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Tavares JV, Oliveira RS, Mencuccini M, Signori-Müller C, Pereira L, Diniz FC, Gilpin M, Marca Zevallos MJ, Salas Yupayccana CA, Acosta M, Pérez Mullisaca FM, Barros FDV, Bittencourt P, Jancoski H, Scalon MC, Marimon BS, Oliveras Menor I, Marimon BH, Fancourt M, Chambers-Ostler A, Esquivel-Muelbert A, Rowland L, Meir P, Lola da Costa AC, Nina A, Sanchez JMB, Tintaya JS, Chino RSC, Baca J, Fernandes L, Cumapa ERM, Santos JAR, Teixeira R, Tello L, Ugarteche MTM, Cuellar GA, Martinez F, Araujo-Murakami A, Almeida E, da Cruz WJA, Del Aguila Pasquel J, Aragāo L, Baker TR, de Camargo PB, Brienen R, Castro W, Ribeiro SC, Coelho de Souza F, Cosio EG, Davila Cardozo N, da Costa Silva R, Disney M, Espejo JS, Feldpausch TR, Ferreira L, Giacomin L, Higuchi N, Hirota M, Honorio E, Huaraca Huasco W, Lewis S, Flores Llampazo G, Malhi Y, Monteagudo Mendoza A, Morandi P, Chama Moscoso V, Muscarella R, Penha D, Rocha MC, Rodrigues G, Ruschel AR, Salinas N, Schlickmann M, Silveira M, Talbot J, Vásquez R, Vedovato L, Vieira SA, Phillips OL, Gloor E, Galbraith DR. Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests. Nature 2023; 617:111-117. [PMID: 37100901 PMCID: PMC10156596 DOI: 10.1038/s41586-023-05971-3] [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: 09/07/2021] [Accepted: 03/17/2023] [Indexed: 04/28/2023]
Abstract
Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, [Formula: see text]50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters [Formula: see text]50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both [Formula: see text]50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.
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Affiliation(s)
- Julia Valentim Tavares
- School of Geography, University of Leeds, Leeds, UK.
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | | - Caroline Signori-Müller
- School of Geography, University of Leeds, Leeds, UK
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Department of Plant Biology, Institute of Biology, Programa de Pós Graduação em Biologia Vegetal, University of Campinas, Campinas, Brazil
| | - Luciano Pereira
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | | | | | | | | | - Martin Acosta
- Programa de Pós-Graduação em Ecologia e Manejo de Recursos Naturais, Universidade Federal do Acre, Rio Branco, Brazil
| | | | - Fernanda de V Barros
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Department of Plant Biology, Institute of Biology, Programa de Pós Graduação em Ecologia, University of Campinas, Campinas, Brazil
| | - Paulo Bittencourt
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Halina Jancoski
- Departamento de Ciências Biológicas, Universidade do Estado de Mato Grosso (UNEMAT), Nova Xavantina, Brazil
| | - Marina Corrêa Scalon
- Departamento de Ciências Biológicas, Universidade do Estado de Mato Grosso (UNEMAT), Nova Xavantina, Brazil
- Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, Brazil
| | - Beatriz S Marimon
- Departamento de Ciências Biológicas, Universidade do Estado de Mato Grosso (UNEMAT), Nova Xavantina, Brazil
| | - Imma Oliveras Menor
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
- AMAP (Botanique et Modélisation de l'Architecture des Plantes et des Végétations), CIRAD, CNRS, INRA, IRD, Université de Montpellier, Montpellier, France
| | - Ben Hur Marimon
- Departamento de Ciências Biológicas, Universidade do Estado de Mato Grosso (UNEMAT), Nova Xavantina, Brazil
| | - Max Fancourt
- School of Geography, University of Leeds, Leeds, UK
| | | | - Adriane Esquivel-Muelbert
- School of Geography, University of Birmingham, Birmingham, UK
- Birmingham Institute of Forest Research (BIFoR), Birmingham, UK
| | - Lucy Rowland
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh, UK
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | | | - Alex Nina
- Pontificia Universidad Católica del Perú, Lima, Peru
| | | | - Jose S Tintaya
- Universidad Nacional de San Antonio Abad del Cusco, Cusco, Peru
| | | | - Jean Baca
- Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | | | - Edwin R M Cumapa
- Instituto de Geociências, Faculdade de Meteorologia, Universidade Federal do Pará, Belém, Brazil
| | | | - Renata Teixeira
- Universidad Nacional de San Antonio Abad del Cusco, Cusco, Peru
| | - Ligia Tello
- Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - Maira T M Ugarteche
- Museo de Historia Natural Noel Kempff Mercado, Santa Cruz de la Sierra, Bolivia
- Universidad Autonoma Gabriel Rene Moreno, Santa Cruz, Bolivia
| | - Gina A Cuellar
- Museo de Historia Natural Noel Kempff Mercado, Santa Cruz de la Sierra, Bolivia
- Universidad Autonoma Gabriel Rene Moreno, Santa Cruz, Bolivia
| | - Franklin Martinez
- Museo de Historia Natural Noel Kempff Mercado, Santa Cruz de la Sierra, Bolivia
- Universidad Autonoma Gabriel Rene Moreno, Santa Cruz, Bolivia
| | - Alejandro Araujo-Murakami
- Museo de Historia Natural Noel Kempff Mercado, Santa Cruz de la Sierra, Bolivia
- Universidad Autonoma Gabriel Rene Moreno, Santa Cruz, Bolivia
| | - Everton Almeida
- Instituto de Biodiversidade e Florestas, Universidade Federal do Oeste do Pará, Santarém, Brazil
| | | | - Jhon Del Aguila Pasquel
- Universidad Nacional de la Amazonia Peruana (UNAP), Iquitos, Peru
- Instituto de Investigaciones de la Amazonia Peruana, Iquitos, Peru
| | - Luís Aragāo
- National Institute for Space Research (INPE), São José dos Campos-SP, Brazil
| | | | | | - Roel Brienen
- School of Geography, University of Leeds, Leeds, UK
| | - Wendeson Castro
- Laboratório de Botânica e Ecologia Vegetal, Universidade Federal do Acre, Rio Branco, Brazil
- SOS Amazônia, Programa Governança e Proteção da Paisagem Verde na Amazônia, Rio Branco-AC, Brazil
| | | | | | - Eric G Cosio
- Sección Química, Pontificia Universidad Católica del Perú, Lima, Peru
| | | | - Richarlly da Costa Silva
- Programa de Pós-Graduação em Ecologia e Manejo de Recursos Naturais, Universidade Federal do Acre, Rio Branco, Brazil
- Instituto Federal de Educação, Ciência e Tecnologia do Acre, Campus Baixada do Sol, Rio Branco, Brazil
| | - Mathias Disney
- Department of Geography, University College London, London, UK
| | - Javier Silva Espejo
- Universidad Nacional de San Antonio Abad del Cusco, Cusco, Peru
- Departamento de Biología, Universidad de La Serena, La Serena, Chile
| | - Ted R Feldpausch
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | - Leandro Giacomin
- Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, João Pessoa, Brazil
| | - Niro Higuchi
- Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil
| | - Marina Hirota
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
- Department of Physics, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Euridice Honorio
- Instituto de Investigaciones de la Amazonia Peruana, Iquitos, Peru
| | - Walter Huaraca Huasco
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Simon Lewis
- School of Geography, University of Leeds, Leeds, UK
- Department of Geography, University College London, London, UK
| | - Gerardo Flores Llampazo
- Instituto de Investigaciones de la Amazonia Peruana, Iquitos, Peru
- Universidad Nacional Jorge Basadre de Grohmann (UNJBG), Tacna, Peru
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Abel Monteagudo Mendoza
- Universidad Nacional de San Antonio Abad del Cusco, Cusco, Peru
- Jardín Botánico de Missouri, Oxapampa, Peru
| | - Paulo Morandi
- Departamento de Ciências Biológicas, Universidade do Estado de Mato Grosso (UNEMAT), Nova Xavantina, Brazil
| | - Victor Chama Moscoso
- Universidad Nacional de San Antonio Abad del Cusco, Cusco, Peru
- Jardín Botánico de Missouri, Oxapampa, Peru
| | - Robert Muscarella
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Deliane Penha
- Programa de Pós-Graduação em Biodiversidade, Universidade Federal do Oeste do Pará, Santarém, Brazil
| | - Mayda Cecília Rocha
- Instituto de Ciências e Tecnologia das Águas, Universidade Federal do Oeste do Pará, Santarém, Brazil
| | - Gleicy Rodrigues
- Programa de Pós-Graduação em Botânica, Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil
