51
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Traversari S, Neri A, Traversi ML, Giovannelli A, Francini A, Sebastiani L. Daily osmotic adjustments in stem may be good predictors of water stress intensity in poplar. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 146:13-22. [PMID: 31710921 DOI: 10.1016/j.plaphy.2019.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Drought events impair the carbon and water balances in plants. Climate changes highlight the importance to understand the limits of woody species to reallocate carbon in different processes and the mechanisms driving the osmotic adjustments during the day under stress. In this frame, the aim of this work was to investigate the plant capability to shift energy among competing sinks and preserve the osmotic balance during the day under severe short periods of water deficit. The role of carbohydrates as osmolytes as well as energy sources was investigated in poplar plants. Results highlighted that during water deficit soluble sugars, derived both from the new synthetised carbon and starch degradation, were principally convoyed in the bark. This increase in carbohydrates allowed the maintenance of a water reserve used during the day to prevent a water decrease within the xylem. The decrease of xylem sap osmotic potential during the night, driven by an increase of K, Ca, and fructose (+0.46, 0.52, and 0.26 mg ml-1 in water limited plants after 8 days of withholding water, respectively), probably further attracted water into the xylem. This response mechanism increased at higher water deficit intensity. The little variations in carbohydrates and mineral elements within the leaves highlighted the main role of sinks rather than sources in the early response to water deficit.
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Affiliation(s)
- Silvia Traversari
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy
| | - Andrea Neri
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy
| | - Maria Laura Traversi
- Research Institute on Terrestrial Ecosystems (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto F.no, Florence, Italy
| | - Alessio Giovannelli
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy; Research Institute on Terrestrial Ecosystems (IRET-CNR), Via Madonna del Piano 10, 50019, Sesto F.no, Florence, Italy
| | - Alessandra Francini
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy.
| | - Luca Sebastiani
- BioLabs Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy
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52
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Han Q, Guo Q, Korpelainen H, Niinemets Ü, Li C. Rootstock determines the drought resistance of poplar grafting combinations. TREE PHYSIOLOGY 2019; 39:1855-1866. [PMID: 31595965 DOI: 10.1093/treephys/tpz102] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/09/2019] [Accepted: 09/12/2019] [Indexed: 06/10/2023]
Abstract
To increase yield and/or enhance resistance to diseases, grafting is often applied in agriculture and horticulture. Interspecific grafting could possibly be used in forestry as well to improve drought resistance, but our understanding of how the rootstock of a more drought-resistant species can affect the grafted plant is very limited. Reciprocal grafts of two poplar species, Populus cathayana Rehder (less drought-resistant, C) and Populus deltoides Bart. ex Marsh (more drought-resistant, D) were generated. Four grafting combinations (scion/rootstock: C/C, C/D, D/D and D/C) were subjected to well-watered and drought stress treatments. C/D and D/C had a higher diameter growth rate, leaf biomass, intrinsic water-use efficiency (WUEi) and total non-structural carbohydrate (NSC) content than C/C and D/D in well-watered condition. However, drought caused greater differences between P. deltoides-rooted and P. cathayana-rooted grafting combinations, especially between C/D and D/C. The C/D grafting combination showed higher resistance to drought, as indicated by a higher stem growth rate, net photosynthetic rate, WUEi, leaf water potential, proline concentration and NSC concentration and maintenance of integrity of the leaf cellular ultrastructure under drought when compared with D/C. D/C exhibited severely damaged cell membranes, mitochondria and chloroplasts under drought. The scion genotype caused a strong effect on the root proline concentration: the P. cathayana scion increased the root proline concentration more than the P. deltoides scion (C/C vs D/C and C/D vs D/D) under water deficit. Our results demonstrated that mainly the rootstock was responsible for the drought resistance of grafting combinations. Grafting of the P. cathayana scion onto P. deltoides rootstock resulted in superior growth and biomass when compared with the other three combinations both in well-watered and drought stress conditions.
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Affiliation(s)
- Qingquan Han
- Institute of Physical Education, Ludong University, Yantai 264025, China
| | - Qingxue Guo
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Helena Korpelainen
- Department of Agricultural Sciences, Viikki Plant Science Centre, PO Box 27, University of Helsinki, FI-00014 Helsinki, Finland
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia
- Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia
| | - Chunyang Li
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
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53
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Carbon Limitation and Drought Sensitivity at Contrasting Elevation and Competition of Abies pinsapo Forests. Does Experimental Thinning Enhance Water Supply and Carbohydrates? FORESTS 2019. [DOI: 10.3390/f10121132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Stand-level competition and local climate influence tree responses to increased drought at the regional scale. To evaluate stand density and elevation effects on tree carbon and water balances, we monitored seasonal changes in sap-flow density (SFD), gas exchange, xylem water potential, secondary growth, and non-structural carbohydrates (NSCs) in Abies pinsapo. Trees were subjected to experimental thinning within a low-elevation stand (1200 m), and carbon and water balances were compared to control plots at low and high elevation (1700 m). The hydraulic conductivity and the resistance to cavitation were also characterized, showing relatively high values and no significant differences among treatments. Trees growing at higher elevations presented the highest SFD, photosynthetic rates, and secondary growth, mainly because their growing season was extended until summer. Trees growing at low elevation reduced SFD during late spring and summer while SFD and secondary growth were significantly higher in the thinned stands. Declining NSC concentrations in needles, branches, and sapwood suggest drought-induced control of the carbon supply status. Our results might indicate potential altitudinal shifts, as better performance occurs at higher elevations, while thinning may be suitable as adaptive management to mitigate drought effects in endangered Mediterranean trees.
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54
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Vitali V, Ramirez JA, Perrette G, Delagrange S, Paquette A, Messier C. Complex Above- and Below-Ground Growth Responses of Two Urban Tree Species Following Root, Stem, and Foliage Damage-An Experimental Approach. FRONTIERS IN PLANT SCIENCE 2019; 10:1100. [PMID: 31620144 PMCID: PMC6759508 DOI: 10.3389/fpls.2019.01100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Urban trees are subjected to numerous biotic and mechanical damages, which can affect their growth rates and health. However, for most species, a systematic analysis of tree above- and below-ground growth reactions to a variety of damages is still lacking. Under a fully factorial experimental setup, using two common urban trees (Celtis occidentalis, Fraxinus pennsylvanica), we tested the effects of various degrees of frequently occurring damage as defoliation, root reduction, and stem injuries for a total of 18 treatments. We hypothesized that (i) an increasing amount of damage would proportionally negatively affect both root and stem growth; (ii) there would be a lag or lasting effect on growth; and (iii) both species would react similarly to the treatments. Contrary to our expectation, increasing levels of single or combined damage did not have an incremental effect on either stem or root growth. Although Celtis was significantly less vigorous than Fraxinus, it did not react strongly to damage treatments compared to the control. Interestingly, Celtis that experienced stem damage alone or in combination with other damages showed higher growth rates than the control. For Celtis, root injury was the treatment having the most impact, decreasing both root and stem growth consistently throughout the 5 years following treatments, whereas defoliation decreased growth only in the first 2 years. All damage treatments negatively affected stem and root growth of Fraxinus trees. Stem growth was affected the most by defoliation in the first year following the treatment, while root injury became the driving factor in subsequent years. For both species, stem injury showed the least influence on growth rates. The control and low-level damage treatments often affected growth rates in a similar way, suggesting that low-intensity stress triggers compensatory reactions stimulating photosynthetic rates and nutrient utilization. The slower-growing tree species, Celtis, showed a less negative reaction to all damage treatments compared to Fraxinus. This study illustrates that various types of above- and below-ground injuries do not have a simple additive effect on tree growth and that trees are capable of compensating for the loss of foliage, roots, or phloem to meet their metabolic demand.
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Affiliation(s)
- Valentina Vitali
- Faculté des sciences, Département des sciences biologiques, Centre d’Étude de la Forêt (CEF), Université du Québec à Montréal, Montréal, Canada
| | - Jorge A. Ramirez
- Faculté des sciences, Département des sciences biologiques, Centre d’Étude de la Forêt (CEF), Université du Québec à Montréal, Montréal, Canada
- Facultad de Ciencias Agrarias, Universidad del Cauca, Popayán, Colombia
| | - Guillaume Perrette
- Faculté des sciences, Département des sciences biologiques, Centre d’Étude de la Forêt (CEF), Université du Québec à Montréal, Montréal, Canada
| | - Sylvain Delagrange
- Institut des Sciences de la Foret Tempérée, Université du Québec en Outaouais, Ripon, Canada
| | - Alain Paquette
- Faculté des sciences, Département des sciences biologiques, Centre d’Étude de la Forêt (CEF), Université du Québec à Montréal, Montréal, Canada
| | - Christian Messier
- Faculté des sciences, Département des sciences biologiques, Centre d’Étude de la Forêt (CEF), Université du Québec à Montréal, Montréal, Canada
- Institut des Sciences de la Foret Tempérée, Université du Québec en Outaouais, Ripon, Canada
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55
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Blackman CJ, Creek D, Maier C, Aspinwall MJ, Drake JE, Pfautsch S, O'Grady A, Delzon S, Medlyn BE, Tissue DT, Choat B. Drought response strategies and hydraulic traits contribute to mechanistic understanding of plant dry-down to hydraulic failure. TREE PHYSIOLOGY 2019; 39:910-924. [PMID: 30865274 DOI: 10.1093/treephys/tpz016] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/01/2019] [Indexed: 05/17/2023]
Abstract
Drought-induced tree mortality alters forest structure and function, yet our ability to predict when and how different species die during drought remains limited. Here, we explore how stomatal control and drought tolerance traits influence the duration of drought stress leading to critical levels of hydraulic failure. We examined the growth and physiological responses of four woody plant species (three angiosperms and one conifer) representing a range of water-use and drought tolerance traits over the course of two controlled drought-recovery cycles followed by an extended dry-down. At the end of the final dry-down phase, we measured changes in biomass ratios and leaf carbohydrates. During the first and second drought phases, plants of all species closed their stomata in response to decreasing water potential, but only the conifer species avoided water potentials associated with xylem embolism as a result of early stomatal closure relative to thresholds of hydraulic dysfunction. The time it took plants to reach critical levels of water stress during the final dry-down was similar among the angiosperms (ranging from 39 to 57 days to stemP88) and longer in the conifer (156 days to stemP50). Plant dry-down time was influenced by a number of factors including species stomatal-hydraulic safety margin (gsP90 - stemP50), as well as leaf succulence and minimum stomatal conductance. Leaf carbohydrate reserves (starch) were not depleted at the end of the final dry-down in any species, irrespective of the duration of drought. These findings highlight the need to consider multiple structural and functional traits when predicting the timing of hydraulic failure in plants.
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Affiliation(s)
- Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Danielle Creek
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Chelsea Maier
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Michael J Aspinwall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, USA
| | - John E Drake
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Forest and Natural Resources Management, SUNY-ESF, 1 Forestry Drive, Syracuse, NY, USA
| | - Sebastian Pfautsch
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- School of Social Science and Psychology (Urban Studies), Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
| | | | | | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
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56
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Buckley TN, Sack L. The humidity inside leaves and why you should care: implications of unsaturation of leaf intercellular airspaces. AMERICAN JOURNAL OF BOTANY 2019; 106:618-621. [PMID: 31059119 PMCID: PMC6850086 DOI: 10.1002/ajb2.1282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 03/22/2019] [Indexed: 05/23/2023]
Affiliation(s)
| | - Lawren Sack
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCAUSA
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57
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Furze ME, Huggett BA, Aubrecht DM, Stolz CD, Carbone MS, Richardson AD. Whole-tree nonstructural carbohydrate storage and seasonal dynamics in five temperate species. THE NEW PHYTOLOGIST 2019; 221:1466-1477. [PMID: 30368825 PMCID: PMC6587558 DOI: 10.1111/nph.15462] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/25/2018] [Indexed: 05/17/2023]
Abstract
Despite the importance of nonstructural carbohydrates (NSC) for growth and survival in woody plants, we know little about whole-tree NSC storage. The conventional theory suggests that NSC reserves will increase over the growing season and decrease over the dormant season. Here, we compare storage in five temperate tree species to determine the size and seasonal fluctuation of whole-tree total NSC pools as well as the contribution of individual organs. NSC concentrations in the branches, stemwood, and roots of 24 trees were measured across 12 months. We then scaled up concentrations to the whole-tree and ecosystem levels using allometric equations and forest stand inventory data. While whole-tree total NSC pools followed the conventional theory, sugar pools peaked in the dormant season and starch pools in the growing season. Seasonal depletion of total NSCs was minimal at the whole-tree level, but substantial at the organ level, particularly in branches. Surprisingly, roots were not the major storage organ as branches stored comparable amounts of starch throughout the year, and root reserves were not used to support springtime growth. Scaling up NSC concentrations to the ecosystem level, we find that commonly used, process-based ecosystem and land surface models all overpredict NSC storage.
