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Tuma TT, Nyamdari B, Hsieh C, Chen YH, Harding SA, Tsai CJ. Perturbation of tonoplast sucrose transport alters carbohydrate utilization for seasonal growth and defense metabolism in coppiced poplar. TREE PHYSIOLOGY 2024; 44:tpae061. [PMID: 38857382 DOI: 10.1093/treephys/tpae061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 05/23/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
Nonstructural carbohydrate reserves of stems and roots underpin overall tree fitness and productivity under short-rotation management practices such as coppicing for bioenergy. While sucrose and starch comprise the predominant stem carbohydrate reserves of Populus, utilization for fitness and agricultural productivity is understood primarily in terms of starch turnover. The tonoplast sucrose transport protein SUT4 modulates sucrose export from source leaves to distant sinks during photoautotrophic growth, but the possibility of its involvement in remobilizing carbohydrates from storage organs during heterotrophic growth has not been explored. Here, we used PtaSUT4-knockout mutants of Populus tremula × P. alba (INRA 717-1B4) in winter (cool) and summer (warm) glasshouse coppicing experiments to assess SUT4 involvement in reserve utilization. Conditions preceding and supporting summer sprouting were considered favorable for growth, while those preceding and supporting cool temperature sprouting were suboptimal akin to conditions associated with coppicing as generally practiced. Epicormic bud emergence was delayed in sut4 mutants following lower temperature 'winter' but not summer coppicing. Winter xylem hexose increases were observed in control but not in sut4 stumps after coppicing. The magnitude of starch and sucrose reserve depletion was similar in control and sut4 stumps during the winter and did not explain the sprouting and xylem hexose differences. However, winter maintenance costs appeared higher in sut4 based partly on Krebs cycle intermediate levels. In control plants, bark accrual of abundant defense metabolites, including salicinoids and condensed tannins, was higher in summer than in winter, but this increase of summer defense allocations was attenuated in sut4 mutants. Temperature-sensitive trade-offs between growth and other priorities may therefore depend on SUT4 in Populus.
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Affiliation(s)
- Trevor T Tuma
- Warnell School of Forestry and Natural Resources, 180 E. Green Street, University of Georgia, Athens, GA 30602, USA
| | - Batbayar Nyamdari
- Warnell School of Forestry and Natural Resources, 180 E. Green Street, University of Georgia, Athens, GA 30602, USA
| | - Chen Hsieh
- Institute of Bioinformatics, 120 E. Green Street, University of Georgia, Athens, GA 30602, USA
| | - Yen-Ho Chen
- Department of Plant Biology, 2502 Miller Plant Sciences, University of Georgia, Athens, GA 30602, USA
| | - Scott A Harding
- Warnell School of Forestry and Natural Resources, 180 E. Green Street, University of Georgia, Athens, GA 30602, USA
- Department of Genetics, 120 E. Green Street, University of Georgia, Athens, GA 30602, USA
| | - Chung-Jui Tsai
- Warnell School of Forestry and Natural Resources, 180 E. Green Street, University of Georgia, Athens, GA 30602, USA
- Institute of Bioinformatics, 120 E. Green Street, University of Georgia, Athens, GA 30602, USA
- Department of Plant Biology, 2502 Miller Plant Sciences, University of Georgia, Athens, GA 30602, USA
- Department of Genetics, 120 E. Green Street, University of Georgia, Athens, GA 30602, USA
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2
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Liu X, Heinzle J, Tian Y, Salas E, Kwatcho Kengdo S, Borken W, Schindlbacher A, Wanek W. Long-term soil warming changes the profile of primary metabolites in fine roots of Norway spruce in a temperate montane forest. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38935880 DOI: 10.1111/pce.15019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 06/03/2024] [Accepted: 06/14/2024] [Indexed: 06/29/2024]
Abstract
Climate warming poses major threats to temperate forests, but the response of tree root metabolism has largely remained unclear. We examined the impact of long-term soil warming (>14 years, +4°C) on the fine root metabolome across three seasons for 2 years in an old spruce forest, using a liquid chromatography-mass spectrometry platform for primary metabolite analysis. A total of 44 primary metabolites were identified in roots (19 amino acids, 12 organic acids and 13 sugars). Warming increased the concentration of total amino acids and of total sugars by 15% and 21%, respectively, but not organic acids. We found that soil warming and sampling date, along with their interaction, directly influenced the primary metabolite profiles. Specifically, in warming plots, concentrations of arginine, glycine, lysine, threonine, tryptophan, mannose, ribose, fructose, glucose and oxaloacetic acid increased by 51.4%, 19.9%, 21.5%, 19.3%, 22.1%, 23.0%, 38.0%, 40.7%, 19.8% and 16.7%, respectively. Rather than being driven by single compounds, changes in metabolite profiles reflected a general up- or downregulation of most metabolic pathway network. This emphasises the importance of metabolomics approaches in investigating root metabolic pathways and understanding the effects of climate change on tree root metabolism.
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Affiliation(s)
- Xiaofei Liu
- Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
- Key Laboratory of Humid Subtropical Eco-Geographical Process of Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Jakob Heinzle
- Department of Forest Ecology and Soils, Federal Research and Training Centre for Forests, Natural Hazards and Landscape-BFW, Vienna, Austria
| | - Ye Tian
- Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
| | - Erika Salas
- Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
| | - Steve Kwatcho Kengdo
- Department of Soil Ecology, Bayreuth Center of Ecology and Environmental Research (Bayceer), University of Bayreuth, Bayreuth, Germany
| | - Werner Borken
- Department of Soil Ecology, Bayreuth Center of Ecology and Environmental Research (Bayceer), University of Bayreuth, Bayreuth, Germany
| | - Andreas Schindlbacher
- Department of Forest Ecology and Soils, Federal Research and Training Centre for Forests, Natural Hazards and Landscape-BFW, Vienna, Austria
| | - Wolfgang Wanek
- Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
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3
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Netherer S, Lehmanski L, Bachlehner A, Rosner S, Savi T, Schmidt A, Huang J, Paiva MR, Mateus E, Hartmann H, Gershenzon J. Drought increases Norway spruce susceptibility to the Eurasian spruce bark beetle and its associated fungi. THE NEW PHYTOLOGIST 2024; 242:1000-1017. [PMID: 38433329 DOI: 10.1111/nph.19635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/05/2024] [Indexed: 03/05/2024]
Abstract
Drought affects the complex interactions between Norway spruce, the bark beetle Ips typographus and associated microorganisms. We investigated the interplay of tree water status, defense and carbohydrate reserves with the incidence of bark beetle attack and infection of associated fungi in mature spruce trees. We installed roofs to induce a 2-yr moderate drought in a managed spruce stand to examine a maximum of 10 roof and 10 control trees for resin flow (RF), predawn twig water potentials, terpene, phenolic and carbohydrate bark concentrations, and bark beetle borings in field bioassays before and after inoculation with Endoconidiophora polonica and Grosmannia penicillata. Drought-stressed trees showed more attacks and significantly longer fungal lesions than controls, but maintained terpene resin defenses at predrought levels. Reduced RF and lower mono- and diterpene, but not phenolic concentrations were linked with increased host selection. Bark beetle attack and fungi stimulated chemical defenses, yet G. penicillata reduced phenolic and carbohydrate contents. Chemical defenses did not decrease under mild, prolonged drought in our simulated small-scale biotic infestations. However, during natural mass attacks, reductions in carbon fixation under drought, in combination with fungal consumption of carbohydrates, may deplete tree defenses and facilitate colonization by I. typographus.
