1
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West AG, Bloy ST, Skelton RP, Midgley JJ. Hydraulic segmentation explains differences in loss of branch conductance caused by fire. TREE PHYSIOLOGY 2023; 43:2121-2130. [PMID: 37672220 PMCID: PMC10714316 DOI: 10.1093/treephys/tpad108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 08/28/2023] [Accepted: 09/03/2023] [Indexed: 09/07/2023]
Abstract
The hydraulic death hypothesis suggests that fires kill trees by damaging the plant's hydraulic continuum in addition to stem cambium. A corollary to this hypothesis is that plants that survive fires possess 'pyrohydraulic' traits that prevent heat-induced embolism formation in the xylem and aid post-fire survival. We examine whether hydraulic segmentation within stem xylem may act as such a trait. To do so, we measured the percentage loss of conductance (PLC) and vulnerability to embolism axially along segments of branches exposed to heat plumes in two differing species, fire-tolerant Eucalyptus cladocalyx F. Muell and fire-sensitive Kiggelaria africana L., testing model predictions that fire-tolerant species would exhibit higher degrees of hydraulic segmentation (greater PLC in the distal parts of the branch than the basal) than fire-intolerant species (similar PLC between segments). Following exposure to a heat plume, K. africana suffered between 73 and 84% loss of conductance in all branch segments, whereas E. cladocalyx had 73% loss of conductance in whole branches, including the distal tips, falling to 29% in the most basal part of the branch. There was no evidence for differences in resistance segmentation between the species, and there was limited evidence for differences in distal vulnerability to embolism across the branches. Hydraulic segmentation in E. cladocalyx may enable it to resprout effectively post-fire with a functional hydraulic system. The lack of hydraulic segmentation in K. africana reveals the need to understand possible trade-offs associated with hydraulic segmentation in long-lived woody species with respect to drought and fire.
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Affiliation(s)
- Adam G West
- Department of Biological Sciences, University Avenue, University of Cape Town, 7701, Cape Town, South Africa
| | - Shonese T Bloy
- Department of Biological Sciences, University Avenue, University of Cape Town, 7701, Cape Town, South Africa
| | - Robert P Skelton
- SAEON Fynbos Node, Centre for Biodiversity Conservation, Kirstenbosch Gardens, 7708, Cape Town, South Africa
- Animal, Plant and Environmental Sciences, University of the Witwatersrand, 1 Jan Smuts Ave, Braamfontein, 2001, Johannesburg, South Africa
| | - Jeremy J Midgley
- Department of Biological Sciences, University Avenue, University of Cape Town, 7701, Cape Town, South Africa
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2
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Martín-Gómez P, Rodríguez-Robles U, Ogée J, Wingate L, Sancho-Knapik D, Peguero-Pina J, Dos Santos Silva JV, Gil-Pelegrín E, Pemán J, Ferrio JP. Contrasting stem water uptake and storage dynamics of water-saver and water-spender species during drought and recovery. TREE PHYSIOLOGY 2023; 43:1290-1306. [PMID: 36930058 DOI: 10.1093/treephys/tpad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 03/01/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Drought is projected to occur more frequently and intensely in the coming decades, and the extent to which it will affect forest functioning will depend on species-specific responses to water stress. Aiming to understand the hydraulic traits and water dynamics behind water-saver and water-spender strategies in response to drought and recovery, we conducted a pot experiment with two species with contrasting physiological strategies, Scots pine (Pinus sylvestris L.) and Portuguese oak (Quercus faginea L.). We applied two cycles of soil drying and recovery and irrigated with isotopically different water to track fast changes in soil and stem water pools, while continuously measuring physiological status and xylem water content from twigs. Our results provide evidence for a tight link between the leaf-level response and the water uptake and storage patterns in the stem. The water-saver strategy of pines prevented stem dehydration by rapidly closing stomata which limited their water uptake during the early stages of drought and recovery. Conversely, oaks showed a less conservative strategy, maintaining transpiration and physiological activity under dry soil conditions, and consequently becoming more dehydrated at the stem level. We interpreted this dehydration as the release of water from elastic storage tissues as no major loss of hydraulic conductance occurred for this species. After soil rewetting, pines recovered pre-drought leaf water potential rapidly, but it took longer to replace the water from conductive tissues (slower labeling speed). In contrast, water-spender oaks were able to quickly replace xylem water during recovery (fast labeling speed), but it took longer to refill stem storage tissues, and hence to recover pre-drought leaf water potential. These different patterns in sap flow rates, speed and duration of the labeling reflected a combination of water-use and storage traits, linked to the leaf-level strategies in response to drought and recovery.
