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Wang K, Xie G, Wang D, Wang Z, Li Z, Wu L, Zhang Y, Yang D, Sun X. Heat transfer processes in 'Shine Muscat' grapevine leaves in solar greenhouses under different irrigation treatments. Heliyon 2024; 10:e35105. [PMID: 39170329 PMCID: PMC11336416 DOI: 10.1016/j.heliyon.2024.e35105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 07/21/2024] [Accepted: 07/23/2024] [Indexed: 08/23/2024] Open
Abstract
The use of solar greenhouses in China is increasing because they permit environmental conditions to be controlled. Studies of the heat transfer processes in the leaves of plants cultivated within solar greenhouses are needed. Here, we studied heat transfer processes in 'Shine Muscat' grapevine leaves under moderate deficit irrigation (MDI), severe deficit irrigation (SDI), and full irrigation (FI) treatments under varying weather conditions. The stomatal conductance, leaf temperature, and transpiration rate of both shade and sun grapevine leaves were measured, and the effects of ambient temperature and relative humidity on these variables were determined. A thermal physics model of the leaves was established to explore the heat dissipation process. On sunny days, the transpiration heat transfer of sun leaves in the MDI, SDI, and FI treatments was 2.62 MJ m-2·day-1, 2.44 MJ m-2·day-1, and 3.86 MJ m-2·day-1and 0.818 MJ m-2·day-1, 0.782 MJ m-2·day-1, and 1.185 MJ m-2·day-1 on rainy days, respectively. There was a significant difference in transpiration heat transfer under fully irrigated and deficit irrigation conditions under different weather conditions. Furthermore, transpiration heat transfer accounted for 41.49 % and 25.03 % of the total heat transfer of sun leaves in the FI treatment and 33.94 % and 29.43 % of the total heat transfer of shade leaves on rainy days, respectively, indicating that relative humidity plays a key role in determining transpiration heat transfer and leaf temperature and that its effect was greater on sun leaves than on shade leaves.
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Affiliation(s)
- Kaiwen Wang
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Guangyue Xie
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Da Wang
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Ziteng Wang
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Ziyan Li
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Letian Wu
- Agricultural Machanization Institute, Xinjiang Academy of Agricultural Sciences, China
| | - Yingtao Zhang
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Danting Yang
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
| | - Xianpeng Sun
- College of Horticulture, North West Agriculture and Forestry University, Yang Ling, 712100, Shaanxi Province, China
- Key Laboratory of Horticultural Engineering in Northwest Facilities, Ministry of Agriculture, Yang Ling, 712100, Shaanxi Province, China
- Facility Agriculture Engineering Technology Research Center of Shaanxi Province, Yang Ling, 712100, Shaanxi Province, China
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2
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Gauthey A, Kahmen A, Limousin JM, Vilagrosa A, Didion-Gency M, Mas E, Milano A, Tunas A, Grossiord C. High heat tolerance, evaporative cooling, and stomatal decoupling regulate canopy temperature and their safety margins in three European oak species. GLOBAL CHANGE BIOLOGY 2024; 30:e17439. [PMID: 39092538 DOI: 10.1111/gcb.17439] [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: 02/15/2024] [Revised: 06/03/2024] [Accepted: 07/08/2024] [Indexed: 08/04/2024]
Abstract
Heatwaves and soil droughts are increasing in frequency and intensity, leading many tree species to exceed their thermal thresholds, and driving wide-scale forest mortality. Therefore, investigating heat tolerance and canopy temperature regulation mechanisms is essential to understanding and predicting tree vulnerability to hot droughts. We measured the diurnal and seasonal variation in leaf water potential (Ψ), gas exchange (photosynthesis Anet and stomatal conductance gs), canopy temperature (Tcan), and heat tolerance (leaf critical temperature Tcrit and thermal safety margins TSM, i.e., the difference between maximum Tcan and Tcrit) in three oak species in forests along a latitudinal gradient (Quercus petraea in Switzerland, Quercus ilex in France, and Quercus coccifera in Spain) throughout the growing season. Gas exchange and Ψ of all species were strongly reduced by increased air temperature (Tair) and soil drying, resulting in stomatal closure and inhibition of photosynthesis in Q. ilex and Q. coccifera when Tair surpassed 30°C and soil moisture dropped below 14%. Across all seasons, Tcan was mainly above Tair but increased strongly (up to 10°C > Tair) when Anet was null or negative. Although trees endured extreme Tair (up to 42°C), positive TSM were maintained during the growing season due to high Tcrit in all species (average Tcrit of 54.7°C) and possibly stomatal decoupling (i.e., Anet ≤0 while gs >0). Indeed, Q. ilex and Q. coccifera trees maintained low but positive gs (despite null Anet), decreasing Ψ passed embolism thresholds. This may have prevented Tcan from rising above Tcrit during extreme heat. Overall, our work highlighted that the mechanisms behind heat tolerance and leaf temperature regulation in oak trees include a combination of high evaporative cooling, large heat tolerance limits, and stomatal decoupling. These processes must be considered to accurately predict plant damages, survival, and mortality during extreme heatwaves.
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Affiliation(s)
- Alice Gauthey
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK
| | - Ansgar Kahmen
- Physiological Plant Ecology, Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Jean-Marc Limousin
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, EPHE, IRD, Université de Montpellier, Montpellier, France
| | - Alberto Vilagrosa
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department Ecology, University of Alicante, Alicante, Spain
| | - Margaux Didion-Gency
- Forest Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, Birmensdorf, Switzerland
| | - Eugénie Mas
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Washington, District of Columbia, USA
| | - Arianna Milano
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Alex Tunas
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
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3
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Tian R, Li J, Zheng J, Liu L, Han W, Liu Y. The impact of compound drought and heatwave events from 1982 to 2022 on the phenology of Central Asian grasslands. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121624. [PMID: 38968888 DOI: 10.1016/j.jenvman.2024.121624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/06/2024] [Accepted: 06/25/2024] [Indexed: 07/07/2024]
Abstract
In the context of global warming, the occurrence and severity of extreme events like atmospheric drought (AD) and warm spell duration index (WSDI) have increased, causing significant impacts on terrestrial ecosystems in Central Asia's arid regions. Previous research has focused on single extreme events such as AD and WSDI, but the effect of compound hot and dry events (CHWE) on grassland phenology in the arid regions of Central Asia remains unclear. This study utilized structural equation modeling (SEM) and the Pettitt breakpoint test to quantify the direct and indirect responses of grassland phenology (start of season - SOS, length of season - LOS, and end of season - EOS) to AD, WSDI, and CHWE. Furthermore, this research investigated the threshold of grassland phenology response to compound hot and dry events. The research findings indicate a significant increasing trend in AD, WSDI, and CHWE in the arid regions of Central Asia from 1982 to 2022 (0.51 day/year, P < 0.01; 0.25 day/year, P < 0.01; 0.26 day/year, P < 0.01). SOS in the arid regions of Central Asia showed a significant advancement trend, while EOS exhibited a significant advance. LOS demonstrated an increasing trend (-0.23 day/year, P < 0.01; -0.12 day/year, P < 0.01; 0.56 day/year). The temperature primarily governs the variation in SOS. While higher temperatures promote an earlier SOS, they also offset the delaying effect of CHWE on SOS. AD, temperature, and CHWE have negative impacts on EOS, whereas WSDI has a positive effect on EOS. AD exhibits the strongest negative effect on EOS, with an increase in AD leading to an earlier EOS. Temperature and WSDI are positively correlated with LOS, indicating that higher temperatures and increased WSDI contribute to a longer LOS. The threshold values for the response of SOS, EOS, and LOS to CHWE are 16.14, 18.49, and 16.61 days, respectively. When CHWE exceeds these critical thresholds, there are significant changes in the response of SOS, EOS, and LOS to CHWE. These findings deepen our understanding of the mechanisms by which extreme climate events influence grassland phenology dynamics in Central Asia. They can contribute to better protection and management of grassland ecosystems and help in addressing the impacts of global warming and climate change in practice.
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Affiliation(s)
- Ruikang Tian
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, 830046, China
| | - Jianhao Li
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, 830046, China
| | - Jianghua Zheng
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, 830046, China; Xinjiang Oasis Ecology Key Laboratory, Urumqi, 830046, China.
| | - Liang Liu
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, 830046, China
| | - Wanqiang Han
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, 830046, China
| | - Yujia Liu
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, 830046, China
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Andrew SC, Simonsen AK, Coppin CW, Arnold PA, Briceño VF, McLay TGB, Jackson CJ, Gallagher RV, Mokany K. Expression-environment associations in transcriptomic heat stress responses for a global plant lineage. Mol Ecol 2024; 33:e17473. [PMID: 39034607 DOI: 10.1111/mec.17473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 07/08/2024] [Indexed: 07/23/2024]
Abstract
The increasing frequency and severity of heatwaves will intensify stress on plants. Given regional variation in heatwave exposure and expected differences in thermal tolerance between species it is unlikely that all plant species will be affected equally by climate change. However, little is currently known about variation in the responses of plants to heat stress, or how those responses differ among closely related species adapted to different environments. Here we quantify the response of 17 Acacia species (175 RNA-seq libraries), from across Australia's diverse biomes, to a multi-day experimental heatwave treatment to identify variation in transcriptomic and physiological responses to heat stress. Genes with known heat response functions showed consistent responses across Acacia species. Up to 10% of all genes and over 100 gene families showed significant clinal variation in the magnitude of their expression plasticity across species. Specifically, gene families linked to the temperature stress response were overrepresented among significant relationships with home range temperature conditions. Gene expression responses seen on the first day of the heatwave were more frequently associated with home range climates, while expression responses by day four were more commonly related to photosystem II acclimation. Comparative transcriptomics on non-model species has the potential to provide key information on stress response plasticity, especially when linked with our understanding of model species. Our study indicates that the pressing challenge to identifying potentially vulnerable species to climate change could be benefited by the further exploration of clinal variation in transcriptome plasticity.
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Affiliation(s)
- Samuel C Andrew
- Commonwealth Scientific and Industrial Research Organisation, Canberra, Australian Capital Territory, Australia
| | - Anna K Simonsen
- Department of Biological Sciences, Florida International University, Miami, Florida, USA
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Chris W Coppin
- Commonwealth Scientific and Industrial Research Organisation, Canberra, Australian Capital Territory, Australia
| | - Pieter A Arnold
- Division of Ecology & Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Verónica F Briceño
- Division of Ecology & Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Todd G B McLay
- Commonwealth Scientific and Industrial Research Organisation, Canberra, Australian Capital Territory, Australia
- Royal Botanic Gardens Victoria, Melbourne, Victoria, Australia
| | - Chris J Jackson
- Royal Botanic Gardens Victoria, Melbourne, Victoria, Australia
| | - Rachael V Gallagher
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Karel Mokany
- Commonwealth Scientific and Industrial Research Organisation, Canberra, Australian Capital Territory, Australia
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5
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Ziegler C, Cochard H, Stahl C, Foltzer L, Gérard B, Goret JY, Heuret P, Levionnois S, Maillard P, Bonal D, Coste S. Residual water losses mediate the trade-off between growth and drought survival across saplings of 12 tropical rainforest tree species with contrasting hydraulic strategies. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4128-4147. [PMID: 38613495 DOI: 10.1093/jxb/erae159] [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: 07/31/2023] [Accepted: 04/12/2024] [Indexed: 04/15/2024]
Abstract
Knowledge of the physiological mechanisms underlying species vulnerability to drought is critical for better understanding patterns of tree mortality. Investigating plant adaptive strategies to drought should thus help to fill this knowledge gap, especially in tropical rainforests exhibiting high functional diversity. In a semi-controlled drought experiment using 12 rainforest tree species, we investigated the diversity in hydraulic strategies and whether they determined the ability of saplings to use stored non-structural carbohydrates during an extreme imposed drought. We further explored the importance of water- and carbon-use strategies in relation to drought survival through a modelling approach. Hydraulic strategies varied considerably across species with a continuum between dehydration tolerance and avoidance. During dehydration leading to hydraulic failure and irrespective of hydraulic strategies, species showed strong declines in whole-plant starch concentrations and maintenance, or even increases in soluble sugar concentrations, potentially favouring osmotic adjustments. Residual water losses mediated the trade-off between time to hydraulic failure and growth, indicating that dehydration avoidance is an effective drought-survival strategy linked to the 'fast-slow' continuum of plant performance at the sapling stage. Further investigations on residual water losses may be key to understanding the response of tropical rainforest tree communities to climate change.
