots were studied using dendrochronological and isotopic (δ18O and δ13C) approaches. Correlations with climate parameters were investigated and principal component analysis was performed using site-characteristics and tree growth parameters as variables. Results: Correlations between tree-ring width (TRW), tree-ring δ18O, and δ13C-derived intrinsic water-use efficiency (WUEi) revealed stand-dependent effects. The highest Correlations were found between climate and tree-rings’ isotopic composition. Chestnut was sensitive to high-minimum temperature in March and April, with a negative relationship with TRW and a positive relationship with WUEi. δ18O signals were not significantly different among stands. Stand thinning had a positive effect on WUEi after 1–2 years. Stand competition (indicated by shoots/stump and stumps/ha) positively influenced both WUEi and δ¹8O.
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29
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Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency. Proc Natl Acad Sci U S A 2019; 116:16909-16914. [PMID: 31383758 PMCID: PMC6708355 DOI: 10.1073/pnas.1905912116] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Forests remove about 30% of anthropogenic CO2 emissions through photosynthesis and return almost 40% of incident precipitation back to the atmosphere via transpiration. The trade-off between photosynthesis and transpiration through stomata, the water-use efficiency (WUE), is an important driver of plant evolution and ecosystem functioning, and has profound effects on climate. Using stable carbon and oxygen isotope ratios in tree rings, we found that WUE has increased by a magnitude consistent with estimates from atmospheric measurements and model predictions. Enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to moisture-limited forests. This result points to smaller reductions in transpiration in response to increasing atmospheric CO2, with important implications for forest–climate interactions, which remain to be explored. Multiple lines of evidence suggest that plant water-use efficiency (WUE)—the ratio of carbon assimilation to water loss—has increased in recent decades. Although rising atmospheric CO2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystem-scale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO2-induced reductions in stomatal conductance.
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30
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Cernusak LA, Haverd V, Brendel O, Le Thiec D, Guehl JM, Cuntz M. Robust Response of Terrestrial Plants to Rising CO 2. TRENDS IN PLANT SCIENCE 2019; 24:578-586. [PMID: 31104852 DOI: 10.1016/j.tplants.2019.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/08/2019] [Accepted: 04/13/2019] [Indexed: 05/21/2023]
Abstract
Human-caused CO2 emissions over the past century have caused the climate of the Earth to warm and have directly impacted on the functioning of terrestrial plants. We examine the global response of terrestrial gross primary production (GPP) to the historic change in atmospheric CO2. The GPP of the terrestrial biosphere has increased steadily, keeping pace remarkably in proportion to the rise in atmospheric CO2. Water-use efficiency, namely the ratio of CO2 uptake by photosynthesis to water loss by transpiration, has increased as a direct leaf-level effect of rising CO2. This has allowed an increase in global leaf area, which has conspired with stimulation of photosynthesis per unit leaf area to produce a maximal response of the terrestrial biosphere to rising atmospheric CO2 and contemporary climate change.
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Affiliation(s)
- Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, QLD 4879, Australia.
| | - Vanessa Haverd
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere, Canberra, ACT 2601, Australia
| | - Oliver Brendel
- Université de Lorraine, Institut National de la Recherche Agronomique (INRA), AgroParisTech, Unité Mixte de Recherche Silva, 54000 Nancy, France
| | - Didier Le Thiec
- Université de Lorraine, Institut National de la Recherche Agronomique (INRA), AgroParisTech, Unité Mixte de Recherche Silva, 54000 Nancy, France
| | - Jean-Marc Guehl
- Université de Lorraine, Institut National de la Recherche Agronomique (INRA), AgroParisTech, Unité Mixte de Recherche Silva, 54000 Nancy, France
| | - Matthias Cuntz
- Université de Lorraine, Institut National de la Recherche Agronomique (INRA), AgroParisTech, Unité Mixte de Recherche Silva, 54000 Nancy, France
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31
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Lavergne A, Graven H, De Kauwe MG, Keenan TF, Medlyn BE, Prentice IC. Observed and modelled historical trends in the water-use efficiency of plants and ecosystems. GLOBAL CHANGE BIOLOGY 2019; 25:2242-2257. [PMID: 30933410 DOI: 10.1111/gcb.14634] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/29/2019] [Accepted: 03/14/2019] [Indexed: 05/20/2023]
Abstract
Plant water-use efficiency (WUE, the carbon gained through photosynthesis per unit of water lost through transpiration) is a tracer of the plant physiological controls on the exchange of water and carbon dioxide between terrestrial ecosystems and the atmosphere. At the leaf level, rising CO2 concentrations tend to increase carbon uptake (in the absence of other limitations) and to reduce stomatal conductance, both effects leading to an increase in leaf WUE. At the ecosystem level, indirect effects (e.g. increased leaf area index, soil water savings) may amplify or dampen the direct effect of CO2 . Thus, the extent to which changes in leaf WUE translate to changes at the ecosystem scale remains unclear. The differences in the magnitude of increase in leaf versus ecosystem WUE as reported by several studies are much larger than would be expected with current understanding of tree physiology and scaling, indicating unresolved issues. Moreover, current vegetation models produce inconsistent and often unrealistic magnitudes and patterns of variability in leaf and ecosystem WUE, calling for a better assessment of the underlying approaches. Here, we review the causes of variations in observed and modelled historical trends in WUE over the continuum of scales from leaf to ecosystem, including methodological issues, with the aim of elucidating the reasons for discrepancies observed within and across spatial scales. We emphasize that even though physiological responses to changing environmental drivers should be interpreted differently depending on the observational scale, there are large uncertainties in each data set which are often underestimated. Assumptions made by the vegetation models about the main processes influencing WUE strongly impact the modelled historical trends. We provide recommendations for improving long-term observation-based estimates of WUE that will better inform the representation of WUE in vegetation models.