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Affiliation(s)
- Sigrid Netherer
- Department of Forest and Soil Sciences, Institute of Forest Entomology, Forest Pathology and Forest Protection, University of Natural Resources and Life Sciences, Vienna, Peter-Jordan-Straße 82/I, Vienna, 1190, Austria
| | - Linda Lehmanski
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07743, Germany
| | - Albert Bachlehner
- Department of Forest and Soil Sciences, Institute of Forest Entomology, Forest Pathology and Forest Protection, University of Natural Resources and Life Sciences, Vienna, Peter-Jordan-Straße 82/I, Vienna, 1190, Austria
| | - Sabine Rosner
- Department of Integrative Biology and Biodiversity Research, Institute of Botany, University of Natural Resources and Life Sciences, Vienna, Gregor-Mendel-Straße 33, Vienna, 1180, Austria
| | - Tadeja Savi
- Department of Integrative Biology and Biodiversity Research, Institute of Botany, University of Natural Resources and Life Sciences, Vienna, Gregor-Mendel-Straße 33, Vienna, 1180, Austria
| | - Axel Schmidt
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
| | - Jianbei Huang
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07743, Germany
| | - Maria Rosa Paiva
- Department of Environmental Sciences and Engineering, NOVA School of Science and Technology, Center for Environmental and Sustainability Research (CENSE), NOVA University of Lisbon, Caparica, 2829-516, Portugal
| | - Eduardo Mateus
- Department of Environmental Sciences and Engineering, NOVA School of Science and Technology, Center for Environmental and Sustainability Research (CENSE), NOVA University of Lisbon, Caparica, 2829-516, Portugal
| | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07743, Germany
- Institute for Forest Protection, Julius Kühn-Institute for Cultivated Plants, Erwin-Baur-Str. 27, Quedlinburg, 06484, Germany
- Faculty of Forest Sciences and Forest Ecology, Georg-August-University Göttingen, Büsgenweg 5, Göttingen, 37077, Germany
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, Jena, 07745, Germany
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4
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Depardieu C, Lenz P, Marion J, Nadeau S, Girardin MP, Marchand W, Bégin C, Treydte K, Gessler A, Bousquet J, Savard MM, Isabel N. Contrasting physiological strategies explain heterogeneous responses to severe drought conditions within local populations of a widespread conifer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171174. [PMID: 38402972 DOI: 10.1016/j.scitotenv.2024.171174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/12/2024] [Accepted: 02/20/2024] [Indexed: 02/27/2024]
Abstract
Understanding how trees prioritize carbon gain at the cost of drought vulnerability under severe drought conditions is crucial for predicting which genetic groups and individuals will be resilient to future climate conditions. In this study, we investigated variations in growth, tree-ring anatomy as well as carbon and oxygen isotope ratios to assess the sensitivity and the xylem formation process in response to an episode of severe drought in 29 mature white spruce (Picea glauca [Moench] Voss) families grown in a common garden trial. During the drought episode, the majority of families displayed decreased growth and exhibited either sustained or increased intrinsic water-use efficiency (iWUE), which was largely influenced by reduced stomatal conductance as revealed by the dual carbon‑oxygen isotope approach. Different water-use strategies were detected within white spruce populations in response to drought conditions. Our results revealed intraspecific variation in the prevailing physiological mechanisms underlying drought response within and among populations of Picea glauca. The presence of different genetic groups reflecting diverse water-use strategies within this largely-distributed conifer is likely to lessen the negative effects of drought and decrease the overall forest ecosystems' sensitivity to it.
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Affiliation(s)
- Claire Depardieu
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Forest Research Centre, Département des sciences du bois et de la forêt, Université Laval, Québec, QC G1V 0A6, Canada; Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada.
| | - Patrick Lenz
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Natural Resources Canada, Canadian Forest Service, Canadian Wood Fibre Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada
| | - Joelle Marion
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Simon Nadeau
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Natural Resources Canada, Canadian Forest Service, Canadian Wood Fibre Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada
| | - Martin P Girardin
- Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada; Centre d'étude de la forêt, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montréal, QC H3C 3P8, Canada; Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l'Université, Rouyn-Noranda, QC J9X 5E4, Canada
| | - William Marchand
- Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada; Centre d'étude de la forêt, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montréal, QC H3C 3P8, Canada; Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l'Université, Rouyn-Noranda, QC J9X 5E4, Canada
| | - Christian Bégin
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Kerstin Treydte
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland
| | - Jean Bousquet
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Forest Research Centre, Département des sciences du bois et de la forêt, Université Laval, Québec, QC G1V 0A6, Canada
| | - Martine M Savard
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Nathalie Isabel
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada
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5
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Huang J, Ladd SN, Ingrisch J, Kübert A, Meredith LK, van Haren J, Bamberger I, Daber LE, Kühnhammer K, Bailey K, Hu J, Fudyma J, Shi L, Dippold MA, Meeran K, Miller L, O'Brien MJ, Yang H, Herrera-Ramírez D, Hartmann H, Trumbore S, Bahn M, Werner C, Lehmann MM. The mobilization and transport of newly fixed carbon are driven by plant water use in an experimental rainforest under drought. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2545-2557. [PMID: 38271585 DOI: 10.1093/jxb/erae030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/24/2024] [Indexed: 01/27/2024]
Abstract
Non-structural carbohydrates (NSCs) are building blocks for biomass and fuel metabolic processes. However, it remains unclear how tropical forests mobilize, export, and transport NSCs to cope with extreme droughts. We combined drought manipulation and ecosystem 13CO2 pulse-labeling in an enclosed rainforest at Biosphere 2, assessed changes in NSCs, and traced newly assimilated carbohydrates in plant species with diverse hydraulic traits and canopy positions. We show that drought caused a depletion of leaf starch reserves and slowed export and transport of newly assimilated carbohydrates below ground. Drought effects were more pronounced in conservative canopy trees with limited supply of new photosynthates and relatively constant water status than in those with continual photosynthetic supply and deteriorated water status. We provide experimental evidence that local utilization, export, and transport of newly assimilated carbon are closely coupled with plant water use in canopy trees. We highlight that these processes are critical for understanding and predicting tree resistance and ecosystem fluxes in tropical forest under drought.