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Affiliation(s)
- Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Louis Foltzer
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Bastien Gérard
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Jean-Yves Goret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Pascale Maillard
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Damien Bonal
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
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6
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Middleby KB, Cheesman AW, Cernusak LA. Impacts of elevated temperature and vapour pressure deficit on leaf gas exchange and plant growth across six tropical rainforest tree species. THE NEW PHYTOLOGIST 2024; 243:648-661. [PMID: 38757766 DOI: 10.1111/nph.19822] [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: 12/16/2023] [Accepted: 04/30/2024] [Indexed: 05/18/2024]
Abstract
Elevated air temperature (Tair) and vapour pressure deficit (VPDair) significantly influence plant functioning, yet their relative impacts are difficult to disentangle. We examined the effects of elevated Tair (+6°C) and VPDair (+0.7 kPa) on the growth and physiology of six tropical tree species. Saplings were grown under well-watered conditions in climate-controlled glasshouses for 6 months under three treatments: (1) low Tair and low VPDair, (2) high Tair and low VPDair, and (3) high Tair and high VPDair. To assess acclimation, physiological parameters were measured at a set temperature. Warm-grown plants grown under elevated VPDair had significantly reduced stomatal conductance and increased instantaneous water use efficiency compared to plants grown under low VPDair. Photosynthetic biochemistry and thermal tolerance (Tcrit) were unaffected by VPDair, but elevated Tair caused Jmax25 to decrease and Tcrit to increase. Sapling biomass accumulation for all species responded positively to an increase in Tair, but elevated VPDair limited growth. This study shows that stomatal limitation caused by even moderate increases in VPDair can decrease productivity and growth rates in tropical species independently from Tair and has important implications for modelling the impacts of climate change on tropical forests.
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Affiliation(s)
- Kali B Middleby
- College of Science and Engineering, James Cook University, Cairns, QLD, 4878, Australia
| | - Alexander W Cheesman
- College of Science and Engineering, James Cook University, Cairns, QLD, 4878, Australia
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, QLD, 4878, Australia
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7
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Finocchiaro M, Médail F, Saatkamp A, Diadema K, Pavon D, Brousset L, Meineri E. Microrefugia and microclimate: Unraveling decoupling potential and resistance to heatwaves. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171696. [PMID: 38485012 DOI: 10.1016/j.scitotenv.2024.171696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/11/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Microrefugia, defined as small areas maintaining populations of species outside their range margins during environmental extremes, are increasingly recognized for their role in conserving species in the face of climate change. Understanding their microclimatic dynamics becomes crucial with global warming leading to severe temperature and precipitation changes. This study investigates the phenomenon of short-term climatic decoupling within microrefugia and its implications for plant persistence in the Mediterranean region of southeastern France. We focus on microrefugia's ability to climatically disconnect from macroclimatic trends, examining temperature and Vapor Pressure Deficit (VPD) dynamics in microrefugia, adjacent control plots, and weather stations. Our study encompasses both "normal" conditions and heatwave episodes to explore the role of microrefugia as thermal and moisture insulators during extreme events. Landscape attributes such as relative elevation, solar radiation, distance to streams, and vegetation height are investigated for their contribution to short-term decoupling. Our results demonstrate that microrefugia exhibit notable decoupling from macroclimatic trends. This effect is maintained during heatwaves, underscoring microrefugia's vital role in responding to climatic extremes. Importantly, microrefugia maintain lower VPD levels than their surroundings outside and during heatwaves, potentially mitigating water stress for plants. This study advances our understanding of microclimate dynamics within microrefugia and underscores their ecological importance for plant persistence in a changing climate. As heatwaves become more frequent and severe, our findings provide insights into the role of microrefugia in buffering but also decoupling against extreme climatic events and, more generally, against climate warming. This knowledge emphasizes the need to detect and protect existing microrefugia, as they can be integrated into conservation strategies and climate change adaptation plans.
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Affiliation(s)
- Marie Finocchiaro
- Aix Marseille Université, Université Avignon, CNRS, IRD, UMR IMBE, Marseille, France.
| | - Frédéric Médail
- Aix Marseille Université, Université Avignon, CNRS, IRD, UMR IMBE, Marseille, France
| | - Arne Saatkamp
- Aix Marseille Université, Université Avignon, CNRS, IRD, UMR IMBE, Marseille, France
| | - Katia Diadema
- Conservatoire botanique national méditerranéen, 34 avenue Gambetta, F-83400 Hyères, France
| | - Daniel Pavon
- Aix Marseille Université, Université Avignon, CNRS, IRD, UMR IMBE, Marseille, France
| | - Lenka Brousset
- Aix Marseille Université, Université Avignon, CNRS, IRD, UMR IMBE, Marseille, France
| | - Eric Meineri
- Aix Marseille Université, Université Avignon, CNRS, IRD, UMR IMBE, Marseille, France
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8
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Sun W, Maseyk K, Lett C, Seibt U. Restricted internal diffusion weakens transpiration-photosynthesis coupling during heatwaves: Evidence from leaf carbonyl sulphide exchange. PLANT, CELL & ENVIRONMENT 2024; 47:1813-1833. [PMID: 38321806 DOI: 10.1111/pce.14840] [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: 04/19/2023] [Revised: 11/13/2023] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
Increasingly frequent and intense heatwaves threaten ecosystem health in a warming climate. However, plant responses to heatwaves are poorly understood. A key uncertainty concerns the intensification of transpiration when heatwaves suppress photosynthesis, known as transpiration-photosynthesis decoupling. Field observations of such decoupling are scarce, and the underlying physiological mechanisms remain elusive. Here, we use carbonyl sulphide (COS) as a leaf gas exchange tracer to examine potential mechanisms leading to transpiration-photosynthesis decoupling on a coast live oak in a southern California woodland in spring 2013. We found that heatwaves suppressed both photosynthesis and leaf COS uptake but increased transpiration or sustained it at non-heatwave levels throughout the day. Despite statistically significant decoupling between transpiration and photosynthesis, stomatal sensitivity to environmental factors did not change during heatwaves. Instead, midday photosynthesis during heatwaves was restricted by internal diffusion, as indicated by the lower internal conductance to COS. Thus, increased evaporative demand and nonstomatal limitation to photosynthesis act jointly to decouple transpiration from photosynthesis without altering stomatal sensitivity. Decoupling offered limited potential cooling benefits, questioning its effectiveness for leaf thermoregulation in xeric ecosystems. We suggest that adding COS to leaf and ecosystem flux measurements helps elucidate diverse physiological mechanisms underlying transpiration-photosynthesis decoupling.
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Affiliation(s)
- Wu Sun
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
| | - Kadmiel Maseyk
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Céline Lett
- Department of Environmental Research and Innovation, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg
| | - Ulli Seibt
- Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA
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9
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Araújo KC, Souza BC, Carvalho ECD, Freire RS, Teixeira AS, Muniz CR, Martins FR, Oliveira RS, Eller CB, Soares AA. The multiple roles of trichomes in two Croton species. PLANT, CELL & ENVIRONMENT 2024; 47:1685-1700. [PMID: 38282477 DOI: 10.1111/pce.14829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/30/2024]
Abstract
Trichomes are common in plants from dry environments, and despite their recognized role in protection and defense, little is known about their role as absorptive structures and in other aspects of leaf ecophysiology. We combine anatomical and ecophysiological data to evaluate how trichomes affect leaf gas exchange and water balance during drought. We studied two congeneric species with pubescent leaves which co-occur in Brazilian Caatinga: Croton blanchetianus (dense trichomes) and Croton adenocalyx (sparse trichomes). We found a novel foliar water uptake (FWU) pathway in C. blanchetianus composed of stellate trichomes and underlying epidermal cells and sclereids that interconnect the trichomes from both leaf surfaces. The water absorbed by these trichomes is redistributed laterally by pectin protuberances on mesophyll cell walls. This mechanism enables C. blanchetianus leaves to absorb water more efficiently than C. adenocalyx. Consequently, the exposure of C. blanchetianus to dew during drought improved its leaf gas exchange and water status more than C. adenocalyx. C. blanchetianus trichomes also increase their leaf capacity to reflect light and maintain lower temperatures during drought. Our results emphasize the multiple roles that trichomes might have on plant functioning and the importance of FWU for the ecophysiology of Caatinga plants during drought.
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Affiliation(s)
- Karina Crisóstomo Araújo
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Bruno Cruz Souza
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Ellen Cristina Dantas Carvalho
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Rosemeyre Souza Freire
- Centro de Ciências, Central Analítica, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Adunias Santos Teixeira
- Departament of Agricultural Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | - Fernando Roberto Martins
- Department of Plant Biology, Institute of Biology, CP6109, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Rafael Silva Oliveira
- Department of Plant Biology, Institute of Biology, CP6109, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Cleiton Breder Eller
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Arlete Aparecida Soares
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
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10
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Ač A, Jansen MAK, Grace J, Urban O. Unravelling the neglected role of ultraviolet radiation on stomata: A meta-analysis with implications for modelling ecosystem-climate interactions. PLANT, CELL & ENVIRONMENT 2024; 47:1769-1781. [PMID: 38314642 DOI: 10.1111/pce.14841] [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: 11/03/2023] [Revised: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 02/06/2024]
Abstract
Stomata play a pivotal role in regulating gas exchange between plants and the atmosphere controlling water and carbon cycles. Accordingly, we investigated the impact of ultraviolet-B radiation, a neglected environmental factor varying with ongoing global change, on stomatal morphology and function by a Comprehensive Meta-Analysis. The overall UV effect at the leaf level is to decrease stomatal conductance, stomatal aperture and stomatal size, although stomatal density was increased. The significant decline in stomatal conductance is marked (6% in trees and >10% in grasses and herbs) in short-term experiments, with more modest decreases noted in long-term UV studies. Short-term experiments in growth chambers are not representative of long-term field UV effects on stomatal conductance. Important consequences of altered stomatal function are hypothesized. In the short term, UV-mediated stomatal closure may reduce carbon uptake but also water loss through transpiration, thereby alleviating deleterious effects of drought. However, in the long term, complex changes in stomatal aperture, size, and density may reduce the carbon sequestration capacity of plants and increase vegetation and land surface temperatures, potentially exacerbating negative effects of drought and/or heatwaves. Therefore, the expected future strength of carbon sink capacity in high-UV regions is likely overestimated.
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Affiliation(s)
- Alexander Ač
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
| | - Marcel A K Jansen
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
- School of Biological, Earth and Environmental Sciences, Environmental Research Institute, UCC, Cork, Ireland
| | - John Grace
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Otmar Urban
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
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11
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Coupel-Ledru A, Westgeest AJ, Albasha R, Millan M, Pallas B, Doligez A, Flutre T, Segura V, This P, Torregrosa L, Simonneau T, Pantin F. Clusters of grapevine genes for a burning world. THE NEW PHYTOLOGIST 2024; 242:10-18. [PMID: 38320579 DOI: 10.1111/nph.19540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/21/2023] [Indexed: 02/08/2024]
Affiliation(s)
| | | | - Rami Albasha
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
- ITK, 45 Allée Yves Stourdze, F-34830, Clapiers, France
| | - Mathilde Millan
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
| | - Benoît Pallas
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
| | - Agnès Doligez
- AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
- UMT Geno-Vigne®, IFV-INRAE-Institut Agro, F-34398, Montpellier, France
| | - Timothée Flutre
- AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
- UMT Geno-Vigne®, IFV-INRAE-Institut Agro, F-34398, Montpellier, France
- Université Paris-Saclay, INRAE, CNRS, AgroParisTech, GQE-Le Moulon, 91190, Gif-sur-Yvette, France
| | - Vincent Segura
- AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
- UMT Geno-Vigne®, IFV-INRAE-Institut Agro, F-34398, Montpellier, France
| | - Patrice This
- AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
- UMT Geno-Vigne®, IFV-INRAE-Institut Agro, F-34398, Montpellier, France
| | - Laurent Torregrosa
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
- AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
- UMT Geno-Vigne®, IFV-INRAE-Institut Agro, F-34398, Montpellier, France
| | | | - Florent Pantin
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000, Angers, France
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12
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Yao Y, Liu Y, Fu F, Song J, Wang Y, Han Y, Wu T, Fu B. Declined terrestrial ecosystem resilience. GLOBAL CHANGE BIOLOGY 2024; 30:e17291. [PMID: 38647225 DOI: 10.1111/gcb.17291] [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: 03/08/2024] [Accepted: 03/29/2024] [Indexed: 04/25/2024]
Abstract
Terrestrial ecosystem resilience is crucial for maintaining the structural and functional stability of ecosystems following disturbances. However, changes in resilience over the past few decades and the risk of future resilience loss under ongoing climate change are unclear. Here, we identified resilience trends using two remotely sensed vegetation indices, analyzed the relative importance of potential driving factors to resilience changes, and finally assessed the risk of future resilience loss based on the output data of eight models from CMIP6. The results revealed that more than 60% of the ecosystems experienced a conversion from an increased trend to a declined trend in resilience. Attribution analysis showed that the most important driving factors of declined resilience varied regionally. The declined trends in resilience were associated with increased precipitation variability in the tropics, decreased vegetation cover in arid region, increased temperature variability in temperate regions, and increased average temperature in cold regions. CMIP6 reveals that terrestrial ecosystems under SPP585 are expected to experience more intense declines in resilience than those under SSP126 and SSP245, particularly in cold regions. These results highlight the risk of continued degradation of ecosystem resilience in the future and the urgency of climate mitigation actions.