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Affiliation(s)
- Aliénor Lavergne
- Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Ascot, UK
| | - Heather Graven
- Department of Physics, Imperial College London, London, UK
- Grantham Institute - Climate Change and the Environment, Imperial College London, London, UK
| | - Martin G De Kauwe
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, New South Wales, Australia
| | - Trevor F Keenan
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, California
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Iain Colin Prentice
- Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Ascot, UK
- Grantham Institute - Climate Change and the Environment, Imperial College London, London, UK
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
- Department of Earth System Science, Tsinghua University, Beijing, China
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32
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Stangl ZR, Tarvainen L, Wallin G, Ubierna N, Räntfors M, Marshall JD. Diurnal variation in mesophyll conductance and its influence on modelled water-use efficiency in a mature boreal Pinus sylvestris stand. PHOTOSYNTHESIS RESEARCH 2019; 141:53-63. [PMID: 31123952 PMCID: PMC6612512 DOI: 10.1007/s11120-019-00645-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 05/06/2019] [Indexed: 05/02/2023]
Abstract
Mesophyll conductance (gm) is a critical variable for the use of stable carbon isotopes to infer photosynthetic water-use efficiency (WUE). Although gm is similar in magnitude to stomatal conductance (gs), it has been measured less often, especially under field conditions and at high temporal resolution. We mounted an isotopic CO2 analyser on a field photosynthetic gas exchange system to make continuous online measurements of gas exchange and photosynthetic 13C discrimination (Δ13C) on mature Pinus sylvestris trees. This allowed the calculation of gm, gs, net photosynthesis (Anet), and WUE. These measurements highlighted the asynchronous diurnal behaviour of gm and gs. While gs declined from around 10:00, Anet declined first after 12:00, and gm remained near its maximum until 16:00. We suggest that high gm played a role in supporting an extended Anet peak despite stomatal closure. Comparing three models to estimate WUE from ∆13C, we found that a simple model, assuming constant net fractionation during carboxylation (27‰), predicted WUE well, but only for about 75% of the day. A more comprehensive model, accounting explicitly for gm and the effects of daytime respiration and photorespiration, gave reliable estimates of WUE, even in the early morning hours when WUE was more variable. Considering constant, finite gm or gm/gs yielded similar WUE estimates on the diurnal scale, while assuming infinite gm led to overestimation of WUE. These results highlight the potential of high-resolution gm measurements to improve modelling of Anet and WUE and demonstrate that such gm data can be acquired, even under field conditions.
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Affiliation(s)
- Zsofia R Stangl
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Lasse Tarvainen
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Göran Wallin
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Nerea Ubierna
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Mats Räntfors
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - John D Marshall
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
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de Boer HJ, Robertson I, Clisby R, Loader NJ, Gagen M, Young GHF, Wagner-Cremer F, Hipkin CR, McCarroll D. Tree-ring isotopes suggest atmospheric drying limits temperature-growth responses of treeline bristlecone pine. TREE PHYSIOLOGY 2019; 39:983-999. [PMID: 30976807 PMCID: PMC6642877 DOI: 10.1093/treephys/tpz018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 04/24/2019] [Indexed: 06/02/2023]
Abstract
Altitudinally separated bristlecone pine populations in the White Mountains (California, USA) exhibit differential climate-growth responses as temperature and tree-water relations change with altitude. These populations provide a natural experiment to explore the ecophysiological adaptations of this unique tree species to the twentieth century climate variability. We developed absolutely dated annual ring-width chronologies, and cellulose stable carbon and oxygen isotope chronologies from bristlecone pine growing at the treeline (~3500 m) and ~200 m below for the period AD 1710-2010. These chronologies were interpreted in terms of ecophysiological adaptations to climate variability with a dual-isotope model and a leaf gas exchange model. Ring widths show positive tree growth anomalies at treeline and consistent slower growth below treeline in relation to the twentieth century warming and associated atmospheric drying until the 1980s. Growth rates of both populations declined during and after the 1980s when growing-season temperature and atmospheric vapour pressure deficit continued to increase. Our model-based interpretations of the cellulose stable isotopes indicate that positive treeline growth anomalies prior to the 1980s were related to increased stomatal conductance and leaf-level transpiration and photosynthesis. Reduced growth since the 1980s occurred with a shift to more conservative leaf gas exchange in both the treeline and below-treeline populations, whereas leaf-level photosynthesis continued to increase in response to rising atmospheric CO2 concentrations. Our results suggest that warming-induced atmospheric drying confounds positive growth responses of apparent temperature-limited bristlecone pine populations at treeline. In addition, the observed ecophysiological responses of attitudinally separated bristlecone pine populations illustrate the sensitivity of conifers to climate change.
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Affiliation(s)
- Hugo J de Boer
- Department of Environmental Sciences, Utrecht University, Utrecht, The Netherlands
| | - Iain Robertson
- Department of Geography, Swansea University, Swansea, UK
| | - Rory Clisby
- Department of Geography, Swansea University, Swansea, UK
| | - Neil J Loader
- Department of Geography, Swansea University, Swansea, UK
| | - Mary Gagen
- Department of Geography, Swansea University, Swansea, UK
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Voelker SL, Merschel AG, Meinzer FC, Ulrich DEM, Spies TA, Still CJ. Fire deficits have increased drought sensitivity in dry conifer forests: Fire frequency and tree-ring carbon isotope evidence from Central Oregon. GLOBAL CHANGE BIOLOGY 2019; 25:1247-1262. [PMID: 30536531 DOI: 10.1111/gcb.14543] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 10/04/2018] [Indexed: 06/09/2023]
Abstract
A century of fire suppression across the Western United States has led to more crowded forests and increased competition for resources. Studies of forest thinning or stand conditions after mortality events have provided indirect evidence for how competition can promote drought stress and predispose forests to severe fire and/or bark beetle outbreaks. Here, we demonstrate linkages between fire deficits and increasing drought stress through analyses of annually resolved tree-ring growth, fire scars, and carbon isotope discrimination (Δ13 C) across a dry mixed-conifer forest landscape. Fire deficits across the study area have increased the sensitivity of leaf gas exchange to drought stress over the past >100 years. Since 1910, stand basal area in these forests has more than doubled and fire-return intervals have increased from 25 to 140 years. Meanwhile, the portion of interannual variation in tree-ring Δ13 C explained by the Palmer Drought Severity Index has more than doubled in ca. 300-500-year-old Pinus ponderosa as well as in fire-intolerant, ca. 90-190-year-old Abies grandis. Drought stress has increased in stands with a basal area of ≥25 m2 /ha in 1910, as indicated by negative temporal Δ13 C trends, whereas stands with basal area ≤25 m2 /ha in 1910, due to frequent or intense wildfire activity in decades beforehand, were initially buffered from increased drought stress and have benefited more from rising ambient carbon dioxide concentrations, [CO2 ], as demonstrated by positive temporal Δ13 C trends. Furthermore, the average Δ13 C response across all P. ponderosa since 1830 indicates that photosynthetic assimilation rates and stomatal conductance have been reduced by ~10% and ~20%, respectively, compared to expected trends due to increasing [CO2 ]. Although disturbance legacies contribute to local-scale intensity of drought stress, fire deficits have reduced drought resistance of mixed-conifer forests and made them more susceptible to challenges by pests and pathogens and other disturbances.
