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Maes SL, Dietrich J, Midolo G, Schwieger S, Kummu M, Vandvik V, Aerts R, Althuizen IHJ, Biasi C, Björk RG, Böhner H, Carbognani M, Chiari G, Christiansen CT, Clemmensen KE, Cooper EJ, Cornelissen JHC, Elberling B, Faubert P, Fetcher N, Forte TGW, Gaudard J, Gavazov K, Guan Z, Guðmundsson J, Gya R, Hallin S, Hansen BB, Haugum SV, He JS, Hicks Pries C, Hovenden MJ, Jalava M, Jónsdóttir IS, Juhanson J, Jung JY, Kaarlejärvi E, Kwon MJ, Lamprecht RE, Le Moullec M, Lee H, Marushchak ME, Michelsen A, Munir TM, Myrsky EM, Nielsen CS, Nyberg M, Olofsson J, Óskarsson H, Parker TC, Pedersen EP, Petit Bon M, Petraglia A, Raundrup K, Ravn NMR, Rinnan R, Rodenhizer H, Ryde I, Schmidt NM, Schuur EAG, Sjögersten S, Stark S, Strack M, Tang J, Tolvanen A, Töpper JP, Väisänen MK, van Logtestijn RSP, Voigt C, Walz J, Weedon JT, Yang Y, Ylänne H, Björkman MP, Sarneel JM, Dorrepaal E. Environmental drivers of increased ecosystem respiration in a warming tundra. Nature 2024; 629:105-113. [PMID: 38632407 PMCID: PMC11062900 DOI: 10.1038/s41586-024-07274-7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 03/06/2024] [Indexed: 04/19/2024]
Abstract
Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.
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Affiliation(s)
- S L Maes
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden.
- Forest Ecology and Management Group (FORECOMAN), Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium.
| | - J Dietrich
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden
| | - G Midolo
- Department of Spatial Sciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Praha-Suchdol, Czech Republic
| | - S Schwieger
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - M Kummu
- Water and development research group, Aalto University, Espoo, Finland
| | - V Vandvik
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway
| | - R Aerts
- Amsterdam Institute for Life and Environment (A-LIFE), Vrije Universiteit, Amsterdam, The Netherlands
| | - I H J Althuizen
- Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway
- NORCE Climate and Environment, Norwegian Research Centre AS, Bergen, Norway
| | - C Biasi
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - R G Björk
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - H Böhner
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, The Arctic University of Norway, Tromsø, Norway
| | - M Carbognani
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - G Chiari
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - C T Christiansen
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - K E Clemmensen
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - E J Cooper
- Department of Arctic and Marine Biology, UiT-the Arctic University of Norway, Tromsø, Norway
| | - J H C Cornelissen
- Amsterdam Institute for Life and Environment (A-LIFE), Vrije Universiteit, Amsterdam, The Netherlands
| | - B Elberling
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - P Faubert
- Carbone Boréal, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Quebec, Canada
| | - N Fetcher
- Institute for Environmental Science and Sustainability, Wilkes University, Wilkes-Barre, PA, USA
| | - T G W Forte
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - J Gaudard
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway
| | - K Gavazov
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Lausanne, Switzerland
| | - Z Guan
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - J Guðmundsson
- Agricultural University of Iceland, Reykjavik, Iceland
| | - R Gya
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway
| | - S Hallin
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - B B Hansen
- Department of Terrestrial Ecology, Norwegian Institute for Nature Research, Trondheim, Norway
- Gjærevoll Centre for Biodiversity Foresight Analyses & Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - S V Haugum
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- The Heathland Centre, Alver, Norway
| | - J-S He
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
- Institute of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - C Hicks Pries
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - M J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
- Australian Mountain Research Facility, Canberra, Australian Capital Territory, Australia
| | - M Jalava
- Water and development research group, Aalto University, Espoo, Finland
| | - I S Jónsdóttir
- Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | - J Juhanson
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - J Y Jung
- Division of Life Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - E Kaarlejärvi
- Research Centre for Ecological Change, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - M J Kwon
- Korea Polar Research Institute, Incheon, Korea
- Institute of Soil Science, Universität Hamburg, Hamburg, Germany
| | - R E Lamprecht
- University of Eastern Finland, Department of Environmental and Biological Sciences, Kuopio, Finland
| | - M Le Moullec
- Gjærevoll Centre for Biodiversity Foresight Analyses & Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
- Greenland Institute of Natural Resources, Nuuk, Greenland
| | - H Lee
- NORCE, Norwegian Research Centre AS, Bjerknes Centre for Climate Research, Bergen, Norway
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - M E Marushchak
- University of Eastern Finland, Department of Environmental and Biological Sciences, Kuopio, Finland
| | - A Michelsen
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - T M Munir
- Department of Geography, University of Calgary, Calgary, Alberta, Canada
| | - E M Myrsky
- Arctic Centre, University of Lapland, Rovaniemi, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - C S Nielsen
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
- SEGES Innovation P/S, Aarhus, Denmark
| | - M Nyberg
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - J Olofsson
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - H Óskarsson
- Agricultural University of Iceland, Reykjavik, Iceland
| | - T C Parker
- Ecological Sciences, The James Hutton Institute, Aberdeen, UK
| | - E P Pedersen
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - M Petit Bon
- Department of Wildland Resources, Quinney College of Natural Resources and Ecology Center, Utah State University, Logan, UT, USA
- Department of Arctic Biology, University Centre in Svalbard, Longyearbyen, Norway
| | - A Petraglia
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - K Raundrup
- Greenland Institute of Natural Resources, Nuuk, Greenland
| | - N M R Ravn
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - R Rinnan
- Center for Volatile Interactions, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - H Rodenhizer
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - I Ryde
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - N M Schmidt
- Department of Ecoscience, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
| | - E A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - S Sjögersten
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - S Stark
- Arctic Centre, University of Lapland, Rovaniemi, Finland
| | - M Strack
- Department of Geography and Environmental Management, University of Waterloo, Waterloo, Ontario, Canada
| | - J Tang
- The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA, USA
| | - A Tolvanen
- Natural Resources Institute Finland, Helsinki, Finland
| | - J P Töpper
- Norwegian Institute for Nature Research, Bergen, Norway
| | - M K Väisänen
- Arctic Centre, University of Lapland, Rovaniemi, Finland
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - R S P van Logtestijn
- Amsterdam Institute for Life and Environment (A-LIFE), Vrije Universiteit, Amsterdam, The Netherlands
| | - C Voigt
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
- Institute of Soil Science, Universität Hamburg, Hamburg, Germany
| | - J Walz
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden
| | - J T Weedon
- Amsterdam Institute for Life and Environment (A-LIFE), Vrije Universiteit, Amsterdam, The Netherlands
| | - Y Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - H Ylänne
- School of Forest Sciences, University of Eastern Finland, Joensuu, Finland
| | - M P Björkman
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - J M Sarneel
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - E Dorrepaal
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Abisko, Sweden
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Xirocostas ZA, Ollerton J, Tamme R, Peco B, Lesieur V, Slavich E, Junker RR, Pärtel M, Raghu S, Uesugi A, Bonser SP, Chiarenza GM, Hovenden MJ, Moles AT. The great escape: patterns of enemy release are not explained by time, space or climate. Proc Biol Sci 2023; 290:20231022. [PMID: 37583319 PMCID: PMC10427826 DOI: 10.1098/rspb.2023.1022] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/21/2023] [Indexed: 08/17/2023] Open
Abstract
When a plant is introduced to a new ecosystem it may escape from some of its coevolved herbivores. Reduced herbivore damage, and the ability of introduced plants to allocate resources from defence to growth and reproduction can increase the success of introduced species. This mechanism is known as enemy release and is known to occur in some species and situations, but not in others. Understanding the conditions under which enemy release is most likely to occur is important, as this will help us to identify which species and habitats may be most at risk of invasion. We compared in situ measurements of herbivory on 16 plant species at 12 locations within their native European and introduced Australian ranges to quantify their level of enemy release and understand the relationship between enemy release and time, space and climate. Overall, plants experienced approximately seven times more herbivore damage in their native range than in their introduced range. We found no evidence that enemy release was related to time since introduction, introduced range size, temperature, precipitation, humidity or elevation. From here, we can explore whether traits, such as leaf defences or phylogenetic relatedness to neighbouring plants, are stronger indicators of enemy release across species.