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Affiliation(s)
- Morgan E. Furze
- Department of Organismic and Evolutionary BiologyHarvard University26 Oxford StCambridgeMA02138USA
| | | | - Donald M. Aubrecht
- Department of Organismic and Evolutionary BiologyHarvard University26 Oxford StCambridgeMA02138USA
| | - Claire D. Stolz
- Department of Organismic and Evolutionary BiologyHarvard University26 Oxford StCambridgeMA02138USA
| | - Mariah S. Carbone
- Center for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffAZ86011USA
- Department of Biological SciencesNorthern Arizona UniversityFlagstaffAZ86011USA
| | - Andrew D. Richardson
- Center for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffAZ86011USA
- School of Informatics, Computing, and Cyber SystemsNorthern Arizona UniversityFlagstaffAZ86011USA
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58
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Allocation Mechanisms of Non-Structural Carbohydrates of Robinia pseudoacacia L. Seedlings in Response to Drought and Waterlogging. FORESTS 2018. [DOI: 10.3390/f9120754] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Climate change is likely to lead to an increased frequency of droughts and floods, both of which are implicated in large-scale carbon allocation and tree mortality worldwide. Non-structural carbohydrates (NSCs) play an important role in tree survival under stress, but how NSC allocation changes in response to drought or waterlogging is still unclear. We measured soluble sugars (SS) and starch in leaves, twigs, stems and roots of Robinia pseudoacacia L. seedlings that had been subjected to a gradient in soil water availability from extreme drought to waterlogged conditions for a period of 30 days. Starch concentrations decreased and SS concentrations increased in tissues of R. pseudoacacia seedlings, such that the ratio of SS to starch showed a progressive increase under both drought and waterlogging stress. The strength of the response is asymmetric, with the largest increase occurring under extreme drought. While the increase in SS concentration in response to extreme drought is the largest in roots, the increase in the ratio of SS to starch is the largest in leaves. Individual components of SS showed different responses to drought and waterlogging across tissues: glucose concentrations increased significantly with drought in all tissues but showed little response to waterlogging in twigs and stems; sucrose and fructose concentrations showed marked increases in leaves and roots in response to drought but a greater response to drought and waterlogging in stems and twigs. These changes are broadly compatible with the roles of individual SS under conditions of water stress. While it is important to consider the role of NSC in buffering trees against mortality under stress, modelling this behaviour is unlikely to be successful unless it accounts for different responses within organs and the type of stress involved.
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59
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Landhäusser SM, Chow PS, Dickman LT, Furze ME, Kuhlman I, Schmid S, Wiesenbauer J, Wild B, Gleixner G, Hartmann H, Hoch G, McDowell NG, Richardson AD, Richter A, Adams HD. Standardized protocols and procedures can precisely and accurately quantify non-structural carbohydrates. TREE PHYSIOLOGY 2018; 38:1764-1778. [PMID: 30376128 PMCID: PMC6301340 DOI: 10.1093/treephys/tpy118] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/02/2018] [Indexed: 05/08/2023]
Abstract
Non-structural carbohydrates (NSCs), the stored products of photosynthesis, building blocks for growth and fuel for respiration, are central to plant metabolism, but their measurement is challenging. Differences in methods and procedures among laboratories can cause results to vary widely, limiting our ability to integrate and generalize patterns in plant carbon balance among studies. A recent assessment found that NSC concentrations measured for a common set of samples can vary by an order of magnitude, but sources for this variability were unclear. We measured a common set of nine plant material types, and two synthetic samples with known NSC concentrations, using a common protocol for sugar extraction and starch digestion, and three different sugar quantification methods (ion chromatography, enzyme, acid) in six laboratories. We also tested how sample handling, extraction solvent and centralizing parts of the procedure in one laboratory affected results. Non-structural carbohydrate concentrations measured for synthetic samples were within about 11.5% of known values for all three methods. However, differences among quantification methods were the largest source of variation in NSC measurements for natural plant samples because the three methods quantify different NSCs. The enzyme method quantified only glucose, fructose and sucrose, with ion chromatography we additionally quantified galactose, while the acid method quantified a large range of mono- and oligosaccharides. For some natural samples, sugars quantified with the acid method were two to five times higher than with other methods, demonstrating that trees allocate carbon to a range of sugar molecules. Sample handling had little effect on measurements, while ethanol sugar extraction improved accuracy over water extraction. Our results demonstrate that reasonable accuracy of NSC measurements can be achieved when different methods are used, as long as protocols are robust and standardized. Thus, we provide detailed protocols for the extraction, digestion and quantification of NSCs in plant samples, which should improve the comparability of NSC measurements among laboratories.
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Affiliation(s)
- Simon M Landhäusser
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
- Corresponding author ()
| | - Pak S Chow
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - L Turin Dickman
- Los Alamos National Laboratory, Earth and Environmental Sciences, Los Alamos, NM, USA
| | - Morgan E Furze
- Harvard University, Department of Organismic and Evolutionary Biology, 26 Oxford Street, Cambridge, MA, USA
| | - Iris Kuhlman
- Max Planck Institute for Biogeochemistry, Hans-Knöll Str. 10, Jena, Germany
| | - Sandra Schmid
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, Basel, Switzerland
| | - Julia Wiesenbauer
- University of Vienna, Department of Microbiology and Ecosystem Science, Althanstraße 14, Vienna, Austria
| | - Birgit Wild
- Stockholm University, Department of Environmental Science and Analytical Chemistry, Stockholm, Sweden
- University of Gothenburg, Department of Earth Sciences, Guldhedsgatan 5 A, Gothenburg, Sweden
| | - Gerd Gleixner
- Max Planck Institute for Biogeochemistry, Hans-Knöll Str. 10, Jena, Germany
| | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, Hans-Knöll Str. 10, Jena, Germany
| | - Günter Hoch
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, Basel, Switzerland
| | | | - Andrew D Richardson
- Harvard University, Department of Organismic and Evolutionary Biology, 26 Oxford Street, Cambridge, MA, USA
- Northern Arizona University, Center for Ecosystem Science and Society and School of Informatics, Computing and Cyber Systems, Flagstaff, AZ, USA
| | - Andreas Richter
- University of Vienna, Department of Microbiology and Ecosystem Science, Althanstraße 14, Vienna, Austria
| | - Henry D Adams
- Oklahoma State University, Department of Plant Biology, Ecology, and Evolution, 301 Physical Sciences, Stillwater, OK, USA
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60
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Li W, Hartmann H, Adams HD, Zhang H, Jin C, Zhao C, Guan D, Wang A, Yuan F, Wu J. The sweet side of global change-dynamic responses of non-structural carbohydrates to drought, elevated CO2 and nitrogen fertilization in tree species. TREE PHYSIOLOGY 2018; 38:1706-1723. [PMID: 29897549 DOI: 10.1093/treephys/tpy059] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Non-structural carbohydrates (NSC) play a central role in plant functioning as energy carriers and building blocks for primary and secondary metabolism. Many studies have investigated how environmental and anthropogenic changes, like increasingly frequent and severe drought episodes, elevated CO2 and atmospheric nitrogen (N) deposition, influence NSC concentrations in individual trees. However, this wealth of data has not been analyzed yet to identify general trends using a common statistical framework. A thorough understanding of tree responses to global change is required for making realistic predictions of vegetation dynamics. Here we compiled data from 57 experimental studies on 71 tree species and conducted a meta-analysis to evaluate general responses of stored soluble sugars, starch and total NSC (soluble sugars + starch) concentrations in different tree organs (foliage, above-ground wood and roots) to drought, elevated CO2 and N deposition. We found that drought significantly decreased total NSC in roots (-17.3%), but not in foliage and above-ground woody tissues (bole, branch, stem and/or twig). Elevated CO2 significantly increased total NSC in foliage (+26.2%) and roots (+12.8%), but not in above-ground wood. By contrast, total NSC significantly decreased in roots (-17.9%), increased in above-ground wood (+6.1%), but was unaffected in foliage from N fertilization. In addition, the response of NSC to three global change drivers was strongly affected by tree taxonomic type, leaf habit, tree age and treatment intensity. Our results pave the way for a better understanding of general tree function responses to drought, elevated CO2 and N fertilization. The existing data also reveal that more long-term studies on mature trees that allow testing interactions between these factors are urgently needed to provide a basis for forecasting tree responses to environmental change at the global scale.
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Affiliation(s)
- Weibin Li
- State Key Laboratory of Grassland and Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Henrik Hartmann
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, Jena, Germany
| | - Henry D Adams
- Department of Plant Biology, Ecology and Evolution, Oklahoma State University, Stillwater, OK, USA
| | - Hongxia Zhang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Changjie Jin
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Chuanyan Zhao
- State Key Laboratory of Grassland and Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Dexin Guan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Anzhi Wang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Fenghui Yuan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Jiabing Wu
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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61
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Jin Y, Li J, Liu C, Liu Y, Zhang Y, Sha L, Wang Z, Song Q, Lin Y, Zhou R, Chen A, Li P, Fei X, Grace J. Carbohydrate dynamics of three dominant species in a Chinese savanna under precipitation exclusion. TREE PHYSIOLOGY 2018; 38:1371-1383. [PMID: 29474710 DOI: 10.1093/treephys/tpy017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
The potential impact of drought on the carbon balance in plants has gained great attention. Non-structural carbohydrate (NSC) dynamics have been suggested as an important trait reflecting carbon balance under drought conditions. However, NSC dynamics under drought and the response mechanisms of NSC to drought remain unclear, especially in water-limited savanna ecosystems. A precipitation exclusion experiment was performed to simulate different drought intensities in a savanna ecosystem in Yuanjiang valley in southwestern China. Growth, total NSC concentration and diurnal change of NSC were determined for the leaves and non-photosynthetic organs of three dominant species (Lannea coromandelica, Polyalthia cerasoides and Heteropogon contortus) throughout the growing season. Drought significantly reduced the growth of all the three species. Total NSC concentration averaged ~8.1%, varying with species, organ and sampling period, and did not significantly decrease under drought stress. By contrast, the diurnal change of NSC in these three species increased under drought stress. These results indicate that these three dominant species did not undergo carbon limitation. Thus, relative change in NSC is a more sensitive and effective indicator than carbon reserves in evaluation of plant carbon balance. These findings provide new insights for the understanding of carbon balance and the mechanisms of carbon starvation.
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Affiliation(s)
- Yanqiang Jin
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jing Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chenggang Liu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Yuntong Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Yiping Zhang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Liqing Sha
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Zhe Wang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, China
| | - Qinghai Song
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Youxing Lin
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruiwu Zhou
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Aiguo Chen
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, China
| | - Peiguang Li
- Yellow River Delta Ecological Research Station of Coastal Wetland, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Xuehai Fei
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - John Grace
- School of Geosciences, University of Edinburgh, Edinburgh, UK
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Feng X, Ackerly DD, Dawson TE, Manzoni S, Skelton RP, Vico G, Thompson SE. The ecohydrological context of drought and classification of plant responses. Ecol Lett 2018; 21:1723-1736. [DOI: 10.1111/ele.13139] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/12/2018] [Accepted: 07/16/2018] [Indexed: 01/20/2023]
Affiliation(s)
- Xue Feng
- Department of Civil, Environmental, and Geo‐Engineering University of Minnesota Minneapolis MN USA
| | - David D. Ackerly
- Department of Integrative Biology University of California Berkeley CA USA
| | - Todd E. Dawson
- Department of Integrative Biology University of California Berkeley CA USA
- Department of Environmental Sciences, Policy, and Management University of California Berkeley CA USA
| | - Stefano Manzoni
- Department of Physical Geography Stockholm University Stockholm Sweden
- Bolin Centre for Climate Research Stockholm Sweden
| | - Rob P. Skelton
- Department of Integrative Biology University of California Berkeley CA USA
| | - Giulia Vico
- Department of Crop Production Ecology Swedish University of Agricultural Sciences (SLU) Uppsala Sweden
| | - Sally E. Thompson
- Department of Civil and Environmental Engineering University of California Berkeley CA USA
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Xie D, Wu Z, Chen HYH, Wang Z, Wang Q, Yu D. Carbon Gain Limitation Is the Primary Mechanism for the Elevational Distribution Limit of Myriophyllum in the High-Altitude Plateau. FRONTIERS IN PLANT SCIENCE 2018; 9:1129. [PMID: 30116255 PMCID: PMC6083828 DOI: 10.3389/fpls.2018.01129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 07/12/2018] [Indexed: 06/08/2023]
Abstract
Temperature comprises a major driver for species distribution and physiological processes in alpine plants. For all terrestrial plant species tested to date, elevation associated decreases in temperature have been observed to influence the balance between carbon acquisition and usage; restricting the upper limit of most alpine trees (i.e., treeline). However, such a carbon source-sink balance has not been tested in any alpine aquatic plants, which is an important component of the alpine aquatic ecosystem. The Myriophyllum species inhabits a broad range of habitats across the high-altitude plateau. Three Myriophyllum species (Myriophyllum spicatum, Myriophyllum verticillatum, and Myriophyllum sibiricum) from 12 water bodies at elevational gradients between 2766 and 5111 m were collected in the Qinghai-Tibetan Plateau. The late growing seasonal concentrations of non-structural carbohydrates (NSC) in the leaves were measured to find how high-altitude conditions influence the carbon balance in aquatic plants. Regression tree analysis separated the 12 water bodies into two groups according to water turbidity (seven water bodies with high turbidity and five water bodies with low turbidity). Overall, leaf NSC concentrations (primarily starch) decreased significantly with increasing elevation in widely distributed M. spicatum and M. verticillatum. Regression tree analysis indicated that water turbidity (i.e., shady environment) was a strong determinant of leaf NSC. In the low turbidity group (<3.5 NTU), leaf NSC concentrations decreased with increasing elevation; however, in the high turbidity group (>3.5 NTU), leaf NSC concentrations were low and had no association with elevation. Unlike most recent studies in tree species, which show low temperatures limited growth at high-elevations, our results demonstrated that carbon gain limitation is the primary mechanism for the elevational distribution limit of Myriophyllum species in the Qinghai-Tibetan Plateau. Moreover, water turbidity moderated the effects of low temperature by masking the expected carbon limitation trend. Therefore, at least two environmental factors (i.e., temperature and light availability) induced photosynthesis decreases might explain the NSC responses for aquatic plants in response to elevation.