| | | | - Norma Salinas
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
- Sección Química, Pontificia Universidad Católica del Perú, Lima, Peru
| | - Monique Schlickmann
- Programa de Pós-Graduação em Biodiversidade, Universidade Federal do Oeste do Pará, Santarém, Brazil
| | - Marcos Silveira
- Museu Universitário, Centro de Ciências Biológicas e da Natureza, Universidade Federal do Acre, Rio Branco, Brazil
| | - Joey Talbot
- Institute for Transport Studies, University of Leeds, Leeds, UK
| | | | - Laura Vedovato
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Simone Aparecida Vieira
- Núcleo de Estudos e Pesquisas Ambientais, Universidade Estadual de Campinas, Campinas, Brazil
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Esquivel‐Muelbert A, Baker TR, Dexter KG, Lewis SL, Brienen RJW, Feldpausch TR, Lloyd J, Monteagudo‐Mendoza A, Arroyo L, Álvarez-Dávila E, Higuchi N, Marimon BS, Marimon-Junior BH, Silveira M, Vilanova E, Gloor E, Malhi Y, Chave J, Barlow J, Bonal D, Davila Cardozo N, Erwin T, Fauset S, Hérault B, Laurance S, Poorter L, Qie L, Stahl C, Sullivan MJP, ter Steege H, Vos VA, Zuidema PA, Almeida E, Almeida de Oliveira E, Andrade A, Vieira SA, Aragão L, Araujo‐Murakami A, Arets E, Aymard C GA, Baraloto C, Camargo PB, Barroso JG, Bongers F, Boot R, Camargo JL, Castro W, Chama Moscoso V, Comiskey J, Cornejo Valverde F, Lola da Costa AC, del Aguila Pasquel J, Di Fiore A, Fernanda Duque L, Elias F, Engel J, Flores Llampazo G, Galbraith D, Herrera Fernández R, Honorio Coronado E, Hubau W, Jimenez‐Rojas E, Lima AJN, Umetsu RK, Laurance W, Lopez‐Gonzalez G, Lovejoy T, Aurelio Melo Cruz O, Morandi PS, Neill D, Núñez Vargas P, Pallqui Camacho NC, Parada Gutierrez A, Pardo G, Peacock J, Peña‐Claros M, Peñuela‐Mora MC, Petronelli P, Pickavance GC, Pitman N, Prieto A, Quesada C, Ramírez‐Angulo H, Réjou‐Méchain M, Restrepo Correa Z, Roopsind A, Rudas A, Salomão R, Silva N, Silva Espejo J, Singh J, Stropp J, Terborgh J, Thomas R, Toledo M, Torres‐Lezama A, Valenzuela Gamarra L, van de Meer PJ, van der Heijden G, van der Hout P, Vasquez Martinez R, Vela C, Vieira ICG, Phillips OL. Compositional response of Amazon forests to climate change. Glob Chang Biol 2019; 25:39-56. [PMID: 30406962 PMCID: PMC6334637 DOI: 10.1111/gcb.14413] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 06/27/2018] [Accepted: 07/04/2018] [Indexed: 05/05/2023]
Abstract
Most of the planet's diversity is concentrated in the tropics, which includes many regions undergoing rapid climate change. Yet, while climate-induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether the floristic and functional composition of intact lowland Amazonian forests have been changing by evaluating records from 106 long-term inventory plots spanning 30 years. We analyse three traits that have been hypothesized to respond to different environmental drivers (increase in moisture stress and atmospheric CO2 concentrations): maximum tree size, biogeographic water-deficit affiliation and wood density. Tree communities have become increasingly dominated by large-statured taxa, but to date there has been no detectable change in mean wood density or water deficit affiliation at the community level, despite most forest plots having experienced an intensification of the dry season. However, among newly recruited trees, dry-affiliated genera have become more abundant, while the mortality of wet-affiliated genera has increased in those plots where the dry season has intensified most. Thus, a slow shift to a more dry-affiliated Amazonia is underway, with changes in compositional dynamics (recruits and mortality) consistent with climate-change drivers, but yet to significantly impact whole-community composition. The Amazon observational record suggests that the increase in atmospheric CO2 is driving a shift within tree communities to large-statured species and that climate changes to date will impact forest composition, but long generation times of tropical trees mean that biodiversity change is lagging behind climate change.