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Affiliation(s)
- Steven L Voelker
- Plants, Soils and Climate Department, Utah State University, Logan, Utah
| | - Andrew G Merschel
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, Oregon
| | | | | | - Thomas A Spies
- USDA Forest Service Pacific Northwest Research Station, Portland, Oregon
| | - Christopher J Still
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, Oregon
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Giguère-Croteau C, Boucher É, Bergeron Y, Girardin MP, Drobyshev I, Silva LCR, Hélie JF, Garneau M. North America's oldest boreal trees are more efficient water users due to increased [CO 2], but do not grow faster. Proc Natl Acad Sci U S A 2019; 116:2749-2754. [PMID: 30692257 PMCID: PMC6377478 DOI: 10.1073/pnas.1816686116] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Due to anthropogenic emissions and changes in land use, trees are now exposed to atmospheric levels of [[Formula: see text]] that are unprecedented for 650,000 y [Lüthi et al. (2008) Nature 453:379-382] (thousands of tree generations). Trees are expected to acclimate by modulating leaf-gas exchanges and alter water use efficiency which may result in forest productivity changes. Here, we present evidence of one of the strongest, nonlinear, and unequivocal postindustrial increases in intrinsic water use efficiency ([Formula: see text]) ever documented (+59%). A dual-isotope tree-ring analysis ([Formula: see text] and [Formula: see text]) covering 715 y of growth of North America's oldest boreal trees (Thuja occidentalis L.) revealed an unprecedented increase in [Formula: see text] that was directly linked to elevated assimilation rates of [Formula: see text] (A). However, limited nutrient availability, changes in carbon allocation strategies, and changes in stomatal density may have offset stem growth benefits awarded by the increased [Formula: see text] Our results demonstrate that even in scenarios where a positive [Formula: see text] fertilization effect is observed, other mechanisms may prevent trees from assimilating and storing supplementary anthropogenic emissions as above-ground biomass. In such cases, the sink capacity of forests in response to changing atmospheric conditions might be overestimated.
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Affiliation(s)
- Claudie Giguère-Croteau
- Department of Biology, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- GEOTOP, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Centre d'Études sur la Forêt, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
| | - Étienne Boucher
- GEOTOP, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada;
- Department of Geography, Université du Québec à Montréal, Montréal, QC H2X 3R9, Canada
- Centre d'Études Nordiques, Université Laval, Québec, QC G1V 0A6, Canada
| | - Yves Bergeron
- Department of Biology, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Centre d'Études sur la Forêt, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Institut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC J9X 5E4, Canada
| | - Martin P Girardin
- Centre de Foresterie des Laurentides, Ressources Naturelles Canada, Sainte-Foy, QC G1V 4C7, Canada
| | - Igor Drobyshev
- Centre d'Études sur la Forêt, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Institut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC J9X 5E4, Canada
| | - Lucas C R Silva
- Environmental Studies Program, Department of Geography, Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403
| | - Jean-François Hélie
- GEOTOP, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Department of Earth and Atmosphere Sciences, Université du Québec à Montréal, Montréal, QC H2X 3Y7, Canada
| | - Michelle Garneau
- GEOTOP, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Department of Geography, Université du Québec à Montréal, Montréal, QC H2X 3R9, Canada
- Centre d'Études Nordiques, Université Laval, Québec, QC G1V 0A6, Canada
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Liu X, Zhao L, Voelker S, Xu G, Zeng X, Zhang X, Zhang L, Sun W, Zhang Q, Wu G, Li X. Warming and CO2 enrichment modified the ecophysiological responses of Dahurian larch and Mongolia pine during the past century in the permafrost of northeastern China. TREE PHYSIOLOGY 2019; 39:88-103. [PMID: 29920609 DOI: 10.1093/treephys/tpy060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/03/2018] [Indexed: 06/08/2023]
Abstract
Tree-ring δ13C and δ18O of dominant Dahurian larch and Mongolia pine in the permafrost region of the northern Great Higgnan Mountains, China were used to elucidate species-specific ecophysiological responses to warming temperatures and increasing CO2 over the past century. Larch and pine stable carbon discrimination (Δ13C) 13C and δ18O in tree rings both showed synchronous changes during the investigated period (1901-2010), but with species-specific isotopic responses to atmospheric enriched CO2 and warming. Tree-ring Δ13C and δ18O were controlled by both maximum temperature and moisture conditions (precipitation, relative humidity and vapor pressure deficit), but with different growth periods (Δ13C in June-July and δ18O in July-August, respectively). In addition, stable isotopes of larch showed relatively greater sensitivity to moisture deficits than pine. Climatic conditions from 1920 to 1960 strongly and coherently regulated tree-ring Δ13C and δ18O through stomatal conductance. However, climatic-sensitivities of tree-ring Δ13C and δ18O recently diverged, implying substantial adjustments of stomatal conductance, photosynthetic rate and altered water sources over recent decades, which reveal the varied impacts of each factor on tree-ring Δ13C and δ18O over time. Based on expected changes in leaf gas-exchange, we isolated the impacts of atmospheric CO2 and climate change on intrinsic water-use efficiency (iWUE) over the past century. Higher intracellular CO2 in pine than larch from 1960 onwards suggests this species may be more resilient to severe droughts in the future. Our data also illustrated no weakening of the iWUE response to increasing CO2 in trees from this permafrost region. The overall pattern of CO2 enrichment and climate impacts on iWUE of pine and larch were similar, but warming increased iWUE of larch to a greater extent than that of pine over recent two decades. Taken together, our findings highlight the importance of considering how leaf gas-exchange responses to atmospheric CO2 concentration influence species-specific responses to climate and the alteration of the hydrological environment in forests growing in regions historically dominated by permafrost that will be changing rapidly in response to future warming and increased CO2.