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Affiliation(s)
- Zoe A. Xirocostas
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, New South Wales 2052, Australia
| | - Jeff Ollerton
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, People's Republic of China
- Faculty of Arts, Science and Technology, University of Northampton, Northampton, UK
| | - Riin Tamme
- Institute of Ecology and Earth Sciences, University of Tartu, J. Liivi 2, 50409 Tartu, Estonia
| | - Begoña Peco
- Terrestrial Ecology Group (TEG), Department of Ecology, Institute for Biodiversity and Global Change, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Vincent Lesieur
- CSIRO European Laboratory, 830 Avenue du Campus Agropolis, 34980 Montferrier sur Lez, France
| | - Eve Slavich
- Stats Central, Mark Wainwright Analytical Centre, UNSW Sydney, New South Wales 2052, Australia
| | - Robert R. Junker
- Evolutionary Ecology of Plants, Department of Biology, University of Marburg, 35043 Marburg, Germany
- Department of Environment and Biodiversity, University of Salzburg, 5020 Salzburg, Austria
| | - Meelis Pärtel
- Institute of Ecology and Earth Sciences, University of Tartu, J. Liivi 2, 50409 Tartu, Estonia
| | - S. Raghu
- CSIRO Health & Biosecurity, Brisbane, Queensland, Australia
| | - Akane Uesugi
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
- Biosciences and Food Technology Division, School of Science, RMIT University, Bundoora, Victoria 3083, Australia
| | - Stephen P. Bonser
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, New South Wales 2052, Australia
| | - Giancarlo M. Chiarenza
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, New South Wales 2052, Australia
| | - Mark J. Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Angela T. Moles
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, New South Wales 2052, Australia
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3
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White BE, Hovenden MJ, Barmuta LA. Multifunctional redundancy: Impossible or undetected? Ecol Evol 2023; 13:e10409. [PMID: 37593757 PMCID: PMC10427898 DOI: 10.1002/ece3.10409] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 07/25/2023] [Indexed: 08/19/2023] Open
Abstract
The diversity-functioning relationship is a pillar of ecology. Two significant concepts have emerged from this relationship: redundancy, the asymptotic relationship between diversity and functioning, and multifunctionality, a monotonic relationship between diversity and multiple functions occurring simultaneously. However, multifunctional redundancy, an asymptotic relationship between diversity and multiple functions occurring simultaneously, is rarely detected in research. Here we assess whether this lack of detection is due to its true rarity, or due to systematic research error. We discuss how inconsistencies in the use of terms such as 'function' lead to mismatched research. We consider the different techniques used to calculate multifunctionality and point out a rarely considered issue: how determining a function's maximum rate affects multifunctionality metrics. Lastly, we critique how a lack of consideration of multitrophic, spatiotemporal, interactions and community assembly processes in designed experiments significantly reduces the likelihood of detecting multifunctional redundancy. Multifunctionality research up to this stage has made significant contributions to our understanding of the diversity-functioning relationship, and we believe that multifunctional redundancy is detectable with the use of appropriate methodologies.
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Affiliation(s)
- Bridget E. White
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Mark J. Hovenden
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Leon A. Barmuta
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
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4
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Britton TG, Brodribb TJ, Richards SA, Ridley C, Hovenden MJ. Canopy damage during a natural drought depends on species identity, physiology and stand composition. New Phytol 2022; 233:2058-2070. [PMID: 34850394 DOI: 10.1111/nph.17888] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 09/28/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Vulnerability to xylem cavitation is a strong predictor of drought-induced damage in forest communities. However, biotic features of the community itself can influence water availability at the individual tree-level, thereby modifying patterns of drought damage. Using an experimental forest in Tasmania, Australia, we determined the vulnerability to cavitation (leaf P50 ) of four tree species and assessed the drought-induced canopy damage of 2944 6-yr-old trees after an extreme natural drought episode. We examined how individual damage was related to their size and the density and species identity of neighbouring trees. The two co-occurring dominant tree species, Eucalyptus delegatensis and Eucalyptus regnans, were the most vulnerable to drought-induced xylem cavitation and both species suffered significantly greater damage than neighbouring, subdominant species Pomaderris apetala and Acacia dealbata. While the two eucalypts had similar leaf P50 values, E. delegatensis suffered significantly greater damage, which was strongly related to the density of neighbouring P. apetala. Damage in E. regnans was less impacted by neighbouring plants and smaller trees of both eucalypts sustained significantly more damage than larger trees. Our findings demonstrate that natural drought damage is influenced by individual plant physiology as well as the composition, physiology and density of the surrounding stand.
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Affiliation(s)
- Travis G Britton
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Timothy J Brodribb
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Shane A Richards
- School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Chantelle Ridley
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
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5
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Anderegg LDL, Loy X, Markham IP, Elmer CM, Hovenden MJ, HilleRisLambers J, Mayfield MM. Aridity drives coordinated trait shifts but not decreased trait variance across the geographic range of eight Australian trees. New Phytol 2021; 229:1375-1387. [PMID: 32638379 DOI: 10.1111/nph.16795] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [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: 03/07/2020] [Accepted: 06/28/2020] [Indexed: 06/11/2023]
Abstract
Large intraspecific functional trait variation strongly impacts many aspects of communities and ecosystems, and is the medium upon which evolution works. Yet intraspecific trait variation is inconsistent and hard to predict across traits, species and locations. We measured within-species variation in leaf mass per area (LMA), leaf dry matter content (LDMC), branch wood density (WD), and allocation to stem area vs leaf area in branches (branch Huber value (HV)) across the aridity range of seven Australian eucalypts and a co-occurring Acacia species to explore how traits and their variances change with aridity. Within species, we found consistent increases in LMA, LDMC and WD and HV with increasing aridity, resulting in consistent trait coordination across leaves and branches. However, this coordination only emerged across sites with large climate differences. Unlike trait means, patterns of trait variance with aridity were mixed across populations and species. Only LDMC showed constrained trait variation in more xeric species and drier populations that could indicate limits to plasticity or heritable trait variation. Our results highlight that climate can drive consistent within-species trait patterns, but that patterns might often be obscured by the complex nature of morphological traits, sampling incomplete species ranges or sampling confounded stress gradients.