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Affiliation(s)
- Dong Xie
- The National Field Station of Freshwater Ecosystem in Liangzi Lake, College of Life Sciences, Wuhan University, Wuhan, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Zhigang Wu
- The National Field Station of Freshwater Ecosystem in Liangzi Lake, College of Life Sciences, Wuhan University, Wuhan, China
| | - Han Y. H. Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada
| | - Zhong Wang
- The National Field Station of Freshwater Ecosystem in Liangzi Lake, College of Life Sciences, Wuhan University, Wuhan, China
| | - Qiang Wang
- The National Field Station of Freshwater Ecosystem in Liangzi Lake, College of Life Sciences, Wuhan University, Wuhan, China
| | - Dan Yu
- The National Field Station of Freshwater Ecosystem in Liangzi Lake, College of Life Sciences, Wuhan University, Wuhan, China
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64
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Duan H, Chaszar B, Lewis JD, Smith RA, Huxman TE, Tissue DT. CO2 and temperature effects on morphological and physiological traits affecting risk of drought-induced mortality. TREE PHYSIOLOGY 2018; 38:1138-1151. [PMID: 29701843 DOI: 10.1093/treephys/tpy037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 03/21/2018] [Indexed: 06/08/2023]
Abstract
Despite a wealth of eco-physiological assessments of plant response to extreme drought, few studies have addressed the interactive effects of global change factors on traits driving mortality. To understand the interaction between hydraulic and carbon metabolic traits influencing tree mortality, which may be independently influenced by atmospheric [CO2] and temperature, we grew Eucalyptus sideroxylon A. Cunn. ex Woolls from seed in a full-factorial [CO2] (280, 400 and 640 μmol mol-1, Cp, Ca and Ce, respectively) and temperature (ambient and ambient +4 °C, Ta and Te, respectively) experiment. Prior to drought, growth across treatment combinations resulted in significant variation in physiological and morphological traits, including photosynthesis (Asat), respiration (Rd), stomatal conductance, carbohydrate storage, biomass and leaf area (LA). Ce increased Asat, LA and leaf carbohydrate concentration compared with Ca, while Cp generated the opposite response; Te reduced Rd. However, upon imposition of drought, Te hastened mortality (9 days sooner compared with Ta), while Ce significantly exacerbated drought stress when combined with Te. Across treatments, earlier time-to-mortality was mainly associated with lower (more negative) leaf water potential (Ψl) during the initial drought phase, along with higher water loss across the first 3 weeks of water limitation. Among many variables, Ψl was more important than carbon status in predicting time-to-mortality across treatments, yet leaf starch was associated with residual variation within treatments. These results highlight the need to carefully consider the integration, interaction and hierarchy of traits contributing to mortality, along with their responses to environmental drivers. Both morphological traits, which influence soil resource extraction, and physiological traits, which affect water-for-carbon exchange to the atmosphere, must be considered to adequately predict plant response to drought. Researchers have struggled with assessing the relative importance of hydraulic and carbon metabolic traits in determining mortality, yet an integrated trait, time-dependent framework provides considerable insight into the risk of death from drought for trees.
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Affiliation(s)
- Honglang Duan
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems & Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Brian Chaszar
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - James D Lewis
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Louis Calder Center - Biological Field Station and Department of Biological Sciences, Fordham University, Armonk, NY, USA
| | - Renee A Smith
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Travis E Huxman
- School of Biological Sciences, University of California, Irvine, CA, USA
| | - David T Tissue
- Hawkesbury Institute for the Environment, Hawkesbury Campus, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
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65
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Traversari S, Francini A, Traversi ML, Emiliani G, Sorce C, Sebastiani L, Giovannelli A. Can sugar metabolism in the cambial region explain the water deficit tolerance in poplar? JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4083-4097. [PMID: 29846657 PMCID: PMC6054210 DOI: 10.1093/jxb/ery195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/16/2018] [Indexed: 05/06/2023]
Abstract
Drought dramatically affects wood production by adversely impacting cambial cells and their derivatives. Photosynthesis and assimilate transport are also affected by drought conditions. Two poplar genotypes, Populus deltoides 'Dvina' and Populus alba 'Marte', demonstrated contrasting growth performance and water-carbon balance strategies; a mechanistic understanding of the water deficit response was provided by these poplar species. 'Marte' was found to be more anisohydric than 'Dvina'. This characteristic was associated with the capacity to reallocate carbohydrates during water deficits. In contrast, 'Dvina' displayed more conservative water management; carbohydrates were preferably stored or used for cellulose production rather than to achieve an osmotic balance between the phloem and the xylem. Data confirmed that the more 'risk-taking' characteristic of 'Marte' allowed a rapid recovery following water deficit and was connected to a different carbohydrate metabolism.
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Affiliation(s)
- Silvia Traversari
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
| | - Alessandra Francini
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
| | - Maria Laura Traversi
- Trees and Timber Institute (IVALSA-CNR), Via Madonna del Piano, Sesto F.no (Florence), Italy
| | - Giovanni Emiliani
- Trees and Timber Institute (IVALSA-CNR), Via Madonna del Piano, Sesto F.no (Florence), Italy
| | - Carlo Sorce
- Department of Biology, University of Pisa, Via Luca Ghini, Pisa, Italy
| | - Luca Sebastiani
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
| | - Alessio Giovannelli
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà, Pisa, Italy
- Trees and Timber Institute (IVALSA-CNR), Via Madonna del Piano, Sesto F.no (Florence), Italy
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66
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Rogers BM, Solvik K, Hogg EH, Ju J, Masek JG, Michaelian M, Berner LT, Goetz SJ. Detecting early warning signals of tree mortality in boreal North America using multiscale satellite data. GLOBAL CHANGE BIOLOGY 2018; 24:2284-2304. [PMID: 29481709 DOI: 10.1111/gcb.14107] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 02/12/2018] [Indexed: 05/19/2023]
Abstract
Increasing tree mortality from global change drivers such as drought and biotic infestations is a widespread phenomenon, including in the boreal zone where climate changes and feedbacks to the Earth system are relatively large. Despite the importance for science and management communities, our ability to forecast tree mortality at landscape to continental scales is limited. However, two independent information streams have the potential to inform and improve mortality forecasts: repeat forest inventories and satellite remote sensing. Time series of tree-level growth patterns indicate that productivity declines and related temporal dynamics often precede mortality years to decades before death. Plot-level productivity, in turn, has been related to satellite-based indices such as the Normalized difference vegetation index (NDVI). Here we link these two data sources to show that early warning signals of mortality are evident in several NDVI-based metrics up to 24 years before death. We focus on two repeat forest inventories and three NDVI products across western boreal North America where productivity and mortality dynamics are influenced by periodic drought. These data sources capture a range of forest conditions and spatial resolution to highlight the sensitivity and limitations of our approach. Overall, results indicate potential to use satellite NDVI for early warning signals of mortality. Relationships are broadly consistent across inventories, species, and spatial resolutions, although the utility of coarse-scale imagery in the heterogeneous aspen parkland was limited. Longer-term NDVI data and annually remeasured sites with high mortality levels generate the strongest signals, although we still found robust relationships at sites remeasured at a typical 5 year frequency. The approach and relationships developed here can be used as a basis for improving forest mortality models and monitoring systems.
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Affiliation(s)
| | | | - Edward H Hogg
- Northern Forestry Centre, Canadian Forest Service, Natural Resources Canada, Edmonton, AB, Canada
| | - Junchang Ju
- Biospheric Science Laboratory (Code 618), NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Jeffrey G Masek
- Biospheric Science Laboratory (Code 618), NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Michael Michaelian
- Northern Forestry Centre, Canadian Forest Service, Natural Resources Canada, Edmonton, AB, Canada
| | - Logan T Berner
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Scott J Goetz
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
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67
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Sevanto S. Drought impacts on phloem transport. CURRENT OPINION IN PLANT BIOLOGY 2018; 43:76-81. [PMID: 29448177 DOI: 10.1016/j.pbi.2018.01.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 01/03/2018] [Accepted: 01/13/2018] [Indexed: 05/27/2023]
Abstract
Drought impacts on phloem transport have attracted attention only recently, despite the well-established, and empirically verified theories on drought impacts on water transport in plants in general. This is because studying phloem transport is challenging. Phloem tissue is relatively small and delicate, and it has often been assumed not to be impacted by drought, or having insignificant impact on plant function or survival compared to the xylem. New evidence, however, suggests that drought responses of the phloem might hold the key for predicting plant survival time during drought or revival capacity after drought. This review summarizes current theories and empirical evidence on how drought might impact phloem transport, and evaluates these findings in relation to plant survival during drought.
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Affiliation(s)
- Sanna Sevanto
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545, USA.
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68
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Wiley E, Rogers BJ, Griesbauer HP, Landhäusser SM. Spruce shows greater sensitivity to recent warming than Douglas‐fir in central British Columbia. Ecosphere 2018. [DOI: 10.1002/ecs2.2221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Erin Wiley
- Department of Renewable Resources University of Alberta 442 Earth Sciences Building Edmonton Alberta T6G 2E3 Canada
| | - Bruce J. Rogers
- Omineca Research and Stewardship Team British Columbia Ministry of Forests Lands and Natural Resource Operations Prince George British Columbia V2N 4W5 Canada
| | - Hardy P. Griesbauer
- Omineca Research and Stewardship Team British Columbia Ministry of Forests Lands and Natural Resource Operations Prince George British Columbia V2N 4W5 Canada
| | - Simon M. Landhäusser
- Department of Renewable Resources University of Alberta 442 Earth Sciences Building Edmonton Alberta T6G 2E3 Canada
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69
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Hartmann H, Moura CF, Anderegg WRL, Ruehr NK, Salmon Y, Allen CD, Arndt SK, Breshears DD, Davi H, Galbraith D, Ruthrof KX, Wunder J, Adams HD, Bloemen J, Cailleret M, Cobb R, Gessler A, Grams TEE, Jansen S, Kautz M, Lloret F, O'Brien M. Research frontiers for improving our understanding of drought-induced tree and forest mortality. THE NEW PHYTOLOGIST 2018; 218:15-28. [PMID: 29488280 DOI: 10.1111/nph.15048] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 01/08/2018] [Indexed: 05/20/2023]
Abstract
Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit (VPD). Resulting forest die-off events have severe consequences for ecosystem services, biophysical and biogeochemical land-atmosphere processes. Despite advances in monitoring, modelling and experimental studies of the causes and consequences of tree death from individual tree to ecosystem and global scale, a general mechanistic understanding and realistic predictions of drought mortality under future climate conditions are still lacking. We update a global tree mortality map and present a roadmap to a more holistic understanding of forest mortality across scales. We highlight priority research frontiers that promote: (1) new avenues for research on key tree ecophysiological responses to drought; (2) scaling from the tree/plot level to the ecosystem and region; (3) improvements of mortality risk predictions based on both empirical and mechanistic insights; and (4) a global monitoring network of forest mortality. In light of recent and anticipated large forest die-off events such a research agenda is timely and needed to achieve scientific understanding for realistic predictions of drought-induced tree mortality. The implementation of a sustainable network will require support by stakeholders and political authorities at the international level.