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Affiliation(s)
- Jianbei Huang
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
| | - S Nemiah Ladd
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
- Department of Environmental Sciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
| | - Johannes Ingrisch
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
- Department of Ecology, University of Innsbruck, Sternwartestr 15, 6020 Innsbruck, Austria
| | - Angelika Kübert
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Laura K Meredith
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ 85721, USA
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
| | - Joost van Haren
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
- Honors College, University of Arizona, 1101 East Mabel Street, Tucson, AZ 85719, USA
| | - Ines Bamberger
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
- Atmospheric Chemistry Group, University of Bayreuth (BayCEER), Germany
| | - L Erik Daber
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Kathrin Kühnhammer
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Kinzie Bailey
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ 85721, USA
| | - Jia Hu
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ 85721, USA
| | - Jane Fudyma
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
- Department of Land, Air, and Water Resources, University of California, Davis, CA, USA
| | - Lingling Shi
- Biogeochemistry of Agroecosystems, University of Göttingen, Göttingen, Germany
- Geo-Biosphere Interactions, University of Tuebingen, Tuebingen, Germany
| | - Michaela A Dippold
- Biogeochemistry of Agroecosystems, University of Göttingen, Göttingen, Germany
- Geo-Biosphere Interactions, University of Tuebingen, Tuebingen, Germany
| | - Kathiravan Meeran
- Department of Ecology, University of Innsbruck, Sternwartestr 15, 6020 Innsbruck, Austria
| | - Luke Miller
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
| | - Michael J O'Brien
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almería, Spain
| | - Hui Yang
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
| | | | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
- Institute for Forest Protection, Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Erwin-Baur-Straße 27, D-06484 Quedlinburg, Germany
| | - Susan Trumbore
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, Sternwartestr 15, 6020 Innsbruck, Austria
| | - Christiane Werner
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Marco M Lehmann
- Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
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6
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Wei J, von Arx G, Fan Z, Ibrom A, Mund M, Knohl A, Peters RL, Babst F. Drought alters aboveground biomass production efficiency: Insights from two European beech forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170726. [PMID: 38331275 DOI: 10.1016/j.scitotenv.2024.170726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 02/03/2024] [Accepted: 02/03/2024] [Indexed: 02/10/2024]
Abstract
The fraction of photosynthetically assimilated carbon that trees allocate to long-lasting woody biomass pools (biomass production efficiency - BPE), is a key metric of the forest carbon balance. Its apparent simplicity belies the complex interplay between underlying processes of photosynthesis, respiration, litter and fruit production, and tree growth that respond differently to climate variability. Whereas the magnitude of BPE has been routinely quantified in ecological studies, its temporal dynamics and responses to extreme events such as drought remain less well understood. Here, we combine long-term records of aboveground carbon increment (ACI) obtained from tree rings with stand-level gross primary productivity (GPP) from eddy covariance (EC) records to empirically quantify aboveground BPE (= ACI/GPP) and its interannual variability in two European beech forests (Hainich, DE-Hai, Germany; Sorø, DK-Sor, Denmark). We found significant negative correlations between BPE and a daily-resolved drought index at both sites, indicating that woody growth is de-prioritized under water limitation. During identified extreme years, early-season drought reduced same-year BPE by 29 % (Hainich, 2011), 31 % (Sorø, 2006), and 14 % (Sorø, 2013). By contrast, the 2003 late-summer drought resulted in a 17 % reduction of post-drought year BPE at Hainich. Across the entire EC period, the daily-to-seasonal drought response of BPE resembled that of ACI, rather than that of GPP. This indicates that BPE follows sink dynamics more closely than source dynamics, which appear to be decoupled given the distinctive climate response patterns of GPP and ACI. Based on our observations, we caution against estimating the magnitude and variability of the carbon sink in European beech (and likely other temperate forests) based on carbon fluxes alone. We also encourage comparable studies at other long-term EC measurement sites from different ecosystems to further constrain the BPE response to rare climatic events.
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Affiliation(s)
- Jingshu Wei
- School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell Street, Tucson, AZ 85721, USA; Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, CH-8903 Birmensdorf, Switzerland; CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun Town, Mengla County, Yunnan Province 666303, China.
| | - Georg von Arx
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, CH-8903 Birmensdorf, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Hochschulstrasse 4, CH-3012 Bern, Switzerland
| | - Zexin Fan
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun Town, Mengla County, Yunnan Province 666303, China
| | - Andreas Ibrom
- Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, Denmark
| | - Martina Mund
- Forestry Research and Competence Centre Gotha, Jägerstraße1, D-99867 Gotha, Germany
| | - Alexander Knohl
- Bioclimatology, University of Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany
| | - Richard L Peters
- Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, Basel CH-4056, Switzerland
| | - Flurin Babst
- School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell Street, Tucson, AZ 85721, USA; Laboratory of Tree-Ring Research, University of Arizona, 1215 E Lowell Street, Tucson, AZ 85721, USA
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7
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Shestakova TA, Sin E, Gordo J, Voltas J. Tree-ring isotopic imprints on time series of reproductive effort indicate warming-induced co-limitation by sink and source processes in stone pine. TREE PHYSIOLOGY 2024; 44:tpad147. [PMID: 38079520 DOI: 10.1093/treephys/tpad147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/01/2023] [Indexed: 02/09/2024]
Abstract
Increasing evidence indicates that tree growth processes, including reproduction, can be either sink- or source-limited, or simultaneously co-limited by sink and source, depending on the interplay between internal and environmental factors. We tested the hypothesis that the relative strengths of photosynthate supply and demand by stem growth and reproduction create variable competition for substrate that is imprinted in the tree-ring isotopes (C and O) of stone pine (Pinus pinea L.), a masting gymnosperm with large costs of reproduction, under warming-induced drought. Across five representative stands of the Spanish Northern Plateau, we also identified reproductive phases where weather drivers of cone yield (CY) have varied over a 60-year period (1960-2016). We found that these drivers gradually shifted from winter-spring conditions 3 years before seed rain (cone setting) to a combination of 3- and 1-year lagged effects (kernel filling). Additionally, we observed positive regional associations between carbon isotope discrimination (Δ13C) of the year of kernel filling and CY arising at the turn of this century, which progressively offset similarly positive relationships between Δ13C of the year of cone setting and CY found during the first half of the study period. Altogether, these results pinpoint the increasing dependence of reproduction on fresh assimilates and suggest sink and source co-limitation superseding the sink-limited functioning of reproduction dominant before 2000. Under climate warming, it could be expected that drier conditions reinforce the role of source limitation on reproduction and, hence, on regeneration, forest structure and economic profit of the nutlike seeds of the species.