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Affiliation(s)
- Leander D L Anderegg
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94304, USA
| | - Xingwen Loy
- Department of Environmental Sciences, Emory University, Atlanta, GA, 30322, USA
| | | | - Christina M Elmer
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, TAS, 7005, Australia
| | | | - Margaret M Mayfield
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, 4072, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
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6
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Hovenden MJ, Leuzinger S, Newton PCD, Fletcher A, Fatichi S, Lüscher A, Reich PB, Andresen LC, Beier C, Blumenthal DM, Chiariello NR, Dukes JS, Kellner J, Hofmockel K, Niklaus PA, Song J, Wan S, Classen AT, Langley JA. Globally consistent influences of seasonal precipitation limit grassland biomass response to elevated CO 2. Nat Plants 2019; 5:167-173. [PMID: 30737508 DOI: 10.1038/s41477-018-0356-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
Rising atmospheric carbon dioxide concentration should stimulate biomass production directly via biochemical stimulation of carbon assimilation, and indirectly via water savings caused by increased plant water-use efficiency. Because of these water savings, the CO2 fertilization effect (CFE) should be stronger at drier sites, yet large differences among experiments in grassland biomass response to elevated CO2 appear to be unrelated to annual precipitation, preventing useful generalizations. Here, we show that, as predicted, the impact of elevated CO2 on biomass production in 19 globally distributed temperate grassland experiments reduces as mean precipitation in seasons other than spring increases, but that it rises unexpectedly as mean spring precipitation increases. Moreover, because sites with high spring precipitation also tend to have high precipitation at other times, these effects of spring and non-spring precipitation on the CO2 response offset each other, constraining the response of ecosystem productivity to rising CO2. This explains why previous analyses were unable to discern a reliable trend between site dryness and the CFE. Thus, the CFE in temperate grasslands worldwide will be constrained by their natural rainfall seasonality such that the stimulation of biomass by rising CO2 could be substantially less than anticipated.
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Affiliation(s)
- Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia.
| | - Sebastian Leuzinger
- Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Paul C D Newton
- Plant Functional Biology, AgResearch, Palmerston North, New Zealand
| | - Andrew Fletcher
- Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Simone Fatichi
- Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Andreas Lüscher
- Institute of Agricultural Sciences, ETH Zürich, Zürich, Switzerland
- Agroscope, Zürich, Switzerland
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, MN, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, New South Wales, Australia
| | - Louise C Andresen
- Department of Plant Ecology, Justus Liebig University of Giessen, Giessen, Germany
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Claus Beier
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Dana M Blumenthal
- Rangeland Resources Research Unit, USDA Agricultural Research Service, Fort Collins, CO, USA
| | - Nona R Chiariello
- Jasper Ridge Biological Preserve, Stanford University, Stanford, CA, USA
| | - Jeffrey S Dukes
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Juliane Kellner
- Department of Plant Ecology, Justus Liebig University of Giessen, Giessen, Germany
| | - Kirsten Hofmockel
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Pascal A Niklaus
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Jian Song
- College of Life Science, Hebei University, Baoding, Hebei, China
| | - Shiqiang Wan
- College of Life Science, Hebei University, Baoding, Hebei, China
| | - Aimée T Classen
- Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT, USA
| | - J Adam Langley
- Department of Biology, Villanova University, Villanova, PA, USA
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7
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Song J, Wan S, Piao S, Hui D, Hovenden MJ, Ciais P, Liu Y, Liu Y, Zhong M, Zheng M, Ma G, Zhou Z, Ru J. Elevated CO2
does not stimulate carbon sink in a semi-arid grassland. Ecol Lett 2019; 22:458-468. [DOI: 10.1111/ele.13202] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/17/2018] [Accepted: 10/23/2018] [Indexed: 01/19/2023]
Affiliation(s)
- Jian Song
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
- College of Life Sciences; Hebei University; Baoding Hebei 071002 China
| | - Shiqiang Wan
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
- College of Life Sciences; Hebei University; Baoding Hebei 071002 China
| | - Shilong Piao
- Sino-French Institute for Earth System Science; College of Urban and Environmental Sciences; Peking University; Beijing 100871 China
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100085 China
- Centre for Excellence in Tibetan Earth Science; Chinese Academy of Sciences; Beijing 100085 China
| | - Dafeng Hui
- Department of Biological Sciences; Tennessee State University; Nashville TN 37209 USA
| | - Mark J. Hovenden
- Biological Sciences; School of Natural Sciences; University of Tasmania; Private Bag 55 Hobart Tas 7001 Australia
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement; CEA CNRS UVSQ; Gif-sur-Yvette France
| | - Yongwen Liu
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
| | - Yinzhan Liu
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
| | - Mingxing Zhong
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
| | - Mengmei Zheng
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
| | - Gaigai Ma
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
| | - Zhenxing Zhou
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
| | - Jingyi Ru
- International Joint Research Laboratory for Global Change Ecology; School of Life Sciences; Henan University; Kaifeng Henan 475004 China
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Langley JA, Chapman SK, La Pierre KJ, Avolio M, Bowman WD, Johnson DS, Isbell F, Wilcox KR, Foster BL, Hovenden MJ, Knapp AK, Koerner SE, Lortie CJ, Megonigal JP, Newton PCD, Reich PB, Smith MD, Suttle KB, Tilman D. Ambient changes exceed treatment effects on plant species abundance in global change experiments. Glob Chang Biol 2018; 24:5668-5679. [PMID: 30369019 DOI: 10.1111/gcb.14442] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [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: 06/09/2018] [Accepted: 08/02/2018] [Indexed: 06/08/2023]
Abstract
The responses of species to environmental changes will determine future community composition and ecosystem function. Many syntheses of global change experiments examine the magnitude of treatment effect sizes, but we lack an understanding of how plant responses to treatments compare to ongoing changes in the unmanipulated (ambient or background) system. We used a database of long-term global change studies manipulating CO2 , nutrients, water, and temperature to answer three questions: (a) How do changes in plant species abundance in ambient plots relate to those in treated plots? (b) How does the magnitude of ambient change in species-level abundance over time relate to responsiveness to global change treatments? (c) Does the direction of species-level responses to global change treatments differ from the direction of ambient change? We estimated temporal trends in plant abundance for 791 plant species in ambient and treated plots across 16 long-term global change experiments yielding 2,116 experiment-species-treatment combinations. Surprisingly, for most species (57%) the magnitude of ambient change was greater than the magnitude of treatment effects. However, the direction of ambient change, whether a species was increasing or decreasing in abundance under ambient conditions, had no bearing on the direction of treatment effects. Although ambient communities are inherently dynamic, there is now widespread evidence that anthropogenic drivers are directionally altering plant communities in many ecosystems. Thus, global change treatment effects must be interpreted in the context of plant species trajectories that are likely driven by ongoing environmental changes.