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Affiliation(s)
- Henrik Hartmann
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, 07745, Jena, Germany
| | - Catarina F Moura
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, 07745, Jena, Germany
- Faculty of Sciences and Technology, NOVA University of Lisbon, Campus da Caparica, 2829-516, Caparica, Portugal
- Centre for Functional Ecology, Department of Life Sciences, Universilty of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | | | - Nadine K Ruehr
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany
| | - Yann Salmon
- School of Geosciences, University of Edinburgh, Crew Building, The Kings Buildings, Alexander Crum Brown Road, Edinburgh, EH9 3FF, UK
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, 00014, Helsinki, Finland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, 00014, Helsinki, Finland
| | - Craig D Allen
- US Geological Survey, Fort Collins Science Centre, New Mexico Landscapes Field Station, Los Alamos, NM, 87544, USA
| | - Stefan K Arndt
- School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, 3121, Vic., Australia
| | - David D Breshears
- School of Natural Resources and the Environment and Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
| | - Hendrik Davi
- INRA, URFM Ecologie des Forest Méditerranéennes, Domaine Saint Paul, Site Agroparc, 84914, Avignon Cedex 9, France
| | - David Galbraith
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Katinka X Ruthrof
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
- Botanic Gardens and Parks Authority, Fraser Avenue, Kings Park, WA, 6005, Australia
| | - Jan Wunder
- Insubric Ecosystems Research Group, Community Ecology, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, a Ramèl 18, CH-6593, Cadenazzo, Switzerland
- Tree-Ring Laboratory, School of Environment, University of Auckland, Auckland, 1142, New Zealand
| | - Henry D Adams
- Department of Plant Biology, Ecology, and Evolution, 301 Physical Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jasper Bloemen
- Institute of Ecology, University of Innsbruck, Sternwartestraße 15, 6020, Innsbruck, Austria
- Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium
| | - Maxime Cailleret
- Forest Ecology, Department of Environmental Sciences, ETH Zürich. ETH-Zentrum, CHN G77, Universitätstrasse 16, CH-8092, Zürich, Switzerland
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Richard Cobb
- Department of Natural Resources and Environmental Science, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
| | - Arthur Gessler
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technical University of Munich, Von-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Markus Kautz
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany
| | - Francisco Lloret
- CREAF - Centre for Ecological Research and Applied Forestry, Cerdanyola del Vallès, Barcelona, Spain
- Unitat d'Ecologia, Department of Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma Barcelona, Edifici C, Campus UAB, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Michael O'Brien
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Carretera de Sacramento s/n, E-04120 La Cañada, Almería, Spain
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70
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Kannenberg SA, Novick KA, Phillips RP. Coarse roots prevent declines in whole-tree non-structural carbohydrate pools during drought in an isohydric and an anisohydric species. TREE PHYSIOLOGY 2018; 38:582-590. [PMID: 29036648 DOI: 10.1093/treephys/tpx119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/30/2017] [Indexed: 05/17/2023]
Abstract
Predicted increases in the frequency and severity of droughts have led to a renewed focus on how plants physiologically adjust to low water availability. A popular framework for understanding plant responses to drought characterizes species along a spectrum from isohydry to anisohydry based on their regulation of gas exchange and leaf water potential under drying conditions. One prediction that arises from this theory is that plant drought responses may hinge, in part, on their usage of non-structural carbohydrate (NSC) pools. For example, trees that respond to drought by closing stomates (i.e., isohydric) are predicted to deplete NSC reserves to maintain metabolism, whereas plants that keep stomata open during water stress (i.e., anisohydric), may show little change or even increases in NSC concentration. However, empirical tests of this theory largely rely on aboveground measurements of NSC, ignoring the potentially conflicting responses of root NSC pools. We sought to test these predictions by subjecting potted saplings of Quercus alba L. (an anisohydric species) and Liriodendron tulipifera L. (an isohydric species) to a 6 week experimental drought. We found that stem NSC concentrations were depleted in the isohydric L. tulipifera but maintained in the anisohydric Q. alba-as predicted. However, when scaled to whole-plant NSC content, the drought-induced decreases in stem NSCs in L. tulipifera were offset by increases in root NSCs (especially soluble sugars), resulting in no net change to whole-plant NSC content. Similarly, root sugars increased in Q. alba in response to drought. This increase was concurrent with declines in growth, suggesting a potential trade-off between allocation of photoassimilates to root sugars vs biomass during drought. Collectively, our results suggest that the responses of NSC in coarse roots can differ from stems, and indicate a prominent role of coarse roots in mitigating drought-induced declines in whole-tree NSC pools.
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Affiliation(s)
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, USA
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71
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Earles JM, Knipfer T, Tixier A, Orozco J, Reyes C, Zwieniecki MA, Brodersen CR, McElrone AJ. In vivo quantification of plant starch reserves at micrometer resolution using X-ray microCT imaging and machine learning. THE NEW PHYTOLOGIST 2018; 218:1260-1269. [PMID: 29516508 DOI: 10.1111/nph.15068] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/22/2018] [Indexed: 05/16/2023]
Abstract
Starch is the primary energy storage molecule used by most terrestrial plants to fuel respiration and growth during periods of limited to no photosynthesis, and its depletion can drive plant mortality. Destructive techniques at coarse spatial scales exist to quantify starch, but these techniques face methodological challenges that can lead to uncertainty about the lability of tissue-specific starch pools and their role in plant survival. Here, we demonstrate how X-ray microcomputed tomography (microCT) and a machine learning algorithm can be coupled to quantify plant starch content in vivo, repeatedly and nondestructively over time in grapevine stems (Vitis spp.). Starch content estimated for xylem axial and ray parenchyma cells from microCT images was correlated strongly with enzymatically measured bulk-tissue starch concentration on the same stems. After validating our machine learning algorithm, we then characterized the spatial distribution of starch concentration in living stems at micrometer resolution, and identified starch depletion in live plants under experimental conditions designed to halt photosynthesis and starch production, initiating the drawdown of stored starch pools. Using X-ray microCT technology for in vivo starch monitoring should enable novel research directed at resolving the spatial and temporal patterns of starch accumulation and depletion in woody plant species.
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Affiliation(s)
- J Mason Earles
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, 06511, USA
| | - Thorsten Knipfer
- Department of Viticulture and Enology, University of California, Davis, CA, 95616, USA
| | - Aude Tixier
- Department of Plant Sciences, University of California Davis, One Shields Ave., Davis, CA, 95616, USA
| | - Jessica Orozco
- Department of Plant Sciences, University of California Davis, One Shields Ave., Davis, CA, 95616, USA
| | - Clarissa Reyes
- Department of Viticulture and Enology, University of California, Davis, CA, 95616, USA
| | - Maciej A Zwieniecki
- Department of Plant Sciences, University of California Davis, One Shields Ave., Davis, CA, 95616, USA
| | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, 06511, USA
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, CA, 95616, USA
- Crops Pathology and Genetics Research Unit, USDA-ARS, Davis, CA, 95618, USA
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Das B, Sahoo RN, Pargal S, Krishna G, Verma R, Chinnusamy V, Sehgal VK, Gupta VK, Dash SK, Swain P. Quantitative monitoring of sucrose, reducing sugar and total sugar dynamics for phenotyping of water-deficit stress tolerance in rice through spectroscopy and chemometrics. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 192:41-51. [PMID: 29126007 DOI: 10.1016/j.saa.2017.10.076] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/30/2017] [Accepted: 10/31/2017] [Indexed: 05/21/2023]
Abstract
In the present investigation, the changes in sucrose, reducing and total sugar content due to water-deficit stress in rice leaves were modeled using visible, near infrared (VNIR) and shortwave infrared (SWIR) spectroscopy. The objectives of the study were to identify the best vegetation indices and suitable multivariate technique based on precise analysis of hyperspectral data (350 to 2500nm) and sucrose, reducing sugar and total sugar content measured at different stress levels from 16 different rice genotypes. Spectral data analysis was done to identify suitable spectral indices and models for sucrose estimation. Novel spectral indices in near infrared (NIR) range viz. ratio spectral index (RSI) and normalised difference spectral indices (NDSI) sensitive to sucrose, reducing sugar and total sugar content were identified which were subsequently calibrated and validated. The RSI and NDSI models had R2 values of 0.65, 0.71 and 0.67; RPD values of 1.68, 1.95 and 1.66 for sucrose, reducing sugar and total sugar, respectively for validation dataset. Different multivariate spectral models such as artificial neural network (ANN), multivariate adaptive regression splines (MARS), multiple linear regression (MLR), partial least square regression (PLSR), random forest regression (RFR) and support vector machine regression (SVMR) were also evaluated. The best performing multivariate models for sucrose, reducing sugars and total sugars were found to be, MARS, ANN and MARS, respectively with respect to RPD values of 2.08, 2.44, and 1.93. Results indicated that VNIR and SWIR spectroscopy combined with multivariate calibration can be used as a reliable alternative to conventional methods for measurement of sucrose, reducing sugars and total sugars of rice under water-deficit stress as this technique is fast, economic, and noninvasive.
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Affiliation(s)
- Bappa Das
- Division of Agricultural Physics, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Rabi N Sahoo
- Division of Agricultural Physics, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India.
| | - Sourabh Pargal
- Division of Agricultural Physics, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Gopal Krishna
- Division of Agricultural Physics, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Rakesh Verma
- Division of Plant Physiology, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Viswanathan Chinnusamy
- Division of Plant Physiology, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Vinay K Sehgal
- Division of Agricultural Physics, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Vinod K Gupta
- Division of Agricultural Physics, Indian Council for Agricultural Research - Indian Agricultural Research Institute, New Delhi 110012, India
| | - Sushanta K Dash
- Indian Council for Agricultural Research - National Rice Research Institute, Cuttack 753006, Odisha, India
| | - Padmini Swain
- Indian Council for Agricultural Research - National Rice Research Institute, Cuttack 753006, Odisha, India
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73
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Johnson DM, Domec JC, Carter Berry Z, Schwantes AM, McCulloh KA, Woodruff DR, Wayne Polley H, Wortemann R, Swenson JJ, Scott Mackay D, McDowell NG, Jackson RB. Co-occurring woody species have diverse hydraulic strategies and mortality rates during an extreme drought. PLANT, CELL & ENVIRONMENT 2018; 41:576-588. [PMID: 29314069 DOI: 10.1111/pce.13121] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 12/01/2017] [Indexed: 05/25/2023]
Abstract
From 2011 to 2013, Texas experienced its worst drought in recorded history. This event provided a unique natural experiment to assess species-specific responses to extreme drought and mortality of four co-occurring woody species: Quercus fusiformis, Diospyros texana, Prosopis glandulosa, and Juniperus ashei. We examined hypothesized mechanisms that could promote these species' diverse mortality patterns using postdrought measurements on surviving trees coupled to retrospective process modelling. The species exhibited a wide range of gas exchange responses, hydraulic strategies, and mortality rates. Multiple proposed indices of mortality mechanisms were inconsistent with the observed mortality patterns across species, including measures of the degree of iso/anisohydry, photosynthesis, carbohydrate depletion, and hydraulic safety margins. Large losses of spring and summer whole-tree conductance (driven by belowground losses of conductance) and shallower rooting depths were associated with species that exhibited greater mortality. Based on this retrospective analysis, we suggest that species more vulnerable to drought were more likely to have succumbed to hydraulic failure belowground.
