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McDowell NG, Fisher RA, Xu C, Domec JC, Hölttä T, Mackay DS, Sperry JS, Boutz A, Dickman L, Gehres N, Limousin JM, Macalady A, Martínez-Vilalta J, Mencuccini M, Plaut JA, Ogée J, Pangle RE, Rasse DP, Ryan MG, Sevanto S, Waring RH, Williams AP, Yepez EA, Pockman WT. Evaluating theories of drought-induced vegetation mortality using a multimodel-experiment framework. THE NEW PHYTOLOGIST 2013; 200:304-321. [PMID: 24004027 DOI: 10.1111/nph.12465] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/19/2013] [Indexed: 05/05/2023]
Abstract
Model-data comparisons of plant physiological processes provide an understanding of mechanisms underlying vegetation responses to climate. We simulated the physiology of a piñon pine-juniper woodland (Pinus edulis-Juniperus monosperma) that experienced mortality during a 5 yr precipitation-reduction experiment, allowing a framework with which to examine our knowledge of drought-induced tree mortality. We used six models designed for scales ranging from individual plants to a global level, all containing state-of-the-art representations of the internal hydraulic and carbohydrate dynamics of woody plants. Despite the large range of model structures, tuning, and parameterization employed, all simulations predicted hydraulic failure and carbon starvation processes co-occurring in dying trees of both species, with the time spent with severe hydraulic failure and carbon starvation, rather than absolute thresholds per se, being a better predictor of impending mortality. Model and empirical data suggest that limited carbon and water exchanges at stomatal, phloem, and below-ground interfaces were associated with mortality of both species. The model-data comparison suggests that the introduction of a mechanistic process into physiology-based models provides equal or improved predictive power over traditional process-model or empirical thresholds. Both biophysical and empirical modeling approaches are useful in understanding processes, particularly when the models fail, because they reveal mechanisms that are likely to underlie mortality. We suggest that for some ecosystems, integration of mechanistic pathogen models into current vegetation models, and evaluation against observations, could result in a breakthrough capability to simulate vegetation dynamics.
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Affiliation(s)
- Nate G McDowell
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Rosie A Fisher
- Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO, 80305, USA
| | - Chonggang Xu
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - J C Domec
- University of Bordeaux, Bordeaux Sciences Agro, UMR INRA-TCEM 1220, 33140, Villenave d'Ornon, France
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708, USA
| | - Teemu Hölttä
- Department of Forest Sciences, University of Helsinki, PO Box 24, 00014, Helsinki, Finland
| | - D Scott Mackay
- Department of Geography, State University of New York at Buffalo, 105 Wilkeson Quadrangle, Buffalo, NY, 14261, USA
| | - John S Sperry
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA
| | - Amanda Boutz
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131-0001, USA
| | - Lee Dickman
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Nathan Gehres
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131-0001, USA
| | - Jean Marc Limousin
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131-0001, USA
| | - Alison Macalady
- School of Geography and Development and Laboratory of Tree-Ring Research, University of Arizona, 1215 Lowell Street, Tucson, AZ, 85721-0058, USA
| | - Jordi Martínez-Vilalta
- CREAF, Cerdanyola del Vallès, 08193, Spain
- Univ Autònoma Barcelona, Cerdanyola del Vallès, 08193, Spain
| | - Maurizio Mencuccini
- ICREA at CREAF, Cerdanyola del Vallès, 08193, Spain
- School of GeoSciences, University of Edinburgh Crew Building, West Mains Road, Edinburgh, EH9 3JN, UK
| | - Jennifer A Plaut
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131-0001, USA
| | - Jérôme Ogée
- INRA, UR1263 EPHYSE, F-33140, Villenave d'Ornon, France
| | - Robert E Pangle
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131-0001, USA
| | - Daniel P Rasse
- Bioforsk - Norwegian Institute for Agricultural and Environmental Research, Ås, Norway
| | - Michael G Ryan
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523-1499, USA
- USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO, 80526, USA
| | - Sanna Sevanto
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Richard H Waring
- College of Forestry, Oregon State University, Corvallis, OR, 97331-5704, USA
| | - A Park Williams
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Enrico A Yepez
- Departamento de Ciencias del Agua y del Medio Ambiente, Instituto Tecnológico de Sonora, Ciudad Obregón, Sonora, 85000, Mexico
| | - William T Pockman
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131-0001, USA
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152