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Affiliation(s)
- J Adam Langley
- Department of Biology, Villanova University, Villanova, Pennsylvania
| | | | | | - Meghan Avolio
- Department of Earth & Planetary Sciences, Johns Hopkins University, Baltimore, Maryland
| | - William D Bowman
- Department of Ecology and Evolutionary Biology and Mountain Research Station, University of Colorado, Boulder, Colorado
| | - David S Johnson
- Virginia Institute of Marine Science, Gloucester Point, Virginia
| | - Forest Isbell
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota
| | - Kevin R Wilcox
- U.S. Department of Agriculture, Agriculture Research Service, Fort Collins, Colorado
| | - Bryan L Foster
- Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Lawrence, Kansas
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Alan K Knapp
- Department of Biology and Graduate Degree Program in Ecology, Fort Collins, Colorado
| | - Sally E Koerner
- Department of Biology, University of North Carolina Greensboro, Greensboro, North Carolina
| | - Christopher J Lortie
- The National Center for Ecological Analysis and Synthesis, UCSB, Santa Barbara, California
| | | | | | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Melinda D Smith
- Department of Biology and Graduate Degree Program in Ecology, Fort Collins, Colorado
| | - Kenwyn B Suttle
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California
| | - David Tilman
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota
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9
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van Gestel N, Shi Z, van Groenigen KJ, Osenberg CW, Andresen LC, Dukes JS, Hovenden MJ, Luo Y, Michelsen A, Pendall E, Reich PB, Schuur EAG, Hungate BA. Predicting soil carbon loss with warming. Nature 2018; 554:E4-E5. [PMID: 29469098 DOI: 10.1038/nature25745] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/15/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Natasja van Gestel
- Climate Science Center, Texas Tech University, Lubbock, Texas 79409, USA
| | - Zheng Shi
- Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Kees Jan van Groenigen
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK
| | - Craig W Osenberg
- Odum School of Ecology, University of Georgia, Athens, Georgia 30602, USA
| | - Louise C Andresen
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Jeffrey S Dukes
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, USA.,Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
| | - Mark J Hovenden
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Yiqi Luo
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona 86011, USA.,Department of Biology, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Anders Michelsen
- Department of Biology and Center for Permafrost, University of Copenhagen, Copenhagen, Denmark
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - Peter B Reich
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia.,Department of Forest Resources, University of Minnesota, St. Paul, Minnesota 55108, USA
| | - Edward A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona 86011, USA.,Department of Biology, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona 86011, USA.,Department of Biology, Northern Arizona University, Flagstaff, Arizona 86011, USA
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10
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Hovenden MJ, Newton PCD, Porter M. Elevated CO2 and warming effects on grassland plant mortality are determined by the timing of rainfall. Ann Bot 2017; 119:1225-1233. [PMID: 28334161 PMCID: PMC5604550 DOI: 10.1093/aob/mcx006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 12/15/2016] [Accepted: 01/10/2017] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Global warming is expected to increase the mortality rate of established plants in water-limited systems because of its effect on evapotranspiration. The rising CO 2 concentration ([CO 2 ]), however, should have the opposite effect because it reduces plant transpiration, delaying the onset of drought. This potential for elevated [CO 2 ] (eCO 2 ) to modify the warming effect on mortality should be related to prevailing moisture conditions. This study aimed to determine the impacts of warming by 2 °C and eCO 2 (550 μmol mol -1 ) on plant mortality in an Australian temperate grassland over a 6-year period and to test how interannual variation in rainfall influenced treatment effects. METHODS Analyses were based on results from a field experiment, TasFACE, in which grassland plots were exposed to a combination of eCO 2 by free air CO 2 enrichment (FACE) and warming by infrared heaters. Using an annual census of established plants and detailed estimates of recruitment, annual mortality of all established plants was calculated. The influence of rainfall amount and timing on the relative impact of treatments on mortality in each year was analysed using multiple regression techniques. KEY RESULTS Warming and eCO 2 effects had an interactive influence on mortality which varied strongly from year to year and this variation was determined by temporal rainfall patterns. Warming tended to increase density-adjusted mortality and eCO 2 moderated that effect, but to a greater extent in years with fewer dry periods. CONCLUSIONS These results show that eCO 2 reduced the negative effect of warming but this influence varied strongly with rainfall timing. Importantly, indices involving the amount of rainfall were not required to explain interannual variation in mortality or treatment effects on mortality. Therefore, predictions of global warming effects on plant mortality will be reliant not only on other climate change factors, but also on the temporal distribution of rainfall.
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Affiliation(s)
- Mark J. Hovenden
- School of Biological Sciences, University of Tasmania, Hobart, 7001, Tasmania, Australia
- For correspondence. E-mail
| | - Paul C. D. Newton
- Land & Environmental Management, AgResearch, Palmerston North, New Zealand
| | - Meagan Porter
- School of Biological Sciences, University of Tasmania, Hobart, 7001, Tasmania, Australia
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11
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McKiernan AB, Potts BM, Hovenden MJ, Brodribb TJ, Davies NW, Rodemann T, McAdam SAM, O’Reilly-Wapstra JM. A water availability gradient reveals the deficit level required to affect traits in potted juvenile Eucalyptus globulus. Ann Bot 2017; 119:1043-1052. [PMID: 28073772 PMCID: PMC5604578 DOI: 10.1093/aob/mcw266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 09/05/2016] [Accepted: 11/23/2016] [Indexed: 05/25/2023]
Abstract
Background and aims Drought leading to soil water deficit can have severe impacts on plants. Water deficit may lead to plant water stress and affect growth and chemical traits. Plant secondary metabolite (PSM) responses to water deficit vary between compounds and studies, with inconsistent reports of changes to PSM concentrations even within a single species. This disparity may result from experimental water deficit variation among studies, and so multiple water deficit treatments are used to fully assess PSM responses in a single species. Methods Juvenile Eucalyptus globulus were grown for 8 weeks at one of ten water deficit levels based on evapotranspiration from control plants (100 %). Treatments ranged from 90 % of control evapotranspiration (mild water deficit) to 0 % of control evapotranspiration (severe water deficit) in 10 % steps. Plant biomass, foliar abscisic acid (ABA) levels, Ψ leaf , leaf C/N, selected terpenes and phenolics were quantified to assess responses to each level of water deficit relative to a control. Key Results Withholding ≥30 % water resulted in higher foliar ABA levels and withholding ≥40 % water reduced leaf water content. Ψ leaf became more negative when ≥60 % water was withheld. Plant biomass was lower when ≥80 % water was withheld, and no water for 8 weeks (0 % water) resulted in plant death. The total oil concentration was lower and C/N was higher in dead and desiccated juvenile E. globulus leaves (0 % water). Concentrations of individual phenolic and terpene compounds, along with condensed tannin and total phenolic concentrations, remained stable regardless of water deficit or plant stress level. Conclusions These juvenile E. globulus became stressed with a moderate reduction in available water, and yet the persistent concentrations of most PSMs in highly stressed or dead plants suggests no PSM re-metabolization and continued ecological roles of foliar PSMs during drought.