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Affiliation(s)
- Daniel M Johnson
- College of Natural Resources, University of Idaho, Moscow, ID, 83844, USA
| | - Jean-Christophe Domec
- Bordeaux Sciences Agro, UMR INRA-ISPA 1391, Gradignan, 33195, France
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Z Carter Berry
- College of Natural Resources, University of Idaho, Moscow, ID, 83844, USA
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, 03824, USA
| | - Amanda M Schwantes
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | | | - David R Woodruff
- US Forest Service, Pacific Northwest Research Station, Corvallis, OR, 97331, USA
| | - H Wayne Polley
- Grassland, Soil & Water Research Laboratory USDA-Agricultural Research Service, Temple, TX, 76502, USA
| | - Remí Wortemann
- INRA Nancy, UMR INRA-UL 1137 Ecologie et Ecophysiologie Forestières, Champenoux, 54280, France
| | - Jennifer J Swenson
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - D Scott Mackay
- Department of Geography, State University of New York, Buffalo, NY, 14261, USA
| | - Nate G McDowell
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Robert B Jackson
- Department of Earth System Science, Woods Institute for the Environment, and Precourt Institute for Energy, Stanford University, Stanford, CA, 94305, USA
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74
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Dai Y, Wang L, Wan X. Relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality caused by drought. AOB PLANTS 2018; 10:plx069. [PMID: 29367873 PMCID: PMC5774510 DOI: 10.1093/aobpla/plx069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 11/30/2017] [Indexed: 05/29/2023]
Abstract
Drought-induced tree mortality has been observed worldwide. Nevertheless, the physiological mechanisms underlying this phenomenon are still being debated. Potted Robinia pseudoacacia and Platycladus orientalis saplings were subjected to drought and their hydraulic failure and carbon starvation responses were studied. They underwent simulated fast drought (FD) and slow drought (SD) until death. The dynamics of their growth, photosynthesis, water relations and carbohydrate concentration were measured. The results showed that during drought, growth and photosynthesis of all saplings were significantly reduced in both species. The predawn water potential in both species was ~ -8 MPa at mortality. The percentage loss of conductivity (PLC) was at a maximum at mortality under both FD and SD. For R. pseudoacacia and P. orientalis, they were >95 and ~45 %, respectively. At complete defoliation, the PLC of R. pseudoacacia was ~90 % but the trees continued to survive for around 46 days. The non-structural carbohydrate (NSC) concentrations in the stems and roots of both FD and SD R. pseudoacacia declined to a very low level near death. In contrast, the NSC concentrations in the needles, stems and roots of P. orientalis at mortality under FD did not significantly differ from those of the control, whereas the NSC concentrations in SD P. orientalis stems and roots at death were significantly lower than those of the control. These results suggest that the duration of the drought affected NSC at mortality in P. orientalis. In addition, the differences in NSC between FD and SD P. orientalis did not alter mortality thresholds associated with hydraulic failure. The drought-induced death of R. pseudoacacia occurred at 95 % PLC for both FD and SD, indicating that hydraulic failure played an important role in mortality. Nevertheless, the consistent decline in NSC in R. pseudoacacia saplings following drought-induced defoliation may have also contributed to its mortality.
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Affiliation(s)
- Yongxin Dai
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, P.R. China
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, P.R. China
| | - Lin Wang
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, P.R. China
| | - Xianchong Wan
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, P.R. China
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75
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Moran E, Lauder J, Musser C, Stathos A, Shu M. The genetics of drought tolerance in conifers. THE NEW PHYTOLOGIST 2017; 216:1034-1048. [PMID: 28895167 DOI: 10.1111/nph.14774] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/27/2017] [Indexed: 05/20/2023]
Abstract
Contents 1034 I. 1034 II. 1035 III. 1037 IV. 1038 V. 1042 VI. 1043 VII. 1045 References 1045 SUMMARY: As temperatures warm and precipitation patterns shift as a result of climate change, interest in the identification of tree genotypes that will thrive under more arid conditions has grown. In this review, we discuss the multiple definitions of 'drought tolerance' and the biological processes involved in drought responses. We describe the three major approaches taken in the study of genetic variation in drought responses, the advantages and shortcomings of each, and what each of these approaches has revealed about the genetic basis of adaptation to drought in conifers. Finally, we discuss how a greater knowledge of the genetics of drought tolerance may aid forest management, and provide recommendations for how future studies may overcome the limitations of past approaches. In particular, we urge a more direct focus on survival, growth and the traits that directly predict them (rather than on proxies, such as water use efficiency), combining research approaches with complementary strengths and weaknesses, and the inclusion of a wider range of taxa and life stages.
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Affiliation(s)
- Emily Moran
- UC Merced, 5200 N Lake Rd, Merced, CA, 95343, USA
| | | | - Cameron Musser
- Yale School of Forestry & Environmental Studies, 195 Prospect Street, New Haven, CT, 06511, USA
| | | | - Mengjun Shu
- UC Merced, 5200 N Lake Rd, Merced, CA, 95343, USA
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76
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Wiley E, Hoch G, Landhäusser SM. Dying piece by piece: carbohydrate dynamics in aspen (Populus tremuloides) seedlings under severe carbon stress. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5221-5232. [PMID: 29036658 PMCID: PMC5853906 DOI: 10.1093/jxb/erx342] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/14/2017] [Indexed: 05/17/2023]
Abstract
Carbon starvation as a mechanism of tree mortality is poorly understood. We exposed seedlings of aspen (Populus tremuloides) to complete darkness at 20 or 28 °C to identify minimum non-structural carbohydrate (NSC) concentrations at which trees die and to see if these levels vary between organs or with environmental conditions. We also first grew seedlings under different shade levels to determine if size affects survival time under darkness due to changes in initial NSC concentration and pool size and/or respiration rates. Darkness treatments caused a gradual dieback of tissues. Even after half the stem had died, substantial starch reserves were still present in the roots (1.3-3% dry weight), indicating limitations to carbohydrate remobilization and/or transport during starvation in the absence of water stress. Survival time decreased with increased temperature and with increasing initial shade level, which was associated with smaller biomass, higher respiration rates, and initially smaller NSC pool size. Dead tissues generally contained no starch, but sugar concentrations were substantially above zero and differed between organs (~2% in stems up to ~7.5% in leaves) and, at times, between temperature treatments and initial, pre-darkness shade treatments. Minimum root NSC concentrations were difficult to determine because dead roots quickly began to decompose, but we identify 5-6% sugar as a potential threshold for living roots. This variability may complicate efforts to identify critical NSC thresholds below which trees starve.
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Affiliation(s)
- Erin Wiley
- Department of Renewable Resources, University of Alberta, Edmonton, Canada
- Correspondence:
| | - Günter Hoch
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
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von Arx G, Arzac A, Fonti P, Frank D, Zweifel R, Rigling A, Galiano L, Gessler A, Olano JM. Responses of sapwood ray parenchyma and non‐structural carbohydrates of
Pinus sylvestris
to drought and long‐term irrigation. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12860] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Georg von Arx
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- SwissForestLab Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
| | - Alberto Arzac
- School of Ecology and Geography Siberian Federal University 79 Svobodny pr 660041 Krasnoyarsk Russia
- Departamento de Biología Vegetal y Ecología Facultad de Ciencia y Tecnología Universidad del País Vasco Barrio Sarriena s/n E–48940 Leioa Spain
| | - Patrick Fonti
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- SwissForestLab Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
| | - David Frank
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- SwissForestLab Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- Laboratory of Tree‐Ring Research University of Arizona Tucson AZ85721 USA
| | - Roman Zweifel
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- SwissForestLab Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
| | - Andreas Rigling
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- SwissForestLab Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
| | - Lucia Galiano
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest Snow and Landscape Research WSL Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
- SwissForestLab Zuercherstrasse 111 CH‐8903 Birmensdorf Switzerland
| | - José Miguel Olano
- Departamento de Ciencias Agroforestales EU de Ingenierías Agrarias iuFOR‐Universidad de Valladolid Campus Duques de Soria 42004 Soria Spain
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78
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Marias DE, Meinzer FC, Woodruff DR, McCulloh KA. Thermotolerance and heat stress responses of Douglas-fir and ponderosa pine seedling populations from contrasting climates. TREE PHYSIOLOGY 2017; 37:301-315. [PMID: 28008081 DOI: 10.1093/treephys/tpw117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
Temperature and the frequency and intensity of heat waves are predicted to increase throughout the 21st century. Germinant seedlings are expected to be particularly vulnerable to heat stress because they are in the boundary layer close to the soil surface where intense heating occurs in open habitats. We quantified leaf thermotolerance and whole-plant physiological responses to heat stress in first-year germinant seedlings in two populations each of Pinus ponderosa P. and C. Lawson (PIPO) and Pseudotsuga menziesii (Mirb.) Franco (PSME) from climates with contrasting precipitation and temperature regimes. Thermotolerance of detached needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. PSME was more heat tolerant than PIPO according to both independent assessments of thermotolerance. Following exposure of whole seedlings to a simulated heat wave at 45 °C for 1 h in a growth chamber, we monitored FV/FM, photosynthesis, stomatal conductance, non-structural carbohydrates (NSCs) and carbon isotope ratios (δ13C) for 14 days. Heat treatment induced significant reductions in FV/FM in both species and a transient reduction in photosynthetic gas exchange only in PIPO 1 day after treatment. Heat treatment induced an increase in glucose + fructose concurrent with a decrease in starch in both species, whereas total NSC and sucrose were not affected by heat treatment. The negative relationship between glucose + fructose and starch observed in treated plants may be due to the conversion of starch to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites displayed greater δ13C values than those from wetter sites, consistent with higher intrinsic water-use efficiency and drought resistance of populations from drier climates. Thermotolerance and heat stress responses appeared to be phenotypically plastic and representative of the environment in which plants were grown, whereas intrinsic water-use efficiency appeared to reflect ecotypic differentiation and the climate of origin.
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Affiliation(s)
- Danielle E Marias
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA
| | - Frederick C Meinzer
- USDA Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
| | - David R Woodruff
- USDA Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
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79
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Carbohydrate reserves in the facilitator cushion plant Laretia acaulis suggest carbon limitation at high elevation and no negative effects of beneficiary plants. Oecologia 2017; 183:997-1006. [PMID: 28233055 DOI: 10.1007/s00442-017-3840-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 02/10/2017] [Indexed: 10/20/2022]
Abstract
The elevational range of the alpine cushion plant Laretia acaulis (Apiaceae) comprises a cold upper extreme and a dry lower extreme. For this species, we predict reduced growth and increased non-structural carbohydrate (NSC) concentrations (i.e. carbon sink limitation) at both elevational extremes. In a facilitative interaction, these cushions harbor other plant species (beneficiaries). Such interactions appear to reduce reproduction in other cushion species, but not in L. acaulis. However, vegetative effects may be more important in this long-lived species and may be stronger under marginal conditions. We studied growth and NSC concentrations in leaves and stems of L. acaulis collected from cushions along its full elevational range in the Andes of Central Chile. NSC concentrations were lowest and cushions were smaller and much less abundant at the highest elevation. At the lowest elevation, NSC concentrations and cushion sizes were similar to those of intermediate elevations but cushions were somewhat less abundant. NSC concentrations and growth did not change with beneficiary cover at any elevation. Lower NSC concentrations at the upper extreme contradict the sink-limitation hypothesis and may indicate that a lack of warmth is not limiting growth at high-elevation. At the lower extreme, carbon gain and growth do not appear more limiting than at intermediate elevations. The lower population density at both extremes suggests that the regeneration niche exerts important limitations to this species' distribution. The lack of an effect of beneficiaries on reproduction and vegetative performance suggests that the interaction between L. acaulis and its beneficiaries is probably commensalistic.
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80
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O'Brien MJ, Engelbrecht BMJ, Joswig J, Pereyra G, Schuldt B, Jansen S, Kattge J, Landhäusser SM, Levick SR, Preisler Y, Väänänen P, Macinnis-Ng C. A synthesis of tree functional traits related to drought-induced mortality in forests across climatic zones. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.12874] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Michael J. O'Brien
- Estación Experimental de Zonas Áridas; Consejo Superior de Investigaciones Científicas; Carretera de Sacramento s/n E-04120 La Cañada Almería Spain
- Department of Evolutionary Biology and Environmental Studies; University of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Bettina M. J. Engelbrecht
- Department of Plant Ecology; Bayreuth Center for Ecology and Environmental Research; University of Bayreuth; 95440 Bayreuth Germany
- Smithsonian Tropical Research Institute; Apartado 0843-03092 Balboa Ancon Republic of Panama
| | - Julia Joswig
- Max-Plank Institute for Biogeochemistry; Hans-Knöll-Str. 10 07745 Jena Germany
| | - Gabriela Pereyra
- Max-Plank Institute for Biogeochemistry; Hans-Knöll-Str. 10 07745 Jena Germany
| | - Bernhard Schuldt
- Plant Ecology; Albrecht von Haller Institute for Plant Sciences; University of Göttingen; UntereKarspüle 2 37073 Göttingen Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Jens Kattge
- Max-Plank Institute for Biogeochemistry; Hans-Knöll-Str. 10 07745 Jena Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e 04103 Leipzig Germany
| | - Simon M. Landhäusser
- Department of Renewable Resources; University of Alberta; Edmonton AB T6G 2E3 Canada
| | - Shaun R. Levick
- Max-Plank Institute for Biogeochemistry; Hans-Knöll-Str. 10 07745 Jena Germany
| | - Yakir Preisler
- Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture; The Hebrew University of Jerusalem; PO Box 12 Rehovot 76100 Israel
- Department of Earth and Planetary Science; Weizmann Institute of Science; Rehovot Israel
| | - Päivi Väänänen
- Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture; The Hebrew University of Jerusalem; PO Box 12 Rehovot 76100 Israel
| | - Cate Macinnis-Ng
- School of Biological Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
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81
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Liu JF, Arend M, Yang WJ, Schaub M, Ni YY, Gessler A, Jiang ZP, Rigling A, Li MH. Effects of drought on leaf carbon source and growth of European beech are modulated by soil type. Sci Rep 2017; 7:42462. [PMID: 28195166 PMCID: PMC5307967 DOI: 10.1038/srep42462] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 01/11/2017] [Indexed: 02/01/2023] Open
Abstract
Drought potentially affects carbon balance and growth of trees, but little is known to what extent soil plays a role in the trade-off between carbon gain and growth investment. In the present study, we analyzed leaf non-structural carbohydrates (NSC) as an indicator of the balance of photosynthetic carbon gain and carbon use, as well as growth of European beech (Fagus sylvatica L.) saplings, which were grown on two different soil types (calcareous and acidic) in model ecosystems and subjected to a severe summer drought. Our results showed that drought led in general to increased total NSC concentrations and to decreased growth rate, and drought reduced shoot and stem growth of plants in acidic soil rather than in calcareous soil. This result indicated that soil type modulated the carbon trade-off between net leaf carbon gain and carbon investment to growth. In drought-stressed trees, leaf starch concentration and growth correlated negatively whereas soluble sugar:starch ratio and growth correlated positively, which may contribute to a better understanding of growth regulation under drought conditions. Our results emphasize the role of soil in determining the trade-off between the balance of carbon gain and carbon use on the leaf level and growth under stress (e.g. drought).