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Affiliation(s)
- Paula Martín-Gómez
- Joint Research Unit CTFC - AGROTECNIO - CERCA, Ctra de Sant Llorenç de Morunys, km 2, E-25280 Solsona, Lleida, Spain
| | - Ulises Rodríguez-Robles
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Av. Independencia Nacional 151, Autlán de Navarro, 48900 Jalisco, México
| | - Jérôme Ogée
- Atmosphere Plant Soil Interactions Research Unit (UMR ISPA), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), 71 Av. Edouard Bourlaux, F-33140 Villenave d'Ornon, France
| | - Lisa Wingate
- Atmosphere Plant Soil Interactions Research Unit (UMR ISPA), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), 71 Av. Edouard Bourlaux, F-33140 Villenave d'Ornon, France
| | - Domingo Sancho-Knapik
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - José Peguero-Pina
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - José Victor Dos Santos Silva
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - Eustaquio Gil-Pelegrín
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - Jesús Pemán
- Department of Crop and Forest Sciences, Universitat de Lleida (UdL), Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Juan Pedro Ferrio
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
- Aragon Agency for Research and Development (ARAID), E-50018 Zaragoza, Spain
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3
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Chen Z, Li S, Wan X, Liu S. Strategies of tree species to adapt to drought from leaf stomatal regulation and stem embolism resistance to root properties. FRONTIERS IN PLANT SCIENCE 2022; 13:926535. [PMID: 36237513 PMCID: PMC9552884 DOI: 10.3389/fpls.2022.926535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Considerable evidences highlight the occurrence of increasing widespread tree mortality as a result of global climate change-associated droughts. However, knowledge about the mechanisms underlying divergent strategies of various tree species to adapt to drought has remained remarkably insufficient. Leaf stomatal regulation and embolism resistance of stem xylem serves as two important strategies for tree species to prevent hydraulic failure and carbon starvation, as comprising interconnected physiological mechanisms underlying drought-induced tree mortality. Hence, the physiological and anatomical determinants of leaf stomatal regulation and stems xylem embolism resistance are evaluated and discussed. In addition, root properties related to drought tolerance are also reviewed. Species with greater investment in leaves and stems tend to maintain stomatal opening and resist stem embolism under drought conditions. The coordination between stomatal regulation and stem embolism resistance are summarized and discussed. Previous studies showed that hydraulic safety margin (HSM, the difference between minimum water potential and that causing xylem dysfunction) is a significant predictor of tree species mortality under drought conditions. Compared with HSM, stomatal safety margin (the difference between water potential at stomatal closure and that causing xylem dysfunction) more directly merge stomatal regulation strategies with xylem hydraulic strategies, illustrating a comprehensive framework to characterize plant response to drought. A combination of plant traits reflecting species' response and adaptation to drought should be established in the future, and we propose four specific urgent issues as future research priorities.
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Affiliation(s)
- Zhicheng Chen
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
| | - Shan Li
- Department of Environmental Science and Ecology, School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi’an, China
| | - Xianchong Wan
- Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing, China
| | - Shirong Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
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4
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Dória LC, Sonsin-Oliveira J, Rossi S, Marcati CR. Functional trade-offs in volume allocation to xylem cell types in 75 species from the Brazilian savanna Cerrado. ANNALS OF BOTANY 2022; 130:445-456. [PMID: 35863898 PMCID: PMC9486921 DOI: 10.1093/aob/mcac095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/20/2022] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Xylem is a crucial tissue for plant survival, performing the functions of water transport, mechanical support and storage. Functional trade-offs are a result of the different assemblages of xylem cell types within a certain wood volume. We assessed how the volume allocated to different xylem cell types can be associated with wood functional trade-offs (hydraulics, mechanical and storage) in species from the Cerrado, the Brazilian savanna. We also assessed the xylem anatomical characters linked to wood density across species. METHODS We analysed cross-sections of branches collected from 75 woody species belonging to 42 angiosperm families from the Cerrado. We estimated the wood volume fraction allocated to different cell types and performed measurements of vessel diameter and wood density. KEY RESULTS The largest volume of wood is allocated to fibres (0.47), followed by parenchyma (0.33) and vessels (0.20). Wood density is positively correlated to cell wall (fibre and vessel wall), and negatively to the fractions of fibre lumen and gelatinous fibres. We observed a trade-off between hydraulics (vessel diameter) and mechanics (cell wall fraction), and between mechanics and storage (parenchyma fraction). The expected positive functional relationships between hydraulics (vessel diameter) and water and carbohydrate storage (parenchyma and fibre lumen fractions) were not detected, though larger vessels are linked to a larger wood volume allocated to gelatinous fibres. CONCLUSIONS Woody species from the Cerrado show evidence of functional trade-offs between water transport, mechanical support and storage. Gelatinous fibres might be potentially linked to water storage and release by their positive relationship to increased vessel diameter, thus replacing the functional role of parenchyma and fibre lumen cells. Species can profit from the increased mechanical strength under tension provided by the presence of gelatinous fibres, avoiding expensive investments in high wood density.
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Affiliation(s)
| | - Julia Sonsin-Oliveira
- Departamento de Biologia Vegetal, Programa de Pós-Graduação em Botânica, Instituto de Ciências Biológicas, Universidade de Brasilia (UnB), Brasília, DF, Brazil
| | - Sergio Rossi
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Carmen Regina Marcati
- Departamento de Ciência Florestal, Solos e Ambiente, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Agronômicas, Avenida Universitária, Botucatu, SP, Brazil
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5
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Smith-Martin CM, Muscarella R, Ankori-Karlinsky R, Delzon S, Farrar SL, Salva-Sauri M, Thompson J, Zimmerman JK, Uriarte M. Hurricanes increase tropical forest vulnerability to drought. THE NEW PHYTOLOGIST 2022; 235:1005-1017. [PMID: 35608089 DOI: 10.1111/nph.18175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Rapid changes in climate and disturbance regimes, including droughts and hurricanes, are likely to influence tropical forests, but our understanding of the compound effects of disturbances on forest ecosystems is extremely limited. Filling this knowledge gap is necessary to elucidate the future of these ecosystems under a changing climate. We examined the relationship between hurricane response (damage, mortality, and resilience) and four hydraulic traits of 13 dominant woody species in a wet tropical forest subject to periodic hurricanes. Species with high resistance to embolisms (low P50 values) and higher safety margins ( SMP50 ) were more resistant to immediate hurricane mortality and breakage, whereas species with higher hurricane resilience (rapid post-hurricane growth) had high capacitance and P50 values and low SMP50 . During 26 yr of post-hurricane recovery, we found a decrease in community-weighted mean values for traits associated with greater drought resistance (leaf turgor loss point, P50 , SMP50 ) and an increase in capacitance, which has been linked with lower drought resistance. Hurricane damage favors slow-growing, drought-tolerant species, whereas post-hurricane high resource conditions favor acquisitive, fast-growing but drought-vulnerable species, increasing forest productivity at the expense of drought tolerance and leading to higher overall forest vulnerability to drought.