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Affiliation(s)
- Adam B. McKiernan
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Brad M. Potts
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Mark J. Hovenden
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Timothy J. Brodribb
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Noel W. Davies
- Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, TAS 7001, Australia
| | - Thomas Rodemann
- Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, TAS 7001, Australia
| | - Scott A. M. McAdam
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
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12
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Fatichi S, Leuzinger S, Paschalis A, Langley JA, Donnellan Barraclough A, Hovenden MJ. Partitioning direct and indirect effects reveals the response of water-limited ecosystems to elevated CO 2. Proc Natl Acad Sci U S A 2016; 113:12757-12762. [PMID: 27791074 PMCID: PMC5111654 DOI: 10.1073/pnas.1605036113] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Increasing concentrations of atmospheric carbon dioxide are expected to affect carbon assimilation and evapotranspiration (ET), ultimately driving changes in plant growth, hydrology, and the global carbon balance. Direct leaf biochemical effects have been widely investigated, whereas indirect effects, although documented, elude explicit quantification in experiments. Here, we used a mechanistic model to investigate the relative contributions of direct (through carbon assimilation) and indirect (via soil moisture savings due to stomatal closure, and changes in leaf area index) effects of elevated CO2 across a variety of ecosystems. We specifically determined which ecosystems and climatic conditions maximize the indirect effects of elevated CO2 The simulations suggest that the indirect effects of elevated CO2 on net primary productivity are large and variable, ranging from less than 10% to more than 100% of the size of direct effects. For ET, indirect effects were, on average, 65% of the size of direct effects. Indirect effects tended to be considerably larger in water-limited ecosystems. As a consequence, the total CO2 effect had a significant, inverse relationship with the wetness index and was directly related to vapor pressure deficit. These results have major implications for our understanding of the CO2 response of ecosystems and for global projections of CO2 fertilization, because, although direct effects are typically understood and easily reproducible in models, simulations of indirect effects are far more challenging and difficult to constrain. Our findings also provide an explanation for the discrepancies between experiments in the total CO2 effect on net primary productivity.
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Affiliation(s)
- Simone Fatichi
- Institute of Environmental Engineering, ETH Zurich, 8093 Zurich, Switzerland;
| | - Sebastian Leuzinger
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland 1010, New Zealand
| | - Athanasios Paschalis
- Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Nicholas School of the Environment, Duke University, Durham, NC 27708
| | - J Adam Langley
- Department of Biology, Villanova University, Villanova, PA 19085
| | - Alicia Donnellan Barraclough
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland 1010, New Zealand
| | - Mark J Hovenden
- School of Biological Sciences, University of Tasmania, Hobart, 7005 TAS, Australia
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13
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McKiernan AB, Potts BM, Brodribb TJ, Hovenden MJ, Davies NW, McAdam SAM, Ross JJ, Rodemann T, O'Reilly-Wapstra JM. Responses to mild water deficit and rewatering differ among secondary metabolites but are similar among provenances within Eucalyptus species. Tree Physiol 2016; 36:133-147. [PMID: 26496959 DOI: 10.1093/treephys/tpv106] [Citation(s) in RCA: 4] [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: 03/16/2015] [Accepted: 09/08/2015] [Indexed: 06/05/2023]
Abstract
Water deficit associated with drought can severely affect plants and influence ecological interactions involving plant secondary metabolites. We tested the effect of mild water deficit and rewatering on physiological, morphological and chemical traits of juvenile Eucalyptus globulus Labill. and Eucalyptus viminalis Labill. We also tested if responses of juvenile eucalypts to water deficit and rewatering varied within species using provenances across a rainfall gradient. Both species and all provenances were similarly affected by mild water deficit and rewatering, as only foliar abscisic acid levels differed among provenances during water deficit. Across species and provenances, water deficit decreased leaf water potential, above-ground biomass and formylated phloroglucinol compound concentrations, and increased condensed tannin concentrations. Rewatering reduced leaf carbon : nitrogen, and total phenolic and chlorogenic acid concentrations. Water deficit and rewatering had no effect on total oil or individual terpene concentrations. Levels of trait plasticity due to water deficit and rewatering were less than levels of constitutive trait variation among provenances. The overall uniformity of responses to the treatments regardless of native provenance indicates limited diversification of plastic responses when compared with the larger quantitative variation of constitutive traits within these species. These responses to mild water deficit may differ from responses to more extreme water deficit or to responses of juvenile/mature eucalypts growing at each locality.
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Affiliation(s)
- Adam B McKiernan
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia National Centre for Future Forest Industries, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Brad M Potts
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia National Centre for Future Forest Industries, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Timothy J Brodribb
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Mark J Hovenden
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Noel W Davies
- Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, TAS 7001, Australia
| | - Scott A M McAdam
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - John J Ross
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Thomas Rodemann
- Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, TAS 7001, Australia
| | - Julianne M O'Reilly-Wapstra
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia National Centre for Future Forest Industries, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
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14
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Prior LD, Paul KI, Davidson NJ, Hovenden MJ, Nichols SC, Bowman DJMS. Evaluating carbon storage in restoration plantings in the Tasmanian Midlands, a highly modified agricultural landscape. Rangel J 2015. [DOI: 10.1071/rj15070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In recent years there have been incentives to reforest cleared farmland in southern Australia to establish carbon sinks, but the rates of carbon sequestration by such plantings are uncertain at local scales. We used a chronosequence of 21 restoration plantings aged from 6 to 34 years old to measure how above- and belowground carbon relates to the age of the planting. We also compared the amount of carbon in these plantings with that in nearby remnant forest and in adjacent cleared pasture. In terms of total carbon storage in biomass, coarse woody debris and soil, young restoration plantings contained on average much less biomass carbon than the remnant forest (72 versus 203 Mg C ha–1), suggesting that restoration plantings had not yet attained maximum biomass carbon. Mean biomass carbon accumulation during the first 34 years after planting was estimated as 4.2 ± 0.6 Mg C ha–1 year–1, with the 10th and 90th quantile regression estimates being 2.1 and 8.8 Mg C ha–1 year–1. There were no significant differences in soil organic carbon (0–30-cm depth) between the plantings, remnant forest and pasture, with all values in the range of 59–67 Mg ha–1. This is in line with other studies showing that soil carbon is slow to respond to changes in land use. Based on our measured rates of biomass carbon accumulation, it would require ~50 years to accumulate the average carbon content of remnant forests. However, it is more realistic to assume the rates will slow with time, and it could take over 100 years to attain a new equilibrium of biomass carbon stocks.
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15
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Mallett RK, Hovenden MJ. Density and assemblage influence the nature of the species richness-productivity relationship in Australian dry sclerophyll forest species. AUSTRAL ECOL 2014. [DOI: 10.1111/aec.12182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ruth K. Mallett
- School of Plant Science; University of Tasmania; Private Bag 55 Hobart Tas. 7001 Australia
| | - Mark J. Hovenden
- School of Plant Science; University of Tasmania; Private Bag 55 Hobart Tas. 7001 Australia
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16
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Newton PCD, Lieffering M, Parsons AJ, Brock SC, Theobald PW, Hunt CL, Luo D, Hovenden MJ. Selective grazing modifies previously anticipated responses of plant community composition to elevated CO(2) in a temperate grassland. Glob Chang Biol 2014; 20:158-169. [PMID: 23828718 DOI: 10.1111/gcb.12301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 02/27/2013] [Accepted: 06/05/2013] [Indexed: 06/02/2023]
Abstract
Our limited understanding of terrestrial ecosystem responses to elevated CO2 is a major constraint on predicting the impacts of climate change. A change in botanical composition has been identified as a key factor in the CO2 response with profound implications for ecosystem services such as plant production and soil carbon storage. In temperate grasslands, there is a strong consensus that elevated CO2 will result in a greater physiological stimulus to growth in legumes and to a lesser extent forbs, compared with C3 grasses, and the presumption this will lead in turn to a greater proportion of these functional groups in the plant community. However, this view is based on data mainly collected in experiments of three or less years in duration and not in experiments where defoliation has been by grazing animals. Grazing is, however, the most common management of grasslands and known in itself to influence botanical composition. In a long-term Free Air Carbon Dioxide Enrichment (FACE) experiment in a temperate grassland managed with grazing animals (sheep), we found the response to elevated CO2 in plant community composition in the first 5 years was consistent with the expectation of increased proportions of legumes and forbs. However, in the longer term, these differences diminished so that the proportions of grasses, legumes and forbs were the same under both ambient and elevated CO2 . Analysis of vegetation before and after each grazing event showed there was a sustained disproportionately greater removal ('apparent selection') of legumes and forbs by the grazing animals. This bias in removal was greater under elevated CO2 than ambient CO2 . This is consistent with sustained faster growth rates of legumes and forbs under elevated CO2 being countered by selective defoliation, and so leading to little difference in community composition.