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Affiliation(s)
- Jian-Feng Liu
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland
| | - Matthias Arend
- Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland
- Institute of Botany, University of Basel, Basel, Switzerland
| | - Wen-Juan Yang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Marcus Schaub
- Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland
| | - Yan-Yan Ni
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Arthur Gessler
- Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
| | - Ze-Ping Jiang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Andreas Rigling
- Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland
| | - Mai-He Li
- Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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82
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Quentin AG, Rodemann T, Doutreleau MF, Moreau M, Davies NW, Millard P. Application of near-infrared spectroscopy for estimation of non-structural carbohydrates in foliar samples of Eucalyptus globulus Labilladière. TREE PHYSIOLOGY 2017; 37:131-141. [PMID: 28173560 DOI: 10.1093/treephys/tpw083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 05/05/2016] [Accepted: 07/24/2016] [Indexed: 05/26/2023]
Abstract
Near-infrared reflectance spectroscopy (NIRS) is frequently used for the assessment of key nutrients of forage or crops but remains underused in ecological and physiological studies, especially to quantify non-structural carbohydrates. The aim of this study was to develop calibration models to assess the content in soluble sugars (fructose, glucose, sucrose) and starch in foliar material of Eucalyptus globulus. A partial least squares (PLS) regression was used on the sample spectral data and was compared to the contents measured using standard wet chemistry methods. The calibration models were validated using a completely independent set of samples. We used key indicators such as the ratio of prediction to deviation (RPD) and the range error ratio to give an assessment of the performance of the calibration models. Accurate calibration models were obtained for fructose and sucrose content (R2 > 0.85, root mean square error of prediction (RMSEP) of 0.95%–1.26% in the validation models), followed by sucrose and total soluble sugar content (R2 ~ 0.70 and RMSEP > 2.3%). In comparison to the others, calibration of the starch model performed very poorly with RPD = 1.70. This study establishes the ability of the NIRS calibration model to infer soluble sugar content in foliar samples of E. globulus in a rapid and cost-effective way. We suggest a complete redevelopment of the starch analysis using more specific quantification such as an HPLC-based technique to reach higher performance in the starch model. Overall, NIRS could serve as a high-throughput phenotyping tool to study plant response to stress factors.
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Affiliation(s)
- A G Quentin
- CSIRO Land and Water, Private Bag 12, Hobart, Tasmania, Australia
| | - T Rodemann
- Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, Tasmania , Australia
| | - M-F Doutreleau
- Agri'Terr Unit, Esitpa, 3 rue du Tronquet, Mont-Saint-Aignan, France
| | - M Moreau
- Agri'Terr Unit, Esitpa, 3 rue du Tronquet, Mont-Saint-Aignan, France
| | - N W Davies
- Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, Tasmania , Australia
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83
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Zhang Q, Shao M, Jia X, Wei X. Relationship of Climatic and Forest Factors to Drought- and Heat-Induced Tree Mortality. PLoS One 2017; 12:e0169770. [PMID: 28095437 PMCID: PMC5240974 DOI: 10.1371/journal.pone.0169770] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/21/2016] [Indexed: 11/19/2022] Open
Abstract
Tree mortality due to warming and drought is a critical aspect of forest ecosystem in responding to climate change. Spatial patterns of tree mortality induced by drought and its influencing factors, however, have yet to be documented at the global scale. We collected observations from 248 sites globally where trees have died due to drought and then assessed the effects of climatic and forest factors on the rate of tree mortality. The global mean annual mortality rate was 5.5%. The rate of tree mortality was significantly and negatively correlated with mean annual precipitation (P < 0.01). Tree mortality was lowest in tropical rainforests with mean annual precipitation >2000 mm and was severe in regions with mean annual precipitation <1000 mm. Mortality rates varied amongst species. The global annual rate of mortality was much higher for gymnosperms (7.1%) than angiosperms (4.8%) but did not differ significantly between evergreen (6.2%) and deciduous (6.1%) species. Stand age and wood density affected the mortality rate. Saplings (4.6%) had a higher mortality rate than mature trees (3.2%), and mortality rates significantly decreased with increasing wood density for all species (P < 0.01). We therefore concluded that the tree mortality around the globe varied with climatic and forest factors. The differences between tree species, wood density, stand density, and stand age should be considered when evaluating tree mortality at a large spatial scale during future climatic extremes.
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Affiliation(s)
- Qingyin Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Ming’an Shao
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province, China
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi Province, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- * E-mail: (MS); (XJ)
| | - Xiaoxu Jia
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- * E-mail: (MS); (XJ)
| | - Xiaorong Wei
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi Province, China
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84
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Rodríguez-Calcerrada J, Li M, López R, Cano FJ, Oleksyn J, Atkin OK, Pita P, Aranda I, Gil L. Drought-induced shoot dieback starts with massive root xylem embolism and variable depletion of nonstructural carbohydrates in seedlings of two tree species. THE NEW PHYTOLOGIST 2017; 213:597-610. [PMID: 27575435 DOI: 10.1111/nph.14150] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/12/2016] [Indexed: 05/17/2023]
Abstract
Combining hydraulic- and carbon-related measurements helps to understand drought-induced plant mortality. Here, we investigated the role that plant respiration (R) plays in determining carbon budgets under drought. We measured the hydraulic conductivity of stems and roots, and gas exchange and nonstructural carbohydrate (NSC) concentrations of leaves, stems and roots of seedlings of two resprouting species exposed to drought or well-watered conditions: Ulmus minor (riparian tree) and Quercus ilex (dryland tree). With increasing water stress (occurring more rapidly in larger U. minor), declines in leaf, stem and root R were less pronounced than that in leaf net photosynthetic CO2 uptake (Pn ). Daytime whole-plant carbon gain was negative below -4 and -6 MPa midday xylem water potential in U. minor and Q. ilex, respectively. Relative to controls, seedlings exhibiting shoot dieback suffered c. 80% loss of hydraulic conductivity in both species, and reductions in NSC concentrations in U. minor. Higher drought-induced depletion of NSC reserves in U. minor was related to higher plant R, faster stomatal closure, and premature leaf-shedding. Differences in drought resistance relied on the ability to maintain hydraulic conductivity during drought, rather than tolerating conductivity loss. Root hydraulic failure elicited shoot dieback and precluded resprouting without root NSC reserves being apparently limiting for R.
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Affiliation(s)
- Jesús Rodríguez-Calcerrada
- Forest History, Physiology and Genetics Research Group, School of Forestry Engineering, Technical University of Madrid, Madrid, 28040, Spain
| | - Meng Li
- Forest History, Physiology and Genetics Research Group, School of Forestry Engineering, Technical University of Madrid, Madrid, 28040, Spain
| | - Rosana López
- Forest History, Physiology and Genetics Research Group, School of Forestry Engineering, Technical University of Madrid, Madrid, 28040, Spain
- Hawkesbury Institute for the Environment, UWS, Science Road, Richmond, 2753, NSW, Australia
| | - Francisco Javier Cano
- Forest History, Physiology and Genetics Research Group, School of Forestry Engineering, Technical University of Madrid, Madrid, 28040, Spain
- Hawkesbury Institute for the Environment, UWS, Science Road, Richmond, 2753, NSW, Australia
| | - Jacek Oleksyn
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, 62-035, Poland
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Building 134, Canberra, ACT, 2601, Australia
| | - Pilar Pita
- Forest History, Physiology and Genetics Research Group, School of Forestry Engineering, Technical University of Madrid, Madrid, 28040, Spain
| | - Ismael Aranda
- Department of Forest Ecology and Genetics, Forest Research Centre, INIA, Avda. A Coruña km 7.5, 28040, Madrid, Spain
| | - Luis Gil
- Forest History, Physiology and Genetics Research Group, School of Forestry Engineering, Technical University of Madrid, Madrid, 28040, Spain
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85
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Nardini A, Savi T, Trifilò P, Lo Gullo MA. Drought Stress and the Recovery from Xylem Embolism in Woody Plants. PROGRESS IN BOTANY VOL. 79 2017. [DOI: 10.1007/124_2017_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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86
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Martínez-Vilalta J, Sala A, Asensio D, Galiano L, Hoch G, Palacio S, Piper FI, Lloret F. Dynamics of non-structural carbohydrates in terrestrial plants: a global synthesis. ECOL MONOGR 2016. [DOI: 10.1002/ecm.1231] [Citation(s) in RCA: 319] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jordi Martínez-Vilalta
- CREAF; Cerdanyola del Vallès E-08193 Barcelona Spain
- Universitat Autònoma Barcelona; Cerdanyola del Vallès E-08193 Barcelona Spain
| | - Anna Sala
- Division of Biological Sciences; University of Montana; Missoula Montana 59812 USA
| | | | - Lucía Galiano
- Swiss Federal Research Institute WSL; CH-8903 Birmensdorf Switzerland
- Institute of Hydrology; University of Freiburg; Freiburg D-79098 Germany
| | - Günter Hoch
- Department of Environmental Sciences-Botany; University of Basel; 4056 Basel Switzerland
| | - Sara Palacio
- Instituto Pirenaico de Ecología (IPE-CSIC); Avenida Nuestra Señora de la Victoria 16 22700 Jaca Spain
| | - Frida I. Piper
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP); Simpson 471 Coyhaique Chile
- Instituto de Ecología y Biodiversidad; Las Palmeras 3425 Santiago Chile
| | - Francisco Lloret
- CREAF; Cerdanyola del Vallès E-08193 Barcelona Spain
- Universitat Autònoma Barcelona; Cerdanyola del Vallès E-08193 Barcelona Spain
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87
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Savi T, Casolo V, Luglio J, Bertuzzi S, Trifilo' P, Lo Gullo MA, Nardini A. Species-specific reversal of stem xylem embolism after a prolonged drought correlates to endpoint concentration of soluble sugars. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 106:198-207. [PMID: 27174138 DOI: 10.1016/j.plaphy.2016.04.051] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 05/23/2023]
Abstract
Recent reports on tree mortality associated with anomalous drought and heat have raised interest into processes underlying tree resistance/resilience to water stress. Hydraulic failure and carbon starvation have been proposed as main causes of tree decline, with recent theories treating water and carbon metabolism as interconnected processes. We subjected young plants of two native (Quercus pubescens [Qp] and Prunus mahaleb [Pm]) and two invasive (Robinia pseudoacacia [Rp] and Ailanthus altissima [Aa]) woody angiosperms to a prolonged drought leading to stomatal closure and xylem embolism, to induce carbon starvation and hydraulic failure. At the end of the treatment, plants were measured for embolism rates and NSC content, and re-irrigated to monitor recovery of xylem hydraulics. Data highlight different hydraulic strategies in native vs invasive species under water stress, and provide physiological explanations for species-specific impacts of recent severe droughts. Drought-sensitive species (Qp and Rp) suffered high embolism rates and were unable to completely refill xylem conduits upon restoration of water availability. Species that better survived recent droughts were able to limit embolism build-up (Pm) or efficiently restored hydraulic functionality after irrigation (Aa). Species-specific capacity to reverse xylem embolism correlated to stem-level concentration of soluble carbohydrates, but not to starch content.