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Affiliation(s)
- Xiaohong Liu
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, China
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Liangju Zhao
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an, China
| | - Steven Voelker
- Department of Forest Ecosystems & Society, Oregon State University, Corvallis, USA
| | - Guobao Xu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Xiaomin Zeng
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, China
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Xuanwen Zhang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Lingnan Zhang
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, China
| | - Weizhen Sun
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Qiuliang Zhang
- Forest College of Inner Mongolia Agricultural University, Huhhot, China
| | - Guoju Wu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Xiaoqin Li
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, China
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37
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de Simón BF, Cadahía E, Aranda I. Metabolic response to elevated CO 2 levels in Pinus pinaster Aiton needles in an ontogenetic and genotypic-dependent way. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 132:202-212. [PMID: 30216778 DOI: 10.1016/j.plaphy.2018.09.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/04/2018] [Accepted: 09/04/2018] [Indexed: 06/08/2023]
Abstract
Global climate changes involve elevated atmospheric [CO2], fostering the carbon allocation to tree sink tissues, partitioning it into metabolic pathways. We use metabolomics analysis in adult and juvenile needles of four Pinus pinaster genotypes exposed to two levels of growth [CO2]: ambient (400 μmol mol-1) and enriched (800 μmol mol-1), to know if the metabolic responses are genotype-dependent and vary according to the stage of needle ontogeny. The eCO2-induced changes in the needle metabolomes are more significant in secondary metabolism pathways and especially meaningful in juvenile needles. The heteroblasty has important consequences in the expression of the metabolome, and on the plasticity to CO2, determining the level of specific metabolite accumulation, showing an interdependence between adult and juvenile needles. The P. pinaster needle metabolomes also show clear quantitative differences linked to genotype, as well as regarding the metabolic response to eCO2, showing both, common and genotype-specific biochemical responses. Thus, the changes in flavonol levels are mainly genotype-independent, while those in terpenoid and free fatty acids are mainly genotype-dependent, ratifying the importance of genotype to determine the metabolic response to eCO2. To understand the adaptation mechanisms that tree species can develop to cope with eCO2 it is necessary to know the genetically distinct responses within a species to recognize the CO2-induced changes from the divergent approaches, what can facilitate knowing also the possible interrelation of the physiological and metabolic responses. That could explain the controversial effects of eCO2 on the carbon-based metabolite in conifers, at the inter- and intra-specific level.
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Affiliation(s)
- Brígida Fernández de Simón
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, O.A., M.P. (INIA), Centro de Investigación Forestal, Carretera de La Coruña Km 7.5, 28040 Madrid, Spain.
| | - Estrella Cadahía
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, O.A., M.P. (INIA), Centro de Investigación Forestal, Carretera de La Coruña Km 7.5, 28040 Madrid, Spain.
| | - Ismael Aranda
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, O.A., M.P. (INIA), Centro de Investigación Forestal, Carretera de La Coruña Km 7.5, 28040 Madrid, Spain; Instituto de Investigaciones Agroambientales y de Economía Del Agua (INAGEA), Palma de Mallorca, Islas Baleares, Spain.
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38
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Szejner P, Wright WE, Belmecheri S, Meko D, Leavitt SW, Ehleringer JR, Monson RK. Disentangling seasonal and interannual legacies from inferred patterns of forest water and carbon cycling using tree-ring stable isotopes. GLOBAL CHANGE BIOLOGY 2018; 24:5332-5347. [PMID: 29999573 DOI: 10.1111/gcb.14395] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 05/31/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
Tree-ring carbon and oxygen isotope ratios have been used to understand past dynamics in forest carbon and water cycling. Recently, this has been possible for different parts of single growing seasons by isolating anatomical sections within individual annual rings. Uncertainties in this approach are associated with correlated climate legacies that can occur at a higher frequency, such as across successive seasons, or a lower frequency, such as across years. The objective of this study was to gain insight into how legacies affect cross-correlation in the δ13 C and δ18 O isotope ratios in the earlywood (EW) and latewood (LW) fractions of Pinus ponderosa trees at thirteen sites across a latitudinal gradient influenced by the North American Monsoon (NAM) climate system. We observed that δ13 C from EW and LW has significant positive cross-correlations at most sites, whereas EW and LW δ18 O values were cross-correlated at about half the sites. Using combined statistical and mechanistic models, we show that cross-correlations in both δ13 C and δ18 O can be largely explained by a low-frequency (multiple-year) mode that may be associated with long-term climate change. We isolated, and statistically removed, the low-frequency correlation, which resulted in greater geographical differentiation of the EW and LW isotope signals. The remaining higher-frequency (seasonal) cross-correlations between EW and LW isotope ratios were explored using a mechanistic isotope fractionation-climate model. This showed that lower atmospheric vapor pressure deficits associated with monsoon rain increase the EW-LW differentiation for both δ13 C and δ18 O at southern sites, compared to northern sites. Our results support the hypothesis that dominantly unimodal precipitation regimes, such as near the northern boundary of the NAM, are more likely to foster cross-correlations in the isotope signals of EW and LW, potentially due to greater sharing of common carbohydrate and soil water resource pools, compared to southerly sites with bimodal precipitation regimes.