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Affiliation(s)
- Paul C D Newton
- AgResearch, Private Bag 11008, Palmerston North, New Zealand
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17
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Hayden HL, Mele PM, Bougoure DS, Allan CY, Norng S, Piceno YM, Brodie EL, Desantis TZ, Andersen GL, Williams AL, Hovenden MJ. Changes in the microbial community structure of bacteria, archaea and fungi in response to elevated CO(2) and warming in an Australian native grassland soil. Environ Microbiol 2012; 14:3081-96. [PMID: 23039205 DOI: 10.1111/j.1462-2920.2012.02855.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 07/22/2012] [Indexed: 11/28/2022]
Abstract
The microbial community structure of bacteria, archaea and fungi is described in an Australian native grassland soil after more than 5 years exposure to different atmospheric CO2 concentrations ([CO2]) (ambient, +550 ppm) and temperatures (ambient, + 2°C) under different plant functional types (C3 and C4 grasses) and at two soil depths (0-5 cm and 5-10 cm). Archaeal community diversity was influenced by elevated [CO2], while under warming archaeal 16S rRNA gene copy numbers increased for C4 plant Themeda triandra and decreased for the C3 plant community (P < 0.05). Fungal community diversity resulted in three groups based upon elevated [CO2], elevated [CO2] plus warming and ambient [CO2]. Overall bacterial community diversity was influenced primarily by depth. Specific bacterial taxa changed in richness and relative abundance in response to climate change factors when assessed by a high-resolution 16S rRNA microarray (PhyloChip). Operational taxonomic unit signal intensities increased under elevated [CO2] for both Firmicutes and Bacteroidetes, and increased under warming for Actinobacteria and Alphaproteobacteria. For the interaction of elevated [CO2] and warming there were 103 significant operational taxonomic units (P < 0.01) representing 15 phyla and 30 classes. The majority of these operational taxonomic units increased in abundance for elevated [CO2] plus warming plots, while abundance declined in warmed or elevated [CO2] plots. Bacterial abundance (16S rRNA gene copy number) was significantly different for the interaction of elevated [CO2] and depth (P < 0.05) with decreased abundance under elevated [CO2] at 5-10 cm, and for Firmicutes under elevated [CO2] (P < 0.05). Bacteria, archaea and fungi in soil responded differently to elevated [CO2], warming and their interaction. Taxa identified as significantly climate-responsive could show differing trends in the direction of response ('+' or '-') under elevated CO2 or warming, which could then not be used to predict their interactive effects supporting the need to investigate interactive effects for climate change. The approach of focusing on specific taxonomic groups provides greater potential for understanding complex microbial community changes in ecosystems under climate change.
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Affiliation(s)
- Helen L Hayden
- Department of Primary Industries, Biosciences Research Division, Victorian AgriBiosciences Centre, 1 Park Drive, Bundoora, Victoria, 3083, Australia.
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Dieleman WIJ, Vicca S, Dijkstra FA, Hagedorn F, Hovenden MJ, Larsen KS, Morgan JA, Volder A, Beier C, Dukes JS, King J, Leuzinger S, Linder S, Luo Y, Oren R, De Angelis P, Tingey D, Hoosbeek MR, Janssens IA. Simple additive effects are rare: a quantitative review of plant biomass and soil process responses to combined manipulations of CO2 and temperature. Glob Chang Biol 2012; 18:2681-93. [PMID: 24501048 DOI: 10.1111/j.1365-2486.2012.02745.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/25/2012] [Indexed: 05/08/2023]
Abstract
In recent years, increased awareness of the potential interactions between rising atmospheric CO2 concentrations ([ CO2 ]) and temperature has illustrated the importance of multifactorial ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and [ CO2 ] manipulation, and compares it with those obtained in single factor [ CO2 ] and temperature manipulation experiments. Across all combined elevated [ CO2 ] and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the [ CO2 ]-only treatment than to those in the warming-only treatment. In contrast to warming-only experiments, both the combined and the [ CO2 ]-only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the [ CO2 ]-only treatment, possibly due to the warming-induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor [ CO2 ] treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated [ CO2 ] and warming, i.e. the response to the combined treatment was usually less-than-additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long-term) multifactor manipulation experiments. Because single factor CO2 responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
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Affiliation(s)
- Wouter I J Dieleman
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Wilrijk, B-2610, Belgium; School of Earth and Environmental Sciences, Faculty of Science and Engineering, James Cook University, Smithfield, 4878, QLD, Australia
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McKiernan AB, O'Reilly-Wapstra JM, Price C, Davies NW, Potts BM, Hovenden MJ. Stability of plant defensive traits among populations in two Eucalyptus species under elevated carbon dioxide. J Chem Ecol 2012; 38:204-12. [PMID: 22318433 DOI: 10.1007/s10886-012-0071-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 01/12/2012] [Accepted: 01/26/2012] [Indexed: 10/14/2022]
Abstract
Plant secondary metabolites (PSMs) mediate a wide range of ecological interactions. Investigating the effect of environment on PSM production is important for our understanding of how plants will adapt to large scale environmental change, and the extended effects on communities and ecosystems. We explored the production of PSMs under elevated atmospheric carbon dioxide ([CO(2)]) in the species rich, ecologically and commercially important genus Eucalyptus. Seedlings from multiple Eucalyptus globulus and E. pauciflora populations were grown in common glasshouse gardens under elevated or ambient [CO(2)]. Variation in primary and secondary chemistry was determined as a function of genotype and treatment. There were clear population differences in PSM expression in each species. Elevated [CO(2)] did not affect concentrations of individual PSMs, total phenolics, condensed tannins or the total oil yield, and there was no population by [CO(2)] treatment interaction for any traits. Multivariate analysis revealed similar results with significant variation in concentrations of E. pauciflora oil components between populations. A [CO(2)] treatment effect was detected within populations but no interactions were found between elevated [CO(2)] and population. These eucalypt seedlings appear to be largely unresponsive to elevated [CO(2)], indicating stronger genetic than environmental (elevated [CO(2)]) control of expression of PSMs.
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Affiliation(s)
- Adam B McKiernan
- School of Plant Science and CRC for Forestry, University of Tasmania, Hobart, TAS, Australia.