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Affiliation(s)
- Tatiana A Shestakova
- Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
| | - Ester Sin
- Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
| | - Javier Gordo
- Servicio Territorial de Medio Ambiente, Junta de Castilla y León, Duque de la Victoria 5, Valladolid, Castile and León E-47071, Spain
| | - Jordi Voltas
- Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
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8
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Thompson RA. A neutral theory of plant carbon allocation. TREE PHYSIOLOGY 2024; 44:tpad151. [PMID: 38102767 DOI: 10.1093/treephys/tpad151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/10/2023] [Indexed: 12/17/2023]
Abstract
How plants use the carbon they gain from photosynthesis remains a key area of study among plant ecologists. Although numerous theories have been presented throughout the years, the field lacks a clear null model. To fill this gap, I have developed the first null model, or neutral theory, of plant carbon allocation using probability theory, plant biochemistry and graph theory at the level of a leaf. Neutral theories have been used to establish a null hypothesis in molecular evolution and community assembly to describe how much of an ecological phenomenon can be described by chance alone. Here, the aim of a neutral theory of plant carbon allocation is to ask: how is carbon partitioned between sinks if one assumes plants do not prioritize certain sinks over others? Using the biochemical network of plant carbon metabolism, I show that, if allocation was strictly random, carbon is more likely to be allocated to storage, defense, respiration and finally growth. This 'neutral hierarchy' suggests that a sink's biochemical distance from photosynthesis plays an important role in carbon allocation patterns, highlighting the potentially adaptive role of this biochemical network for plant survival in variable environments. A brief simulation underscores that our ability to measure the carbon allocation from photosynthesis to a given sink is unreliable due to simple probabilistic rules. While neutral theory may not explain all patterns of carbon allocation, its utility is in the minimal assumptions and role as a null model against which future data should be tested.
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Affiliation(s)
- R Alex Thompson
- School of the Environment, Washington State University, Pullman, WA 99164, USA
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9
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Peltier DMP, Carbone MS, Enright M, Marshall MC, Trowbridge AM, LeMoine J, Koch G, Richardson AD. Old reserves and ancient buds fuel regrowth of coast redwood after catastrophic fire. NATURE PLANTS 2023; 9:1978-1985. [PMID: 38036621 DOI: 10.1038/s41477-023-01581-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023]
Abstract
For long-lived organisms, investment in insurance strategies such as reserve energy storage can enable resilience to resource deficits, stress or catastrophic disturbance. Recent fire in California damaged coast redwood (Sequoia sempervirens) groves, consuming all foliage on some of the tallest and oldest trees on Earth. Burned trees recovered through resprouting from roots, trunk and branches, necessarily supported by nonstructural carbon reserves. Nonstructural carbon reserves can be many years old, but direct use of old carbon has rarely been documented and never in such large, old trees. We found some sprouts contained the oldest carbon ever observed to be remobilized for growth. For certain trees, simulations estimate up to half of sprout carbon was acquired in photosynthesis more than 57 years prior, and direct observations in sapwood show trees can access reserves at least as old. Sprouts also emerged from ancient buds-dormant under bark for centuries. For organisms with millennial lifespans, traits enabling survival of infrequent but catastrophic events may represent an important energy sink. Remobilization of decades-old photosynthate after disturbance demonstrates substantial amounts of nonstructural carbon within ancient trees cycles on slow, multidecadal timescales.
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Affiliation(s)
- Drew M P Peltier
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
| | - Mariah S Carbone
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Melissa Enright
- Pacific Northwest Research Station, US Forest Service, Portland, OR, USA
| | - Margaret C Marshall
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| | - Amy M Trowbridge
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| | - Jim LeMoine
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - George Koch
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Andrew D Richardson
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
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Mu Y, Lindenmayer D, Zheng S, Yang Y, Wang D, Liu J. Size-focused conservation may fail to protect the world's oldest trees. Curr Biol 2023; 33:4641-4649.e3. [PMID: 37820721 DOI: 10.1016/j.cub.2023.09.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/02/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023]
Abstract
Old trees are irreplaceable natural resources that provide multifaceted benefits to humans. Current conservation strategies focus primarily on large-sized trees that were often considered old. However, some studies have demonstrated that small trees can be more than thousands of years old, suggesting that conventional size-focused perceptions may hamper the efficiency of current conservation strategies for old trees. Here, we compiled paired age and diameter data using tree-ring records sampled from 121,918 trees from 269 species around the world to detect whether tree size is a strong predictor of age for old trees and whether the spatial distribution of small old trees differs from that of large old trees. We found that tree size was a weak predictor of age for old trees, and diameter explained only 10% of the total age variance of old trees. Unlike large-sized trees that are mainly in warm, wet environments and protected, small old trees are predominantly in cold, dry environments and mostly unprotected, indicating that size-focused conservation failed to protect some of the oldest trees. To conserve old trees, comprehensive old-tree recognition systems are needed that consider not only tree size but also age and external characteristics. Protected areas designed for small old trees are urgently needed.
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Affiliation(s)
- Yumei Mu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - David Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT 2601, Australia
| | - Shilu Zheng
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yongchuan Yang
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Deyi Wang
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands
| | - Jiajia Liu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai 200438, China; Institute of Eco-Chongming, Shanghai 202183, China.
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11
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Peltier DMP, Carbone MS, McIntire CD, Robertson N, Thompson RA, Malone S, LeMoine J, Richardson AD, McDowell NG, Adams HD, Pockman WT, Trowbridge AM. Carbon starvation following a decade of experimental drought consumes old reserves in Pinus edulis. THE NEW PHYTOLOGIST 2023; 240:92-104. [PMID: 37430467 DOI: 10.1111/nph.19119] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/12/2023] [Indexed: 07/12/2023]
Abstract
Shifts in the age or turnover time of non-structural carbohydrates (NSC) may underlie changes in tree growth under long-term increases in drought stress associated with climate change. But NSC responses to drought are challenging to quantify, due in part to large NSC stores in trees and subsequently long response times of NSC to climate variation. We measured NSC age (Δ14 C) along with a suite of ecophysiological metrics in Pinus edulis trees experiencing either extreme short-term drought (-90% ambient precipitation plot, 2020-2021) or a decade of severe drought (-45% plot, 2010-2021). We tested the hypothesis that carbon starvation - consumption exceeding synthesis and storage - increases the age of sapwood NSC. One year of extreme drought had no impact on NSC pool size or age, despite significant reductions in predawn water potential, photosynthetic rates/capacity, and twig and needle growth. By contrast, long-term drought halved the age of the sapwood NSC pool, coupled with reductions in sapwood starch concentrations (-75%), basal area increment (-39%), and bole respiration rates (-28%). Our results suggest carbon starvation takes time, as tree carbon reserves appear resilient to extreme disturbance in the short term. However, after a decade of drought, trees apparently consumed old stored NSC to support metabolism.