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Affiliation(s)
- Chris M Smith-Martin
- Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, NY, 10027, USA
| | - Robert Muscarella
- Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, 752 36, Sweden
| | - Roi Ankori-Karlinsky
- Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, NY, 10027, USA
| | - Sylvain Delzon
- INRA, BIOGECO, Université Bordeaux, Pessac, 33615, France
| | - Samuel L Farrar
- Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, 752 36, Sweden
| | - Melissa Salva-Sauri
- Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, NY, 10027, USA
- Department of Environmental Sciences, University of Puerto Rico, San Juan, PR, 00925, USA
| | - Jill Thompson
- UK Centre for Ecology & Hydrology Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Jess K Zimmerman
- Department of Environmental Sciences, University of Puerto Rico, San Juan, PR, 00925, USA
| | - María Uriarte
- Department of Ecology, Evolution and Environmental Biology, Columbia University, 1200 Amsterdam Avenue, New York, NY, 10027, USA
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6
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Signori‐Müller C, Oliveira RS, Valentim Tavares J, Carvalho Diniz F, Gilpin M, de V. Barros F, Marca Zevallos MJ, Salas Yupayccana CA, Nina A, Brum M, Baker TR, Cosio EG, Malhi Y, Monteagudo Mendoza A, Phillips OL, Rowland L, Salinas N, Vasquez R, Mencuccini M, Galbraith D. Variation of non‐structural carbohydrates across the fast–slow continuum in Amazon Forest canopy trees. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Caroline Signori‐Müller
- Geography 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
- School of Geography University of Leeds Leeds UK
| | - Rafael S. Oliveira
- Department of Plant Biology Institute of Biology University of Campinas Campinas Brazil
| | | | | | | | - Fernanda de V. Barros
- Geography 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
| | - Manuel J. Marca Zevallos
- Universidad Nacional de San Antonio Abad del Cusco Cusco Peru
- Pontificia Universidad Católica del Perú Lima Perú
| | | | - Alex Nina
- Pontificia Universidad Católica del Perú Lima Perú
| | - Mauro Brum
- Department of Plant Biology Institute of Biology Programa de Pós Graduação em Ecologia University of Campinas Campinas Brazil
- Department of Ecology and Evolutionary Biology University of Arizona Tucson AZ USA
| | | | - Eric G. Cosio
- Sección Química Pontificia Universidad Católica del Perú Lima Peru
| | - Yadvinder Malhi
- Environmental Change Institute School of Geography and the Environment University of Oxford Oxford UK
| | | | | | - Lucy Rowland
- Geography College of Life and Environmental Sciences University of Exeter Exeter UK
| | - Norma Salinas
- Sección Química Pontificia Universidad Católica del Perú Lima Peru
- Environmental Change Institute School of Geography and the Environment University of Oxford Oxford UK
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7
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Jupa R, Krabičková D, Plichta R, Mayr S, Gloser V. Do angiosperm tree species adjust intervessel lateral contact in response to soil drought? PHYSIOLOGIA PLANTARUM 2021; 172:2048-2058. [PMID: 33876443 DOI: 10.1111/ppl.13435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
During soil drought (i.e. limited soil water availability to plants), woody species may adjust the structure of their vessel network to improve their resistance against future soil drought stress. Impacts of soil drought on intervessel lateral contact remain poorly understood despite of its significance to xylem transport efficiency and safety. Here, we analysed drought-induced modifications in xylem structures of temperate angiosperm trees with a focus on intervessel lateral contact. Anatomical analyses were performed both in stems of seedlings cultivated under different substrate water availability and annual rings of mature individuals developed during years of low and high soil drought intensities. In response to limited water availability, a decrease in vessel diameter (up to -20%) and simultaneous increase in vessel density (up to +60%) were observed both in seedlings and mature trees. Conversely, there were only small and inconsistent drought-induced changes in intervessel contact frequency and intervessel contact fraction (typically up to ±15%) observed across species, indicating that intervessel lateral contact is a conservative trait. The small adjustments in intervessel lateral contacts were primarily driven by changes in the contact frequencies between neighbouring vessels (i.e. vessel grouping) rather than by changes in proportions of shared cell walls. Our results demonstrate that angiosperm tree species, despite remarkable adjustments in vessel dimensions and densities upon soil drought, exhibit surprisingly invariant intervessel lateral contact architecture.
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Affiliation(s)
- Radek Jupa
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Department of Forest Botany, Dendrology and Geobiocenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Dita Krabičková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Roman Plichta
- Department of Forest Botany, Dendrology and Geobiocenology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Vít Gloser
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
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8
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Lai HR, Craven D, Hall JS, Hui FKC, van Breugel M. Successional syndromes of saplings in tropical secondary forests emerge from environment-dependent trait-demography relationships. Ecol Lett 2021; 24:1776-1787. [PMID: 34170613 DOI: 10.1111/ele.13784] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/03/2021] [Accepted: 04/21/2021] [Indexed: 11/27/2022]
Abstract
Identifying generalisable processes that underpin population dynamics is crucial for understanding successional patterns. While longitudinal or chronosequence data are powerful tools for doing so, the traditional focus on community-level shifts in taxonomic and functional composition rather than species-level trait-demography relationships has made generalisation difficult. Using joint species distribution models, we demonstrate how three traits-photosynthetic rate, adult stature, and seed mass-moderate recruitment and sapling mortality rates of 46 woody species during secondary succession. We show that the pioneer syndrome emerges from higher photosynthetic rates, shorter adult statures and lighter seeds that facilitate exploitation of light in younger secondary forests, while 'long-lived pioneer' and 'late successional' syndromes are associated with trait values that enable species to persist in the understory or reach the upper canopy in older secondary forests. Our study highlights the context dependency of trait-demography relationships, which drive successional shifts in sapling's species composition in secondary forests.
