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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. New Phytol 2022; 236:1296-1309. [PMID: 35927942 DOI: 10.1111/nph.18421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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2
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Miao G, Noormets A, Gavazzi M, Mitra B, Domec JC, Sun G, McNulty S, King JS. Beyond carbon flux partitioning: Carbon allocation and nonstructural carbon dynamics inferred from continuous fluxes. Ecol Appl 2022; 32:e2655. [PMID: 35567435 DOI: 10.1002/eap.2655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 03/04/2022] [Accepted: 03/21/2022] [Indexed: 06/15/2023]
Abstract
Carbon (C) allocation and nonstructural carbon (NSC) dynamics play essential roles in plant growth and survival under stress and disturbance. However, quantitative understanding of these processes remains limited. Here we propose a framework where we connect commonly measured carbon cycle components (eddy covariance fluxes of canopy CO2 exchange, soil CO2 efflux, and allometry-based biomass and net primary production) by a simple mass balance model to derive ecosystem-level NSC dynamics (NSCi ), C translocation (dCi ), and the biomass production efficiency (BPEi ) in above- and belowground plant (i = agp and bgp) compartments. We applied this framework to two long-term monitored loblolly pine (Pinus taeda) plantations of different ages in North Carolina and characterized the variations of NSC and allocation in years under normal and drought conditions. The results indicated that the young stand did not have net NSC flux at the annual scale, whereas the mature stand stored a near-constant proportion of new assimilates as NSC every year under normal conditions, which was comparable in magnitude to new structural growth. Roots consumed NSC in drought and stored a significant amount of NSC post drought. The above- and belowground dCi and BPEi varied more from year to year in the young stand and approached a relatively stable pattern in the mature stand. The belowground BPEbgp differed the most between the young and mature stands and was most responsive to drought. With the internal C dynamics quantified, this framework may also improve biomass production estimation, which reveals the variations resulting from droughts. Overall, these quantified ecosystem-scale dynamics were consistent with existing evidence from tree-based manipulative experiments and measurements and demonstrated that combining the continuous fluxes as proposed here can provide additional information about plant internal C dynamics. Given that it is based on broadly available flux data, the proposed framework is promising to improve the allocation algorithms in ecosystem C cycle models and offers new insights into observed variability in soil-plant-climate interactions.
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Affiliation(s)
- Guofang Miao
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian Province, China
- School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian Province, China
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
| | - Asko Noormets
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
- Department of Ecosystem Science and Management, Texas A&M University, College Station, Texas, USA
| | - Michael Gavazzi
- Eastern Forest Environmental Threat Assessment Center, Southern Research Station, USDA Forest Service, Research Triangle Park, North Carolina, USA
| | - Bhaskar Mitra
- School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, Arizona, USA
| | - Jean-Christophe Domec
- Bordeaux Sciences AGRO, UMR1391 ISPA INRA, Gradignan Cedex, France
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Ge Sun
- Eastern Forest Environmental Threat Assessment Center, Southern Research Station, USDA Forest Service, Research Triangle Park, North Carolina, USA
| | - Steve McNulty
- Eastern Forest Environmental Threat Assessment Center, Southern Research Station, USDA Forest Service, Research Triangle Park, North Carolina, USA
| | - John S King
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
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3
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D'Andrea E, Rezaie N, Battistelli A, Gavrichkova O, Kuhlmann I, Matteucci G, Moscatello S, Proietti S, Scartazza A, Trumbore S, Muhr J. Winter's bite: beech trees survive complete defoliation due to spring late-frost damage by mobilizing old C reserves. New Phytol 2019; 224:625-631. [PMID: 31282591 DOI: 10.1111/nph.16047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 06/30/2019] [Indexed: 05/12/2023]
Abstract
Late frost can destroy the photosynthetic apparatus of trees. We hypothesized that this can alter the normal cyclic dynamics of C-reserves in the wood. We measured soluble sugar concentrations and radiocarbon signatures (Δ14 C) of soluble nonstructural carbon (NSC) in woody tissues sampled from a Mediterranean beech forest that was completely defoliated by an exceptional late frost in 2016. We used the bomb radiocarbon approach to estimate the time elapsed since fixation of mobilized soluble sugars. During the leafless period after the frost event, soluble sugar concentrations declined sharply while Δ14 C of NSC increased. This can be explained by the lack of fresh assimilate supply and a mobilization of C from reserve pools. Soluble NSC became increasingly older during the leafless period, with a maximum average age of 5 yr from samples collected 27 d before canopy recovery. Following leaf re-growth, soluble sugar concentrations increased and Δ14 C of soluble NSC decreased, indicating the allocation of new assimilates to the stem soluble sugars pool. These data highlight that beech trees rapidly mobilize reserve C to survive strong source-sink imbalances, for example due to late frost, and show that NSC is a key trait for tree resilience under global change.