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Affiliation(s)
- Ying Yao
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yanxu Liu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Fengyu Fu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Jiaxi Song
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yijia Wang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yu Han
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Tianjing Wu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Bojie Fu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
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13
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Ning QR, Li Q, Zhang HP, Jin Y, Gong XW, Jiao RF, Bakpa EP, Zhao H, Liu H. Weak correlations among leaf thermal metrics, economic traits and damages under natural heatwaves. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170022. [PMID: 38220006 DOI: 10.1016/j.scitotenv.2024.170022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/29/2023] [Accepted: 01/07/2024] [Indexed: 01/16/2024]
Abstract
The frequency and intensity of heatwaves are increasing around the world, causing severe damages to plants, but whether leaf thermal metrics is in line with leaf economic spectrum is still controversial. Here, we measured leaf damage ratio, leaf thermal metrics (tolerance and sensitivity) and economic traits of 131 woody species across five cities along the Yangtze River after a two-month natural extreme temperature event. We found that leaf thermal sensitivity but not thermal tolerance was correlated with leaf damage ratio, and the relationships between leaf thermal metrics and economic traits were weak, indicating that leaf thermal adaptation may be independent from leaf carbon construction. This study suggests a potential indicator for predicting plant survival under heatwaves, urging future research to explore more physiological traits to comprehensively understand plant heat responses and adaptations.
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Affiliation(s)
- Qiu-Rui Ning
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Qiang Li
- School of Tropical Medicine, Hainan Medical University, Haikou, China
| | - Hao-Ping Zhang
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yi Jin
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, China
| | - Xue-Wei Gong
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Rui-Fang Jiao
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Emily Patience Bakpa
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Han Zhao
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Hui Liu
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
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14
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Cook AM, Rezende EL, Petrou K, Leigh A. Beyond a single temperature threshold: Applying a cumulative thermal stress framework to plant heat tolerance. Ecol Lett 2024; 27:e14416. [PMID: 38549256 DOI: 10.1111/ele.14416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 02/27/2024] [Indexed: 04/02/2024]
Abstract
Most plant thermal tolerance studies focus on single critical thresholds, which limit the capacity to generalise across studies and predict heat stress under natural conditions. In animals and microbes, thermal tolerance landscapes describe the more realistic, cumulative effects of temperature. We tested this in plants by measuring the decline in leaf photosynthetic efficiency (FV/FM) following a combination of temperatures and exposure times and then modelled these physiological indices alongside recorded environmental temperatures. We demonstrate that a general relationship between stressful temperatures and exposure durations can be effectively employed to quantify and compare heat tolerance within and across plant species and over time. Importantly, we show how FV/FM curves translate to plants under natural conditions, suggesting that environmental temperatures often impair photosynthetic function. Our findings provide more robust descriptors of heat tolerance in plants and suggest that heat tolerance in disparate groups of organisms can be studied with a single predictive framework.
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Affiliation(s)
- Alicia M Cook
- School of Life Sciences, University of Technology Sydney (UTS), Broadway, New South Wales, Australia
| | - Enrico L Rezende
- Departamento de Ecología, Center of Applied Ecology and Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney (UTS), Broadway, New South Wales, Australia
| | - Andy Leigh
- School of Life Sciences, University of Technology Sydney (UTS), Broadway, New South Wales, Australia
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15
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Diao H, Cernusak LA, Saurer M, Gessler A, Siegwolf RTW, Lehmann MM. Uncoupling of stomatal conductance and photosynthesis at high temperatures: mechanistic insights from online stable isotope techniques. THE NEW PHYTOLOGIST 2024; 241:2366-2378. [PMID: 38303410 DOI: 10.1111/nph.19558] [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: 11/20/2023] [Accepted: 01/12/2024] [Indexed: 02/03/2024]
Abstract
The strong covariation of temperature and vapour pressure deficit (VPD) in nature limits our understanding of the direct effects of temperature on leaf gas exchange. Stable isotopes in CO2 and H2 O vapour provide mechanistic insight into physiological and biochemical processes during leaf gas exchange. We conducted combined leaf gas exchange and online isotope discrimination measurements on four common European tree species across a leaf temperature range of 5-40°C, while maintaining a constant leaf-to-air VPD (0.8 kPa) without soil water limitation. Above the optimum temperature for photosynthesis (30°C) under the controlled environmental conditions, stomatal conductance (gs ) and net photosynthesis rate (An ) decoupled across all tested species, with gs increasing but An decreasing. During this decoupling, mesophyll conductance (cell wall, plasma membrane and chloroplast membrane conductance) consistently and significantly decreased among species; however, this reduction did not lead to reductions in CO2 concentration at the chloroplast surface and stroma. We question the conventional understanding that diffusional limitations of CO2 contribute to the reduction in photosynthesis at high temperatures. We suggest that stomata and mesophyll membranes could work strategically to facilitate transpiration cooling and CO2 supply, thus alleviating heat stress on leaf photosynthetic function, albeit at the cost of reduced water-use efficiency.
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Affiliation(s)
- Haoyu Diao
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Qld, 4879, Australia
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, 8092, Switzerland
| | - Rolf T W Siegwolf
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - Marco M Lehmann
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
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16
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Kullberg AT, Coombs L, Soria Ahuanari RD, Fortier RP, Feeley KJ. Leaf thermal safety margins decline at hotter temperatures in a natural warming 'experiment' in the Amazon. THE NEW PHYTOLOGIST 2024; 241:1447-1463. [PMID: 37984063 DOI: 10.1111/nph.19413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/28/2023] [Indexed: 11/22/2023]
Abstract
The threat of rising global temperatures may be especially pronounced for low-latitude, lowland plant species that have evolved under stable climatic conditions. However, little is known about how these species may acclimate to elevated temperatures. Here, we leveraged a strong, steep thermal gradient along a natural geothermal river to assess the ability of woody plants in the Amazon to acclimate to elevated air temperatures. We measured leaf traits in six common tropical woody species along the thermal gradient to investigate whether individuals of these species: acclimate their thermoregulatory traits to maintain stable leaf temperatures despite higher ambient temperatures; acclimate their photosynthetic thermal tolerances to withstand hotter leaf temperatures; and whether acclimation is sufficient to maintain stable leaf thermal safety margins (TSMs) across different growth temperatures. Individuals of three species acclimated their thermoregulatory traits, and three species increased their thermal tolerances with growth temperature. However, acclimation was generally insufficient to maintain constant TSMs. Notwithstanding, leaf health was generally consistent across growth temperatures. Acclimation in woody Amazonian plants is generally too weak to maintain TSMs at high growth temperatures, supporting previous findings that Amazonian plants will be increasingly vulnerable to thermal stress as temperatures rise.
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Affiliation(s)
- Alyssa T Kullberg
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Lauren Coombs
- Hussman Institute of Human Genomics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Roy D Soria Ahuanari
- Herbario Regional de Ucayali IVITA, Pucallpa (HRUIP), Universidad Nacional Mayor de San Marcos, Pucallpa, 25001, Peru
| | - Riley P Fortier
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Kenneth J Feeley
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
- Fairchild Tropical Botanic Garden, Coral Gables, FL, 33156, USA
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17
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O'Connell BP, Wiley E. Heatwaves do not limit recovery following defoliation but alter leaf drought tolerance traits. PLANT, CELL & ENVIRONMENT 2024; 47:482-496. [PMID: 37877185 DOI: 10.1111/pce.14750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/20/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
As heatwave frequency increases, they are more likely to coincide with other disturbances like insect defoliation. But it is unclear if high temperatures after defoliation impact canopy recovery or leaf traits which may affect response to further stressors like drought. To examine these stressor interactions, we subjected defoliated (DEF) and undefoliated (UNDEF) oak saplings to a simulated spring heatwave of +10°C for 25 days. We measured gas exchange, leaf area recovery, carbohydrate storage, turgor loss point (ΨTLP ), and minimum leaf conductance (gmin ). During the heatwave, stem respiration exhibited stronger thermal acclimation in DEF than UNDEF saplings, while stomatal conductance and net photosynthesis increased. The heatwave did not affect leaf area recovery or carbohydrate storage of DEF saplings, but reflush leaves had higher gmin than UNDEF leaves, and this was amplified by the heatwave. Across all treatments, higher gmin was associated with higher daytime stomatal conductance and a lower ΨTLP . The results suggest defoliation stress may not be exacerbated by higher temperatures. However, reflush leaves are less conservative in their water use, limiting their ability to minimise water loss. While lower ΨTLP could help DEF trees maintain gas exchange under mild drought, they may be more vulnerable to dehydration under severe drought.
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Affiliation(s)
| | - Erin Wiley
- Department of Biology, University of Central Arkansas, Conway, Arkansas, USA
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18
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Mas E, Cochard H, Deluigi J, Didion-Gency M, Martin-StPaul N, Morcillo L, Valladares F, Vilagrosa A, Grossiord C. Interactions between beech and oak seedlings can modify the effects of hotter droughts and the onset of hydraulic failure. THE NEW PHYTOLOGIST 2024; 241:1021-1034. [PMID: 37897156 DOI: 10.1111/nph.19358] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023]
Abstract
Mixing species with contrasting resource use strategies could reduce forest vulnerability to extreme events. Yet, how species diversity affects seedling hydraulic responses to heat and drought, including mortality risk, is largely unknown. Using open-top chambers, we assessed how, over several years, species interactions (monocultures vs mixtures) modulate heat and drought impacts on the hydraulic traits of juvenile European beech and pubescent oak. Using modeling, we estimated species interaction effects on timing to drought-induced mortality and the underlying mechanisms driving these impacts. We show that mixtures mitigate adverse heat and drought impacts for oak (less negative leaf water potential, higher stomatal conductance, and delayed stomatal closure) but enhance them for beech (lower water potential and stomatal conductance, narrower leaf safety margins, faster tree mortality). Potential underlying mechanisms include oak's larger canopy and higher transpiration, allowing for quicker exhaustion of soil water in mixtures. Our findings highlight that diversity has the potential to alter the effects of extreme events, which would ensure that some species persist even if others remain sensitive. Among the many processes driving diversity effects, differences in canopy size and transpiration associated with the stomatal regulation strategy seem the primary mechanisms driving mortality vulnerability in mixed seedling plantations.
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Affiliation(s)
- Eugénie Mas
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Janisse Deluigi
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Margaux Didion-Gency
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Nicolas Martin-StPaul
- Unité Ecologie des Forêts Méditerranéennes (UR629), INRAE, DomaineSaint Paul, Site Agroparc, 84914, Avignon Cedex 9, France
| | - Luna Morcillo
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, 03080, Alicante, Spain
| | - Fernando Valladares
- Depto de Biogeografía y Cambio Global, LINCGlobal, Museo Nacional de Ciencias Naturales (MNCN-CSIC), 28006, Madrid, Spain
- Área de Biodiversidad y Conservación, Univ. Rey Juan Carlos, Móstoles, 28933, Madrid, Spain
| | - Alberto Vilagrosa
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, 03080, Alicante, Spain
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
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19
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Duan X, Gu H, Lam SS, Sonne C, Lu W, Li H, Chen X, Peng W. Recent progress on phytoremediation of urban air pollution. CHEMOSPHERE 2024; 349:140821. [PMID: 38042424 DOI: 10.1016/j.chemosphere.2023.140821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 11/24/2023] [Accepted: 11/25/2023] [Indexed: 12/04/2023]
Abstract
The rapid growth of population and economy has led to an increase in urban air pollutants, greenhouse gases, energy shortages, environmental degradation, and species extinction, all of which affect ecosystems, biodiversity, and human health. Atmospheric pollution sources are divided into direct and indirect pollutants. Through analysis of the sources of pollutants, the self-functioning of different plants can be utilized to purify the air quality more effectively. Here, we explore the absorption of greenhouse gases and particulate matter in cities as well as the reduction of urban temperatures by plants based on international scientific literature on plant air pollution mitigation, according to the adsorption, dust retention, and transpiration functions of plants. At the same time, it can also reduce the occurrence of extreme weather. It is necessary to select suitable tree species for planting according to different plant functions and environmental needs. In the context of tight urban land use, the combination of vertical greening and urban architecture, through the rational use of plants, has comprehensively addressed urban air pollution. In the future, in urban construction, attention should be paid to the use of heavy plants and the protection and development of green spaces. Our review provides necessary references for future urban planning and research.
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Affiliation(s)
- Xiaoyi Duan
- Henan Province Engineering Research Center for Biomass Value-added Products, Forestry College, Henan Agricultural University, Zhengzhou, 450002, China
| | - Haiping Gu
- Henan Province Engineering Research Center for Biomass Value-added Products, Forestry College, Henan Agricultural University, Zhengzhou, 450002, China
| | - Su Shiung Lam
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia; Center for Global Health Research (CGHR), Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, India.
| | - Christian Sonne
- Aarhus University, Faculty of Technological Sciences, Department of Ecoscience, DK-4000, Roskilde, Denmark; Sustainability Cluster, School of Engineering, University of Petroleum & Energy Studies, Dehradun, Uttarakhand, 248007, India.
| | - Wenjie Lu
- Henan Province Engineering Research Center for Biomass Value-added Products, Forestry College, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hanyin Li
- Henan Province Engineering Research Center for Biomass Value-added Products, Forestry College, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xiangmeng Chen
- Henan Province Engineering Research Center for Biomass Value-added Products, Forestry College, Henan Agricultural University, Zhengzhou, 450002, China
| | - Wanxi Peng
- Henan Province Engineering Research Center for Biomass Value-added Products, Forestry College, Henan Agricultural University, Zhengzhou, 450002, China.