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Affiliation(s)
- Drew M P Peltier
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Mariah S Carbone
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Cameron D McIntire
- Northeastern Area State, Private, and Tribal Forestry, USDA Forest Service, 271 Mast Road, Durham, NH, 03824, USA
| | - Nathan Robertson
- Biology Department, University of New Mexico, Albuquerque, NM, 87106, USA
| | - R Alex Thompson
- School of the Environment, Washington State University, Pullman, WA, 99163, USA
| | - Shealyn Malone
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jim LeMoine
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Andrew D Richardson
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Nate G McDowell
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Lab, PO Box 999, Richland, WA, 99352, USA
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA, 99164, USA
| | - Henry D Adams
- School of the Environment, Washington State University, Pullman, WA, 99163, USA
| | - William T Pockman
- Biology Department, University of New Mexico, Albuquerque, NM, 87106, USA
| | - Amy M Trowbridge
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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12
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Fernández-de-Uña L, Martínez-Vilalta J, Poyatos R, Mencuccini M, McDowell NG. The role of height-driven constraints and compensations on tree vulnerability to drought. THE NEW PHYTOLOGIST 2023; 239:2083-2098. [PMID: 37485545 DOI: 10.1111/nph.19130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/07/2023] [Indexed: 07/25/2023]
Abstract
Frequent observations of higher mortality in larger trees than in smaller ones during droughts have sparked an increasing interest in size-dependent drought-induced mortality. However, the underlying physiological mechanisms are not well understood, with height-associated hydraulic constraints often being implied as the potential mechanism driving increased drought vulnerability. We performed a quantitative synthesis on how key traits that drive plant water and carbon economy change with tree height within species and assessed the implications that the different constraints and compensations may have on the interacting mechanisms (hydraulic failure, carbon starvation and/or biotic-agent attacks) affecting tree vulnerability to drought. While xylem tension increases with tree height, taller trees present a range of structural and functional adjustments, including more efficient water use and transport and greater water uptake and storage capacity, that mitigate the path-length-associated drop in water potential. These adaptations allow taller trees to withstand episodic water stress. Conclusive evidence for height-dependent increased vulnerability to hydraulic failure and carbon starvation, and their coupling to defence mechanisms and pest and pathogen dynamics, is still lacking. Further research is needed, particularly at the intraspecific level, to ascertain the specific conditions and thresholds above which height hinders tree survival under drought.
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Affiliation(s)
- Laura Fernández-de-Uña
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
| | - Rafael Poyatos
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
| | - Maurizio Mencuccini
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- ICREA, Barcelona, 08010, Spain
| | - Nate G McDowell
- Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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Hillabrand RM, Gordon H, Hynes B, Constabel CP, Landhäusser SM. Populus root salicinoid phenolic glycosides are not mobilized to support metabolism and regrowth under carbon limited conditions. TREE PHYSIOLOGY 2023:tpad020. [PMID: 36809479 DOI: 10.1093/treephys/tpad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Remobilization of carbon storage compounds in trees is crucial for the resilience to disturbances, stress, and the requirements of their perennial lifestyle, all of which can impact photosynthetic carbon gain. Trees contain abundant non-structural carbohydrates (NSC) in the form of starch and sugars for long term carbon storage, yet questions remain about the ability of trees to remobilize non-conventional carbon compounds under stress. Aspens, like other members of the genus Populus, have abundant specialized metabolites called salicinoid phenolic glycosides, which contain a core glucose moiety. In this study, we hypothesized that the glucose-containing salicinoids could be remobilized as an additional carbon source during severe carbon limitation. We made use of genetically modified hybrid aspen (Populus tremula x P. alba) with minimal salicinoid content and compared these to control plants with high salicinoid content during resprouting (suckering) in dark (carbon limited) conditions. As salicinoids are abundant anti-herbivore compounds, identification of such a secondary function for salicinoids may provide insight to the evolutionary pressures that drive their accumulation. Our results show that salicinoid biosynthesis is maintained during carbon limitation and suggests that salicinoids are not remobilized as a carbon source for regenerating shoot tissue. However, we found that salicinoid-producing aspens had reduced resprouting capacity per available root biomass when compared to salicinoid-deficient aspens. Therefore, our work shows that the constitutive salicinoid production in aspens can reduce the capacity for resprouting and survival in carbon limited conditions.
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Affiliation(s)
- R M Hillabrand
- Department of Renewable Resources, University of Alberta, 442 ESB, Edmonton, Alberta, T6G 2E3, Canada
| | - H Gordon
- Centre for Forest Biology & Department of Biology, University of Victoria, 3800 Finnerty Road, V8P 5C2, Victoria, British Columbia, Canada
| | - B Hynes
- Department of Renewable Resources, University of Alberta, 442 ESB, Edmonton, Alberta, T6G 2E3, Canada
| | - C P Constabel
- Centre for Forest Biology & Department of Biology, University of Victoria, 3800 Finnerty Road, V8P 5C2, Victoria, British Columbia, Canada
| | - S M Landhäusser
- Department of Renewable Resources, University of Alberta, 442 ESB, Edmonton, Alberta, T6G 2E3, Canada
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Zavadilová I, Szatniewska J, Petrík P, Mauer O, Pokorný R, Stojanović M. Sap flow and growth response of Norway spruce under long-term partial rainfall exclusion at low altitude. FRONTIERS IN PLANT SCIENCE 2023; 14:1089706. [PMID: 36866386 PMCID: PMC9974152 DOI: 10.3389/fpls.2023.1089706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Under ongoing climate change, more frequent and severe drought periods accompanied by heat waves are expected in the future. Under these conditions, the tree's survival is conditioned by fast recovery of functions after drought release. Therefore, in the presented study, we evaluated the effect of long-term water reduction in soil on tree water use and growth dynamics of Norway spruce. METHODS The experiment was conducted in two young Norway spruce plots located on suboptimal sites at a low altitude of 440 m a.s.l. In the first plot (PE), 25% of precipitation throughfall was excluded since 2007, and the second one represented the control treatment with ambient conditions (PC). Tree sap flow, stem radial increment, and tree water deficit were monitored in two consecutive growing seasons: 2015-2016, with contrasting hydro-climatic conditions. RESULTS Trees in both treatments showed relatively isohydric behavior reflected in a strong reduction of sap flow under the exceptional drought of 2015. Nevertheless, trees from PE treatment reduced sap flow faster than PC under decreasing soil water potential, exhibiting faster stomatal response. This led to a significantly lower sap flow of PE, compared to PC in 2015. The maximal sap flow rates were also lower for PE treatment, compared to PC. Both treatments experienced minimal radial growth during the 2015 drought and subsequent recovery of radial growth under the more the humid year of 2016. However, treatments did not differ significantly in stem radial increments within respective years. DISCUSSION Precipitation exclusion treatment, therefore, led to water loss adjustment, but did not affect growth response to intense drought and growth recovery in the year after drought.