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Affiliation(s)
- Hao Ran Lai
- Yale-NUS College, Singapore, Republic of Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore.,Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Dylan Craven
- Centro de Modelación y Monitoreo de Ecosistemas, Universidad Mayor, Santiago, Chile
| | - Jefferson S Hall
- ForestGEO, Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Francis K C Hui
- Research School of Finance, Actuarial Studies & Statistics, Australian National University, Acton, ACT, Australia
| | - Michiel van Breugel
- Yale-NUS College, Singapore, Republic of Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore.,ForestGEO, Smithsonian Tropical Research Institute, Panama, Republic of Panama
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9
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Ziemińska K, Rosa E, Gleason SM, Holbrook NM. Wood day capacitance is related to water content, wood density, and anatomy across 30 temperate tree species. PLANT, CELL & ENVIRONMENT 2020; 43:3048-3067. [PMID: 32935340 DOI: 10.1111/pce.13891] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 09/05/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
Water released from wood during transpiration (capacitance) can meaningfully affect daily water use and drought response. To provide context for better understanding of capacitance mechanisms, we investigated links between capacitance and wood anatomy. On twigs of 30 temperate angiosperm tree species, we measured day capacitance (between predawn and midday), water content, wood density, and anatomical traits, that is, vessel dimensions, tissue fractions, and vessel-tissue contact fractions (fraction of vessel circumference in contact with other tissues). Across all species, wood density (WD) and predawn lumen volumetric water content (VWCL-pd ) together were the strongest predictors of day capacitance (r2adj = .44). Vessel-tissue contact fractions explained an additional ~10% of the variation in day capacitance. Regression models were not improved by including tissue lumen fractions. Among diffuse-porous species, VWCL-pd and vessel-ray contact fraction together were the best predictors of day capacitance, whereas among semi/ring-porous species, VWCL-pd , WD and vessel-fibre contact fraction were the best predictors. At predawn, wood was less than fully saturated for all species (lumen relative water content = 0.52 ± 0.17). Our findings imply that day capacitance depends on the amount of stored water, tissue connectivity and the bulk wood properties arising from WD (e.g., elasticity), rather than the fraction of any particular tissue.
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Affiliation(s)
- Kasia Ziemińska
- Arnold Arboretum of Harvard University, Boston, Massachusetts, USA
- Department of Plant Ecology and Evolution, Uppsala University, Uppsala, Sweden
| | - Emily Rosa
- Department of Biology, Sonoma State University, Rohnert Park, California, USA
| | - Sean M Gleason
- United States Department of Agriculture - Agricultural Research Service, Water Management and Systems Research Unit, Fort Collins, Colorado, USA
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
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10
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Janssen TAJ, Hölttä T, Fleischer K, Naudts K, Dolman H. Wood allocation trade-offs between fiber wall, fiber lumen, and axial parenchyma drive drought resistance in neotropical trees. PLANT, CELL & ENVIRONMENT 2020; 43:965-980. [PMID: 31760666 PMCID: PMC7155043 DOI: 10.1111/pce.13687] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/14/2019] [Accepted: 11/18/2019] [Indexed: 05/25/2023]
Abstract
Functional relationships between wood density and measures of xylem hydraulic safety and efficiency are ambiguous, especially in wet tropical forests. In this meta-analysis, we move beyond wood density per se and identify relationships between xylem allocated to fibers, parenchyma, and vessels and measures of hydraulic safety and efficiency. We analyzed published data of xylem traits, hydraulic properties and measures of drought resistance from neotropical tree species retrieved from 346 sources. We found that xylem volume allocation to fiber walls increases embolism resistance, but at the expense of specific conductivity and sapwood capacitance. Xylem volume investment in fiber lumen increases capacitance, while investment in axial parenchyma is associated with higher specific conductivity. Dominant tree taxa from wet forests prioritize xylem allocation to axial parenchyma at the expense of fiber walls, resulting in a low embolism resistance for a given wood density and a high vulnerability to drought-induced mortality. We conclude that strong trade-offs between xylem allocation to fiber walls, fiber lumen, and axial parenchyma drive drought resistance in neotropical trees. Moreover, the benefits of xylem allocation to axial parenchyma in wet tropical trees might not outweigh the consequential low embolism resistance under more frequent and severe droughts in a changing climate.
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Affiliation(s)
- Thomas A. J. Janssen
- Department of Earth Sciences, Cluster Earth and ClimateVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Teemu Hölttä
- Institute for Atmospheric and Earth System Research/Forest Sciences, Faculty of Agriculture and ForestryUniversity of HelsinkiHelsinkiFinland
| | - Katrin Fleischer
- Land Surface‐Atmosphere InteractionsTechnical University of MunichFreisingGermany
| | - Kim Naudts
- Department of Earth Sciences, Cluster Earth and ClimateVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Han Dolman
- Department of Earth Sciences, Cluster Earth and ClimateVrije Universiteit AmsterdamAmsterdamThe Netherlands
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11
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McCulloh KA, Domec JC, Johnson DM, Smith DD, Meinzer FC. A dynamic yet vulnerable pipeline: Integration and coordination of hydraulic traits across whole plants. PLANT, CELL & ENVIRONMENT 2019; 42:2789-2807. [PMID: 31273812 DOI: 10.1111/pce.13607] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/01/2019] [Accepted: 07/02/2019] [Indexed: 06/09/2023]
Abstract
The vast majority of measurements in the field of plant hydraulics have been on small-diameter branches from woody species. These measurements have provided considerable insight into plant functioning, but our understanding of plant physiology and ecology would benefit from a broader view, because branch hydraulic properties are influenced by many factors. Here, we discuss the influence that other components of the hydraulic network have on branch vulnerability to embolism propagation. We also modelled the impact of changes in the ratio of root-to-leaf areas and soil texture on vulnerability to hydraulic failure along the soil-to-leaf continuum and showed that hydraulic function is better maintained through changes in root vulnerability and root-to-leaf area ratio than in branch vulnerability. Differences among species in the stringency with which they regulate leaf water potential and in reliance on stored water to buffer changes in water potential also affect the need to construct embolism resistant branches. Many approaches, such as measurements on fine roots, small individuals, combining sap flow and psychrometry techniques, and modelling efforts, could vastly improve our understanding of whole-plant hydraulic functioning. A better understanding of how traits are coordinated across the whole plant will improve predictions for plant function under future climate conditions.