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20
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Huang Q, Xu C, Haase D, Teng Y, Su M, Yang Z. Heterogeneous effects of the availability and spatial configuration of urban green spaces on their cooling effects in China. ENVIRONMENT INTERNATIONAL 2024; 183:108385. [PMID: 38109832 DOI: 10.1016/j.envint.2023.108385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/15/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023]
Abstract
The impacts of the availability and spatial configuration of urban green spaces (UGS) on their cooling effects can vary with background climate conditions. However, large-scale studies that assess the potential heterogeneous relationships of UGS availability and spatial configuration with urban thermal environment are still lacking. In this study, we investigated the impacts of UGS availability and spatial configuration on urban land surface temperature (LST) taking 306 cities in China as a case study covering a multi-biome-scale. We first calculated the availability of surrounding UGS for urban built-up pixels in each city using a distance-weighted approach, and its spatial configuration was quantified through the Gini coefficient. Then, we employed various regression models to explore how the impacts of UGS availability and the Gini coefficient on LST varies across different LST quantiles and between day- and nighttime. The results revealed that UGS availability was negatively associated with both daytime and nighttime LST, while the Gini coefficient showed a positive impact solely on daytime LST, indicating that an adequate and equally distributed UGS contributes to lower environmental temperatures during the daytime. Furthermore, the impact of UGS availability on LST decreased during both day- and nighttime with increased background LST quantiles. Whereas the impact of the Gini coefficient increased only with daytime LST quantile levels, with its effect remaining almost insignificant during the night. Our findings provide new insights into the impacts of UGS on urban thermal environment, offering significant implications for urban green infrastructure planning aiming at lowering the urban heat island.
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Affiliation(s)
- Qianyuan Huang
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Chao Xu
- Institute of Geography, Humboldt University of Berlin, Berlin 12489, Germany.
| | - Dagmar Haase
- Institute of Geography, Humboldt University of Berlin, Berlin 12489, Germany; Department of Computational Landscape Ecology, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany
| | - Yanmin Teng
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Meirong Su
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
| | - Zhifeng Yang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
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21
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Qu LP, Chen J, Xiao J, De Boeck HJ, Dong G, Jiang SC, Hu YL, Wang YX, Shao CL. The complexity of heatwaves impact on terrestrial ecosystem carbon fluxes: Factors, mechanisms and a multi-stage analytical approach. ENVIRONMENTAL RESEARCH 2024; 240:117495. [PMID: 37890820 DOI: 10.1016/j.envres.2023.117495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 10/29/2023]
Abstract
Extreme heatwaves have become more frequent and severe in recent decades, and are expected to significantly influence carbon fluxes at regional scales across global terrestrial ecosystems. Nevertheless, accurate prediction of future heatwave impacts remains challenging due to a lack of a consistent comprehension of intrinsic and extrinsic mechanisms. We approached this knowledge gap by analyzing the complexity factors in heatwave studies, including the methodology for determining heatwave events, divergent responses of individual ecosystem components at multiple ecological and temporal scales, and vegetation status and hydrothermal environment, among other factors. We found that heatwaves essentially are continuously changing compound environmental stress that can unfold into multiple chronological stages, and plant physiology and carbon flux responses differs in each of these stages. This approach offers a holistic perspective, recognizing that the impacts of heatwaves on ecosystems can be better understood when evaluated over time. These stages include instantaneous, post-heatwave, legacy, and cumulative effects, each contributing uniquely to the overall impact on the ecosystem carbon cycle. Next, we investigated the importance of the timing of heatwaves and the possible divergent consequences caused by different annual heatwave patterns. Finally, a conceptual framework is proposed to establish a united foundation for the study and comprehension of the consequences of heatwaves on ecosystem carbon cycle. This instrumental framework will assist in guiding regional assessments of heatwave impacts, shedding light on the underlying mechanisms responsible for the varied responses of terrestrial ecosystems to specific heatwave events, which are imperative for devising efficient adaptation and mitigation approaches.
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Affiliation(s)
- Lu-Ping Qu
- College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
| | - Jiquan Chen
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI, 48823, USA.
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, 03824, USA.
| | - Hans J De Boeck
- Research Group of Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium.
| | - Gang Dong
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; School of Life Science, Shanxi University, Taiyuan, China.
| | | | - Ya-Lin Hu
- College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
| | - Yi-Xuan Wang
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Chang-Liang Shao
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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22
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Zhu L, Scafaro AP, Vierling E, Ball MC, Posch BC, Stock F, Atkin OK. Heat tolerance of a tropical-subtropical rainforest tree species Polyscias elegans: time-dependent dynamic responses of physiological thermostability and biochemistry. THE NEW PHYTOLOGIST 2024; 241:715-731. [PMID: 37932881 DOI: 10.1111/nph.19356] [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: 10/26/2022] [Accepted: 10/01/2023] [Indexed: 11/08/2023]
Abstract
Heat stress interrupts physiological thermostability and triggers biochemical responses that are essential for plant survival. However, there is limited knowledge on the speed plants adjust to heat in hours and days, and which adjustments are crucial. Tropical-subtropical rainforest tree species (Polyscias elegans) were heated at 40°C for 5 d, before returning to 25°C for 13 d of recovery. Leaf heat tolerance was quantified using the temperature at which minimal chl a fluorescence sharply rose (Tcrit ). Tcrit , metabolites, heat shock protein (HSP) abundance and membrane lipid fatty acid (FA) composition were quantified. Tcrit increased by 4°C (48-52°C) within 2 h of 40°C exposure, along with rapid accumulation of metabolites and HSPs. By contrast, it took > 2 d for FA composition to change. At least 2 d were required for Tcrit , HSP90, HSP70 and FAs to return to prestress levels. The results highlight the multi-faceted response of P. elegans to heat stress, and how this response varies over the scale of hours to days, culminating in an increased level of photosynthetic heat tolerance. These responses are important for survival of plants when confronted with heat waves amidst ongoing global climate change.
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Affiliation(s)
- Lingling Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, China
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
| | - Andrew P Scafaro
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
| | - Elizabeth Vierling
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Marilyn C Ball
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
| | - Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
- Department of Research, Conservation, and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
| | - Frederike Stock
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
- Australian Plant Phenomics Facility, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT, 2601, Australia
- Division of Plant Sciences, Research School of Biology, Building 46, The Australian National University, Canberra, ACT, 2601, Australia
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23
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Liang J, Krauss KW, Finnigan J, Stuart-Williams H, Farquhar GD, Ball MC. Linking water use efficiency with water use strategy from leaves to communities. THE NEW PHYTOLOGIST 2023; 240:1735-1742. [PMID: 37823336 DOI: 10.1111/nph.19308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/04/2023] [Indexed: 10/13/2023]
Abstract
Limitations and utility of three measures of water use characteristics were evaluated: water use efficiency (WUE), intrinsic WUE and marginal water cost of carbon gain ( ∂ E / ∂ A ) estimated, respectively, as ratios of assimilation (A) to transpiration (E), of A to stomatal conductance (gs ) and of sensitivities of E and A with variation in gs . Only the measure ∂ E / ∂ A estimates water use strategy in a way that integrates carbon gain relative to water use under varying environmental conditions across scales from leaves to communities. This insight provides updated and simplified ways of estimating ∂ E / ∂ A and adds depth to understanding ways that plants balance water expenditure against carbon gain, uniquely providing a mechanistic means of predicting water use characteristics under changing environmental scenarios.
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Affiliation(s)
- Jie Liang
- Plant Science Division, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
| | - Ken W Krauss
- Wetland and Aquatic Research Center, US Geological Survey, 70506, LA, Lafayette, USA
| | - John Finnigan
- Plant Science Division, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
| | - Hilary Stuart-Williams
- Plant Science Division, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
| | - Graham D Farquhar
- Plant Science Division, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
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24
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Moran ME, Aparecido LMT, Koepke DF, Cooper HF, Doughty CE, Gehring CA, Throop HL, Whitham TG, Allan GJ, Hultine KR. Limits of thermal and hydrological tolerance in a foundation tree species (Populus fremontii) in the desert southwestern United States. THE NEW PHYTOLOGIST 2023; 240:2298-2311. [PMID: 37680030 DOI: 10.1111/nph.19247] [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: 05/26/2023] [Accepted: 08/05/2023] [Indexed: 09/09/2023]
Abstract
Populus fremontii is among the most dominant, and ecologically important riparian tree species in the western United States and can thrive in hyper-arid riparian corridors. Yet, P. fremontii forests have rapidly declined over the last decade, particularly in places where temperatures sometimes exceed 50°C. We evaluated high temperature tolerance of leaf metabolism, leaf thermoregulation, and leaf hydraulic function in eight P. fremontii populations spanning a 5.3°C mean annual temperature gradient in a well-watered common garden, and at source locations throughout the lower Colorado River Basin. Two major results emerged. First, despite having an exceptionally high Tcrit (the temperature at which Photosystem II is disrupted) relative to other tree taxa, recent heat waves exceeded Tcrit , requiring evaporative leaf cooling to maintain leaf-to-air thermal safety margins. Second, in midsummer, genotypes from the warmest locations maintained lower midday leaf temperatures, a higher midday stomatal conductance, and maintained turgor pressure at lower water potentials than genotypes from more temperate locations. Taken together, results suggest that under well-watered conditions, P. fremontii can regulate leaf temperature below Tcrit along the warm edge of its distribution. Nevertheless, reduced Colorado River flows threaten to lower water tables below levels needed for evaporative cooling during episodic heat waves.
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Affiliation(s)
- Madeline E Moran
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Luiza M T Aparecido
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, 85287, USA
| | - Dan F Koepke
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
| | - Hillary F Cooper
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Christopher E Doughty
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Catherine A Gehring
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Heather L Throop
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, 85287, USA
| | - Thomas G Whitham
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Gerard J Allan
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
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25
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Liu M, Zhou Y, Sun J, Mao F, Yao Q, Li B, Wang Y, Gao Y, Dong X, Liao S, Wang P, Huang S. From the floret to the canopy: High temperature tolerance during flowering. PLANT COMMUNICATIONS 2023; 4:100629. [PMID: 37226443 PMCID: PMC10721465 DOI: 10.1016/j.xplc.2023.100629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/29/2023] [Accepted: 05/22/2023] [Indexed: 05/26/2023]
Abstract
Heat waves induced by climate warming have become common in food-producing regions worldwide, frequently coinciding with high temperature (HT)-sensitive stages of many crops and thus threatening global food security. Understanding the HT sensitivity of reproductive organs is currently of great interest for increasing seed set. The responses of seed set to HT involve multiple processes in both male and female reproductive organs, but we currently lack an integrated and systematic summary of these responses for the world's three leading food crops (rice, wheat, and maize). In the present work, we define the critical high temperature thresholds for seed set in rice (37.2°C ± 0.2°C), wheat (27.3°C ± 0.5°C), and maize (37.9°C ± 0.4°C) during flowering. We assess the HT sensitivity of these three cereals from the microspore stage to the lag period, including effects of HT on flowering dynamics, floret growth and development, pollination, and fertilization. Our review synthesizes existing knowledge about the effects of HT stress on spikelet opening, anther dehiscence, pollen shedding number, pollen viability, pistil and stigma function, pollen germination on the stigma, and pollen tube elongation. HT-induced spikelet closure and arrest of pollen tube elongation have a catastrophic effect on pollination and fertilization in maize. Rice benefits from pollination under HT stress owing to bottom anther dehiscence and cleistogamy. Cleistogamy and secondary spikelet opening increase the probability of pollination success in wheat under HT stress. However, cereal crops themselves also have protective measures under HT stress. Lower canopy/tissue temperatures compared with air temperatures indicate that cereal crops, especially rice, can partly protect themselves from heat damage. In maize, husk leaves reduce inner ear temperature by about 5°C compared with outer ear temperature, thereby protecting the later phases of pollen tube growth and fertilization processes. These findings have important implications for accurate modeling, optimized crop management, and breeding of new varieties to cope with HT stress in the most important staple crops.