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Affiliation(s)
- Ina Zavadilová
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czechia
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University, Brno, Czechia
| | - Justyna Szatniewska
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czechia
- Department of Silviculture, Faculty of Forestry and Wood Technology, Mendel University, Brno, Czechia
| | - Peter Petrík
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czechia
| | - Oldřich Mauer
- Department of Silviculture, Faculty of Forestry and Wood Technology, Mendel University, Brno, Czechia
| | - Radek Pokorný
- Department of Silviculture, Faculty of Forestry and Wood Technology, Mendel University, Brno, Czechia
| | - Marko Stojanović
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czechia
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15
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Begović K, Schurman JS, Svitok M, Pavlin J, Langbehn T, Svobodová K, Mikoláš M, Janda P, Synek M, Marchand W, Vitková L, Kozák D, Vostarek O, Čada V, Bače R, Svoboda M. Large old trees increase growth under shifting climatic constraints: Aligning tree longevity and individual growth dynamics in primary mountain spruce forests. GLOBAL CHANGE BIOLOGY 2023; 29:143-164. [PMID: 36178428 DOI: 10.1111/gcb.16461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/30/2022] [Indexed: 06/16/2023]
Abstract
In a world of accelerating changes in environmental conditions driving tree growth, tradeoffs between tree growth rate and longevity could curtail the abundance of large old trees (LOTs), with potentially dire consequences for biodiversity and carbon storage. However, the influence of tree-level tradeoffs on forest structure at landscape scales will also depend on disturbances, which shape tree size and age distribution, and on whether LOTs can benefit from improved growing conditions due to climate warming. We analyzed temporal and spatial variation in radial growth patterns from ~5000 Norway spruce (Picea abies [L.] H. Karst) live and dead trees from the Western Carpathian primary spruce forest stands. We applied mixed-linear modeling to quantify the importance of LOT growth histories and stand dynamics (i.e., competition and disturbance factors) on lifespan. Finally, we assessed regional synchronization in radial growth variability over the 20th century, and modeled the effects of stand dynamics and climate on LOTs recent growth trends. Tree age varied considerably among forest stands, implying an important role of disturbance as an age constraint. Slow juvenile growth and longer period of suppressed growth prolonged tree lifespan, while increasing disturbance severity and shorter time since last disturbance decreased it. The highest age was not achieved only by trees with continuous slow growth, but those with slow juvenile growth followed by subsequent growth releases. Growth trend analysis demonstrated an increase in absolute growth rates in response to climate warming, with late summer temperatures driving the recent growth trend. Contrary to our expectation that LOTs would eventually exhibit declining growth rates, the oldest LOTs (>400 years) continuously increase growth throughout their lives, indicating a high phenotypic plasticity of LOTs for increasing biomass, and a strong carbon sink role of primary spruce forests under rising temperatures, intensifying droughts, and increasing bark beetle outbreaks.
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Affiliation(s)
- Krešimir Begović
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Jonathan S Schurman
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Marek Svitok
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
- Department of Biology and General Ecology, Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, Zvolen, Slovakia
| | - Jakob Pavlin
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Thomas Langbehn
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Kristyna Svobodová
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Martin Mikoláš
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Pavel Janda
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Michal Synek
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - William Marchand
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Lucie Vitková
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Daniel Kozák
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Ondrej Vostarek
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Vojtech Čada
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Radek Bače
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Miroslav Svoboda
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
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Mirabel A, Girardin MP, Metsaranta J, Campbell EM, Arsenault A, Reich PB, Way D. New tree-ring data from Canadian boreal and hemi-boreal forests provide insight for improving the climate sensitivity of terrestrial biosphere models. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158062. [PMID: 35981579 DOI: 10.1016/j.scitotenv.2022.158062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/28/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Understanding boreal/hemi-boreal forest growth sensitivity to seasonal variations in temperature and water availability provides important basis for projecting the potential impacts of climate change on the productivity of these ecosystems. Our best available information currently comes from a limited number of field experiments and terrestrial biosphere model (TBM) simulations of varying predictive accuracy. Here, we assessed the sensitivity of annual boreal/hemi-boreal forest growth in Canada to yearly fluctuations in seasonal climate variables using a large tree-ring dataset and compared this to the climate sensitivity of annual net primary productivity (NPP) estimates obtained from fourteen TBMs. We found that boreal/hemi-boreal forest growth sensitivity to fluctuations in seasonal temperature and precipitation variables changed along a southwestern to northeastern gradient, with growth limited almost entirely by temperature in the northeast and west and by water availability in the southwest. We also found a lag in growth climate sensitivity, with growth largely determined by the climate during the summer prior to ring formation. Analyses of NPP sensitivity to the same climate variables produced a similar southwest to northeast gradient in growth climate sensitivity for NPP estimates from all but three TBMs. However, analyses of growth from tree-ring data and analyses of NPP from TBMs produced contrasting evidence concerning the key climate variables limiting growth. While analyses of NPP primarily indicated a positive relationship between growth and seasonal temperature, tree-ring analyses indicated negative growth relationships to temperature. Also, the positive effect of precipitation on NPP derived from most TBMs was weaker than the positive effect of precipitation on tree-ring based growth: temperature had a more important limiting effect on NPP than tree-ring data indicated. These mismatches regarding the key climate variables limiting growth suggested that characterization of tree growth in TBMs might need revision, particularly regarding the effects of stomatal conductance and carbohydrate reserve dynamics.