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Affiliation(s)
- Paul Szejner
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - William E Wright
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - Soumaya Belmecheri
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - David Meko
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - Steven W Leavitt
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - James R Ehleringer
- Stable Isotope Ratio Facility for Environmental Research, Department of Biology, University of Utah, Salt Lake City, Utah
| | - 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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Disentangling Contributions of CO2 Concentration and Climate to Changes in Intrinsic Water-Use Efficiency in the Arid Boreal Forest in China’s Altay Mountains. FORESTS 2018. [DOI: 10.3390/f9100642] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intrinsic water-use efficiency (iWUE) is affected by the balance of photosynthetic rate, stomatal conductance, and climate, along with many other exogenous factors, such as the CO2 concentration in the atmosphere (CO2atm), nutrients, and water holding capacity of the soil. The relative contributions of CO2atm and climate to iWUE are still incompletely understood, particularly for boreal forests where the climate is undergoing unprecedented warming. We combined δ13C and δ18O in tree rings from the Siberian larch (Larix sibirica Ledeb.) in Northwestern China’s Altay Mountains, which receives 190 mm in annual precipitation, to detect the drivers of long-term iWUE changes and their time-varying contributions over the past 222 years. A climate optimization approach was used to isolate the influence of climate from CO2atm influence on iWUE. We found that iWUE increased about 33.6% from 1790 to 2011, and rising CO2atm contributed 48.8% to this iWUE increase. The contributions of CO2atm and climate (drought conditions) varied during the study period 1790–2011. From 1790 to 1876, the climate was the most important factor contributing to the changes in iWUE. From 1877 to 1972, CO2atm was the main contributor; however, after 1973, the climate was again the dominant contributor to the increase in iWUE, especially during 1996–2011. During the period 1996–2011, climate substantially (83%) contributed to the iWUE increase. Our findings imply that, in the boreal forest in Northwestern China’s arid region, iWUE experienced three changes: (1) the climate dominating from 1790 to 1876; (2) CO2atm dominating from 1877 to 1972, and (3) climate dominating again during the past four decades. We observed that the relationships between iWUE and tree-ring width shifted from positive to negative from 1996 onwards. These relationship changes indicate that CO2atm-mediated effects of increasing iWUE on tree growth are counteracted by climatic drought stress and iWUE increase cannot counter the stress from drought on tree growth in China’s arid boreal forest.
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40
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Rezaie N, D'Andrea E, Bräuning A, Matteucci G, Bombi P, Lauteri M. Do atmospheric CO2 concentration increase, climate and forest management affect iWUE of common beech? Evidences from carbon isotope analyses in tree rings. TREE PHYSIOLOGY 2018; 38:1110-1126. [PMID: 29579292 DOI: 10.1093/treephys/tpy025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 02/13/2018] [Indexed: 06/08/2023]
Abstract
Beech is one of the most important forest tree species in Europe, hence possible adverse factors affecting its physiology and productivity can have strong ecological and economic impacts. In this context, four beech forests along a latitudinal gradient from southern Apennines to middle European lowlands were selected for chronological determinations of carbon isotope composition (δ13C) in tree-ring cellulose. The main objectives of this study were to assess (i) the effect of climate on the carbon signature of tree-ring cellulose (δ13C); (ii) the physiological response to recent CO2 concentration increment and to climatic variation; and (iii) the relationship between intrinsic water-use efficiency (iWUE, here the average long-term ratio of net photosynthesis to stomatal conductance) and growth of trees in different sites since 1950. Our results demonstrated that site climatic conditions peculiarly affect δ13C. In northern sites, a climatic control of summer precipitation and temperature on stomatal conductance was demonstrated by their opposite correlations with δ13C, negative and positive, respectively. Furthermore, an 'earliness effect' was suggested by a significant relationship between spring temperature and δ13C in the coldest sites and by a positive one between winter temperature and δ13C in the warmest ones. In all the study sites, during the maturity phase, a positive correlation between the increment of CO2 and iWUE was observed, due to an active response of trees to CO2 increment. This increment of CO2 was the main driver of the long term increasing trend of iWUE, resulting by an active response of trees to CO2 fertilization. Moreover, precipitation mostly influences positively and negatively the inter-annual variations of iWUE of the southernmost and northernmost sites, respectively. Overall, we observed a mean increment of 40% of iWUE. Moreover, the sensitivity of iWUE to the increase of CO2 was different between the northernmost and southernmost sites. Increasing iWUE was correlated to growth in the two sites during the release phase and we hypothesize a positive effect of silvicultural treatments.
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Affiliation(s)
- Negar Rezaie
- Istituto di Biologia Agroambientale e Forestale (IBAF), Consiglio Nazionale delle Ricerche (CNR), Via Salaria km 29,300, Monterotondo Scalo (RM), Italy
| | - Ettore D'Andrea
- Istituto di Biologia Agroambientale e Forestale (IBAF), Consiglio Nazionale delle Ricerche (CNR), Via Salaria km 29,300, Monterotondo Scalo (RM), Italy
| | - Achim Bräuning
- Institute of Geography, Friedrich Alexander University Erlangen Nürnberg, Erlangen, Germany
| | - Giorgio Matteucci
- Istituto per i Sistemi Agricoli e Forestali del Mediterraneo (ISAFoM), Consiglio Nazionale delle Ricerche (CNR), Via Patacca, 85 Ercolano (NA) Italy
| | - Pierluigi Bombi
- Istituto di Biologia Agroambientale e Forestale (IBAF), Consiglio Nazionale delle Ricerche (CNR), Via Salaria km 29,300, Monterotondo Scalo (RM), Italy
| | - Marco Lauteri
- Istituto di Biologia Agroambientale e Forestale (IBAF), Consiglio Nazionale delle Ricerche (CNR), Viale G. Marconi 2, Porano (TR), Italy
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Distinctions in heterotrophic and autotrophic-based metabolism as recorded in the hydrogen and carbon isotope ratios of normal alkanes. Oecologia 2018; 187:1053-1075. [DOI: 10.1007/s00442-018-4189-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 06/05/2018] [Indexed: 10/28/2022]
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42
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Weigt RB, Streit K, Saurer M, Siegwolf RTW. The influence of increasing temperature and CO2 concentration on recent growth of old-growth larch: contrasting responses at leaf and stem processes derived from tree-ring width and stable isotopes. TREE PHYSIOLOGY 2018; 38:706-720. [PMID: 29194509 DOI: 10.1093/treephys/tpx148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 11/03/2017] [Indexed: 06/07/2023]
Abstract
Time series of tree-ring growth show significant increases since the early 1970s at the alpine tree line, with simultaneously increasing temperatures and atmospheric CO2 concentration. For a comprehensive understanding of this growth change, the physiological response patterns at both the leaf and stem level need to be separately analyzed and identified, and can be retrieved from tree-ring growth and isotope (δ13C, δ18O) series. In this study, we assessed the relative contribution of environmental factors to interannual tree-ring variability by multivariate linear mixed-effects models and the dual isotope approach on a dataset of tree-ring records of ~400-year-old larch (Larix decidua Mill.) from a non-water-limited high-elevation site in the Swiss Alps. The models suggest that summer temperatures and the recent lack of larch budmoth outbreaks were most important for explaining growth variations and trends, while a significant direct effect of the continuously increasing CO2 concentration could not be confirmed. In contrast, δ13C and δ18O, which are strongly influenced by fractionation changes in the leaf, clearly reflected the impact of air humidity (precipitation and vapor pressure deficit) and CO2 concentration: the increase in (δ13C-derived) intrinsic water-use efficiency over the second half of the 20th century suggests an increase in carbon assimilation as a result of enhanced CO2 concentration. The tree-ring δ18O largely reflected recent precipitation as source water, thus indicating a low variability in stomatal conductance, which was confirmed by the dual isotope approach. These leaf-level effects were not reflected in stem growth as they may have been masked by the temperature-caused growth limitation controlling the allocation of increased amounts of photosynthates into wood growth. Our approach demonstrates that the identification of different roles of environmental factors on leaf and stem processes helps to improve the assessment of site-specific changes of carbon fluxes and growth performance under future environmental conditions.