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Affiliation(s)
- Mayang Liu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Yuhan Zhou
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Jiaxin Sun
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Fen Mao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Qian Yao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Baole Li
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Yuanyuan Wang
- College of Agronomy, South China Agricultural University, Guangdong, China
| | - Yingbo Gao
- Shandong Academy of Agricultural Sciences, Jinan, China
| | - Xin Dong
- Chongqing Academy of Agricultural Sciences, Chongqing, China
| | - Shuhua Liao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Pu Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Shoubing Huang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
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26
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Sun T, Zhang X, Lv S, Lin X, Ma J, Liu J, Fang Q, Tang L, Liu L, Cao W, Liu B, Zhu Y. Improving the predictions of leaf photosynthesis during and after short-term heat stress with current rice models. PLANT, CELL & ENVIRONMENT 2023; 46:3353-3370. [PMID: 37575035 DOI: 10.1111/pce.14683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/15/2023]
Abstract
In response to increasing global warming, extreme heat stress significantly alters photosynthetic production. While numerous studies have investigated the temperature effects on photosynthesis, factors like vapour pressure deficit (VPD), leaf nitrogen, and feedback of sink limitation during and after extreme heat stress remain underexplored. This study assessed photosynthesis calculations in seven rice growth models using observed maximum photosynthetic rate (Pmax ) during and after short-term extreme heat stress in multi-year environment-controlled experiments. Biochemical models (FvCB-type) outperformed light response curve-based models (LRC-type) when incorporating observed leaf nitrogen, photosynthetically active radiation, temperatures, and intercellular CO2 concentration (Ci ) as inputs. Prediction uncertainty during heat stress treatment primarily resulted from variation in temperatures and Ci . Improving FVPD (the slope for the linear effect of VPD on Ci /Ca ) to be temperature-dependent, rather than constant as in original models, significantly improved Ci prediction accuracy under heat stress. Leaf nitrogen response functions led to model variation in leaf photosynthesis predictions after heat stress, which was mitigated by calibrated nitrogen response functions based on active photosynthetic nitrogen. Additionally, accounting for observed differences in carbohydrate accumulation between panicles and stems during grain filling improved the feedback of sink limitation, reducing Ci overestimation under heat stress treatments.
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Affiliation(s)
- Ting Sun
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
- Key Laboratory of Specialty Agri-product Quality and Hazard Controlling Technology of Zhejiang Province, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang, China
| | - Xiaohu Zhang
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Suyu Lv
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xuanhao Lin
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jifeng Ma
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jiaming Liu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Qizhao Fang
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Liang Tang
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Leilei Liu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Weixing Cao
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Bing Liu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yan Zhu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
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27
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Marchin RM, Medlyn BE, Tjoelker MG, Ellsworth DS. Decoupling between stomatal conductance and photosynthesis occurs under extreme heat in broadleaf tree species regardless of water access. GLOBAL CHANGE BIOLOGY 2023; 29:6319-6335. [PMID: 37698501 DOI: 10.1111/gcb.16929] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/09/2023] [Indexed: 09/13/2023]
Abstract
High air temperatures increase atmospheric vapor pressure deficit (VPD) and the severity of drought, threatening forests worldwide. Plants regulate stomata to maximize carbon gain and minimize water loss, resulting in a close coupling between net photosynthesis (Anet ) and stomatal conductance (gs ). However, evidence for decoupling of gs from Anet under extreme heat has been found. Such a response both enhances survival of leaves during heat events but also quickly depletes available water. To understand the prevalence and significance of this decoupling, we measured leaf gas exchange in 26 tree and shrub species growing in the glasshouse or at an urban site in Sydney, Australia on hot days (maximum Tair > 40°C). We hypothesized that on hot days plants with ample water access would exhibit reduced Anet and use transpirational cooling leading to stomatal decoupling, whereas plants with limited water access would rely on other mechanisms to avoid lethal temperatures. Instead, evidence for stomatal decoupling was found regardless of plant water access. Transpiration of well-watered plants was 23% higher than model predictions during heatwaves, which effectively cooled leaves below air temperature. For hotter, droughted plants, the increase in transpiration during heatwaves was even more pronounced-gs was 77% higher than model predictions. Stomatal decoupling was found for most broadleaf evergreen and broadleaf deciduous species at the urban site, including some wilted trees with limited water access. Decoupling may simply be a passive consequence of the physical effects of high temperature on plant leaves through increased cuticular conductance of water vapor, or stomatal decoupling may be an adaptive response that is actively regulated by stomatal opening under high temperatures. This temperature response is not yet included in any land surface model, suggesting that model predictions of evapotranspiration may be underpredicted at high temperature and high VPD.
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Affiliation(s)
- Renée M Marchin
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
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28
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Muller JD, Rotenberg E, Tatarinov F, Oz I, Yakir D. Detailed in situ leaf energy budget permits the assessment of leaf aerodynamic resistance as a key to enhance non-evaporative cooling under drought. PLANT, CELL & ENVIRONMENT 2023; 46:3128-3143. [PMID: 36794448 DOI: 10.1111/pce.14571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 02/03/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
The modulation of the leaf energy budget components to maintain optimal leaf temperature are fundamental aspects of plant functioning and survival. Better understanding these aspects becomes increasingly important under a drying and warming climate when cooling through evapotranspiration (E) is suppressed. Combining novel measurements and theoretical estimates, we obtained unusually comprehensive twig-scale leaf energy budgets under extreme field conditions in droughted (suppressed E) and non-droughted (enhanced E) plots of a semi-arid pine forest. Under the same high mid-summer radiative load, leaf cooling shifted from relying on nearly equal contributions of sensible (H) and latent (LE) energy fluxes in non-droughted trees to relying almost exclusively on H in droughted ones, with no change in leaf temperature. Relying on our detailed leaf energy budget, we could demonstrate that this is due to a 2× reduction in leaf aerodynamic resistance. This capability for LE-to-H shift in leaves of mature Aleppo pine trees under droughted field conditions without increasing leaf temperature is likely a critical factor in the resilience and relatively high productivity of this important Mediterranean tree species under drying conditions.
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Affiliation(s)
- Jonathan D Muller
- Earth & Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Eyal Rotenberg
- Earth & Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Fyodor Tatarinov
- Earth & Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Itay Oz
- Earth & Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Dan Yakir
- Earth & Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
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29
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Gauthey A, Bachofen C, Deluigi J, Didion-Gency M, D'Odorico P, Gisler J, Mas E, Schaub M, Schuler P, Still CJ, Tunas A, Grossiord C. Absence of canopy temperature variation despite stomatal adjustment in Pinus sylvestris under multidecadal soil moisture manipulation. THE NEW PHYTOLOGIST 2023; 240:127-137. [PMID: 37483100 DOI: 10.1111/nph.19136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 06/23/2023] [Indexed: 07/25/2023]
Abstract
Global warming and droughts push forests closer to their thermal limits, altering tree carbon uptake and growth. To prevent critical overheating, trees can adjust their thermotolerance (Tcrit ), temperature and photosynthetic optima (Topt and Aopt ), and canopy temperature (Tcan ) to stay below damaging thresholds. However, we lack an understanding of how soil droughts affect photosynthetic thermal plasticity and Tcan regulation. In this study, we measured the effect of soil moisture on the seasonal and diurnal dynamics of net photosynthesis (A), stomatal conductance (gs ), and Tcan , as well as the thermal plasticity of photosynthesis (Tcrit , Topt , and Aopt ), over the course of 1 yr using a long-term irrigation experiment in a drought-prone Pinus sylvestris forest in Switzerland. Irrigation resulted in higher needle-level A, gs , Topt , and Aopt compared with naturally drought-exposed trees. No daily or seasonal differences in Tcan were observed between treatments. Trees operated below their thermal thresholds (Tcrit ), independently of soil moisture content. Despite strong Tcan and Tair coupling, we provide evidence that drought reduces trees' temperature optimum due to a substantial reduction of gs during warm and dry periods of the year. These findings provide important insights regarding the effects of soil drought on the thermal tolerance of P. sylvestris.
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Affiliation(s)
- Alice Gauthey
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, CH-1015, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Christoph Bachofen
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, CH-1015, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Janisse Deluigi
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, CH-1015, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Margaux Didion-Gency
- Forest Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Petra D'Odorico
- Land Change Science Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Jonas Gisler
- Forest Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Eugénie Mas
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, CH-1015, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Marcus Schaub
- Forest Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Philipp Schuler
- Forest Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Christopher J Still
- Forest Ecosystems and Society, Oregon State University, Corvallis, 97331, OR, USA
| | - Alex Tunas
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, CH-1015, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, CH-1015, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
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Doughty CE, Keany JM, Wiebe BC, Rey-Sanchez C, Carter KR, Middleby KB, Cheesman AW, Goulden ML, da Rocha HR, Miller SD, Malhi Y, Fauset S, Gloor E, Slot M, Oliveras Menor I, Crous KY, Goldsmith GR, Fisher JB. Tropical forests are approaching critical temperature thresholds. Nature 2023; 621:105-111. [PMID: 37612501 DOI: 10.1038/s41586-023-06391-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 06/30/2023] [Indexed: 08/25/2023]
Abstract
The critical temperature beyond which photosynthetic machinery in tropical trees begins to fail averages approximately 46.7 °C (Tcrit)1. However, it remains unclear whether leaf temperatures experienced by tropical vegetation approach this threshold or soon will under climate change. Here we found that pantropical canopy temperatures independently triangulated from individual leaf thermocouples, pyrgeometers and remote sensing (ECOSTRESS) have midday peak temperatures of approximately 34 °C during dry periods, with a long high-temperature tail that can exceed 40 °C. Leaf thermocouple data from multiple sites across the tropics suggest that even within pixels of moderate temperatures, upper canopy leaves exceed Tcrit 0.01% of the time. Furthermore, upper canopy leaf warming experiments (+2, 3 and 4 °C in Brazil, Puerto Rico and Australia, respectively) increased leaf temperatures non-linearly, with peak leaf temperatures exceeding Tcrit 1.3% of the time (11% for more than 43.5 °C, and 0.3% for more than 49.9 °C). Using an empirical model incorporating these dynamics (validated with warming experiment data), we found that tropical forests can withstand up to a 3.9 ± 0.5 °C increase in air temperatures before a potential tipping point in metabolic function, but remaining uncertainty in the plasticity and range of Tcrit in tropical trees and the effect of leaf death on tree death could drastically change this prediction. The 4.0 °C estimate is within the 'worst-case scenario' (representative concentration pathway (RCP) 8.5) of climate change predictions2 for tropical forests and therefore it is still within our power to decide (for example, by not taking the RCP 6.0 or 8.5 route) the fate of these critical realms of carbon, water and biodiversity3,4.
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Affiliation(s)
- Christopher E Doughty
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA.
| | - Jenna M Keany
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Benjamin C Wiebe
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Camilo Rey-Sanchez
- Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
| | - Kelsey R Carter
- College of Forest Resources and Environmental Sciences, Michigan Technological University, Houghton, MI, USA
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Kali B Middleby
- Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, Queensland, Australia
| | - Alexander W Cheesman
- Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, Queensland, Australia
| | - Michael L Goulden
- Department of Earth System Science, University of California, Irvine, CA, USA
| | - Humberto R da Rocha
- Departamento de Ciencias Atmosfericas, Universidade de São Paulo, São Paulo, Brazil
| | - Scott D Miller
- Atmospheric Sciences Research Center, State University of New York at Albany, Albany, NY, USA
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Sophie Fauset
- School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth, UK
| | | | - Martijn Slot
- Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama
| | - Imma Oliveras Menor
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
- AMAP (Botanique et Modélisation de l'Architecture des Plantes et des Végétations), CIRAD, CNRS, INRA, IRD, Université de Montpellier, Montpellier, France
| | - Kristine Y Crous
- Western Sydney University, Hawkesbury Institute for the Environment, Penrith, New South Wales, Australia
| | - Gregory R Goldsmith
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA
| | - Joshua B Fisher
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA
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31
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Crous KY, Cheesman AW, Middleby K, Rogers EIE, Wujeska-Klause A, Bouet AYM, Ellsworth DS, Liddell MJ, Cernusak LA, Barton CVM. Similar patterns of leaf temperatures and thermal acclimation to warming in temperate and tropical tree canopies. TREE PHYSIOLOGY 2023; 43:1383-1399. [PMID: 37099805 PMCID: PMC10423462 DOI: 10.1093/treephys/tpad054] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/22/2023] [Accepted: 04/17/2023] [Indexed: 06/19/2023]
Abstract
As the global climate warms, a key question is how increased leaf temperatures will affect tree physiology and the coupling between leaf and air temperatures in forests. To explore the impact of increasing temperatures on plant performance in open air, we warmed leaves in the canopy of two mature evergreen forests, a temperate Eucalyptus woodland and a tropical rainforest. The leaf heaters consistently maintained leaves at a target of 4 °C above ambient leaf temperatures. Ambient leaf temperatures (Tleaf) were mostly coupled to air temperatures (Tair), but at times, leaves could be 8-10 °C warmer than ambient air temperatures, especially in full sun. At both sites, Tleaf was warmer at higher air temperatures (Tair > 25 °C), but was cooler at lower Tair, contrary to the 'leaf homeothermy hypothesis'. Warmed leaves showed significantly lower stomatal conductance (-0.05 mol m-2 s-1 or -43% across species) and net photosynthesis (-3.91 μmol m-2 s-1 or -39%), with similar rates in leaf respiration rates at a common temperature (no acclimation). Increased canopy leaf temperatures due to future warming could reduce carbon assimilation via reduced photosynthesis in these forests, potentially weakening the land carbon sink in tropical and temperate forests.