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Hovenden MJ, Wills KE, Vander Schoor JK, Williams AL, Newton PCD. Flowering phenology in a species-rich temperate grassland is sensitive to warming but not elevated CO2. New Phytol 2008; 178:815-822. [PMID: 18346104 DOI: 10.1111/j.1469-8137.2008.02419.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
* Flowering is a critical stage in plant life cycles, and changes might alter processes at the species, community and ecosystem levels. Therefore, likely flowering-time responses to global change drivers are needed for predictions of global change impacts on natural and managed ecosystems. * Here, the impact of elevated atmospheric CO2 concentration ([CO2]) (550 micromol mol(-1)) and warming (+2 masculineC) is reported on flowering times in a native, species-rich, temperate grassland in Tasmania, Australia in both 2004 and 2005. * Elevated [CO2] did not affect average time of first flowering in either year, only affecting three out of 23 species. Warming reduced time to first flowering by an average of 19.1 d in 2004, acting on most species, but did not significantly alter flowering time in 2005, which might be related to the timing of rainfall. Elevated [CO2] and warming treatments did not interact on flowering time. * These results show elevated [CO2] did not alter average flowering time or duration in this grassland; neither did it alter the response to warming. Therefore, flowering phenology appears insensitive to increasing [CO2] in this ecosystem, although the response to warming varies between years but can be strong.
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Affiliation(s)
- Mark J Hovenden
- School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia
| | - Karen E Wills
- School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Amity L Williams
- School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia
| | - Paul C D Newton
- Land & Environmental Management, AgResearch, Palmerston North, New Zealand
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Hovenden MJ, Newton PCD, Wills KE, Janes JK, Williams AL, Vander Schoor JK, Nolan MJ. Influence of warming on soil water potential controls seedling mortality in perennial but not annual species in a temperate grassland. New Phytol 2008; 180:143-152. [PMID: 18631296 DOI: 10.1111/j.1469-8137.2008.02563.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In a water-limited system, the following hypotheses are proposed: warming will increase seedling mortality; elevated atmospheric CO2 will reduce seedling mortality by reducing transpiration, thereby increasing soil water availability; and longevity (i.e. whether a species is annual or perennial) will affect the response of a species to global changes. Here, these three hypotheses are tested by assessing the impact of elevated CO2 (550 micromol mol(-1) and warming (+2 degrees C) on seedling emergence, survivorship and establishment in an Australian temperate grassland from autumn 2004 to autumn 2007. Warming impacts on seedling survivorship were dependent upon species longevity. Warming reduced seedling survivorship of perennials through its effects on soil water potential but the seedling survivorship of annuals was reduced to a greater extent than could be accounted for by treatment effects on soil water potential. Elevated CO2 did not significantly affect seedling survivorship in annuals or perennials. These results show that warming will alter recruitment of perennial species by changing soil water potential but will reduce recruitment of annual species independent of any effects on soil moisture. The results also show that exposure to elevated CO2 does not make seedlings more resistant to dry soils.
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Affiliation(s)
- Mark J Hovenden
- School of Plant Science, University of Tasmania, Hobart, 7001, Tasmania, Australia
| | - Paul C D Newton
- Land & Environmental Management, AgResearch, Palmerston North, New Zealand
| | - Karen E Wills
- School of Plant Science, University of Tasmania, Hobart, 7001, Tasmania, Australia
| | - Jasmine K Janes
- School of Plant Science, University of Tasmania, Hobart, 7001, Tasmania, Australia
| | - Amity L Williams
- School of Plant Science, University of Tasmania, Hobart, 7001, Tasmania, Australia
| | | | - Michaela J Nolan
- School of Plant Science, University of Tasmania, Hobart, 7001, Tasmania, Australia
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Williams AL, Wills KE, Janes JK, Vander Schoor JK, Newton PCD, Hovenden MJ. Warming and free-air CO2 enrichment alter demographics in four co-occurring grassland species. New Phytol 2007; 176:365-374. [PMID: 17888117 DOI: 10.1111/j.1469-8137.2007.02170.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Species differ in their responses to global changes such as rising CO(2) and temperature, meaning that global changes are likely to change the structure of plant communities. Such alterations in community composition must be underlain by changes in the population dynamics of component species. Here, the impact of elevated CO(2) (550 micromol mol(-1)) and warming (+2 degrees C) on the population growth of four plant species important in Australian temperate grasslands is reported. Data collected from the Tasmanian free-air CO(2) enrichment (TasFACE) experiment between 2003 and 2006 were analysed using population matrix models. Population growth of Themeda triandra, a perennial C(4) grass, was largely unaffected by either factor but population growth of Austrodanthonia caespitosa, a perennial C(3) grass, was reduced substantially in elevated CO(2) plots. Warming and elevated CO(2) had antagonistic effects on population growth of two invasive weeds, Hypochaeris radicata and Leontodon taraxacoides, with warming causing population decline. Analysis of life cycle stages showed that seed production, seedling emergence and establishment were important factors in the responses of the species to global changes. These results show that the demographic approach is very useful in understanding the variable responses of plants to global changes and in elucidating the life cycle stages that are most responsive.
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Affiliation(s)
- Amity L Williams
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart 7001, Tasmania, Australia
| | - Karen E Wills
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart 7001, Tasmania, Australia
| | - Jasmine K Janes
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart 7001, Tasmania, Australia
| | | | - Paul C D Newton
- AgResearch Grasslands Research Institute, Private Bag 11008, Palmerston North, New Zealand
| | - Mark J Hovenden
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart 7001, Tasmania, Australia
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Abstract
Leaf morphology varies reliably with increasing altitude in many species, and this is generally considered to be related to temperature. Changes in irradiance with elevation may confound any relationships between a morphological character and altitude, particularly if altitude of origin affects the response to irradiance. Here we describe the interaction between irradiance and altitude of origin on leaf morphology of Southern beech, Nothofagus cunninghamii. Cuttings from each of four altitudes were grown in a glasshouse under full sunlight or 50% shade, and leaf morphology was related to irradiance, altitude of origin and accession. There was a significant interaction between irradiance and altitude of origin for leaf length, width, thickness, area, weight, specific leaf area and stomatal density. There was no effect of altitude on leaf length to width ratio or stomatal index, nor was there an interaction between irradiance and altitude of origin for these variables. These results show that the altitude of origin of a plant has an overriding impact on the leaf morphological response to irradiance. This must be considered in climatic reconstructions.
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Affiliation(s)
- Mark J Hovenden
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas 7001, Australia.
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Shaw JD, Hovenden MJ, Bergstrom DM. The impact of introduced ship rats (Rattus rattus) on seedling recruitment and distribution of a subantarctic megaherb (Pleurophyllum hookeri). AUSTRAL ECOL 2005. [DOI: 10.1111/j.1442-9993.2005.01430.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kern SO, Hovenden MJ, Jordan GJ. The impacts of leaf shape and arrangement on light interception and potential photosynthesis in southern beech (Nothofagus cunninghamii). Funct Plant Biol 2004; 31:471-480. [PMID: 32688919 DOI: 10.1071/fp03211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The impact of differences in leaf shape, size and arrangement on the efficiency of light interception, and in particular the avoidance of photoinhibition, are poorly understood. We therefore estimated light exposure of branches in the cool temperate rainforest tree, Nothofagus cunninghamii (Hook.) Oerst., in which leaf shape, size and arrangement vary systematically with altitude and geographic origin. Measurements of incident photosynthetic photon flux density (PPFD) were made in the laboratory at solar angles corresponding to noon at summer solstice, winter solstice and equinox on branches collected from a common garden experiment. Tasmanian plants showed more self-shading than Victorian plants in summer and equinox. This was related to branch angle, leaf arrangement and leaf shape. Using a modelled light response-curve, we estimated the carbon assimilation rate and the flux density of excess photons at different incident PPFD. Victorian plants had higher predicted assimilation rates than Tasmanian plants in summer and equinox, but were exposed to substantially greater levels of excess photons. Because of the shape of the light-response curve, self-shading appears to reduce the plant's exposure to excess photons, thus providing photoprotection, without substantially reducing the carbon assimilation rate. This is dependent on both regional origin and season.