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Simard S, Giovannelli A, Treydte K, Traversi ML, King GM, Frank D, Fonti P. Intra-annual dynamics of non-structural carbohydrates in the cambium of mature conifer trees reflects radial growth demands. TREE PHYSIOLOGY 2013; 33:913-23. [PMID: 24128848 DOI: 10.1093/treephys/tpt075] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The presence of soluble carbohydrates in the cambial zone, either from sugars recently produced during photosynthesis or from starch remobilized from storage organs, is necessary for radial tree growth. However, considerable uncertainties on carbohydrate dynamics and the consequences on tree productivity exist. This study aims to better understand the variation in different carbon pools at intra-annual resolution by quantifying how cambial zone sugar and starch concentrations fluctuate over the season and in relation to cambial phenology. A comparison between two physiologically different species growing at the same site, i.e., the evergreen Picea abies Karst. and the deciduous Larix decidua Mill., and between L. decidua from two contrasting elevations, is presented to identify mechanisms of growth limitation. Results indicate that the annual cycle of sugar concentration within the cambial zone is coupled to the process of wood formation. The highest sugar concentration is observed when the number of cells in secondary wall formation and lignification stages is at a maximum, subsequent to most radial growth. Starch disappears in winter, while other freeze-resistant non-structural carbohydrates (NSCs) increase. Slight differences in NSC concentration between species are consistent with the differing climate sensitivity of the evergreen and deciduous species investigated. The general absence of differences between elevations suggests that the cambial activity of trees growing at the treeline was not limited by the availability of carbohydrates at the cambial zone but instead by environmental controls on the growing season duration.
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Affiliation(s)
- Sonia Simard
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
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153
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Fajardo A, Piper FI, Hoch G. Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients. ANNALS OF BOTANY 2013; 112:623-31. [PMID: 23788748 PMCID: PMC3718216 DOI: 10.1093/aob/mct127] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND AIMS The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. METHODS Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). KEY RESULTS Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P < 0·001) and branch sapwood (P = 0·012) tissues. Deciduous species showed significantly higher NSCs than evergreens for all tissues; on average, the former had 11 % (leaves), 158 % (branch) and 103 % (sapwood) significantly (P < 0·001) higher NSCs than the latter. Finally, deciduous species had higher NSC (particularly starch) increases with elevation than evergreens for stem sapwood, but the opposite was true for leaves and branch sapwood. CONCLUSIONS Considering the observed decrease in tree growth and increase in NSCs with elevation, it is concluded that both deciduous and evergreen treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.
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Affiliation(s)
- Alex Fajardo
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP) Conicyt-Regional R10C1003, Universidad Austral de Chile, Ignacio Serrano 509, Coyhaique, Chile.
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154
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Cernusak LA, Winter K, Dalling JW, Holtum JAM, Jaramillo C, K Rner C, Leakey ADB, Norby RJ, Poulter B, Turner BL, Wright SJ. Tropical forest responses to increasing atmospheric CO 2: current knowledge and opportunities for future research. FUNCTIONAL PLANT BIOLOGY : FPB 2013; 40:531-551. [PMID: 32481129 DOI: 10.1071/fp12309] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 03/21/2013] [Indexed: 05/06/2023]
Abstract
Elevated atmospheric CO2 concentrations (ca) will undoubtedly affect the metabolism of tropical forests worldwide; however, critical aspects of how tropical forests will respond remain largely unknown. Here, we review the current state of knowledge about physiological and ecological responses, with the aim of providing a framework that can help to guide future experimental research. Modelling studies have indicated that elevated ca can potentially stimulate photosynthesis more in the tropics than at higher latitudes, because suppression of photorespiration by elevated ca increases with temperature. However, canopy leaves in tropical forests could also potentially reach a high temperature threshold under elevated ca that will moderate the rise in photosynthesis. Belowground responses, including fine root production, nutrient foraging and soil organic matter processing, will be especially important to the integrated ecosystem response to elevated ca. Water use efficiency will increase as ca rises, potentially impacting upon soil moisture status and nutrient availability. Recruitment may be differentially altered for some functional groups, potentially decreasing ecosystem carbon storage. Whole-forest CO2 enrichment experiments are urgently needed to test predictions of tropical forest functioning under elevated ca. Smaller scale experiments in the understorey and in gaps would also be informative, and could provide stepping stones towards stand-scale manipulations.