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Affiliation(s)
- K Y Crous
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - A W Cheesman
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - K Middleby
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - E I E Rogers
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - A Wujeska-Klause
- Urban Studies, School of Social Science, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - A Y M Bouet
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - D S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - M J Liddell
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - L A Cernusak
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - C V M Barton
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
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32
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Milner KV, French K, Krix DW, Valenzuela SM, Leigh A. The effects of spring versus summer heat events on two arid zone plant species under field conditions. FUNCTIONAL PLANT BIOLOGY : FPB 2023; 50:455-469. [PMID: 37081720 DOI: 10.1071/fp22135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 03/15/2023] [Indexed: 05/03/2023]
Abstract
Heatwaves are increasingly occurring out-of-season, which may affect plants not primed for the event. Further, heat stress often coincides with water and/or nutrient stress, impairing short-term physiological function and potentially causing downstream effects on reproductive fitness. We investigated the response of water-stressed arid-zone Solanum oligacanthum and Solanum orbiculatum to spring vs summer heat stress under differing nutrient conditions. Heat stress events were imposed in open-topped chambers under in situ desert conditions. To assess short-term impacts, we measured leaf photosystem responses (F v /F m ) and membrane stability; long-term effects were compared via biomass allocation, visible damage, flowering and fruiting. Plants generally fared more poorly following summer than spring heat stress, with the exception of F v /F m . Summer heat stress caused greater membrane damage, reduced growth and survival compared with spring. Nutrient availability had a strong influence on downstream effects of heat stress, including species-specific outcomes for reproductive fitness. Overall, high temperatures during spring posed a lower threat to fitness than in severe arid summer conditions of high temperature and low water availability, which were more detrimental to plants in both the short and longer term. Our study highlights the importance of considering ecologically relevant, multiple-stressor events to understand different species responses to extreme heat.
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Affiliation(s)
- K V Milner
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - K French
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospherics and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - D W Krix
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - S M Valenzuela
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - A Leigh
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
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33
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Zhang Z, Cescatti A, Wang YP, Gentine P, Xiao J, Guanter L, Huete AR, Wu J, Chen JM, Ju W, Peñuelas J, Zhang Y. Large diurnal compensatory effects mitigate the response of Amazonian forests to atmospheric warming and drying. SCIENCE ADVANCES 2023; 9:eabq4974. [PMID: 37235657 DOI: 10.1126/sciadv.abq4974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 04/25/2023] [Indexed: 05/28/2023]
Abstract
Photosynthesis and evapotranspiration in Amazonian forests are major contributors to the global carbon and water cycles. However, their diurnal patterns and responses to atmospheric warming and drying at regional scale remain unclear, hindering the understanding of global carbon and water cycles. Here, we used proxies of photosynthesis and evapotranspiration from the International Space Station to reveal a strong depression of dry season afternoon photosynthesis (by 6.7 ± 2.4%) and evapotranspiration (by 6.1 ± 3.1%). Photosynthesis positively responds to vapor pressure deficit (VPD) in the morning, but negatively in the afternoon. Furthermore, we projected that the regionally depressed afternoon photosynthesis will be compensated by their increases in the morning in future dry seasons. These results shed new light on the complex interplay of climate with carbon and water fluxes in Amazonian forests and provide evidence on the emerging environmental constraints of primary productivity that may improve the robustness of future projections.
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Affiliation(s)
- Zhaoying Zhang
- Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, International Institute for Earth System Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
- Yuxiu Postdoctoral Institute, Nanjing University, Nanjing, Jiangsu 210023, China
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China
| | | | - Ying-Ping Wang
- CSIRO, Oceans and Atmosphere, Private Bag 1, Aspendale, Victoria 3195, Australia
| | - Pierre Gentine
- Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Luis Guanter
- Research Institute of Water and Environmental Engineering (IIAMA), Department of Applied Physics, Polytechnic University of Valencia, Valencia, Spain
| | - Alfredo R Huete
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Jin Wu
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Jing M Chen
- Department of Geography and Planning, University of Toronto, Toronto, Ontario, Canada
| | - Weimin Ju
- Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, International Institute for Earth System Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Josep Peñuelas
- CSIC, Global ecology Unit CREAF-CSIC-UAB, Bellaterra 08193, Catalonia, Spain
- CREAF, Cerdanyola del Vallès 08193, Catalonia, Spain
| | - Yongguang Zhang
- Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, International Institute for Earth System Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China
- International Joint Carbon Neutrality Laboratory, Nanjing University, Nanjing, Jiangsu 210023 China
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34
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Scafaro AP, Posch BC, Evans JR, Farquhar GD, Atkin OK. Rubisco deactivation and chloroplast electron transport rates co-limit photosynthesis above optimal leaf temperature in terrestrial plants. Nat Commun 2023; 14:2820. [PMID: 37198175 DOI: 10.1038/s41467-023-38496-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 05/03/2023] [Indexed: 05/19/2023] Open
Abstract
Net photosynthetic CO2 assimilation rate (An) decreases at leaf temperatures above a relatively mild optimum (Topt) in most higher plants. This decline is often attributed to reduced CO2 conductance, increased CO2 loss from photorespiration and respiration, reduced chloroplast electron transport rate (J), or deactivation of Ribulose-1,5-bisphosphate Carboxylase Oxygenase (Rubisco). However, it is unclear which of these factors can best predict species independent declines in An at high temperature. We show that independent of species, and on a global scale, the observed decline in An with rising temperatures can be effectively accounted for by Rubisco deactivation and declines in J. Our finding that An declines with Rubisco deactivation and J supports a coordinated down-regulation of Rubisco and chloroplast electron transport rates to heat stress. We provide a model that, in the absence of CO2 supply limitations, can predict the response of photosynthesis to short-term increases in leaf temperature.
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Affiliation(s)
- Andrew P Scafaro
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.
- Centre for Entrepreneurial Agri-Technology, Gould Building, Australian National University, Canberra, 2601, Australia.
| | - Bradley C Posch
- Department of Research, Collections and Conservation, Desert Botanical Garden, Phoenix, AZ, USA
| | - John R Evans
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Graham D Farquhar
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Owen K Atkin
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Centre for Entrepreneurial Agri-Technology, Gould Building, Australian National University, Canberra, 2601, Australia
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35
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Still CJ, Sibley A, DePinte D, Busby PE, Harrington CA, Schulze M, Shaw DR, Woodruff D, Rupp DE, Daly C, Hammond WM, Page GFM. Causes of widespread foliar damage from the June 2021 Pacific Northwest Heat Dome: more heat than drought. TREE PHYSIOLOGY 2023; 43:203-209. [PMID: 36611006 DOI: 10.1093/treephys/tpac143] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Affiliation(s)
- C J Still
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA
| | - A Sibley
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA
| | - D DePinte
- US Department of Agriculture, Forest Service, Pacific Northwest Region, State & Private Forestry, Forest Health Protection, Redmond, OR 97756, USA
| | - P E Busby
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - C A Harrington
- US Department of Agriculture, Forest Service, Pacific Northwest Research Station, Olympia, WA 98512, USA
| | - M Schulze
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA
| | - D R Shaw
- Department of Forest Engineering, Resources, and Management, Oregon State University, Corvallis, OR 97331, USA
| | - D Woodruff
- US Department of Agriculture, Forest Service, Pacific Northwest Research Station, Corvallis, OR 97331, USA
| | - D E Rupp
- Oregon Climate Change Research Institute, College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - C Daly
- PRISM Climate Group, Northwest Alliance for Computational Science and Engineering, Oregon State University, Corvallis, OR 97331, USA
| | - W M Hammond
- Agronomy Department, University of Florida, Institute of Food and Agricultural Sciences, Gainesville, FL 32611, USA
| | - G F M Page
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre, Bentley, Western Australia 6983, Australia
- CSIRO Land and Water, Private Bag 5, Wembley, Western Australia 6913, Australia
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36
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Gong XW, Hao GY. The synergistic effect of hydraulic and thermal impairments accounts for the severe crown damage in Fraxinus mandshurica seedlings following the combined drought-heatwave stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159017. [PMID: 36167124 DOI: 10.1016/j.scitotenv.2022.159017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Drought combined with extreme heatwaves has been increasingly identified as the important trigger of worldwide tree mortality in the context of climate change; nonetheless, our understanding of the potential hydraulic and thermal impairments of hot droughts to trees and the subsequent post-recovery process remains limited. To investigate the response of tree water and carbon relations to drought, heatwave, and combined drought-heatwave stresses, three-year-old potted seedlings of Fraxinus mandshurica Rupr., a dominant tree species in temperate forests of northeast China, were grown under well-watered and drought-stressed conditions and exposed to a rapid, acute heatwave treatment. During the heatwave treatment with a maximum temperature exceeding 40 °C for two days, the leaf temperature of drought-stressed seedlings was, on average, 5 °C higher than that of well-watered counterparts due to less effective evaporative cooling, indicating that soil water availability influenced leaf thermoregulatory capacity during hot extremes. Consistently, more pronounced crown damage, as shown by 13 % irreversible leaf scorch, was found in seedlings under the drought-heatwave treatment relative to sole heatwave treatment, alongside the more severe stem xylem embolism and leaf electrolyte leakage. While the heatwave treatment accelerated the depletion of non-structural carbohydrates in drought-stressed seedlings, the increase of branch soluble sugar concentration in response to heatwave might be related to the requirement for maintaining hydraulic functioning via osmoregulation under high dehydration risk. The coordination between leaf stomatal conductance and total non-structural carbohydrate content during the post-heatwave recovery phase implied that plant-water relations and carbon physiology were closely coupled in coping with hot droughts. This study highlights that, under scenarios of aggravating drought co-occurring with heatwaves, tree seedlings could face a high risk of crown decline in relation to the synergistically increased hydraulic and thermal impairments.
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Affiliation(s)
- Xue-Wei Gong
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning Province, Shenyang 110016, China; Qingyuan Forest CERN, National Observation and Research Station, Liaoning Province, Shenyang 110016, China
| | - Guang-You Hao
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning Province, Shenyang 110016, China; Qingyuan Forest CERN, National Observation and Research Station, Liaoning Province, Shenyang 110016, China.
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37
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Andrew SC, Arnold PA, Simonsen AK, Briceño VF. Consistently high heat tolerance acclimation in response to a simulated heatwave across species from the broadly distributed Acacia genus. FUNCTIONAL PLANT BIOLOGY : FPB 2023; 50:71-83. [PMID: 36210348 DOI: 10.1071/fp22173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/18/2022] [Indexed: 06/16/2023]
Abstract
When leaves exceed their thermal threshold during heatwaves, irreversible damage to the leaf can accumulate. However, few studies have explored short-term acclimation of leaves to heatwaves that could help plants to prevent heat damage with increasing heatwave intensity. Here, we studied the heat tolerance of PSII (PHT) in response to a heatwave in Acacia species from across a strong environmental gradient in Australia. We compared PHT metrics derived from temperature-dependent chlorophyll fluorescence response curves (T-F 0 ) before and during a 4-day 38°C heatwave in a controlled glasshouse experiment. We found that the 15 Acacia species displayed surprisingly large and consistent PHT acclimation responses with a mean tolerance increase of 12°C (range, 7.7-19.1°C). Despite species originating from diverse climatic regions, neither maximum temperature of the warmest month nor mean annual precipitation at origin were clear predictors of PHT. To our knowledge, these are some of the largest measured acclimation responses of PHT from a controlled heatwave experiment. This remarkable capacity could partially explain why this genus has become more diverse and common as the Australian continent became more arid and suggests that the presence of Acacia in Australian ecosystems will remain ubiquitous with climate change.
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Affiliation(s)
| | - Pieter A Arnold
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
| | - Anna K Simonsen
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA; and Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
| | - Verónica F Briceño
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
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38
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Docherty EM, Gloor E, Sponchiado D, Gilpin M, Pinto CAD, Junior HM, Coughlin I, Ferreira L, Junior JAS, da Costa ACL, Meir P, Galbraith D. Long-term drought effects on the thermal sensitivity of Amazon forest trees. PLANT, CELL & ENVIRONMENT 2023; 46:185-198. [PMID: 36230004 PMCID: PMC10092618 DOI: 10.1111/pce.14465] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/07/2022] [Accepted: 10/09/2022] [Indexed: 06/16/2023]
Abstract
The continued functioning of tropical forests under climate change depends on their resilience to drought and heat. However, there is little understanding of how tropical forests will respond to combinations of these stresses, and no field studies to date have explicitly evaluated whether sustained drought alters sensitivity to temperature. We measured the temperature response of net photosynthesis, foliar respiration and the maximum quantum efficiency of photosystem II (Fv /Fm ) of eight hyper-dominant Amazonian tree species at the world's longest-running tropical forest drought experiment, to investigate the effect of drought on forest thermal sensitivity. Despite a 0.6°C-2°C increase in canopy air temperatures following long-term drought, no change in overall thermal sensitivity of net photosynthesis or respiration was observed. However, photosystem II tolerance to extreme-heat damage (T50 ) was reduced from 50.0 ± 0.3°C to 48.5 ± 0.3°C under drought. Our results suggest that long-term reductions in precipitation, as projected across much of Amazonia by climate models, are unlikely to greatly alter the response of tropical forests to rising mean temperatures but may increase the risk of leaf thermal damage during heatwaves.