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Affiliation(s)
- Tadeja Savi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Valentino Casolo
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, Viale delle Scienze 91, 33100 Udine, Italy
| | - Jessica Luglio
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Stefano Bertuzzi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Patrizia Trifilo'
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Maria A Lo Gullo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy.
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88
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Seidel H, Menzel A. Above-Ground Dimensions and Acclimation Explain Variation in Drought Mortality of Scots Pine Seedlings from Various Provenances. FRONTIERS IN PLANT SCIENCE 2016; 7:1014. [PMID: 27458477 PMCID: PMC4935725 DOI: 10.3389/fpls.2016.01014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/27/2016] [Indexed: 05/04/2023]
Abstract
Seedling establishment is a critical part of the life cycle, thus seedling survival might be even more important for forest persistence under recent and future climate change. Scots pine forests have been disproportionally more affected by climate change triggered forest-dieback. Nevertheless, some Scots pine provenances might prove resilient to future drought events because of the species' large distributional range, genetic diversity, and adaptation potential. However, there is a lack of knowledge on provenance-specific survival under severe drought events and on how acclimation alters survival rates in Scots pine seedlings. We therefore conducted two drought-induced mortality experiments with potted Scots pine seedlings in a greenhouse. In the first experiment, 760 three-year-old seedlings from 12 different provenances of the south-western distribution range were subjected to the same treatment followed by the mortality experiment in 2014. In the second experiment, we addressed the question of whether acclimation to re-occurring drought stress events and to elevated temperature might decrease mortality rates. Thus, 139 four-year-old seedlings from France, Germany, and Poland were subjected to different temperature regimes (2012-2014) and drought treatments (2013-2014) before the mortality experiment in 2015. Provenances clearly differed in their hazard of drought-induced mortality, which was only partly related to the climate of their origin. Drought acclimation decreased the hazard of drought-induced mortality. Above-ground dry weight and height were the main determinants for the hazard of mortality, i.e., heavier and taller seedlings were more prone to mortality. Consequently, Scots pine seedlings exhibit a considerable provenance-specific acclimation potential against drought mortality and the selection of suitable provenances might thus facilitate seedling establishment and the persistence of Scots pine forest.
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Affiliation(s)
- Hannes Seidel
- Professorship of Ecoclimatology, Department of Ecology and Ecosystem Management, TUM School of Life Sciences Weihenstephan, Technische Universität MünchenFreising, Germany
| | - Annette Menzel
- Professorship of Ecoclimatology, Department of Ecology and Ecosystem Management, TUM School of Life Sciences Weihenstephan, Technische Universität MünchenFreising, Germany
- Institute for Advanced Study, Technische Universität MünchenGarching, Germany
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89
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Hartmann H, Trumbore S. Understanding the roles of nonstructural carbohydrates in forest trees - from what we can measure to what we want to know. THE NEW PHYTOLOGIST 2016; 211:386-403. [PMID: 27061438 DOI: 10.1111/nph.13955] [Citation(s) in RCA: 280] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/01/2016] [Indexed: 05/17/2023]
Abstract
Contents 386 I. 386 II. 388 III. 392 IV. 392 V. 396 VI. 399 399 References 399 SUMMARY: Carbohydrates provide the building blocks for plant structures as well as versatile resources for metabolic processes. The nonstructural carbohydrates (NSC), mainly sugars and starch, fulfil distinct functional roles, including transport, energy metabolism and osmoregulation, and provide substrates for the synthesis of defence compounds or exchange with symbionts involved in nutrient acquisition or defence. At the whole-plant level, NSC storage buffers the asynchrony of supply and demand on diel, seasonal or decadal temporal scales and across plant organs. Despite its central role in plant function and in stand-level carbon cycling, our understanding of storage dynamics, its controls and response to environmental stresses is very limited, even after a century of research. This reflects the fact that often storage is defined by what we can measure, that is, NSC concentrations, and the interpretation of these as a proxy for a single function, storage, rather than the outcome of a range of NSC source and sink functions. New isotopic tools allow direct quantification of timescales involved in NSC dynamics, and show that NSC-C fixed years to decades previously is used to support tree functions. Here we review recent advances, with emphasis on the context of the interactions between NSC, drought and tree mortality.
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Affiliation(s)
- Henrik Hartmann
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, 07745, Jena, Germany
| | - Susan Trumbore
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, 07745, Jena, Germany
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90
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Dynamic allocation and transfer of non-structural carbohydrates, a possible mechanism for the explosive growth of Moso bamboo (Phyllostachys heterocycla). Sci Rep 2016; 6:25908. [PMID: 27181522 PMCID: PMC4867622 DOI: 10.1038/srep25908] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 04/25/2016] [Indexed: 11/08/2022] Open
Abstract
Moso bamboo can rapidly complete its growth in both height and diameter within only 35-40 days after shoot emergence. However, the underlying mechanism for this "explosive growth" remains poorly understood. We investigated the dynamics of non-structural carbohydrates (NSCs) in shoots and attached mature bamboos over a 20-month period. The results showed that Moso bamboos rapidly completed their height and diameter growth within 38 days. At the same time, attached mature bamboos transferred almost all the NSCs of their leaves, branches, and especially trunks and rhizomes to the "explosively growing" shoots via underground rhizomes for the structural growth and metabolism of shoots. Approximately 4 months after shoot emergence, this transfer stopped when the leaves of the young bamboos could independently provide enough photoassimilates to meet the carbon demands of the young bamboos. During this period, the NSC content of the leaves, branches, trunks and rhizomes of mature bamboos declined by 1.5, 23, 28 and 5 fold, respectively. The trunk contributed the most NSCs to the shoots. Our findings provide new insight and a possible rational mechanism explaining the "explosive growth" of Moso bamboo and shed new light on understanding the role of NSCs in the rapid growth of Moso bamboo.
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91
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Mitchell PJ, O'Grady AP, Pinkard EA, Brodribb TJ, Arndt SK, Blackman CJ, Duursma RA, Fensham RJ, Hilbert DW, Nitschke CR, Norris J, Roxburgh SH, Ruthrof KX, Tissue DT. An ecoclimatic framework for evaluating the resilience of vegetation to water deficit. GLOBAL CHANGE BIOLOGY 2016; 22:1677-1689. [PMID: 26643922 DOI: 10.1111/gcb.13177] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/18/2015] [Indexed: 06/05/2023]
Abstract
The surge in global efforts to understand the causes and consequences of drought on forest ecosystems has tended to focus on specific impacts such as mortality. We propose an ecoclimatic framework that takes a broader view of the ecological relevance of water deficits, linking elements of exposure and resilience to cumulative impacts on a range of ecosystem processes. This ecoclimatic framework is underpinned by two hypotheses: (i) exposure to water deficit can be represented probabilistically and used to estimate exposure thresholds across different vegetation types or ecosystems; and (ii) the cumulative impact of a series of water deficit events is defined by attributes governing the resistance and recovery of the affected processes. We present case studies comprising Pinus edulis and Eucalyptus globulus, tree species with contrasting ecological strategies, which demonstrate how links between exposure and resilience can be examined within our proposed framework. These examples reveal how climatic thresholds can be defined along a continuum of vegetation functional responses to water deficit regimes. The strength of this framework lies in identifying climatic thresholds on vegetation function in the absence of more complete mechanistic understanding, thereby guiding the formulation, application and benchmarking of more detailed modelling.
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Affiliation(s)
| | - Anthony P O'Grady
- CSIRO Land and Water, 15 College Rd, Sandy Bay, TAS, 7005, Australia
| | | | - Timothy J Brodribb
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7005, Australia
| | - Stefan K Arndt
- School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, VIC, 3121, Australia
| | - Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Science Rd, Richmond, NSW, 2753, Australia
| | - Remko A Duursma
- Hawkesbury Institute for the Environment, Western Sydney University, Science Rd, Richmond, NSW, 2753, Australia
| | - Rod J Fensham
- Queensland Herbarium, Environmental Protection Agency, Mount Coot-tha Road, Toowong, QLD, 4066, Australia
- School of Biological Sciences, University of Queensland, Chancellors Pl., St Lucia, QLD, 4072, Australia
| | - David W Hilbert
- CSIRO Ecosystem Sciences, Tropical Forest Research Centre, Atherton, QLD, 4883, Australia
| | - Craig R Nitschke
- School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, VIC, 3121, Australia
| | - Jaymie Norris
- Department of Environment, Land, Water and Planning, Victorian Government, Melbourne, VIC, 3000, Australia
| | - Stephen H Roxburgh
- CSIRO Land and Water, Clunies Ross St, Black Mountain, ACT, 2601, Australia
| | - Katinka X Ruthrof
- Centre of Excellence for Climate Change, Woodland and Forest Health, School of Veterinary and Life Sciences Murdoch University, 90 South St, Murdoch, WA, 6150, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Science Rd, Richmond, NSW, 2753, Australia
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92
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Meta-analysis reveals that hydraulic traits explain cross-species patterns of drought-induced tree mortality across the globe. Proc Natl Acad Sci U S A 2016; 113:5024-9. [PMID: 27091965 DOI: 10.1073/pnas.1525678113] [Citation(s) in RCA: 331] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Drought-induced tree mortality has been observed globally and is expected to increase under climate change scenarios, with large potential consequences for the terrestrial carbon sink. Predicting mortality across species is crucial for assessing the effects of climate extremes on forest community biodiversity, composition, and carbon sequestration. However, the physiological traits associated with elevated risk of mortality in diverse ecosystems remain unknown, although these traits could greatly improve understanding and prediction of tree mortality in forests. We performed a meta-analysis on species' mortality rates across 475 species from 33 studies around the globe to assess which traits determine a species' mortality risk. We found that species-specific mortality anomalies from community mortality rate in a given drought were associated with plant hydraulic traits. Across all species, mortality was best predicted by a low hydraulic safety margin-the difference between typical minimum xylem water potential and that causing xylem dysfunction-and xylem vulnerability to embolism. Angiosperms and gymnosperms experienced roughly equal mortality risks. Our results provide broad support for the hypothesis that hydraulic traits capture key mechanisms determining tree death and highlight that physiological traits can improve vegetation model prediction of tree mortality during climate extremes.
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93
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Baer A, Wheeler JK, Pittermann J. Not dead yet: the seasonal water relations of two perennial ferns during California's exceptional drought. THE NEW PHYTOLOGIST 2016; 210:122-132. [PMID: 26660879 DOI: 10.1111/nph.13770] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/17/2015] [Indexed: 06/05/2023]
Abstract
The understory of the redwood forests of California's coast harbors perennial ferns, including Polystichum munitum and Dryopteris arguta. Unusual for ferns, these species are adapted to the characteristic Mediterranean-type dry season, but the mechanisms of tolerance have not been studied. The water relations of P. munitum and D. arguta were surveyed for over a year, including measures of water potential (Ψ), stomatal conductance (gs) and frond stipe hydraulic conductivity (K). A dehydration and re-watering experiment on potted P. munitum plants corroborated the field data. The seasonal Ψ varied from 0 to below -3 MPa in both species, with gs and K generally tracking Ψ; the loss of K rarely exceeded 80%. Quantile regression analysis showed that, at the 0.1 quantile, 50% of K was lost at -2.58 and -3.84 MPa in P. munitum and D. arguta, respectively. The hydraulic recovery of re-watered plants was attributed to capillarity. The seasonal water relations of P. munitum and D. arguta are variable, but consistent with laboratory-based estimates of drought tolerance. Hydraulic and Ψ recovery following rain allows perennial ferns to survive severe drought, but prolonged water deficit, coupled with insect damage, may hamper frond survival. The legacy effects of drought on reproductive capacity and community dynamics are unknown.