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3
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Powell TL, Wheeler JK, de Oliveira AAR, da Costa ACL, Saleska SR, Meir P, Moorcroft PR. Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees. Glob Chang Biol 2017; 23:4280-4293. [PMID: 28426175 DOI: 10.1111/gcb.13731] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [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: 12/22/2016] [Accepted: 02/23/2017] [Indexed: 05/24/2023]
Abstract
Considerable uncertainty surrounds the impacts of anthropogenic climate change on the composition and structure of Amazon forests. Building upon results from two large-scale ecosystem drought experiments in the eastern Brazilian Amazon that observed increases in mortality rates among some tree species but not others, in this study we investigate the physiological traits underpinning these differential demographic responses. Xylem pressure at 50% conductivity (xylem-P50 ), leaf turgor loss point (TLP), cellular osmotic potential (πo ), and cellular bulk modulus of elasticity (ε), all traits mechanistically linked to drought tolerance, were measured on upper canopy branches and leaves of mature trees from selected species growing at the two drought experiment sites. Each species was placed a priori into one of four plant functional type (PFT) categories: drought-tolerant versus drought-intolerant based on observed mortality rates, and subdivided into early- versus late-successional based on wood density. We tested the hypotheses that the measured traits would be significantly different between the four PFTs and that they would be spatially conserved across the two experimental sites. Xylem-P50 , TLP, and πo , but not ε, occurred at significantly higher water potentials for the drought-intolerant PFT compared to the drought-tolerant PFT; however, there were no significant differences between the early- and late-successional PFTs. These results suggest that these three traits are important for determining drought tolerance, and are largely independent of wood density-a trait commonly associated with successional status. Differences in these physiological traits that occurred between the drought-tolerant and drought-intolerant PFTs were conserved between the two research sites, even though they had different soil types and dry-season lengths. This more detailed understanding of how xylem and leaf hydraulic traits vary between co-occuring drought-tolerant and drought-intolerant tropical tree species promises to facilitate a much-needed improvement in the representation of plant hydraulics within terrestrial ecosystem and biosphere models, which will enhance our ability to make robust predictions of how future changes in climate will affect tropical forests.