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Affiliation(s)
- Emma M. Docherty
- Department of Earth and Environment, School of GeographyUniversity of LeedsLeedsUK
| | - Emanuel Gloor
- Department of Earth and Environment, School of GeographyUniversity of LeedsLeedsUK
| | - Daniela Sponchiado
- Departamento de Ciências Biológicas, Laboratório de Ecologia VegetalUniversidade do Estado de Mato GrossoNova XavantinaMato GrossoBrasil
| | - Martin Gilpin
- Department of Earth and Environment, School of GeographyUniversity of LeedsLeedsUK
| | | | | | - Ingrid Coughlin
- Departamento de Biologia, FFCLRPUniversidade de São PauloRibeirao PretoSão PauloBrasil
- College of Science, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritorAustralia
| | | | | | - Antonio C. L. da Costa
- Instituto de GeosciênciasUniversidade Federaldo ParáBelémParáBrasil
- Museu Paraense Emílio GoeldiBelémParáBrasil
| | - Patrick Meir
- College of Science, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritorAustralia
- College of Science and Engineering, School of GeoSciencesUniversity of EdinburghEdinburghUK
| | - David Galbraith
- Department of Earth and Environment, School of GeographyUniversity of LeedsLeedsUK
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39
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Ibsen PC, Santiago LS, Shiflett SA, Chandler M, Jenerette GD. Irrigated urban trees exhibit greater functional trait plasticity compared to natural stands. Biol Lett 2023; 19:20220448. [PMID: 36596464 PMCID: PMC9810417 DOI: 10.1098/rsbl.2022.0448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Urbanization creates novel ecosystems comprised of species assemblages and environments with no natural analogue. Moreover, irrigation can alter plant function compared to non-irrigated systems. However, the capacity of irrigation to alter functional trait patterns across multiple species is unknown but may be important for the dynamics of urban ecosystems. We evaluated the hypothesis that urban irrigation influences plasticity in functional traits by measuring carbon-gain and water-use traits of 30 tree species planted in Southern California, USA spanning a coastal-to-desert gradient. Tree species respond to irrigation through increasing the carbon-gain trait relationship of leaf nitrogen per specific leaf area compared to their native habitat. Moreover, most species shift to a water-use strategy of greater water loss through stomata when planted in irrigated desert-like environments compared to coastal environments, implying that irrigated species capitalize on increased water availability to cool their leaves in extreme heat and high evaporative demand conditions. Therefore, irrigated urban environments increase the plasticity of trait responses compared to native ecosystems, allowing for novel response to climatic variation. Our results indicate that trees grown in water-resource-rich urban ecosystems can alter their functional traits plasticity beyond those measured in native ecosystems, which can lead to plant trait dynamics with no natural analogue.
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Affiliation(s)
- Peter C. Ibsen
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92521, USA,Geosciences and Environmental Change Science Center, United States Geological Survey, Denver, CO 80225, USA
| | - Louis S. Santiago
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92521, USA
| | - Sheri A. Shiflett
- Department of Environmental Sciences, University of North Carolina Wilmington, Wilmington, NC 28403, USA
| | | | - G. Darrel Jenerette
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92521, USA
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40
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Kefford BJ, Ghalambor CK, Dewenter B, Poff NL, Hughes J, Reich J, Thompson R. Acute, diel, and annual temperature variability and the thermal biology of ectotherms. GLOBAL CHANGE BIOLOGY 2022; 28:6872-6888. [PMID: 36177681 PMCID: PMC9828456 DOI: 10.1111/gcb.16453] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Global warming is increasing mean temperatures and altering temperature variability at multiple temporal scales. To better understand the consequences of changes in thermal variability for ectotherms it is necessary to consider thermal variation at different time scales (i.e., acute, diel, and annual) and the responses of organisms within and across generations. Thermodynamics constrain acute responses to temperature, but within these constraints and over longer time periods, organisms have the scope to adaptively acclimate or evolve. Yet, hypotheses and predictions about responses to future warming tend not to explicitly consider the temporal scale at which temperature varies. Here, focusing on multicellular ectothermic animals, we argue that consideration of multiple processes and constraints associated with various timescales is necessary to better understand how altered thermal variability because of climate change will affect ectotherms.
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Affiliation(s)
- Ben J. Kefford
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Cameron K. Ghalambor
- Department of Biology and Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
- Department of Biology, Centre for Biodiversity Dynamics (CBD)Norwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Beatrice Dewenter
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - N. LeRoy Poff
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
- Department of Biology and Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
| | - Jane Hughes
- Australian Rivers InstituteGriffith UniversityNathanQueenslandAustralia
| | - Jollene Reich
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Ross Thompson
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
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41
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Kullberg AT, Feeley KJ. Limited acclimation of leaf traits and leaf temperatures in a subtropical urban heat island. TREE PHYSIOLOGY 2022; 42:2266-2281. [PMID: 35708568 DOI: 10.1093/treephys/tpac066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 06/11/2022] [Indexed: 06/15/2023]
Abstract
The consequences of rising temperatures for trees will vary between species based on their abilities to acclimate their leaf thermoregulatory traits and photosynthetic thermal tolerances. We tested the hypotheses that adult trees in warmer growing conditions (i) acclimate their thermoregulatory traits to regulate leaf temperatures, (ii) acclimate their thermal tolerances such that tolerances are positively correlated with leaf temperature and (iii) that species with broader thermal niche breadths have greater acclimatory abilities. To test these hypotheses, we measured leaf traits and thermal tolerances of seven focal tree species across steep thermal gradients in Miami's urban heat island. We found that some functional traits varied significantly across air temperatures within species. For example, leaf thickness increased with maximum air temperature in three species, and leaf mass per area and leaf reflectance both increased with air temperature in one species. Only one species was marginally more homeothermic than expected by chance due to acclimation of its thermoregulatory traits, but this acclimation was insufficient to offset elevated air temperatures. Thermal tolerances acclimated to higher maximum air temperatures in two species. As a result of limited acclimation, leaf thermal safety margins (TSMs) were narrower for trees in hotter areas. We found some support for our hypothesis that species with broader thermal niches are better at acclimating to maintain more stable TSMs across the temperature gradients. These findings suggest that trees have limited abilities to acclimate to high temperatures and that thermal niche specialists may be at a heightened risk of thermal stress as global temperatures continue to rise.
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Affiliation(s)
- Alyssa T Kullberg
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | - Kenneth J Feeley
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
- Fairchild Tropical Botanic Garden, Coral Gables, FL 33156, USA
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42
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Schönbeck LC, Schuler P, Lehmann MM, Mas E, Mekarni L, Pivovaroff AL, Turberg P, Grossiord C. Increasing temperature and vapour pressure deficit lead to hydraulic damages in the absence of soil drought. PLANT, CELL & ENVIRONMENT 2022; 45:3275-3289. [PMID: 36030547 PMCID: PMC9826222 DOI: 10.1111/pce.14425] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Temperature (T) and vapour pressure deficit (VPD) are important drivers of plant hydraulic conductivity, growth, mortality, and ecosystem productivity, independently of soil water availability. Our goal was to disentangle the effects of T and VPD on plant hydraulic responses. Young trees of Fagus sylvatica L., Quercus pubescens Willd. and Quercus ilex L. were exposed to a cross-combination of a T and VPD manipulation under unlimited soil water availability. Stem hydraulic conductivity and leaf-level hydraulic traits (e.g., gas exchange and osmotic adjustment) were tracked over a full growing season. Significant loss of xylem conductive area (PLA) was found in F. sylvatica and Q. pubescens due to rising VPD and T, but not in Q. ilex. Increasing T aggravated the effects of high VPD in F. sylvatica only. PLA was driven by maximum hydraulic conductivity and minimum leaf conductance, suggesting that high transpiration and water loss after stomatal closure contributed to plant hydraulic stress. This study shows for the first time that rising VPD and T lead to losses of stem conductivity even when soil water is not limiting, highlighting their rising importance in plant mortality mechanisms in the future.
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Affiliation(s)
- Leonie C. Schönbeck
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering ENACEPFLLausanneSwitzerland
- Community Ecology Unit, Swiss Federal Institute for ForestSnow and Landscape WSLLausanneSwitzerland
- Department of Botany & Plant SciencesUniversity of California, RiversideRiversideCaliforniaUSA
| | - Philipp Schuler
- Forest Dynamics Unit, Swiss Federal Institute for ForestSnow and Landscape WSLBirmensdorfSwitzerland
- Institute of Agricultural SciencesETH ZurichZurichSwitzerland
| | - Marco M. Lehmann
- Forest Dynamics Unit, Swiss Federal Institute for ForestSnow and Landscape WSLBirmensdorfSwitzerland
| | - Eugénie Mas
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering ENACEPFLLausanneSwitzerland
- Community Ecology Unit, Swiss Federal Institute for ForestSnow and Landscape WSLLausanneSwitzerland
| | - Laura Mekarni
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering ENACEPFLLausanneSwitzerland
- Community Ecology Unit, Swiss Federal Institute for ForestSnow and Landscape WSLLausanneSwitzerland
| | | | - Pascal Turberg
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering ENACEPFLLausanneSwitzerland
- Community Ecology Unit, Swiss Federal Institute for ForestSnow and Landscape WSLLausanneSwitzerland
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering ENACEPFLLausanneSwitzerland
- Community Ecology Unit, Swiss Federal Institute for ForestSnow and Landscape WSLLausanneSwitzerland
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43
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No evidence of canopy-scale leaf thermoregulation to cool leaves below air temperature across a range of forest ecosystems. Proc Natl Acad Sci U S A 2022; 119:e2205682119. [PMID: 36095211 PMCID: PMC9499539 DOI: 10.1073/pnas.2205682119] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding and predicting the relationship between leaf temperature (Tleaf) and air temperature (Tair) is essential for projecting responses to a warming climate, as studies suggest that many forests are near thermal thresholds for carbon uptake. Based on leaf measurements, the limited leaf homeothermy hypothesis argues that daytime Tleaf is maintained near photosynthetic temperature optima and below damaging temperature thresholds. Specifically, leaves should cool below Tair at higher temperatures (i.e., > ∼25-30°C) leading to slopes <1 in Tleaf/Tair relationships and substantial carbon uptake when leaves are cooler than air. This hypothesis implies that climate warming will be mitigated by a compensatory leaf cooling response. A key uncertainty is understanding whether such thermoregulatory behavior occurs in natural forest canopies. We present an unprecedented set of growing season canopy-level leaf temperature (Tcan) data measured with thermal imaging at multiple well-instrumented forest sites in North and Central America. Our data do not support the limited homeothermy hypothesis: canopy leaves are warmer than air during most of the day and only cool below air in mid to late afternoon, leading to Tcan/Tair slopes >1 and hysteretic behavior. We find that the majority of ecosystem photosynthesis occurs when canopy leaves are warmer than air. Using energy balance and physiological modeling, we show that key leaf traits influence leaf-air coupling and ultimately the Tcan/Tair relationship. Canopy structure also plays an important role in Tcan dynamics. Future climate warming is likely to lead to even greater Tcan, with attendant impacts on forest carbon cycling and mortality risk.
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44
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Carter KR, Dickman LT. Recovery of seedling carbon balance despite hydraulic impairment following hot drought. TREE PHYSIOLOGY 2022; 42:1527-1531. [PMID: 35445728 DOI: 10.1093/treephys/tpac045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Affiliation(s)
- Kelsey R Carter
- Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - L Turin Dickman
- Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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45
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Rehschuh R, Ruehr NK. Diverging responses of water and carbon relations during and after heat and hot drought stress in Pinus sylvestris. TREE PHYSIOLOGY 2022; 42:1532-1548. [PMID: 34740258 PMCID: PMC9366868 DOI: 10.1093/treephys/tpab141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Forests are increasingly affected by heatwaves, often co-occurring with drought, with consequences for water and carbon (C) cycling. However, our ability to project tree resilience to more intense hot droughts remains limited. Here, we used single tree chambers (n = 18) to investigate transpiration (E), net assimilation (Anet), root respiration (Rroot) and stem diameter change in Scots pine seedlings in a control treatment and during gradually intensifying heat or drought-heat stress (max. 42 °C), including recovery. Alongside this, we assessed indicators of stress impacts and recovery capacities. In the heat treatment, excessive leaf heating was mitigated via increased E, while under drought-heat, E ceased and leaf temperatures reached 46 °C. However, leaf electrolyte leakage was negligible, while light-adapted quantum yield of photosystem II (F'v/F'm) declined alongside Anet moderately in heat, but strongly in drought-heat seedlings, in which respiration exceeded C uptake. Drought-heat largely affected the hydraulic system as apparent in stem diameter shrinkage, declining relative needle water content (RWCNeedle) and water potential (ΨNeedle) reaching -2.7 MPa, alongside a 90% decline of leaf hydraulic conductance (KLeaf). Heat alone resulted in low functional impairment and all measured parameters recovered quickly. Contrary, following drought-heat, the recovery of KLeaf was incomplete and stem hydraulic conductivity (KS) was 25% lower than the control. However, F'v/F'm recovered and the tree net C balance reached control values 2 days post-stress, with stem increment rates accelerating during the second recovery week. This indicates a new equilibrium of C uptake and release in drought-heat seedlings independent of hydraulic impairment, which may slowly contribute to the repair of damaged tissues. In summary, Scots pine recovered rapidly following moderate heat stress, while combined with drought, hydraulic and thermal stress intensified, resulting in functional damage and slow recovery of hydraulic conductance. This incomplete hydraulic recovery could critically limit evaporative cooling capacities and C uptake under repeated heatwaves.