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Affiliation(s)
| | - Jean-Christophe Domec
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- Bordeaux Sciences Agro, UMR 1391 INRA-ISPA, 33175, Gradignan Cedex, France
| | - Daniel M Johnson
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
| | - Duncan D Smith
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Frederick C Meinzer
- USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, 97331, USA
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12
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Dos Santos EA, Filho USDS, Barroso GM, Rocha BPJS, Possato EL. Tolerance and remedial potential of trees submitted to atrazine and sulfentrazone in the rhizosphere. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2019; 22:78-86. [PMID: 31364395 DOI: 10.1080/15226514.2019.1644290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Residual herbicides are important for agricultural production but they may be lost underground. Trees capable of removing or degrading these products are interesting to the agro system. The objective was to evaluate the tolerance and remedial potential of trees in soil contaminated by atrazine and sulfentrazone. The experiment was arranged in a 7 × 3 factorial scheme. Factor one was composed of Inga edulis Mart., Myrsine gardneriana A.DC., Schizolobium parahyba (Vell.) Blake, Toona ciliata M. Roem., Trichilia hirta L. and Triplaris americana L. Factor two consisted of monthly solutions of atrazine (1000 g ha-1), sulfentrazone (150 g ha-1) and water only (control), applied through subgrade irrigation. The following parameters were evaluated: visual intoxication, plant growth, and biomass accumulation. Cucumber biomass was used as an indicator of herbicide residues in soil. Symptoms of intoxication were found only in S. parahyba and T. americana. Growth and biomass of the species were not affected by herbicides, except for T. americana. The herbicides provided higher biomass for T. hirta. Saplings of I. edulis, M. gardneriana, S. parahyba, T. ciliate, and T. hirta tolerate atrazine and sulfentrazone. Triplaris americana is sensitive to sulfentrazone. Inga edulis decreased sulfentrazone residues in the soil.
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Affiliation(s)
| | | | - Gabriela Madureira Barroso
- Departamento de Engenharia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Minas Gerais, Brasil
| | | | - Ernani Lopes Possato
- Departamento de Engenharia Florestal, Universidade Federal de Viçosa, Minas Gerais, Brazil
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13
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Siddiq Z, Zhang YJ, Zhu SD, Cao KF. Canopy water status and photosynthesis of tropical trees are associated with trunk sapwood hydraulic properties. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 139:724-730. [PMID: 31055133 DOI: 10.1016/j.plaphy.2019.04.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/21/2019] [Accepted: 04/23/2019] [Indexed: 06/09/2023]
Abstract
Tree trunks not only provide physical support for canopy leaves but also supply and store water for transpiration. However, the relationships between trunk hydraulic properties and canopy leaf physiology in tropical trees are not well-understood. In this study we concurrently measured morning and midday canopy leaf photosynthesis (A), stomatal conductance (gs), and leaf water potentials (ΨL) in 40 tropical trees representing 14 species at the beginning of the rainy season in Xishuangbanna, Southwest China. We also measured trunk sapwood capacitance (C), wood density, and sap flux density to assess their association with canopy leaf physiology. Among the 14 studied species, only three and four species did not show a significant midday reduction in A and gs respectively. The diurnally maximum A and gs were significantly positively related to sapwood hydraulic capacitance, maximum sap flux density (midday), and sap flux density at 11:00. Those species with lower wood density and higher C showed a lower reduction in ΨL at midday, whereas, species with high C, and large values of maximum sap flux density also showed high carbon assimilation at midday. Our results provide new insights into the close coordination between canopy physiology and trunk sapwood hydraulic properties in tropical trees.
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Affiliation(s)
- Zafar Siddiq
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, 666303, China; Department of Botany, Government College University, Lahore, 54000, Pakistan; University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
| | - Shi-Dan Zhu
- Plant Ecophysiology and Evolution Group, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, and Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, 530005, China
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, and Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, 530005, China.
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14
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Petruzzellis F, Nardini A, Savi T, Tonet V, Castello M, Bacaro G. Less safety for more efficiency: water relations and hydraulics of the invasive tree Ailanthus altissima (Mill.) Swingle compared with native Fraxinus ornus L. TREE PHYSIOLOGY 2019; 39:76-87. [PMID: 29982793 DOI: 10.1093/treephys/tpy076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/03/2018] [Indexed: 05/23/2023]
Abstract
Invasion of natural habitats by alien trees is a threat to forest conservation. Our understanding of fundamental ecophysiological mechanisms promoting plant invasions is still limited, and hydraulic and water relation traits have been only seldom included in studies comparing native and invasive trees. We compared several leaf and wood functional and mechanistic traits in co-occurring Ailanthus altissima (Mill.) Swingle (Aa) and Fraxinus ornus L. (Fo). Aa is one of the most invasive woody species in Europe and North America, currently outcompeting several native trees including Fo. We aimed at quantifying inter-specific differences in terms of: (i) performance in resource use and acquisition; (ii) hydraulic efficiency and safety; (iii) carbon costs associated to leaf and wood construction; and (iv) plasticity of functional and mechanistic traits in response to light availability. Traits related to leaf and wood construction and drought resistance significantly differed between the two species. Fo sustained higher structural costs than Aa, but was more resistant to drought. The lower resistance to drought stress of Aa was counterbalanced by higher water transport efficiency, but possibly required mechanisms of resilience to drought-induced hydraulic damage. Larger phenotypic plasticity of Aa in response to light availability could also promote the invasive potential of the species.