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Affiliation(s)
- Rosemarie B Weigt
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Kathrin Streit
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Matthias Saurer
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
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43
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Kardiman R, Ræbild A. Relationship between stomatal density, size and speed of opening in Sumatran rainforest species. TREE PHYSIOLOGY 2018; 38:696-705. [PMID: 29186586 DOI: 10.1093/treephys/tpx149] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 11/02/2017] [Indexed: 05/07/2023]
Abstract
Recent studies have suggested that an association between size and speed of stomatal opening of stomata within taxa is likely to play a role in photosynthesis and transpiration. In this study we investigate whether this correlation applies for seedlings of 11 rainforest species from different taxa, and whether differences in stomatal and gas exchange parameters were related to initial growth under field and controlled conditions. The experiment was conducted on seedlings of nine late successional species and two early successional species, placed in full sunlight or 70% shade. We assessed density, size, length and width of guard cells, coupled with gas exchange parameters in the transition from darkness to light, recording minimum stomatal conductance during daytime darkness (gs-dark), operating maximum stomatal conductance (gs-op), speed of stomatal opening and the time to reach 50% conductance (T-50%). All stomata and gas exchange parameters were different between species. Shade significantly affected size and density, and all gas exchange parameters except gs-op were different between light situations. Stomatal size correlated negatively with speed of opening and positively with T-50%, confirming that smaller stomata open faster than large stomata. The two early successional species were very different in stomatal size and density, and in response to light. Anatomic parameters and physiological traits were not related to height growth, but gs-dark, gs-op and speed of stomatal opening were associated with biomass growth in a subselection of six late successional species.
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Affiliation(s)
- Reki Kardiman
- Burung Indonesia, Jl. Dadali No. 32, PO Box 310/Boo, Bogor 16161, Indonesia
- Department of Biology, University of Andalas, Limau Manis, Padang 25163, Indonesia
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - Anders Ræbild
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
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Nackley LL, Midgley GF, Bösenberg JDW, Donaldson JS. A cycad's non-saturating response to carbon dioxide enrichment indicates Cenozoic carbon limitation in pre-historic plants. AUSTRAL ECOL 2018. [DOI: 10.1111/aec.12581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lloyd L. Nackley
- Kirstenbosch Research Center; South African National Biodiversity Institute; Cape Town South Africa
- Oregon State University; Corvallis Oregon USA
| | - Guy F. Midgley
- Department of Botany and Zoology; Stellenbosch University; Stellenbosch Private Bag X1 Matieland 7602 South Africa
| | - Jacques de Wet Bösenberg
- Kirstenbosch Research Center; South African National Biodiversity Institute; Cape Town South Africa
| | - John S. Donaldson
- Kirstenbosch Research Center; South African National Biodiversity Institute; Cape Town South Africa
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45
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Hare VJ, Loftus E, Jeffrey A, Ramsey CB. Atmospheric CO 2 effect on stable carbon isotope composition of terrestrial fossil archives. Nat Commun 2018; 9:252. [PMID: 29343713 PMCID: PMC5772509 DOI: 10.1038/s41467-017-02691-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 12/19/2017] [Indexed: 11/21/2022] Open
Abstract
The 13C/12C ratio of C3 plant matter is thought to be controlled by the isotopic composition of atmospheric CO2 and stomatal response to environmental conditions, particularly mean annual precipitation (MAP). The effect of CO2 concentration on 13C/12C ratios is currently debated, yet crucial to reconstructing ancient environments and quantifying the carbon cycle. Here we compare high-resolution ice core measurements of atmospheric CO2 with fossil plant and faunal isotope records. We show the effect of pCO2 during the last deglaciation is stronger for gymnosperms (-1.4 ± 1.2‰) than angiosperms/fauna (-0.5 ± 1.5‰), while the contributions from changing MAP are -0.3 ± 0.6‰ and -0.4 ± 0.4‰, respectively. Previous studies have assumed that plant 13C/12C ratios are mostly determined by MAP, an assumption which is sometimes incorrect in geological time. Atmospheric effects must be taken into account when interpreting terrestrial stable carbon isotopes, with important implications for past environments and climates, and understanding plant responses to climate change.
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Affiliation(s)
- Vincent J Hare
- Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, 1 South Parks Road, Oxford, OX1 3TG, UK.