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Affiliation(s)
- Lucas A Cernusak
- School of Marine and Tropical Biology, James Cook University, Cairns, Qld 4878, Australia
| | - Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| | - James W Dalling
- Department of Plant Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Joseph A M Holtum
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| | - Carlos Jaramillo
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| | - Christian K Rner
- Institute of Botany, University of Basel, Basel, CH-4056, Switzerland
| | - Andrew D B Leakey
- Department of Plant Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Richard J Norby
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Benjamin Poulter
- Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette French Centre National de la Recherche Scientifique, the Atomic Energy Commission and the University of Versailles Saint-Quentin, 91191, France
| | - Benjamin L Turner
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
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155
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Krause GH, Cheesman AW, Winter K, Krause B, Virgo A. Thermal tolerance, net CO2 exchange and growth of a tropical tree species, Ficus insipida, cultivated at elevated daytime and nighttime temperatures. JOURNAL OF PLANT PHYSIOLOGY 2013; 170:822-7. [PMID: 23399405 DOI: 10.1016/j.jplph.2013.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 01/09/2013] [Indexed: 05/11/2023]
Abstract
Global warming and associated increases in the frequency and amplitude of extreme weather events, such as heat waves, may adversely affect tropical rainforest plants via significantly increased tissue temperatures. In this study, the response to two temperature regimes was assessed in seedlings of the neotropical pioneer tree species, Ficus insipida. Plants were cultivated in growth chambers at strongly elevated daytime temperature (39°C), combined with either close to natural (22°C) or elevated (32°C) nighttime temperatures. Under both growth regimes, the critical temperature for irreversible leaf damage, determined by changes in chlorophyll a fluorescence, was approximately 51°C. This is comparable to values found in F. insipida growing under natural ambient conditions and indicates a limited potential for heat tolerance acclimation of this tropical forest tree species. Yet, under high nighttime temperature, growth was strongly enhanced, accompanied by increased rates of net photosynthetic CO2 uptake and diminished temperature dependence of leaf-level dark respiration, consistent with thermal acclimation of these key physiological parameters.
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Affiliation(s)
- G Heinrich Krause
- Smithsonian Tropical Research Institute, P.O. Box 0843-03092, Balboa, Ancón, Republic of Panama.
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156
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Bahn M, Lattanzi FA, Hasibeder R, Wild B, Koranda M, Danese V, Brüggemann N, Schmitt M, Siegwolf R, Richter A. Responses of belowground carbon allocation dynamics to extended shading in mountain grassland. THE NEW PHYTOLOGIST 2013; 198:116-126. [PMID: 23383758 PMCID: PMC3592993 DOI: 10.1111/nph.12138] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/30/2012] [Indexed: 05/04/2023]
Abstract
Carbon (C) allocation strongly influences plant and soil processes. Short-term C allocation dynamics in ecosystems and their responses to environmental changes are still poorly understood. Using in situ (13) CO(2) pulse labeling, we studied the effects of 1 wk of shading on the transfer of recent photoassimilates between sugars and starch of above- and belowground plant organs and to soil microbial communities of a mountain meadow. C allocation to roots and microbial communities was rapid. Shading strongly reduced sucrose and starch concentrations in shoots, but not roots, and affected tracer dynamics in sucrose and starch of shoots, but not roots: recent C was slowly incorporated into root starch irrespective of the shading treatment. Shading reduced leaf respiration more strongly than root respiration. It caused no reduction in the amount of (13) C incorporated into fungi and Gram-negative bacteria, but increased its residence time. These findings suggest that, under interrupted C supply, belowground C allocation (as reflected by the amount of tracer allocated to root starch, soil microbial communities and belowground respiration) was maintained at the expense of aboveground C status, and that C source strength may affect the turnover of recent plant-derived C in soil microbial communities.