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Affiliation(s)
- Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italy
| | - Tadeja Savi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italy
- University of Natural Resources and Life Sciences, Division of Viticulture and Pomology, Department of Crop Sciences, Konrad Lorenz Straße 24, Tulln, Vienna, Austria
| | - Vanessa Tonet
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italy
| | - Miris Castello
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italy
| | - Giovanni Bacaro
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italy
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15
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Knipfer T, Barrios-Masias FH, Cuneo IF, Bouda M, Albuquerque CP, Brodersen CR, Kluepfel DA, McElrone AJ. Variations in xylem embolism susceptibility under drought between intact saplings of three walnut species. TREE PHYSIOLOGY 2018; 38:1180-1192. [PMID: 29850910 DOI: 10.1093/treephys/tpy049] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
A germplasm collection containing varied Juglans genotypes holds potential to improve drought resistance of plant materials for commercial production. We used X-ray computed microtomography to evaluate stem xylem embolism susceptibility/repair in relation to vessel anatomical features (size, arrangement, connectivity and pit characteristics) in 2-year-old saplings of three Juglans species. In vivo analysis revealed interspecific variations in embolism susceptibility among Juglans microcarpa, J. hindsii (both native to arid habitats) and J. ailantifolia (native to mesic habitats). Stem xylem of J. microcarpa was more resistant to drought-induced embolism as compared with J. hindsii and J. ailantifolia (differences in embolism susceptibility among older and current year xylem were not detected in any species). Variations in most vessel anatomical traits were negligible among the three species; however, we detected substantial interspecific differences in intervessel pit characteristics. As compared with J. hindsii and J. ailantifolia, low embolism susceptibility in J. microcarpa was associated with smaller pit size in larger diameter vessels, a smaller area of the shared vessel wall occupied by pits, lower pit frequency and no changes in pit characteristics as vessel diameters increased. Changes in amount of embolized vessels following 40 days of re-watering were minor in intact saplings of all three species highlighting that an embolism repair mechanism did not contribute to drought recovery. In conclusion, our data indicate that interspecific variations in drought-induced embolism susceptibility are associated with species-specific pit characteristics, and these traits may provide a future target for breeding efforts aimed at selecting walnut germplasm with improved drought resistance.
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Affiliation(s)
- Thorsten Knipfer
- Department of Viticulture & Enology, University of California, Davis, CA, USA
| | | | - Italo F Cuneo
- Department of Viticulture & Enology, University of California, Davis, CA, USA
| | - Martin Bouda
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
| | | | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
| | - Daniel A Kluepfel
- USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA, USA
| | - Andrew J McElrone
- Department of Viticulture & Enology, University of California, Davis, CA, USA
- USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA, USA
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16
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Plant Hydraulic Trait Covariation: A Global Meta-Analysis to Reduce Degrees of Freedom in Trait-Based Hydrologic Models. FORESTS 2018. [DOI: 10.3390/f9080446] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Current vegetation modeling strategies use broad categorizations of plants to estimate transpiration and biomass functions. A significant source of model error stems from vegetation categorizations that are mostly taxonomical with no basis in plant hydraulic strategy and response to changing environmental conditions. Here, we compile hydraulic traits from 355 species around the world to determine trait covariations in order to represent hydraulic strategies. Simple and stepwise regression analyses demonstrate the interconnectedness of multiple vegetative hydraulic traits, specifically, traits defining hydraulic conductivity and vulnerability to embolism with wood density and isohydricity. Drought sensitivity is strongly (Adjusted R2 = 0.52, p < 0.02) predicted by a stepwise linear model combining rooting depth, wood density, and isohydricity. Drought tolerance increased with increasing wood density and anisohydric response, but with decreasing rooting depth. The unexpected response to rooting depth may be due to other tradeoffs within the hydraulic system. Rooting depth was able to be predicted from sapwood specific conductivity and the water potential at 50% loss of conductivity. Interestingly, the influences of biome or growth form do not increase the accuracy of the drought tolerance model and were able to be omitted. Multiple regression analysis revealed 3D trait spaces and tradeoff axes along which species’ hydraulic strategies can be analyzed. These numerical trait spaces can reduce the necessary input to and parameterization of plant hydraulics modules, while increasing the physical representativeness of such simulations.