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, 14627, USA.
| | - Emma Loftus
- Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, 1 South Parks Road, Oxford, OX1 3TG, UK
- Merton College, University of Oxford, Merton Street, Oxford, OX1 4JD, UK
| | - Amy Jeffrey
- Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, 1 South Parks Road, Oxford, OX1 3TG, UK
| | - Christopher Bronk Ramsey
- Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, 1 South Parks Road, Oxford, OX1 3TG, UK
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Brienen RJW, Gloor E, Clerici S, Newton R, Arppe L, Boom A, Bottrell S, Callaghan M, Heaton T, Helama S, Helle G, Leng MJ, Mielikäinen K, Oinonen M, Timonen M. Tree height strongly affects estimates of water-use efficiency responses to climate and CO 2 using isotopes. Nat Commun 2017; 8:288. [PMID: 28819277 PMCID: PMC5561090 DOI: 10.1038/s41467-017-00225-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 06/09/2017] [Indexed: 11/29/2022] Open
Abstract
Various studies report substantial increases in intrinsic water-use efficiency (W i ), estimated using carbon isotopes in tree rings, suggesting trees are gaining increasingly more carbon per unit water lost due to increases in atmospheric CO2. Usually, reconstructions do not, however, correct for the effect of intrinsic developmental changes in W i as trees grow larger. Here we show, by comparing W i across varying tree sizes at one CO2 level, that ignoring such developmental effects can severely affect inferences of trees' W i . W i doubled or even tripled over a trees' lifespan in three broadleaf species due to changes in tree height and light availability alone, and there are also weak trends for Pine trees. Developmental trends in broadleaf species are as large as the trends previously assigned to CO2 and climate. Credible future tree ring isotope studies require explicit accounting for species-specific developmental effects before CO2 and climate effects are inferred.Intrinsic water-use efficiency (W i ) reconstructions using tree rings often disregard developmental changes in W i as trees age. Here, the authors compare W i across varying tree sizes at a fixed CO2 level and show that ignoring developmental changes impacts conclusions on trees' W i responses to CO2 or climate.
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Affiliation(s)
- R J W Brienen
- School of Geography, University of Leeds, Leeds, LS6 9JT, UK.
| | - E Gloor
- School of Geography, University of Leeds, Leeds, LS6 9JT, UK
| | - S Clerici
- School of Geography, University of Leeds, Leeds, LS6 9JT, UK
| | - R Newton
- School of Earth and Environment, University of Leeds, Leeds, LS6 9JT, UK
| | - L Arppe
- Laboratory of Chronology, Finnish Museum of Natural History-Luomus, University of Helsinki, PO Box 64, 00014, Helsinki, Finland
| | - A Boom
- School of Geography, University of Leicester, Leicester, LE1 7RH, UK
| | - S Bottrell
- School of Earth and Environment, University of Leeds, Leeds, LS6 9JT, UK
| | - M Callaghan
- School of Geography, University of Leeds, Leeds, LS6 9JT, UK
| | - T Heaton
- NERC Isotope Geosciences Facilities, British Geological Survey, Nottingham, NG12 5GG, UK
| | - S Helama
- Natural Resources Institute Finland, Eteläranta 55, PO Box 16, 96301, Rovaniemi, Finland
| | - G Helle
- GFZ - German Research Centre for Geosciences, Section 5.2 Climate Dynamics and Landscape Evolution, Telegrafenberg, 14473, Potsdam, Germany
| | - M J Leng
- NERC Isotope Geosciences Facilities, British Geological Survey, Nottingham, NG12 5GG, UK
- Centre for Environmental Geochemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - K Mielikäinen
- Natural Resources Institute Finland, Jokiniemenkuja 1, PO Box 18, Vantaa, 01301, Finland
| | - M Oinonen
- Laboratory of Chronology, Finnish Museum of Natural History-Luomus, University of Helsinki, PO Box 64, 00014, Helsinki, Finland
| | - M Timonen
- Natural Resources Institute Finland, Eteläranta 55, PO Box 16, 96301, Rovaniemi, Finland
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Domec JC, Smith DD, McCulloh KA. A synthesis of the effects of atmospheric carbon dioxide enrichment on plant hydraulics: implications for whole-plant water use efficiency and resistance to drought. PLANT, CELL & ENVIRONMENT 2017; 40:921-937. [PMID: 27739596 DOI: 10.1111/pce.12843] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/18/2016] [Accepted: 09/21/2016] [Indexed: 06/06/2023]
Abstract
Here, we summarize studies on the effects of elevated [CO2 ] (CO2e ) on the structure and function of plant hydraulic architecture and explore the implications of those changes using a model. Changes in conduit diameter and hydraulic conductance due to CO2e vary among species. Ring-porous species tend towards an increase in conduit size and consequently conductivity. The effect in diffuse-porous species is much more limited. In conifers, the results are mixed, some species show minor changes in xylem structure, while other studies found increases in tracheid density and diameter. Non-woody plants generally exhibited the reverse pattern with narrower conduits and lower hydraulic conductivity under CO2e . Further, changes in drought-resistance traits suggest that non-woody plants were the most affected by CO2e , which may permit them to better resist drought-induced embolism under future conditions. Due to their complexity, acclimation in hydraulic traits in response to CO2e is difficult to interpret when relying solely on measurements. When we examined how the observed tissues-specific trends might alter plant function, our modelling results suggest that these hydraulic changes would lead to reduced conductance and more frequent drought stress in trees that develop under CO2e with a more pronounced effect in isohydric than in anisohydric species.