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Affiliation(s)
| | - Negar Rezaie
- CNR-ISAFOM, via Patacca 2, 80056, Ercolano, Italy
| | | | - Olga Gavrichkova
- CNR-IRET, via Marconi 2, 05010, Porano, Italy
- Agro-Technology Institute, Peoples Friendship University of Russia, 117198, Moscow, Russia
| | - Iris Kuhlmann
- 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
| | - Jan Muhr
- Max-Planck-Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
- Bioclimatology, University of Göttingen, Büsgenweg 2, 37077, Göttingen, Germany
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4
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Gougherty AV, Gougherty SW. Sequence of flower and leaf emergence in deciduous trees is linked to ecological traits, phylogenetics, and climate. New Phytol 2018; 220:121-131. [PMID: 29900552 DOI: 10.1111/nph.15270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/12/2018] [Indexed: 06/08/2023]
Abstract
While much research has focused on the timing of individual plant phenological events, the sequence of phenological events has received considerably less attention. Here we identify drivers and patterns of flower and leaf emergence sequence (FLS) in deciduous tree species of the Great Lakes region of North America. Five hypotheses related to cold tolerance, water dynamics, seed mass, pollination syndrome, and xylem anatomy type were compared for their ability to explain FLS. Phylogenetic and geographic patterns of FLS were also assessed. We identified additional traits associated with FLS using Random Forest models. Of the hypotheses assessed, those related to species' water dynamics and seed mass had the greatest support. The spatial pattern of FLS was found to be strongly related to minimum monthly temperature and the phylogenetic pattern was clustered among species. Based on results from Random Forest models, species' fruiting characteristics were found to be the most important variables in explaining FLS. Our results show that FLS is related to a suite of plant traits and environmental tolerances. We emphasize the need to expand phenological research to include both the timing and sequence of plant's entire phenology, in particular in relation to plant physiology and global change.
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Affiliation(s)
- Andrew V Gougherty
- Appalachian Lab, University of Maryland Center for Environmental Science, Frostburg, MD, 21532, USA
| | - Steven W Gougherty
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, 49060, USA
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5
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Aubrey DP, Teskey RO. Stored root carbohydrates can maintain root respiration for extended periods. New Phytol 2018; 218:142-152. [PMID: 29281746 DOI: 10.1111/nph.14972] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 11/29/2017] [Indexed: 05/17/2023]
Abstract
Tight coupling between below-ground autotrophic respiration and the availability of recently assimilated carbon (C) has become a paradigm in the ecophysiological literature. Here, we show that stored carbohydrates can decouple respiration from assimilation for prolonged periods by mobilizing reserves from transport roots to absorptive roots. We permanently disrupted the below-ground transfer of recently assimilated C using stem girdling and root trenching and measured soil CO2 efflux for over 1 yr in longleaf pine (Pinus palustris), a species that has large reserves of stored carbohydrates in roots. Soil CO2 efflux was not influenced by girdling or trenching through the 14-month observation period. Stored carbohydrate concentrations in absorptive roots were not affected by the disrupted supply of current photosynthate for over 1 yr; however, carbohydrate concentrations in transport roots decreased. Our results indicate that root respiration can be decoupled from recent canopy assimilation and that stored carbohydrates can be mobilized from transport roots to absorptive roots to maintain respiration for over 1 yr. This refines the current paradigm that canopy assimilation and below-ground respiration are tightly coupled and provides evidence of the mechanism and dynamics responsible for decoupling the above- and below-ground processes.
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Affiliation(s)
- Doug P Aubrey
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, 29802, USA
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
| | - Robert O Teskey
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
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6
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Wiley E, Rogers BJ, Hodgkinson R, Landhäusser SM. Nonstructural carbohydrate dynamics of lodgepole pine dying from mountain pine beetle attack. New Phytol 2016; 209:550-562. [PMID: 26256444 DOI: 10.1111/nph.13603] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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