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17
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Sampaio Filho IDJ, Jardine KJ, de Oliveira RCA, Gimenez BO, Cobello LO, Piva LRDO, Candido LA, Higuchi N, Chambers JQ. Below versus above Ground Plant Sources of Abscisic Acid (ABA) at the Heart of Tropical Forest Response to Warming. Int J Mol Sci 2018; 19:E2023. [PMID: 30002274 PMCID: PMC6073271 DOI: 10.3390/ijms19072023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 11/26/2022] Open
Abstract
Warming surface temperatures and increasing frequency and duration of widespread droughts threaten the health of natural forests and agricultural crops. High temperatures (HT) and intense droughts can lead to the excessive plant water loss and the accumulation of reactive oxygen species (ROS) resulting in extensive physical and oxidative damage to sensitive plant components including photosynthetic membranes. ROS signaling is tightly integrated with signaling mechanisms of the potent phytohormone abscisic acid (ABA), which stimulates stomatal closure leading to a reduction in transpiration and net photosynthesis, alters hydraulic conductivities, and activates defense gene expression including antioxidant systems. While generally assumed to be produced in roots and transported to shoots following drought stress, recent evidence suggests that a large fraction of plant ABA is produced in leaves via the isoprenoid pathway. Thus, through stomatal regulation and stress signaling which alters water and carbon fluxes, we highlight the fact that ABA lies at the heart of the Carbon-Water-ROS Nexus of plant response to HT and drought stress. We discuss the current state of knowledge of ABA biosynthesis, transport, and degradation and the role of ABA and other isoprenoids in the oxidative stress response. We discuss potential variations in ABA production and stomatal sensitivity among different plant functional types including isohydric/anisohydric and pioneer/climax tree species. We describe experiments that would demonstrate the possibility of a direct energetic and carbon link between leaf ABA biosynthesis and photosynthesis, and discuss the potential for a positive feedback between leaf warming and enhanced ABA production together with reduced stomatal conductance and transpiration. Finally, we propose a new modeling framework to capture these interactions. We conclude by discussing the importance of ABA in diverse tropical ecosystems through increases in the thermotolerance of photosynthesis to drought and heat stress, and the global importance of these mechanisms to carbon and water cycling under climate change scenarios.
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Affiliation(s)
- Israel de Jesus Sampaio Filho
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
| | - Kolby Jeremiah Jardine
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
- Climate Science Department, Earth Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Rd., Building 64-241, Berkeley, CA 94720, USA.
| | | | - Bruno Oliva Gimenez
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
| | - Leticia Oliveira Cobello
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
| | - Luani Rosa de Oliveira Piva
- Federal University of Paraná (UFPR), Ave. Pref. Lothario Meissner 632, Campus III, Forest Sciences Department, Curitiba, PR 80210-170, Brazil.
| | - Luiz Antonio Candido
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
| | - Niro Higuchi
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
| | - Jeffrey Quintin Chambers
- National Institute for Amazon Research (INPA), Ave. Andre Araujo 2936, Campus II, Building LBA, Manaus, AM 69080-97, Brazil.
- Climate Science Department, Earth Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Rd., Building 64-241, Berkeley, CA 94720, USA.
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18
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Werden LK, Waring BG, Smith-Martin CM, Powers JS. Tropical dry forest trees and lianas differ in leaf economic spectrum traits but have overlapping water-use strategies. TREE PHYSIOLOGY 2018; 38:517-530. [PMID: 29087514 DOI: 10.1093/treephys/tpx135] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Tree species in tropical dry forests employ a wide range of strategies to cope with seasonal drought, including regulation of hydraulic function. However, it is uncertain if co-occurring lianas also possess a diversity of strategies. For a taxonomically diverse group of 14 tree and 7 liana species, we measured morphological and hydraulic functional traits during an unusual drought and under non-drought conditions to determine (i) if trees have different water-use strategies than lianas and (ii) if relationships among these traits can be used to better understand how tree and liana species regulate diurnal leaf water potential (Ψdiurnal). In this Costa Rican tropical dry forest, lianas and trees had overlapping water-use strategies, but differed in many leaf economic spectrum traits. Specifically, we found that both lianas and trees employed a diversity of Ψdiurnal regulation strategies, which did not differ statistically. However, lianas and trees did significantly differ in terms of certain traits including leaf area, specific leaf area, petiole length, wood vessel diameter and xylem vessel density. All liana and tree species we measured fell along a continuum of isohydric (partial) to anisohydric (strict or extreme) Ψdiurnal regulation strategies, and leaf area, petiole length, stomatal conductance and wood vessel diameter correlated with these strategies. These findings contribute to a trait-based understanding of how plants regulate Ψdiurnal under both drought stress and sufficient water availability, and underscore that lianas and trees employ a similarly wide range of Ψdiurnal regulation strategies, despite having vastly different growth forms.
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Affiliation(s)
- Leland K Werden
- Department of Plant and Microbial Biology, University of Minnesota, 1445 Gortner Ave., Saint Paul, MN 55108, USA
| | - Bonnie G Waring
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Ave., Saint Paul, MN 55108, USA
| | - Christina M Smith-Martin
- Department of Plant and Microbial Biology, University of Minnesota, 1445 Gortner Ave., Saint Paul, MN 55108, USA
| | - Jennifer S Powers
- Department of Plant and Microbial Biology, University of Minnesota, 1445 Gortner Ave., Saint Paul, MN 55108, USA
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Ave., Saint Paul, MN 55108, USA
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19
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Pita P, Rodríguez-Calcerrada J, Medel D, Gil L. Further insights into the components of resistance to Ophiostoma novo-ulmi in Ulmus minor: hydraulic conductance, stomatal sensitivity and bark dehydration. TREE PHYSIOLOGY 2018; 38:252-262. [PMID: 29040781 DOI: 10.1093/treephys/tpx123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
Dutch elm disease (DED) is a vascular disease that has killed over 1 billion elm trees. The pathogen spreads throughout the xylem network triggering vessel blockage, which results in water stress, tissue dehydration and extensive leaf wilting in susceptible genotypes. We investigated the differences between four Ulmus minor Mill. clones of contrasting susceptibility to Ophiostoma novo-ulmi Brasier regarding morphological, anatomical and physiological traits affecting water transport, in order to gain a better understanding of the mechanisms underlying DED susceptibility. We analyzed the differential response to water shortage and increased air vapor pressure deficit (VPD) to investigate whether resistance to water stress might be related to DED tolerance. Sixteen plants per clone, aged 2 years, were grown inside a greenhouse under differential watering. Stomatal conductance was measured under ambient and increased VPD. Growth, bark water content and stem hydraulic and anatomical parameters were measured 22 days after starting differential watering. Vessel lumen area, lumen fraction and hydraulic conductance were highest in susceptible clones. Stomatal conductance was lowest under low VPD and decreased faster under increased VPD in resistant clones. We found a negative relationship between the decrease in stomatal conductance at increased VPD and specific hydraulic conductance, revealing a narrower hydraulic margin for sustaining transpiration in resistant clones. The effect of water shortage was greater on radial stem growth than on leaf area, which could be explained through an extensive use of capacitance water to buffer xylem water potential. Water shortage reduced stomatal conductance and vessel lumen area. Bark water content under conditions of water shortage only decreased in susceptible clones. Higher hydraulic constraints to sap flow in resistant clones may determine higher stomatal sensitivity to VPD and so contribute to DED resistance by limiting pathogen expansion and reducing water loss and metabolic impairment in cells involved in fighting against infection.