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Affiliation(s)
- Stephen O Kern
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas. 7001, Australia
| | - Mark J Hovenden
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas. 7001, Australia. Corresponding author;
| | - Gregory J Jordan
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas. 7001, Australia
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Abstract
• Leaf morphology varies predictably with altitude, and leaf morphological features have been used to estimate average temperatures from fossil leaves. The altitude-leaf morphology relationship is confounded by the two processes of acclimation and adaptation, which reflect environmental and genetic influences, respectively. • Here we describe the relationship between altitude and leaf morphology for Southern beech, Nothofagus cunninghamii (Hook.) Oerst.. Cuttings from several trees from each of four altitudes were grown in a common glasshouse experiment, and leaf morphology related to both genotype and altitude of origin. • Genotype had a significant impact on leaf morphology, but in the field there was also a significant, overriding effect of altitude. This altitude effect disappeared in glasshouse-grown plants for all morphological variables other than leaf thickness and specific leaf area. • These results show that, while leaf length, width and area are partially controlled by genetic factors, these variables are plastic and respond to environmental influences associated with a particular altitude. Thus altitudinal trends in leaf size in N. cunninghamii are unlikely to be the result of adaptation.
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Affiliation(s)
- Mark J Hovenden
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tasmania 7001, Australia
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Hovenden MJ. Photosynthesis of coppicing poplar clones in a free-air CO2 enrichment (FACE) experiment in a short-rotation forest. Funct Plant Biol 2003; 30:391-400. [PMID: 32689023 DOI: 10.1071/fp02233] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Photosynthetic capacity was assessed in coppices of three poplar clones (Populus alba L. genotype 2AS11, P. × euramericana (Dode) Guinier genotype I-214 and P. nigra L. genotype Jean Pourtet) growing in the POPFACE/EUROFACE free-air CO2 enrichment experiment in central Italy. Plants were grown either at an elevated CO2 concentration of 550 μmol mol-1 or in control conditions for 3 years and were then harvested and allowed to coppice. Plants were either fertilised with the addition of liquid fertiliser at a level of 212 kg N ha-1 year-1 or unfertilised after harvesting. No evidence was found of changes in the maximum Rubisco carboxylation rate (VCmax) and thus there was no photosynthetic downregulation caused by the FACE treatment in either P. × euramericana or P. nigra, but there was a marginally significant reduction in VCmax of fertilised P. alba (P<0.09). Carbon assimilation rates were significantly higher in FACE plants than control plants. Maximum carbon assimilation rate was stimulated by an average of 32.8% in these clones, with individual stimulation values of 27.6% for P. alba, 32.1% for P. × euramericana and 49.5% for P. nigra. No significant interactions between the FACE and fertilisation treatments were found for any of the photosynthetic variables measured. The day respiration rate in leaves of P.×euramericana was significantly increased by FACE treatment, but it was unaffected in the other clones. This work shows that photosynthesis remains stimulated at elevated CO2 concentration in these plants following harvesting, although to a lesser extent than seen normally, which may be related to a reduction in sink strength.
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Affiliation(s)
- Mark J Hovenden
- School of Plant Science, University of Tasmania, GPO Box 252-55, Hobart, Tas. 7001, Australia.
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Close DC, Beadle CL, Hovenden MJ. Interactive effects of nitrogen and irradiance on sustained xanthophyll cycle engagement in Eucalyptus nitens leaves during winter. Oecologia 2003; 134:32-6. [PMID: 12647176 DOI: 10.1007/s00442-002-1097-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2001] [Revised: 03/29/2002] [Accepted: 09/26/2002] [Indexed: 11/28/2022]
Abstract
Eucalyptus nitens is a species that is adapted to low temperature. This study examines xanthophyll-cycle engagement in E. nitens seedlings exposed to cold-induced photoinhibitory conditions under different levels of irradiance and nutrient status. Xanthophyll-cycle pool size indicated an increased requirement for light energy dissipation under high irradiance and low nutrient status. Greater sensitivity to photoinhibition of non-shaded seedlings indicated that sustained xanthophyll-cycle engagement may occur in response to damaged chlorophyll. Within irradiance treatments, fertilised seedlings had higher photochemical efficiency and faster recovery from photoinhibition than unfertilised seedlings. These results demonstrate that fertilised compared to unfertilised seedlings can utilise a greater proportion of incident light under cold temperature conditions
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Affiliation(s)
- Dugald C Close
- Cooperative Research Centre for Sustainable Production Forestry, GPO Box 252-12, Hobart 7001, Australia.
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Williams EL, Hovenden MJ, Close DC. Strategies of light energy utilisation, dissipation and attenuation in six co-occurring alpine heath species in Tasmania. Funct Plant Biol 2003; 30:1205-1218. [PMID: 32689102 DOI: 10.1071/fp03145] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Alpine environments are characterised by low temperatures and high light intensities. This combination leads to high light stress owing to the imbalance between light energy harvesting and its use in photochemistry. In extreme cases, high light stress can lead to the level of photo-oxidative damage exceeding the rate of repair to the photosynthetic apparatus. Plant species may vary in the mechanisms they use to prevent photodamage, but most comparisons are of geographically and ecologically distinct species. Differences in leaf colouration suggested that photoprotective strategies might differ among Tasmanian evergreen alpine shrub species. We compared chlorophyll fluorescence and leaf pigment composition in six co-occurring alpine shrub species on the summit of Mt Wellington, southern Tasmania, Australia, during spring and autumn. We found marked differences among species in light energy utilisation, attenuation and dissipation. Ozothamnus ledifolius maintained a large capacity for photosynthetic light utilisation and thus, had a low requirement for light dissipation. All five of the other species relied on xanthophyll-cycle-dependent thermal energy dissipation. In addition Epacris serpyllifolia, Richea sprengelioides and Leptospermum rupestre had foliar anthocyanins that would attenuate photosynthetically active light in the leaf. During spring, all species retained de-epoxidised xanthophylls through the night and the pre-dawn concentration of antheraxanthin and zeaxanthin was significantly correlated with reductions in pre-dawn Fv / Fm. We propose that these species use three photoprotective strategies to cope with the combination of high light and low temperature.
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Affiliation(s)
- Erica L Williams
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas. 7001, Australia. Current address; Department of Biological Sciences, Macquarie University, NSW 2109, Australia
| | - Mark J Hovenden
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas. 7001, Australia. Corresponding author;
| | - Dugald C Close
- School of Plant Science, University of Tasmania, Locked Bag 55, Hobart, Tas. 7001, Australia. CRC Sustainable Production Forestry, Locked Bag 12, Hobart, Tas. 7001, Australia
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Warren CR, Hovenden MJ, Davidson NJ, Beadle CL. Cold hardening reduces photoinhibition of Eucalypts nitens and E. pauciflora at frost temperatures. Oecologia 1998; 113:350-359. [DOI: 10.1007/s004420050386] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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