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Affiliation(s)
- A Mirabel
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada.
| | - M P Girardin
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - J Metsaranta
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB, Canada
| | - E M Campbell
- Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC, Canada
| | - A Arsenault
- Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, Corner Brook, NL, Canada
| | - P B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, USA; Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2753, Australia; Institute for Global Change Biology, School for the Environment and Sustainability, University of Michigan, Ann Arbor, MI 48109, United States
| | - D Way
- Department of Biology, University of Western Ontario, London, Ontario, Canada; Nicholas School of the Environment, Duke University, Durham, NC, USA; Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
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Rademacher T, Fonti P, LeMoine JM, Fonti MV, Bowles F, Chen Y, Eckes-Shephard AH, Friend AD, Richardson AD. Insights into source/sink controls on wood formation and photosynthesis from a stem chilling experiment in mature red maple. THE NEW PHYTOLOGIST 2022; 236:1296-1309. [PMID: 35927942 DOI: 10.1111/nph.18421] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/30/2022] [Indexed: 06/15/2023]
Abstract
Whether sources or sinks control wood growth remains debated with a paucity of evidence from mature trees in natural settings. Here, we altered carbon supply rate in stems of mature red maples (Acer rubrum) within the growing season by restricting phloem transport using stem chilling; thereby increasing carbon supply above and decreasing carbon supply below the restrictions, respectively. Chilling successfully altered nonstructural carbon (NSC) concentrations in the phloem without detectable repercussions on bulk NSC in stems and roots. Ring width responded strongly to local variations in carbon supply with up to seven-fold differences along the stem of chilled trees; however, concurrent changes in the structural carbon were inconclusive at high carbon supply due to large local variability of wood growth. Above chilling-induced bottlenecks, we also observed higher leaf NSC concentrations, reduced photosynthetic capacity, and earlier leaf coloration and fall. Our results indicate that the cambial sink is affected by carbon supply, but within-tree feedbacks can downregulate source activity, when carbon supply exceeds demand. Such feedbacks have only been hypothesized in mature trees. Consequently, these findings constitute an important advance in understanding source-sink dynamics, suggesting that mature red maples operate close to both source- and sink-limitation in the early growing season.
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Affiliation(s)
- Tim Rademacher
- Harvard Forest, Harvard University, Petersham, MA, 01366, USA
- School of Informatics, Computing and Cyber Systems and Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, Ripon, J0V 1V0, QC, Canada
| | - Patrick Fonti
- Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
| | - James M LeMoine
- School of Informatics, Computing and Cyber Systems and Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Marina V Fonti
- Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, 8903, Switzerland
- Institute of Ecology and Geography, Siberian Federal University, Krasnoyarsk, 660041, Russia
| | | | - Yizhao Chen
- Department of Geography, University of Cambridge, Cambridge, CB2 1BY, UK
| | - Annemarie H Eckes-Shephard
- Department of Geography, University of Cambridge, Cambridge, CB2 1BY, UK
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, 223 62, Sweden
| | - Andrew D Friend
- Department of Geography, University of Cambridge, Cambridge, CB2 1BY, UK
| | - Andrew D Richardson
- School of Informatics, Computing and Cyber Systems and Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
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Mu Y, Lyu L, Li Y, Fang O. Tree-ring evidence of ecological stress memory. Proc Biol Sci 2022; 289:20221850. [PMID: 36285497 PMCID: PMC9597412 DOI: 10.1098/rspb.2022.1850] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 10/05/2022] [Indexed: 10/21/2023] Open
Abstract
Plants experiencing stress could develop the ability to reshape their response toward present stress based on past stress experience, called 'ecological stress memory' (ESM), which is important for plant acclimation to repeated stresses. Although ESM has been largely reported, it remains unclear whether ESM could improve tree resistance to recurrent stress in subsequent decades. Here, we explore it from a tree-ring network of 1491 trees from 50 long-living juniper forests on the Tibetan Plateau. Through comparing performances of tree radial growth in past sequential growth stresses, we found that trees could obtain ESM under antecedent stresses and elevate resistance to subsequent stress after several years or even decades. Such positive effects of ESM are associated with post-stress recovery. Trees with slow recovery trajectories after antecedent stress show significantly improved resistance to subsequent stress, while trees with extremely fast post-stress recovery showed decreased resistance to subsequent stress. These results imply that temporary depressive tree radial growth after antecedent stress might be a trigger of long storage of ESM. Incorporating positive effects of ESM and relationship between ESM activation and post-stress recovery into future Earth system models could advance our capacity to predict forest dynamics and forest ecosystem stabilization under future stress conditions.
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Affiliation(s)
- Yumei Mu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
| | - Lixin Lyu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
| | - Yan Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Ouya Fang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
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19
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Harner AD, Leach HL, Briggs L, Centinari M. Prolonged phloem feeding by the spotted lanternfly, an invasive planthopper, alters resource allocation and inhibits gas exchange in grapevines. PLANT DIRECT 2022; 6:e452. [PMID: 36226305 PMCID: PMC9533444 DOI: 10.1002/pld3.452] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Spotted lanternfly (Lycorma delicatula White; SLF) is a phloem-feeding planthopper invasive to the Eastern United States that can feed on a range of wild and cultivated plant species. Since its 2014 introduction in the United States, large infestations and subsequent economic damage have been reported in cultivated grapevines, but no studies have detailed grapevine physiological responses to SLF phloem feeding. This study investigated grapevine-SLF interactions, detailing how different infestation densities affect leaf gas exchange and end-season concentrations of nonstructural carbohydrates and nitrogen in vegetative and perennial tissues of two Vitis species. Effects on fruit ripeness parameters and dormant bud freeze tolerance were examined, in addition to other year-after effects. Phloem feeding by low densities (≤4 SLF shoot-1) had minimal effects, whereas greater densities (5-15 SLF shoot-1) increasingly affected carbohydrate and nitrogen dynamics in both Vitis species. Phloem feeding substantially affected starch and, to a lesser extent, total nitrogen concentrations of woody roots. Prolonged exposure strongly reduced leaf gas exchange. We conclude that intensive late-season phloem feeding by large adult SLF population densities (≥8 SLF shoot-1) can induce carbon limitation, with the potential for negative year-after effects in cases of severe belowground carbon depletion. This work presents novel insights into SLF-grapevine interactions, identifies avenues of future SLF-plant research, and assists the development of action thresholds for SLF management in vineyards.