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Affiliation(s)
- Michael Bahn
- Institute of Ecology, University of InnsbruckSternwartestr. 15, 6020, Innsbruck, Austria
| | - Fernando A Lattanzi
- Technische Universität München, Lehrstuhl für GrünlandlehreAlte Akademie 12, D-85350, Freising-Weihenstephan, Germany
| | - Roland Hasibeder
- Institute of Ecology, University of InnsbruckSternwartestr. 15, 6020, Innsbruck, Austria
| | - Birgit Wild
- Department of Terrestrial Ecosystem Research, Faculty of Life Sciences, University of ViennaAlthanstrasse 14, A-1090, Vienna, Austria
| | - Marianne Koranda
- Department of Terrestrial Ecosystem Research, Faculty of Life Sciences, University of ViennaAlthanstrasse 14, A-1090, Vienna, Austria
| | - Valentina Danese
- Institute of Ecology, University of InnsbruckSternwartestr. 15, 6020, Innsbruck, Austria
| | - Nicolas Brüggemann
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, Agrosphere Institute (IBG-3)Leo-Brandt-Straße, 52425, Jülich, Germany
| | - Michael Schmitt
- Institute of Ecology, University of InnsbruckSternwartestr. 15, 6020, Innsbruck, Austria
| | - Rolf Siegwolf
- Paul Scherrer Institute5232, Villigen PSI, Switzerland
| | - Andreas Richter
- Department of Terrestrial Ecosystem Research, Faculty of Life Sciences, University of ViennaAlthanstrasse 14, A-1090, Vienna, Austria
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157
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McNown RW, Sullivan PF. Low photosynthesis of treeline white spruce is associated with limited soil nitrogen availability in the Western Brooks Range,
A
laska. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12082] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert W. McNown
- Environment and Natural Resources Institute University of Alaska Anchorage Anchorage AK 99508 USA
- Department of Biological Sciences University of Alaska Anchorage Anchorage AK 99508 USA
| | - Patrick F. Sullivan
- Environment and Natural Resources Institute University of Alaska Anchorage Anchorage AK 99508 USA
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158
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Adams HD, Germino MJ, Breshears DD, Barron-Gafford GA, Guardiola-Claramonte M, Zou CB, Huxman TE. Nonstructural leaf carbohydrate dynamics of Pinus edulis during drought-induced tree mortality reveal role for carbon metabolism in mortality mechanism. THE NEW PHYTOLOGIST 2013; 197:1142-1151. [PMID: 23311898 DOI: 10.1111/nph.12102] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 11/04/2012] [Indexed: 05/04/2023]
Abstract
Vegetation change is expected with global climate change, potentially altering ecosystem function and climate feedbacks. However, causes of plant mortality, which are central to vegetation change, are understudied, and physiological mechanisms remain unclear, particularly the roles of carbon metabolism and xylem function. We report analysis of foliar nonstructural carbohydrates (NSCs) and associated physiology from a previous experiment where earlier drought-induced mortality of Pinus edulis at elevated temperatures was associated with greater cumulative respiration. Here, we predicted faster NSC decline for warmed trees than for ambient-temperature trees. Foliar NSC in droughted trees declined by 30% through mortality and was lower than in watered controls. NSC decline resulted primarily from decreased sugar concentrations. Starch initially declined, and then increased above pre-drought concentrations before mortality. Although temperature did not affect NSC and sugar, starch concentrations ceased declining and increased earlier with higher temperatures. Reduced foliar NSC during lethal drought indicates a carbon metabolism role in mortality mechanism. Although carbohydrates were not completely exhausted at mortality, temperature differences in starch accumulation timing suggest that carbon metabolism changes are associated with time to death. Drought mortality appears to be related to temperature-dependent carbon dynamics concurrent with increasing hydraulic stress in P. edulis and potentially other similar species.
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Affiliation(s)
- Henry D Adams
- Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
- Biosphere 2, University of Arizona, Tucson, AZ, 85721, USA
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Matthew J Germino
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Snake River Field Station, 970 Lusk St, Boise, ID, 83706, USA
- Department of Biological Sciences, Idaho State University, Pocatello, ID, 83209, USA
| | - David D Breshears
- Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
- Biosphere 2, University of Arizona, Tucson, AZ, 85721, USA
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA
| | | | | | - Chris B Zou
- Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Travis E Huxman
- Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
- Biosphere 2, University of Arizona, Tucson, AZ, 85721, USA
- Ecology and Evolutionary Biology, University of California, Irvine, CA, 92617, USA
- Center for Environmental Biology, University of California, Irvine, CA, 92617, USA
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159
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Richardson AD, Carbone MS, Keenan TF, Czimczik CI, Hollinger DY, Murakami P, Schaberg PG, Xu X. Seasonal dynamics and age of stemwood nonstructural carbohydrates in temperate forest trees. THE NEW PHYTOLOGIST 2013. [PMID: 23190200 DOI: 10.1111/nph.12042] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Nonstructural carbohydrate reserves support tree metabolism and growth when current photosynthates are insufficient, offering resilience in times of stress. We monitored stemwood nonstructural carbohydrate (starch and sugars) concentrations of the dominant tree species at three sites in the northeastern United States. We estimated the mean age of the starch and sugars in a subset of trees using the radiocarbon ((14) C) bomb spike. With these data, we then tested different carbon (C) allocation schemes in a process-based model of forest C cycling. We found that the nonstructural carbohydrates are both highly dynamic and about a decade old. Seasonal dynamics in starch (two to four times higher in the growing season, lower in the dormant season) mirrored those of sugars. Radiocarbon-based estimates indicated that the mean age of the starch and sugars in red maple (Acer rubrum) was 7-14 yr. A two-pool (fast and slow cycling reserves) model structure gave reasonable estimates of the size and mean residence time of the total NSC pool, and greatly improved model predictions of interannual variability in woody biomass increment, compared with zero- or one-pool structures used in the majority of existing models. This highlights the importance of nonstructural carbohydrates in the context of forest ecosystem carbon cycling.