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Affiliation(s)
- Thomas L Powell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Earth and Environmental Sciences Area, Lawrence Berkeley National Lab, Berkeley, CA, USA
| | - James K Wheeler
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Alex A R de Oliveira
- Museu Paraense Emílio Goeldi, Programa de Pós-Graduação em Biodiversidade e Evolução, Belém, Pará, Brazil
| | | | - Scott R Saleska
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - Patrick Meir
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Paul R Moorcroft
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
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4
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Esquivel-Muelbert A, Galbraith D, Dexter KG, Baker TR, Lewis SL, Meir P, Rowland L, Costa ACLD, Nepstad D, Phillips OL. Biogeographic distributions of neotropical trees reflect their directly measured drought tolerances. Sci Rep 2017; 7:8334. [PMID: 28827613 PMCID: PMC5567183 DOI: 10.1038/s41598-017-08105-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/10/2017] [Indexed: 11/09/2022] Open
Abstract
High levels of species diversity hamper current understanding of how tropical forests may respond to environmental change. In the tropics, water availability is a leading driver of the diversity and distribution of tree species, suggesting that many tropical taxa may be physiologically incapable of tolerating dry conditions, and that their distributions along moisture gradients can be used to predict their drought tolerance. While this hypothesis has been explored at local and regional scales, large continental-scale tests are lacking. We investigate whether the relationship between drought-induced mortality and distributions holds continentally by relating experimental and observational data of drought-induced mortality across the Neotropics to the large-scale bioclimatic distributions of 115 tree genera. Across the different experiments, genera affiliated to wetter climatic regimes show higher drought-induced mortality than dry-affiliated ones, even after controlling for phylogenetic relationships. This pattern is stronger for adult trees than for saplings or seedlings, suggesting that the environmental filters exerted by drought impact adult tree survival most strongly. Overall, our analysis of experimental, observational, and bioclimatic data across neotropical forests suggests that increasing moisture-stress is indeed likely to drive significant changes in floristic composition.
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Affiliation(s)
| | - David Galbraith
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Kyle G Dexter
- Royal Botanic Garden of Edinburgh, EH3 5LR, Edinburgh, UK
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Timothy R Baker
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Simon L Lewis
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
- Department of Geography, University College London, London, UK
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh, UK
- Research School of Biology, Australian National University, Canberra, Australia
| | - Lucy Rowland
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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5
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Binks O, Meir P, Rowland L, da Costa ACL, Vasconcelos SS, de Oliveira AAR, Ferreira L, Mencuccini M. Limited acclimation in leaf anatomy to experimental drought in tropical rainforest trees. Tree Physiol 2016; 36:1550-1561. [PMID: 27614360 PMCID: PMC5165703 DOI: 10.1093/treephys/tpw078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/12/2016] [Accepted: 07/16/2016] [Indexed: 05/10/2023]
Abstract
Dry periods are predicted to become more frequent and severe in the future in some parts of the tropics, including Amazonia, potentially causing reduced productivity, higher tree mortality and increased emissions of stored carbon. Using a long-term (12 year) through-fall exclusion (TFE) experiment in the tropics, we test the hypothesis that trees produce leaves adapted to cope with higher levels of water stress, by examining the following leaf characteristics: area, thickness, leaf mass per area, vein density, stomatal density, the thickness of palisade mesophyll, spongy mesophyll and both of the epidermal layers, internal cavity volume and the average cell sizes of the palisade and spongy mesophyll. We also test whether differences in leaf anatomy are consistent with observed differential drought-induced mortality responses among taxa, and look for relationships between leaf anatomy, and leaf water relations and gas exchange parameters. Our data show that trees do not produce leaves that are more xeromorphic in response to 12 years of soil moisture deficit. However, the drought treatment did result in increases in the thickness of the adaxial epidermis (TFE: 20.5 ± 1.5 µm, control: 16.7 ± 1.0 µm) and the internal cavity volume (TFE: 2.43 ± 0.50 mm3 cm-2, control: 1.77 ± 0.30 mm3 cm-2). No consistent differences were detected between drought-resistant and drought-sensitive taxa, although interactions occurred between drought-sensitivity status and drought treatment for the palisade mesophyll thickness (P = 0.034) and the cavity volume of the leaves (P = 0.025). The limited response to water deficit probably reflects a tight co-ordination between leaf morphology, water relations and photosynthetic properties. This suggests that there is little plasticity in these aspects of plant anatomy in these taxa, and that phenotypic plasticity in leaf traits may not facilitate the acclimation of Amazonian trees to the predicted future reductions in dry season water availability.