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Affiliation(s)
- Alex Baer
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95064, USA
| | - James K Wheeler
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95064, USA
| | - Jarmila Pittermann
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95064, USA
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94
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Atkin O. New Phytologist: bridging the 'plant function - climate modelling divide'. THE NEW PHYTOLOGIST 2016; 209:1329-1332. [PMID: 26840246 DOI: 10.1111/nph.13876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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95
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Du B, Jansen K, Kleiber A, Eiblmeier M, Kammerer B, Ensminger I, Gessler A, Rennenberg H, Kreuzwieser J. A coastal and an interior Douglas fir provenance exhibit different metabolic strategies to deal with drought stress. TREE PHYSIOLOGY 2016; 36:148-63. [PMID: 26491053 DOI: 10.1093/treephys/tpv105] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 09/04/2015] [Indexed: 05/28/2023]
Abstract
Drought is a major environmental stress affecting growth and vitality of forest ecosystems. In the present study, foliar nitrogen (N) and carbon (C) metabolism of two Douglas fir (Pseudotsuga menziesii) provenances with assumed different drought tolerance were investigated. We worked with 1-year-old seedlings of the interior provenance Fehr Lake (FEHR) originating from a dry environment and the coastal provenance Snoqualmie (SNO) from a more humid origin. Total C and N, structural N and the concentrations of soluble protein, total amino acids (TAAs) and individual amino acids as well as the relative abundance of polar, low-molecular-weight metabolites including antioxidants were determined in current-year needles exposed either to 42 days of drought or to 42 days drought plus 14 days of rewatering. The seedlings reacted in a provenance-specific manner to drought stress. Coastal provenance SNO showed considerably increased contents of TAAs, which were caused by increased abundance of the quantitatively most important amino acids arginine, ornithine and lysine. Additionally, the polyamine putrescine accumulated exclusively in drought-stressed trees of this provenance. In contrast, the interior provenance FEHR showed the opposite response, i.e., drastically reduced concentrations of these amino acids. However, FEHR showed considerably increased contents of pyruvate-derived and aromatic amino acids, and also higher drought-induced levels of the antioxidants ascorbate and α-tocopherol. In response to drought, both provenances produced large amounts of carbohydrates, such as glucose and fructose, most likely as osmolytes that can readily be metabolized for protection against osmotic stress. We conclude that FEHR and SNO cope with drought stress in a provenance-specific manner: the coastal provenance SNO was mainly synthesizing N-based osmolytes, a reaction not observed in the interior provenance FEHR; instead, the latter increased the levels of scavengers of reactive oxygen species. Our results underline the importance of provenance-specific reactions to abiotic stress.
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Affiliation(s)
- Baoguo Du
- Key Laboratory for Ecological Security and Protection of Sichuan Province, Mianyang Normal University, Mianxing Road West 166, 621000 Mianyang, China Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 53, 79110 Freiburg, Germany
| | - Kirstin Jansen
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany
| | - Anita Kleiber
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 53, 79110 Freiburg, Germany
| | - Monika Eiblmeier
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 53, 79110 Freiburg, Germany
| | - Bernd Kammerer
- Core Facility Metabolomics, Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs-Universität Freiburg, Habsburgerstr. 49, 79104 Freiburg, Germany
| | - Ingo Ensminger
- Department of Biology, Graduate Programs in Cell and Systems Biology and Ecology and Evolutionary Biology, University of Toronto, 3359 Mississauga Road, Mississauga, ON, Canada L5L 1C6 Forstliche Versuchs- und Forschungsanstalt Baden-Württemberg, Wonnhaldestr. 4, 79100 Freiburg, Germany
| | - Arthur Gessler
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903 Birmensdorf, Switzerland
| | - Heinz Rennenberg
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 53, 79110 Freiburg, Germany
| | - Jürgen Kreuzwieser
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 53, 79110 Freiburg, Germany
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96
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Zhou SX, Medlyn BE, Prentice IC. Long-term water stress leads to acclimation of drought sensitivity of photosynthetic capacity in xeric but not riparian Eucalyptus species. ANNALS OF BOTANY 2016; 117:133-44. [PMID: 26493470 PMCID: PMC4701155 DOI: 10.1093/aob/mcv161] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 03/10/2015] [Accepted: 09/10/2015] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Experimental drought is well documented to induce a decline in photosynthetic capacity. However, if given time to acclimate to low water availability, the photosynthetic responses of plants to low soil moisture content may differ from those found in short-term experiments. This study aims to test whether plants acclimate to long-term water stress by modifying the functional relationships between photosynthetic traits and water stress, and whether species of contrasting habitat differ in their degree of acclimation. METHODS Three Eucalyptus taxa from xeric and riparian habitats were compared with regard to their gas exchange responses under short- and long-term drought. Photosynthetic parameters were measured after 2 and 4 months of watering treatments, namely field capacity or partial drought. At 4 months, all plants were watered to field capacity, then watering was stopped. Further measurements were made during the subsequent 'drying-down', continuing until stomata were closed. KEY RESULTS Two months of partial drought consistently reduced assimilation rate, stomatal sensitivity parameters (g1), apparent maximum Rubisco activity (V'(cmax)) and maximum electron transport rate (J'(max)). Eucalyptus occidentalis from the xeric habitat showed the smallest decline in V'(cmax) and J'(max); however, after 4 months, V'(cmax) and J'(max) had recovered. Species differed in their degree of V'(cmax) acclimation. Eucalyptus occidentalis showed significant acclimation of the pre-dawn leaf water potential at which the V'(cmax) and 'true' V(cmax) (accounting for mesophyll conductance) declined most steeply during drying-down. CONCLUSIONS The findings indicate carbon loss under prolonged drought could be over-estimated without accounting for acclimation. In particular, (1) species from contrasting habitats differed in the magnitude of V'(cmax) reduction in short-term drought; (2) long-term drought allowed the possibility of acclimation, such that V'(cmax) reduction was mitigated; (3) xeric species showed a greater degree of V'(cmax) acclimation; and (4) photosynthetic acclimation involves hydraulic adjustments to reduce water loss while maintaining photosynthesis.
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Affiliation(s)
- Shuang-Xi Zhou
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia,
| | - Belinda E Medlyn
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia, Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia and
| | - Iain Colin Prentice
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia, AXA Chair of Biosphere and Climate Impacts, Grand Challenges in Ecosystems and the Environment and Grantham Institute - Climate Change and the Environment, Department of Life Sciences, Imperial College London, Silwood Park, Buckhurst Road, Ascot SL5 7PY, UK
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97
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Wiley E, Rogers BJ, Hodgkinson R, Landhäusser SM. Nonstructural carbohydrate dynamics of lodgepole pine dying from mountain pine beetle attack. THE NEW PHYTOLOGIST 2016; 209:550-562. [PMID: 26256444 DOI: 10.1111/nph.13603] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/13/2015] [Indexed: 06/04/2023]
Abstract
Bark beetle outbreaks are an important cause of tree death, but the process by which trees die remains poorly understood. The effect of beetle attack on whole-tree nonstructural carbohydrate (NSC) dynamics is particularly unclear, despite the potential role of carbohydrates in plant defense and survival. We monitored NSC dynamics of all organs in attacked and protected lodgepole pines (Pinus contorta) during a mountain pine beetle (Dendroctonus ponderosae) outbreak in British Columbia, starting before beetle flight in June 2011 through October 2012, when most attacked trees had died. Following attack, NSC concentrations were first reduced in the attacked region of the bole. The first NSC reduction in a distant organ appeared in the needles at the end of 2011, while branch and root NSC did not decline until much later in 2012. Attacked trees that were still alive in October 2012 had less beetle damage, which was negatively correlated with initial bark sugar concentrations in the attack region. The NSC dynamics of dying trees indicate that trees were killed by a loss of water conduction and not girdling. Further, our results identify locally reduced carbohydrate availability as an important mechanism by which stressors like drought may increase tree susceptibility to biotic attack.
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Affiliation(s)
- Erin Wiley
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada
| | - Bruce J Rogers
- Omineca Research and Stewardship Team, British Columbia Ministry of Forests Lands and Natural Resource Operations, Prince George, BC, V2N 4W5, Canada
| | - Robert Hodgkinson
- Omineca Research and Stewardship Team, British Columbia Ministry of Forests Lands and Natural Resource Operations, Prince George, BC, V2N 4W5, Canada
| | - Simon M Landhäusser
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada
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98
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Seidel H, Menzel A. Above-Ground Dimensions and Acclimation Explain Variation in Drought Mortality of Scots Pine Seedlings from Various Provenances. FRONTIERS IN PLANT SCIENCE 2016. [PMID: 27458477 DOI: 10.3389/fpls.2016.01014/full] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Seedling establishment is a critical part of the life cycle, thus seedling survival might be even more important for forest persistence under recent and future climate change. Scots pine forests have been disproportionally more affected by climate change triggered forest-dieback. Nevertheless, some Scots pine provenances might prove resilient to future drought events because of the species' large distributional range, genetic diversity, and adaptation potential. However, there is a lack of knowledge on provenance-specific survival under severe drought events and on how acclimation alters survival rates in Scots pine seedlings. We therefore conducted two drought-induced mortality experiments with potted Scots pine seedlings in a greenhouse. In the first experiment, 760 three-year-old seedlings from 12 different provenances of the south-western distribution range were subjected to the same treatment followed by the mortality experiment in 2014. In the second experiment, we addressed the question of whether acclimation to re-occurring drought stress events and to elevated temperature might decrease mortality rates. Thus, 139 four-year-old seedlings from France, Germany, and Poland were subjected to different temperature regimes (2012-2014) and drought treatments (2013-2014) before the mortality experiment in 2015. Provenances clearly differed in their hazard of drought-induced mortality, which was only partly related to the climate of their origin. Drought acclimation decreased the hazard of drought-induced mortality. Above-ground dry weight and height were the main determinants for the hazard of mortality, i.e., heavier and taller seedlings were more prone to mortality. Consequently, Scots pine seedlings exhibit a considerable provenance-specific acclimation potential against drought mortality and the selection of suitable provenances might thus facilitate seedling establishment and the persistence of Scots pine forest.
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Affiliation(s)
- Hannes Seidel
- Professorship of Ecoclimatology, Department of Ecology and Ecosystem Management, TUM School of Life Sciences Weihenstephan, Technische Universität München Freising, Germany
| | - Annette Menzel
- Professorship of Ecoclimatology, Department of Ecology and Ecosystem Management, TUM School of Life Sciences Weihenstephan, Technische Universität MünchenFreising, Germany; Institute for Advanced Study, Technische Universität MünchenGarching, Germany
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99
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Garcia-Forner N, Adams HD, Sevanto S, Collins AD, Dickman LT, Hudson PJ, Zeppel MJB, Jenkins MW, Powers H, Martínez-Vilalta J, Mcdowell NG. Responses of two semiarid conifer tree species to reduced precipitation and warming reveal new perspectives for stomatal regulation. PLANT, CELL & ENVIRONMENT 2016; 39:38-49. [PMID: 26081870 DOI: 10.1111/pce.12588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 05/29/2015] [Accepted: 06/01/2015] [Indexed: 05/13/2023]
Abstract
Relatively anisohydric species are predicted to be more predisposed to hydraulic failure than relatively isohydric species, as they operate with narrower hydraulic safety margins. We subjected co-occurring anisohydric Juniperus monosperma and isohydric Pinus edulis trees to warming, reduced precipitation, or both, and measured their gas exchange and hydraulic responses. We found that reductions in stomatal conductance and assimilation by heat and drought were more frequent during relatively moist periods, but these effects were not exacerbated in the combined heat and drought treatment. Counter to expectations, both species exhibited similar gs temporal dynamics in response to drought. Further, whereas P. edulis exhibited chronic embolism, J. monosperma showed very little embolism due to its conservative stomatal regulation and maintenance of xylem water potential above the embolism entry point. This tight stomatal control and low levels of embolism experienced by juniper refuted the notion that very low water potentials during drought are associated with loose stomatal control and with the hypothesis that anisohydric species are more prone to hydraulic failure than isohydric species. Because direct association of stomatal behaviour with embolism resistance can be misleading, we advocate consideration of stomatal behaviour relative to embolism resistance for classifying species drought response strategies.
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Affiliation(s)
- Núria Garcia-Forner
- CREAF, Cerdanyola del Vallès, 08193, Spain
- Universitat Autònoma Barcelona, Cerdanyola del Vallès, 08193, Spain
| | - Henry D Adams
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Sanna Sevanto
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Adam D Collins
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Lee T Dickman
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Patrick J Hudson
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Melanie J B Zeppel
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Michael W Jenkins
- Department of Environmental Studies, University of California, Santa Cruz, California, 95064, USA
| | - Heath Powers
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Jordi Martínez-Vilalta
- CREAF, Cerdanyola del Vallès, 08193, Spain
- Universitat Autònoma Barcelona, Cerdanyola del Vallès, 08193, Spain
| | - Nate G Mcdowell
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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100
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Sperling O, Earles JM, Secchi F, Godfrey J, Zwieniecki MA. Frost Induces Respiration and Accelerates Carbon Depletion in Trees. PLoS One 2015; 10:e0144124. [PMID: 26629819 PMCID: PMC4668004 DOI: 10.1371/journal.pone.0144124] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/15/2015] [Indexed: 11/27/2022] Open
Abstract
Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm(-3) yr(-1) on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics.
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Affiliation(s)
- Or Sperling
- Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America
| | - J. Mason Earles
- Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America
- Ecology Graduate Group, University of California Davis, Davis, CA 95616, United States of America
| | - Francesca Secchi
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Via 15 Leonardo da Vinci 44, 10095 Grugliasco, TO, Italy
| | - Jessie Godfrey
- Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America
| | - Maciej A. Zwieniecki
- Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America
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