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Affiliation(s)
- Andrew D Richardson
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Mariah S Carbone
- National Center for Ecological Analysis and Synthesis, Santa Barbara, CA, 93101, USA
| | - Trevor F Keenan
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Claudia I Czimczik
- Department of Earth System Science, University of California, Irvine, CA, 92697, USA
| | - David Y Hollinger
- USDA Forest Service, Northern Research Station, Durham, NH, 03824, USA
| | - Paula Murakami
- USDA Forest Service, Northern Research Station, Burlington, VT, 05403, USA
| | - Paul G Schaberg
- USDA Forest Service, Northern Research Station, Burlington, VT, 05403, USA
| | - Xiaomei Xu
- Department of Earth System Science, University of California, Irvine, CA, 92697, USA
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160
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Affiliation(s)
- Adrian V Rocha
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
- Environmental Change Initiative, University of Notre Dame, Notre Dame, IN, USA
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161
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Rosas T, Galiano L, Ogaya R, Peñuelas J, Martínez-Vilalta J. Dynamics of non-structural carbohydrates in three Mediterranean woody species following long-term experimental drought. FRONTIERS IN PLANT SCIENCE 2013; 4:400. [PMID: 24130568 PMCID: PMC3795346 DOI: 10.3389/fpls.2013.00400] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 09/20/2013] [Indexed: 05/08/2023]
Abstract
Stored non-structural carbohydrates (NSC) have been proposed as a key determinant of drought resistance in plants. However, the evidence for this role is controversial, as it comes mostly from observational, short-term studies. Here, we take advantage of a long-term experimental throughfall reduction to elucidate the response of NSC to increased drought 14 years after the beginning of the treatment in three Mediterranean resprouter trees (Quercus ilex L., Arbutus unedo L. and Phillyrea latifolia L.). In addition, we selected 20 Q. ilex individuals outside the experimental plots to directly assess the relationship between defoliation and NSC at the individual level. We measured the seasonal course of NSC concentrations in leaves, branches and lignotuber in late winter, late spring, summer, and autumn 2012. Total concentrations of NSC were highest in the lignotuber for all species. In the long-term drought experiment we found significant depletion in concentrations of total NSC in treatment plots only in the lignotuber of A. unedo. At the same time, A. unedo was the only species showing a significant reduction in BAI under the drought treatment during the 14 years of the experiment. By contrast, Q. ilex just reduced stem growth only during the first 4 years of treatment and P. latifolia remained unaffected over the whole study period. However, we found a clear association between the concentrations of NSC and defoliation in Q. ilex individuals sampled outside the experimental plots, with lower total concentrations of NSC and lower proportion of starch in defoliated individuals. Taken together, our results suggest that stabilizing processes, probably at the stand level, may have been operating in the long-term to mitigate any impact of drought on NSC levels, and highlight the necessity to incorporate long-term experimental studies of plant responses to drought.
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Affiliation(s)
- Teresa Rosas
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF)Cerdanyola del Vallès, Spain
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma de BarcelonaCerdanyola del Vallès, Spain
- *Correspondence: Teresa Rosas, Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), Universitat Autònoma de Barcelona, Edifici C, Cerdanyola del Vallès 08193, Spain e-mail:
| | - Lucía Galiano
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF)Cerdanyola del Vallès, Spain
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma de BarcelonaCerdanyola del Vallès, Spain
- Leibniz Centre for Agricultural Landscape Research (ZALF), Institute for Landscape BiogeochemistryMüncheberg, Germany
| | - Romà Ogaya
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF)Cerdanyola del Vallès, Spain
- Consejo Superior de Investigaciones Científicas, Global Ecology Unit CREAF-CEAB-CSIC-UABCerdanyola del Vallès, Spain
| | - Josep Peñuelas
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF)Cerdanyola del Vallès, Spain
- Consejo Superior de Investigaciones Científicas, Global Ecology Unit CREAF-CEAB-CSIC-UABCerdanyola del Vallès, Spain
| | - Jordi Martínez-Vilalta
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF)Cerdanyola del Vallès, Spain
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma de BarcelonaCerdanyola del Vallès, Spain
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