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Affiliation(s)
- Oliver Binks
- School of Geosciences, The Crew Building, The King's Buildings, University of Edinburgh, Edinburgh, EH9 3JN, UK
| | - Patrick Meir
- School of Geosciences, The Crew Building, The King's Buildings, University of Edinburgh, Edinburgh, EH9 3JN, UK
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Lucy Rowland
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | | | | | | | | | - Maurizio Mencuccini
- School of Geosciences, The Crew Building, The King's Buildings, University of Edinburgh, Edinburgh, EH9 3JN, UK
- ICREA at CREAF , 08193 Cerdanyola del Vallés, Spain
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6
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Binks O, Meir P, Rowland L, da Costa ACL, Vasconcelos SS, de Oliveira AAR, Ferreira L, Christoffersen B, Nardini A, Mencuccini M. Plasticity in leaf-level water relations of tropical rainforest trees in response to experimental drought. New Phytol 2016; 211:477-88. [PMID: 27001030 PMCID: PMC5071722 DOI: 10.1111/nph.13927] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [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: 10/09/2015] [Accepted: 02/07/2016] [Indexed: 05/25/2023]
Abstract
The tropics are predicted to become warmer and drier, and understanding the sensitivity of tree species to drought is important for characterizing the risk to forests of climate change. This study makes use of a long-term drought experiment in the Amazon rainforest to evaluate the role of leaf-level water relations, leaf anatomy and their plasticity in response to drought in six tree genera. The variables (osmotic potential at full turgor, turgor loss point, capacitance, elastic modulus, relative water content and saturated water content) were compared between seasons and between plots (control and through-fall exclusion) enabling a comparison between short- and long-term plasticity in traits. Leaf anatomical traits were correlated with water relation parameters to determine whether water relations differed among tissues. The key findings were: osmotic adjustment occurred in response to the long-term drought treatment; species resistant to drought stress showed less osmotic adjustment than drought-sensitive species; and water relation traits were correlated with tissue properties, especially the thickness of the abaxial epidermis and the spongy mesophyll. These findings demonstrate that cell-level water relation traits can acclimate to long-term water stress, and highlight the limitations of extrapolating the results of short-term studies to temporal scales associated with climate change.
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Affiliation(s)
- Oliver Binks
- School of GeoSciencesUniversity of EdinburghEdinburghEH9 3FEUK
| | - Patrick Meir
- School of GeoSciencesUniversity of EdinburghEdinburghEH9 3FEUK
- Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Lucy Rowland
- School of GeoSciencesUniversity of EdinburghEdinburghEH9 3FEUK
| | | | | | | | | | | | - Andrea Nardini
- Dipartimento di Scienze della VitaUniversitá di TriesteVia L. Giorgieri 1034127TriesteItaly
| | - Maurizio Mencuccini
- School of GeoSciencesUniversity of EdinburghEdinburghEH9 3FEUK
- ICREA at CREAF08193Cerdanyola del VallésSpain
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7
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Powell TL, Galbraith DR, Christoffersen BO, Harper A, Imbuzeiro HMA, Rowland L, Almeida S, Brando PM, da Costa ACL, Costa MH, Levine NM, Malhi Y, Saleska SR, Sotta E, Williams M, Meir P, Moorcroft PR. Confronting model predictions of carbon fluxes with measurements of Amazon forests subjected to experimental drought. New Phytol 2013; 200:350-365. [PMID: 23844931 DOI: 10.1111/nph.12390] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [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: 02/12/2013] [Accepted: 05/20/2013] [Indexed: 05/08/2023]
Abstract
Considerable uncertainty surrounds the fate of Amazon rainforests in response to climate change. Here, carbon (C) flux predictions of five terrestrial biosphere models (Community Land Model version 3.5 (CLM3.5), Ecosystem Demography model version 2.1 (ED2), Integrated BIosphere Simulator version 2.6.4 (IBIS), Joint UK Land Environment Simulator version 2.1 (JULES) and Simple Biosphere model version 3 (SiB3)) and a hydrodynamic terrestrial ecosystem model (the Soil-Plant-Atmosphere (SPA) model) were evaluated against measurements from two large-scale Amazon drought experiments. Model predictions agreed with the observed C fluxes in the control plots of both experiments, but poorly replicated the responses to the drought treatments. Most notably, with the exception of ED2, the models predicted negligible reductions in aboveground biomass in response to the drought treatments, which was in contrast to an observed c. 20% reduction at both sites. For ED2, the timing of the decline in aboveground biomass was accurate, but the magnitude was too high for one site and too low for the other. Three key findings indicate critical areas for future research and model development. First, the models predicted declines in autotrophic respiration under prolonged drought in contrast to measured increases at one of the sites. Secondly, models lacking a phenological response to drought introduced bias in the sensitivity of canopy productivity and respiration to drought. Thirdly, the phenomenological water-stress functions used by the terrestrial biosphere models to represent the effects of soil moisture on stomatal conductance yielded unrealistic diurnal and seasonal responses to drought.