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Affiliation(s)
| | - Nadine K Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research-Atmospheric Environmental Research (KIT/IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
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46
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Trainin T, Brukental H, Shapira O, Attia Z, Tiwari V, Hatib K, Gal S, Zemach H, Belausov E, Charuvi D, Holland D, Azoulay-Shemer T. Physiological characterization of the wild almond Prunus arabica stem photosynthetic capability. FRONTIERS IN PLANT SCIENCE 2022; 13:941504. [PMID: 35968090 PMCID: PMC9372545 DOI: 10.3389/fpls.2022.941504] [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: 05/11/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Leaves are the major plant tissue for transpiration and carbon fixation in deciduous trees. In harsh habitats, atmospheric CO2 assimilation via stem photosynthesis is common, providing extra carbon gain to cope with the detrimental conditions. We studied two almond species, the commercial Prunus dulcis cultivar "Um-el-Fahem" and the rare wild Prunus arabica. Our study revealed two distinctive strategies for carbon gain in these almond species. While, in P. dulcis, leaves possess the major photosynthetic surface area, in P. arabica, green stems perform this function, in particular during the winter after leaf drop. These two species' anatomical and physiological comparisons show that P. arabica carries unique features that support stem gas exchange and high-gross photosynthetic rates via stem photosynthetic capabilities (SPC). On the other hand, P. dulcis stems contribute low gross photosynthesis levels, as they are designed solely for reassimilation of CO2 from respiration, which is termed stem recycling photosynthesis (SRP). Results show that (a) P. arabica stems are covered with a high density of sunken stomata, in contrast to the stomata on P. dulcis stems, which disappear under a thick peridermal (bark) layer by their second year of development. (b) P. arabica stems contain significantly higher levels of chlorophyll compartmentalized to a mesophyll-like, chloroplast-rich, parenchyma layer, in contrast to rounded-shape cells of P. dulcis's stem parenchyma. (c) Pulse amplitude-modulated (PAM) fluorometry of P. arabica and P. dulcis stems revealed differences in the chlorophyll fluorescence and quenching parameters between the two species. (d) Gas exchange analysis showed that guard cells of P. arabica stems tightly regulate water loss under elevated temperatures while maintaining constant and high assimilation rates throughout the stem. Our data show that P. arabica uses a distinctive strategy for tree carbon gain via stem photosynthetic capability, which is regulated efficiently under harsh environmental conditions, such as elevated temperatures. These findings are highly important and can be used to develop new almond cultivars with agriculturally essential traits.
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Affiliation(s)
- Taly Trainin
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Hillel Brukental
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
- Faculty of Agriculture, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, Rehovot, Israel
| | - Or Shapira
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Ziv Attia
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Vivekanand Tiwari
- Volcani Center, Institute of Plant Sciences, Agricultural Research Organization, Rishon LeZion, Israel
| | - Kamel Hatib
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Shira Gal
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Hanita Zemach
- Volcani Center, Institute of Plant Sciences, Agricultural Research Organization, Rishon LeZion, Israel
| | - Eduard Belausov
- Volcani Center, Institute of Plant Sciences, Agricultural Research Organization, Rishon LeZion, Israel
| | - Dana Charuvi
- Volcani Center, Institute of Plant Sciences, Agricultural Research Organization, Rishon LeZion, Israel
| | - Doron Holland
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Tamar Azoulay-Shemer
- Department of Fruit Tree Sciences, Volcani Center, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
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Beringer J, Moore CE, Cleverly J, Campbell DI, Cleugh H, De Kauwe MG, Kirschbaum MUF, Griebel A, Grover S, Huete A, Hutley LB, Laubach J, Van Niel T, Arndt SK, Bennett AC, Cernusak LA, Eamus D, Ewenz CM, Goodrich JP, Jiang M, Hinko‐Najera N, Isaac P, Hobeichi S, Knauer J, Koerber GR, Liddell M, Ma X, Macfarlane C, McHugh ID, Medlyn BE, Meyer WS, Norton AJ, Owens J, Pitman A, Pendall E, Prober SM, Ray RL, Restrepo‐Coupe N, Rifai SW, Rowlings D, Schipper L, Silberstein RP, Teckentrup L, Thompson SE, Ukkola AM, Wall A, Wang Y, Wardlaw TJ, Woodgate W. Bridge to the future: Important lessons from 20 years of ecosystem observations made by the OzFlux network. GLOBAL CHANGE BIOLOGY 2022; 28:3489-3514. [PMID: 35315565 PMCID: PMC9314624 DOI: 10.1111/gcb.16141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/30/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
In 2020, the Australian and New Zealand flux research and monitoring network, OzFlux, celebrated its 20th anniversary by reflecting on the lessons learned through two decades of ecosystem studies on global change biology. OzFlux is a network not only for ecosystem researchers, but also for those 'next users' of the knowledge, information and data that such networks provide. Here, we focus on eight lessons across topics of climate change and variability, disturbance and resilience, drought and heat stress and synergies with remote sensing and modelling. In distilling the key lessons learned, we also identify where further research is needed to fill knowledge gaps and improve the utility and relevance of the outputs from OzFlux. Extreme climate variability across Australia and New Zealand (droughts and flooding rains) provides a natural laboratory for a global understanding of ecosystems in this time of accelerating climate change. As evidence of worsening global fire risk emerges, the natural ability of these ecosystems to recover from disturbances, such as fire and cyclones, provides lessons on adaptation and resilience to disturbance. Drought and heatwaves are common occurrences across large parts of the region and can tip an ecosystem's carbon budget from a net CO2 sink to a net CO2 source. Despite such responses to stress, ecosystems at OzFlux sites show their resilience to climate variability by rapidly pivoting back to a strong carbon sink upon the return of favourable conditions. Located in under-represented areas, OzFlux data have the potential for reducing uncertainties in global remote sensing products, and these data provide several opportunities to develop new theories and improve our ecosystem models. The accumulated impacts of these lessons over the last 20 years highlights the value of long-term flux observations for natural and managed systems. A future vision for OzFlux includes ongoing and newly developed synergies with ecophysiologists, ecologists, geologists, remote sensors and modellers.
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48
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Blasini DE, Koepke DF, Bush SE, Allan GJ, Gehring CA, Whitham TG, Day TA, Hultine KR. Tradeoffs between leaf cooling and hydraulic safety in a dominant arid land riparian tree species. PLANT, CELL & ENVIRONMENT 2022; 45:1664-1681. [PMID: 35147232 DOI: 10.1111/pce.14292] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Leaf carbon gain optimization in hot environments requires balancing leaf thermoregulation with avoiding excessive water loss via transpiration and hydraulic failure. The tradeoffs between leaf thermoregulation and transpirational water loss can determine the ecological consequences of heat waves that are increasing in frequency and intensity. We evaluated leaf thermoregulation strategies in warm- (>40°C maximum summer temperature) and cool-adapted (<40°C maximum summer temperature) genotypes of the foundation tree species, Populus fremontii, using a common garden near the mid-elevational point of its distribution. We measured leaf temperatures and assessed three modes of leaf thermoregulation: leaf morphology, midday canopy stomatal conductance and stomatal sensitivity to vapour pressure deficit. Data were used to parameterize a leaf energy balance model to estimate contrasts in midday leaf temperature in warm- and cool-adapted genotypes. Warm-adapted genotypes had 39% smaller leaves and 38% higher midday stomatal conductance, reflecting a 3.8°C cooler mean leaf temperature than cool-adapted genotypes. Leaf temperatures modelled over the warmest months were on average 1.1°C cooler in warm- relative to cool-adapted genotypes. Results show that plants adapted to warm environments are predisposed to tightly regulate leaf temperatures during heat waves, potentially at an increased risk of hydraulic failure.
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Affiliation(s)
- Davis E Blasini
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Dan F Koepke
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, USA
| | - Susan E Bush
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, USA
| | - Gerard J Allan
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Catherine A Gehring
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Thomas G Whitham
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Thomas A Day
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, USA
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49
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Pan L, George-Jaeggli B, Borrell A, Jordan D, Koller F, Al-Salman Y, Ghannoum O, Cano FJ. Coordination of stomata and vein patterns with leaf width underpins water-use efficiency in a C 4 crop. PLANT, CELL & ENVIRONMENT 2022; 45:1612-1630. [PMID: 34773276 DOI: 10.1111/pce.14225] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 10/08/2021] [Accepted: 11/05/2021] [Indexed: 06/13/2023]
Abstract
Despite its importance for crop water use and productivity, especially in drought-affected environments, the underlying mechanisms of variation in intrinsic water-use efficiency (iWUE = net photosynthesis/stomatal conductance for water vapour, gsw ) are not well understood, especially in C4 plants. Recently, we discovered that leaf width (LW) correlated negatively with iWUE and positively with gsw across several C4 grasses. Here, we confirmed these relationships within 48 field-grown genotypes differing in LW in Sorghum bicolor, a C4 crop adapted to dry and hot conditions. We measured leaf gas exchange and modelled leaf energy balance three times a day, alongside anatomical traits as potential predictors of iWUE. LW correlated negatively with iWUE and stomatal density, but positively with gsw , interveinal distance of longitudinal veins, and the percentage of stomatal aperture relative to maximum. Energy balance modelling showed that wider leaves needed to open their stomata more to generate a more negative leaf-to-air temperature difference, especially at midday when air temperatures exceeded 40°C. These results highlight the important role that LW plays in shaping iWUE through coordination of vein and stomatal traits and by affecting stomatal aperture. Therefore, LW could be used as a predictor of higher iWUE among sorghum genotypes.
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Affiliation(s)
- Ling Pan
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, China
- College of Forestry, Hainan University, Haikou, Hainan, China
| | - Barbara George-Jaeggli
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Queensland Alliance for Agriculture and Food Innovation, Hermitage Research Facility, The University of Queensland, Warwick, Queensland, Australia
- Department of Agriculture and Fisheries, Agri-Science Queensland, Hermitage Research Facility, Warwick, Queensland, Australia
| | - Andrew Borrell
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Queensland Alliance for Agriculture and Food Innovation, Hermitage Research Facility, The University of Queensland, Warwick, Queensland, Australia
| | - David Jordan
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Queensland Alliance for Agriculture and Food Innovation, Hermitage Research Facility, The University of Queensland, Warwick, Queensland, Australia
| | - Fiona Koller
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Yazen Al-Salman
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Oula Ghannoum
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Francisco J Cano
- ARC Centre of Excellence for Translational Photosynthesis, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Centro de Investigación Forestal (CIFOR), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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Posch BC, Hammer J, Atkin OK, Bramley H, Ruan YL, Trethowan R, Coast O. Wheat photosystem II heat tolerance responds dynamically to short- and long-term warming. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:erac039. [PMID: 35604885 PMCID: PMC9127437 DOI: 10.1093/jxb/erac039] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 01/31/2022] [Indexed: 05/10/2023]
Abstract
Wheat photosynthetic heat tolerance can be characterized using minimal chlorophyll fluorescence to quantify the critical temperature (Tcrit) above which incipient damage to the photosynthetic machinery occurs. We investigated intraspecies variation and plasticity of wheat Tcrit under elevated temperature in field and controlled-environment experiments, and assessed whether intraspecies variation mirrored interspecific patterns of global heat tolerance. In the field, wheat Tcrit varied diurnally-declining from noon through to sunrise-and increased with phenological development. Under controlled conditions, heat stress (36 °C) drove a rapid (within 2 h) rise in Tcrit that peaked after 3-4 d. The peak in Tcrit indicated an upper limit to PSII heat tolerance. A global dataset [comprising 183 Triticum and wild wheat (Aegilops) species] generated from the current study and a systematic literature review showed that wheat leaf Tcrit varied by up to 20 °C (roughly two-thirds of reported global plant interspecies variation). However, unlike global patterns of interspecies Tcrit variation that have been linked to latitude of genotype origin, intraspecific variation in wheat Tcrit was unrelated to that. Overall, the observed genotypic variation and plasticity of wheat Tcrit suggest that this trait could be useful in high-throughput phenotyping of wheat photosynthetic heat tolerance.
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Affiliation(s)
- Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Julia Hammer
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
- Department of Biology, The University of Western Ontario, 1151 Richmond St, N6A 3K7, London, Canada
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Helen Bramley
- Plant Breeding Institute, Sydney Institute of Agriculture & School of Life and Environmental Sciences, The University of Sydney, Narrabri, NSW 2390, Australia
| | - Yong-Ling Ruan
- Australia-China Research Centre for Crop Improvement and School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Richard Trethowan
- Plant Breeding Institute, Sydney Institute of Agriculture & School of Life and Environmental Sciences, The University of Sydney, Narrabri, NSW 2390, Australia
- School of Life and Environmental Sciences, Plant Breeding Institute, Sydney Institute of Agriculture, The University of Sydney, Cobbitty, NSW 2570, Australia
| | - Onoriode Coast
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
- School of Environmental and Rural Sciences, University of New England, Armidale, NSW 2351, Australia
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