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Affiliation(s)
- Jean-Christophe Domec
- Bordeaux Sciences Agro, UMR 1391 INRA-ISPA, 33175, Gradignan Cedex, France
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708, USA
| | - Duncan D Smith
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Kate A McCulloh
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
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48
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Levesque M, Andreu-Hayles L, Pederson N. Water availability drives gas exchange and growth of trees in northeastern US, not elevated CO 2 and reduced acid deposition. Sci Rep 2017; 7:46158. [PMID: 28393872 PMCID: PMC5385545 DOI: 10.1038/srep46158] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/10/2017] [Indexed: 11/11/2022] Open
Abstract
Dynamic global vegetation models (DGVM) exhibit high uncertainty about how climate change, elevated atmospheric CO2 (atm. CO2) concentration, and atmospheric pollutants will impact carbon sequestration in forested ecosystems. Although the individual roles of these environmental factors on tree growth are understood, analyses examining their simultaneous effects are lacking. We used tree-ring isotopic data and structural equation modeling to examine the concurrent and interacting effects of water availability, atm. CO2 concentration, and SO4 and nitrogen deposition on two broadleaf tree species in a temperate mesic forest in the northeastern US. Water availability was the strongest driver of gas exchange and tree growth. Wetter conditions since the 1980s have enhanced stomatal conductance, photosynthetic assimilation rates and, to a lesser extent, tree radial growth. Increased water availability seemingly overrides responses to reduced acid deposition, CO2 fertilization, and nitrogen deposition. Our results indicate that water availability as a driver of ecosystem productivity in mesic temperate forests is not adequately represented in DGVMs, while CO2 fertilization is likely overrepresented. This study emphasizes the importance to simultaneously consider interacting climatic and biogeochemical drivers when assessing forest responses to global environmental changes.
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Affiliation(s)
- Mathieu Levesque
- Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Laia Andreu-Hayles
- Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Neil Pederson
- Harvard Forest, Harvard University, Petersham, MA 01366, USA
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49
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Voelker SL, Stambaugh MC, Renée Brooks J, Meinzer FC, Lachenbruch B, Guyette RP. Evidence that higher [CO 2] increases tree growth sensitivity to temperature: a comparison of modern and paleo oaks. Oecologia 2017; 183:1183-1195. [PMID: 28220301 DOI: 10.1007/s00442-017-3831-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 01/29/2017] [Indexed: 12/13/2022]
Abstract
To test tree growth sensitivity to temperature under different ambient CO2 concentrations, we determined stem radial growth rates as they relate to variation in temperature during the last deglacial period, and compare these to modern tree growth rates as they relate to spatial variation in temperature across the modern species distributional range. Paleo oaks were sampled from Northern Missouri, USA and compared to a pollen-based, high-resolution paleo temperature reconstruction from Northern Illinois, USA. Growth data were from 53 paleo bur oak log cross sections collected in Missouri. These oaks were preserved in river and stream sediments and were radiocarbon-dated to a period of rapid climate change during the last deglaciation (10.5 and 13.3 cal kyr BP). Growth data from modern bur oaks were obtained from increment core collections paired with USDA Forest Service Forest Inventory and Analysis data collected across the Great Plains, Midwest, and Upper Great Lakes regions. For modern oaks growing at an average [CO2] of 330 ppm, growth sensitivity to temperature (i.e., the slope of growth rate versus temperature) was about twice that of paleo oaks growing at an average [CO2] of 230 ppm. These data help to confirm that leaf-level predictions that photosynthesis and thus growth will be more sensitive to temperature at higher [CO2] in mature trees-suggesting that tree growth forest productivity will be increasingly sensitive to temperature under projected global warming and high-[CO2] conditions.
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Affiliation(s)
- Steven L Voelker
- Department of Plants, Soils and Climate, Utah State University, Logan, UT, 84322, USA.
| | - Michael C Stambaugh
- Department of Forestry, University of Missouri, 203ABNR Building, Columbia, MO, 65211, USA
| | - J Renée Brooks
- National Health and Environmental Effects Research Laboratory (NHEERL), Western Ecology Division, U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR, 97333, USA
| | - Frederick C Meinzer
- Pacific Northwest Research Station, U.S.D.A. Forest Service, 3200 Jefferson Way, Corvallis, OR, 97330, USA
| | - Barbara Lachenbruch
- Department of Forest Ecosystems, Society, Oregon State University, Corvallis, OR, 97330, USA
| | - Richard P Guyette
- Department of Forestry, University of Missouri, 203ABNR Building, Columbia, MO, 65211, USA
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50
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Drake BL, Hanson DT, Lowrey TK, Sharp ZD. The carbon fertilization effect over a century of anthropogenic CO 2 emissions: higher intracellular CO 2 and more drought resistance among invasive and native grass species contrasts with increased water use efficiency for woody plants in the US Southwest. GLOBAL CHANGE BIOLOGY 2017; 23:782-792. [PMID: 27483457 DOI: 10.1111/gcb.13449] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/13/2016] [Accepted: 07/15/2016] [Indexed: 05/22/2023]
Abstract
From 1890 to 2015, anthropogenic carbon dioxide emissions have increased atmospheric CO2 concentrations from 270 to 400 mol mol-1 . The effect of increased carbon emissions on plant growth and reproduction has been the subject of study of free-air CO2 enrichment (FACE) experiments. These experiments have found (i) an increase in internal CO2 partial pressure (ci ) alongside acclimation of photosynthetic capacity, (ii) variable decreases in stomatal conductance, and (iii) that increases in yield do not increase commensurate with CO2 concentrations. Our data set, which includes a 115-year-long selection of grasses collected in New Mexico since 1892, is consistent with an increased ci as a response to historical CO2 increase in the atmosphere, with invasive species showing the largest increase. Comparison with Palmer Drought Sensitivity Index (PDSI) for New Mexico indicates a moderate correlation with Δ13 C (r2 = 0.32, P < 0.01) before 1950, with no correlation (r2 = 0.00, P = 0.91) after 1950. These results indicate that increased ci may have conferred some drought resistance to these grasses through increased availability of CO2 in the event of reduced stomatal conductance in response to short-term water shortage. Comparison with C3 trees from arid environments (Pinus longaeva and Pinus edulis in the US Southwest) as well as from wetter environments (Bromus and Poa grasses in New Mexico) suggests differing responses based on environment; arid environments in New Mexico see increased intrinsic water use efficiency (WUE) in response to historic elevated CO2 while wetter environments see increased ci . This study suggests that (i) the observed increases in ci in FACE experiments are consistent with historical CO2 increases and (ii) the CO2 increase influences plant sensitivity to water shortage, through either increased WUE or ci in arid and wet environments, respectively.
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Affiliation(s)
- Brandon L Drake
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
| | - David T Hanson
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Timothy K Lowrey
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Zachary D Sharp
- Department of Earth Sciences, University of New Mexico, Albuquerque, NM 87131, USA
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