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Affiliation(s)
- Thomas L Powell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - David R Galbraith
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, UK
| | | | - Anna Harper
- College of Engineering, Mathematics, and Physical Science, University of Exeter, Exeter, EX4 4QF, UK
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Hewlley M A Imbuzeiro
- Grupo de Pesquisas em Interação Atmosfera-Biosfera, Universidade Federal de Viçosa, Viçosa, CEP 36570-000, Minas Gerias, Brazil
| | - Lucy Rowland
- School of GeoSciences, University of Edinburgh, Edinburgh, EH8 9XP, UK
| | - Samuel Almeida
- Museu Paraense Emilio Goeldi, Belém, CEP 66077-530, Pará, Brazil
| | - Paulo M Brando
- Instituto de Pesquisa Ambiental da Amazônia, CEP 71503-505, Brasília, Distrito Federal, Brazil
| | | | - Marcos Heil Costa
- Grupo de Pesquisas em Interação Atmosfera-Biosfera, Universidade Federal de Viçosa, Viçosa, CEP 36570-000, Minas Gerias, Brazil
| | - Naomi M Levine
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, UK
| | - Scott R Saleska
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
| | | | - Mathew Williams
- School of GeoSciences, University of Edinburgh, Edinburgh, EH8 9XP, UK
| | - Patrick Meir
- School of GeoSciences, University of Edinburgh, Edinburgh, EH8 9XP, UK
| | - Paul R Moorcroft
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
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da Costa ACL, Galbraith D, Almeida S, Portela BTT, da Costa M, Silva Junior JDA, Braga AP, de Gonçalves PHL, de Oliveira AAR, Fisher R, Phillips OL, Metcalfe DB, Levy P, Meir P. Effect of 7 yr of experimental drought on vegetation dynamics and biomass storage of an eastern Amazonian rainforest. New Phytol 2010; 187:579-91. [PMID: 20553386 DOI: 10.1111/j.1469-8137.2010.03309.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [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
*At least one climate model predicts severe reductions of rainfall over Amazonia during this century. Long-term throughfall exclusion (TFE) experiments represent the best available means to investigate the resilience of the Amazon rainforest to such droughts. *Results are presented from a 7 yr TFE study at Caxiuanã National Forest, eastern Amazonia. We focus on the impacts of the drought on tree mortality, wood production and above-ground biomass. *Tree mortality in the TFE plot over the experimental period was 2.5% yr(-1), compared with 1.25% yr(-1) in a nearby control plot experiencing normal rainfall. Differences in stem mortality between plots were greatest in the largest (> 40 cm diameter at breast height (dbh)) size class (4.1% yr(-1) in the TFE and 1.4% yr(-1) in the control). Wood production in the TFE plot was c. 30% lower than in the control plot. Together, these changes resulted in a loss of 37.8 +/- 2.0 Mg carbon (C) ha(-1) in the TFE plot (2002-2008), compared with no change in the control. *These results are remarkably consistent with those from another TFE (at Tapajós National Forest), suggesting that eastern Amazonian forests may respond to prolonged drought in a predictable manner.
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