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Affiliation(s)
- Andrew D. Harner
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Heather L. Leach
- Department of EntomologyThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Lauren Briggs
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Michela Centinari
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
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20
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Korolyova N, Buechling A, Lieutier F, Yart A, Cudlín P, Turčáni M, Jakuš R. Primary and secondary host selection by Ips typographus depends on Norway spruce crown characteristics and phenolic-based defenses. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 321:111319. [PMID: 35696919 DOI: 10.1016/j.plantsci.2022.111319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 05/05/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Climate change is expected to intensify bark beetle population outbreaks in forests globally, affecting biodiversity and trajectories of change. Aspects of individual tree resistance remain poorly quantified, particularly with regard to the role of phenolic compounds, hindering robust predictions of forest response to future conditions. In 2003, we conducted a mechanical wounding experiment in a Norway spruce forest that coincided with an outbreak of the bark beetle, Ips typographus. We collected phloem samples from 97 trees and monitored tree survival for 5 months. Using high-performance liquid chromatography, we quantified induced changes in the concentrations of phenolics. Classification and regression tools were used to evaluate relationships between phenolic production and bark beetle resistance, in the context of other survival factors. The proximity of beetle source populations was a principal determinant of survival. Proxy measures of tree vigor, such as crown defoliation, mediated tree resistance. Controlling for these factors, synthesis of catechin was found to exponentially increase tree survival probability. However, even resistant trees were susceptible in late season due to high insect population growth. Our results show that incorporating trait-mediated effects improves predictions of survival. Using an integrated analytical approach, we demonstrate that phenolics play a direct role in tree defense to herbivory.
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Affiliation(s)
- Nataliya Korolyova
- Fac. of Forestry and Wood Sciences, Czech Univ. of Life Sciences, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic.
| | - Arne Buechling
- Fac. of Forestry and Wood Sciences, Czech Univ. of Life Sciences, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic.
| | - François Lieutier
- Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, B.P. 6749, F-45067 Orléans, France.
| | - Annie Yart
- Institut National de la Recherche Agronomique, Zoologie Forestiere, Ardon, 45160 Olivet, France.
| | - Pavel Cudlín
- Global Change Research Institute of the Czech Academy of Sciences, Department of Carbon Storage in the Landscape, Bělidla 986/4a, 603 00 Brno, Czech Republic.
| | - Marek Turčáni
- Fac. of Forestry and Wood Sciences, Czech Univ. of Life Sciences, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic.
| | - Rastislav Jakuš
- Fac. of Forestry and Wood Sciences, Czech Univ. of Life Sciences, Kamýcká 129, 165 00 Praha-Suchdol, Czech Republic; Inst. of Forest Ecology, Slovak Acad. of Sciences, Ľ. Štúra 2, 960 53 Zvolen, Slovak Republic.
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21
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Wang W, Talide L, Viljamaa S, Niittylä T. Aspen growth is not limited by starch reserves. Curr Biol 2022; 32:3619-3627.e4. [PMID: 35820419 DOI: 10.1016/j.cub.2022.06.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/13/2022] [Accepted: 06/16/2022] [Indexed: 11/16/2022]
Abstract
All photosynthetic organisms balance CO2 assimilation with growth and carbon storage. Stored carbon is used for growth at night and when demand exceeds assimilation. Gaining a mechanistic understanding of carbon partitioning between storage and growth in trees is important for biological studies and for estimating the potential of terrestrial photosynthesis to sequester anthropogenic CO2 emissions.1,2 Starch represents the main carbon storage in plants.3,4 To examine the carbon storage mechanism and role of starch during tree growth, we generated and characterized low-starch hybrid aspen (Populus tremula × tremuloides) trees using CRISPR-Cas9-mediated gene editing of two PHOSPHOGLUCOMUTASE (PGM) genes coding for plastidial PGM isoforms essential for starch biosynthesis. We demonstrate that starch deficiency does not reduce tree growth even in short days, showing that starch is not a critical carbon reserve during diel growth of aspen. The low-starch trees assimilated up to ∼30% less CO2 compared to the wild type under a range of irradiance levels, but this did not reduce growth or wood density. This implies that aspen growth is not limited by carbon assimilation under benign growth conditions. Moreover, the timing of bud set and bud flush in the low-starch trees was not altered, implying that starch reserves are not critical for the seasonal growth-dormancy cycle. The findings are consistent with a passive starch storage mechanism that contrasts with the annual Arabidopsis and indicate that the capacity of the aspen to absorb CO2 is limited by the rate of sink tissue growth.
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Affiliation(s)
- Wei Wang
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå Plant Science Centre, Umeå S-901 83, Sweden
| | - Loic Talide
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå Plant Science Centre, Umeå S-901 83, Sweden
| | - Sonja Viljamaa
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå Plant Science Centre, Umeå S-901 83, Sweden
| | - Totte Niittylä
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå Plant Science Centre, Umeå S-901 83, Sweden.
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22
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Han Y, Deng J, Zhou W, Wang QW, Yu D. Seasonal Responses of Hydraulic Function and Carbon Dynamics in Spruce Seedlings to Continuous Drought. FRONTIERS IN PLANT SCIENCE 2022; 13:868108. [PMID: 35599899 PMCID: PMC9115555 DOI: 10.3389/fpls.2022.868108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/18/2022] [Indexed: 06/15/2023]
Abstract
Drought is expected to increase in the frequency and duration associated with climate change. Although hydraulic function and carbon (C) storage have been widely recognized as key components to plant survival under a single drought, the physiological responses to continuous drought remain largely unknown, particularly for high northern temperate and boreal forests which are sensitive to water stress. In this study, we quantified the survival, growth, gas exchange, water relations, and nonstructural carbohydrates (NSCs) in 3-year-old Jezo spruce (Picea jezoensis) seedlings responding to continuous drought stress. Seedlings were maintained in drought conditions for 392 days, covering two growing and one dormant winter season. Seedlings subjected to drought showed a significant decrease in net photosynthesis rate (A net ) and stomatal conductance (g s ) in both growing seasons, and biomass in the second growing season. The seedling mortality continuously increased to 35.6% at the experimental end. Notably, responses of C storage and leaf water potential to drought varied greatly depending on seasons. Living seedlings exposed to drought and control treatments had similar NSC concentrations in both growing seasons. However, seedlings with concentrations of both the soluble sugars and starch less than 1% in root died in the winter dormant season. In the second growing season, compared with the control treatment, droughted seedlings had significantly lower leaf water potential and stem wood-specific hydraulic conductivity (K w). Meanwhile, the leaf predawn water potential did not recover overnight. These suggest that C starvation might be an important reason for seedlings that died in the winter dormant season, while in the growing season drought may limit seedling survival and growth through inducing hydraulic failure. Such seasonal dependence in hydraulic dysfunction and C depletion may lead to higher mortality in spruce forests facing extended drought duration expected in the future.
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Affiliation(s)
- Yangang Han
- CAS 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
| | - Jiaojiao Deng
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Wangming Zhou
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Qing-Wei Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Dapao Yu
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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