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Affiliation(s)
- Pilar Pita
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Jesús Rodríguez-Calcerrada
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - David Medel
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Luis Gil
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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20
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Garrido M, Silva H, Franck N, Arenas J, Acevedo E. Evaluation of Morpho-Physiological Traits Adjustment of Prosopis tamarugo Under Long-Term Groundwater Depletion in the Hyper-Arid Atacama Desert. FRONTIERS IN PLANT SCIENCE 2018; 9:453. [PMID: 29686691 PMCID: PMC5900453 DOI: 10.3389/fpls.2018.00453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/22/2018] [Indexed: 05/06/2023]
Abstract
Water extraction from the underground aquifers of the Pampa del Tamarugal (Atacama Desert, Chile) reduced the growing area of Prosopis tamarugo, a strict phreatic species endemic to northern Chile. The objective of this work was to evaluate the effect of various architectural and morpho-physiological traits adjustment of P. tamarugo subjected to three groundwater depletion intervals (GWDr): <1 m (control), 1-4 m and 6-9 m. The traits were evaluated at three levels, plant [height, trunk cross-section area, leaf fraction (fGCC), and crown size], organ [length of internodes, leaf mass per unit area (LMA), leaflet mass and area], and tissue level [wood density (WD), leaf 13C, 18O isotope composition (δ), and intrinsic water use efficiency (iWUE)]. In addition, soil water content (VWC) to 1.3 m soil depth, pre-dawn and midday water potential difference (ΔΨ), and stomatal conductance (gs) were evaluated. At the deeper GWDr, P. tamarugo experienced significant growth restriction and reduced fGCC, the remaining canopy had a significantly higher LMA associated with smaller leaflets. No differences in internode length and WD were observed. Values for δ13C and δ18O indicated that as GWDr increased, iWUE increased as a result of partial stomata closure with no significant effect on net assimilation over time. The morpho-physiological changes experienced by P. tamarugo allowed it to acclimate and survive in a condition of groundwater depletion, keeping a functional but diminished canopy. These adjustments allowed maintenance of a relatively high gs; ΔΨ was not different among GWDrs despite smaller VWC at greater GWDr. Although current conservation initiatives of this species are promising, forest deterioration is expected continue as groundwater depth increases.
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Affiliation(s)
- Marco Garrido
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
| | - Herman Silva
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
| | - Nicolás Franck
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
| | - Jorge Arenas
- Faculty of Natural Renewable Resources, Desert Agriculture, Universidad Arturo Prat, Iquique, Chile
| | - Edmundo Acevedo
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
- *Correspondence: Edmundo Acevedo
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21
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Osazuwa-Peters OL, Wright SJ, Zanne AE. Linking wood traits to vital rates in tropical rainforest trees: Insights from comparing sapling and adult wood. AMERICAN JOURNAL OF BOTANY 2017; 104:1464-1473. [PMID: 29885221 DOI: 10.3732/ajb.1700242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 09/18/2017] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Wood density is the top predictor of growth and mortality rates (vital rates) but with modest explanatory power at best. Stronger links to vital rates are expected if wood density is decomposed into its anatomical properties at sapling and adult stages, since saplings and adults differ in wood traits and vital rates. We examined whether anatomical determinants of wood density and strength of the relationship between wood traits and vital rates shift between saplings and adults. METHODS Using wood segments from near pith (sapling) and near bark (adult) for 20 tree species (three adults each) from Barro Colorado Island, Panama, we quantified wood traits. Vital rates for saplings and adults were obtained from an earlier study. KEY RESULTS Anatomical predictors of wood density were similar for sapling and adult wood, with wood density variation largely explained by fiber lumen area and fiber wall fraction. In sapling wood only, growth rates decreased with fiber wall fraction and increased with fiber lumen area, while mortality rates increased with vessel area but decreased with fiber wall fraction and vessel density. CONCLUSIONS Wood traits of sapling trees provide functional insight into the growth-mortality tradeoff. Sapling wood with relatively large fiber lumen area and wide vessels, enabling faster hydraulic transport but less mechanical strength, is associated with fast growth and high mortality. Sapling wood with relatively more fiber wall and many narrow vessels, enabling greater mechanical strength but slower hydraulic transport, is associated with slow growth and low mortality.
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Affiliation(s)
- Oyomoare L Osazuwa-Peters
- Department of Biology, University of Missouri Saint Louis, Saint Louis, Missouri 63121 USA
- Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis, Missouri 63166 USA
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, Apartado 0843 - 03092 Balboa, Panama
| | - Amy E Zanne
- Department of Biological Sciences, The George Washington University, Washington, DC DC 20052 USA
- Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis, Missouri 63166 USA
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22
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Sapes G, Serra-Diaz JM, Lloret F. Species climatic niche explains drought-induced die-off in a Mediterranean woody community. Ecosphere 2017. [DOI: 10.1002/ecs2.1833] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Gerard Sapes
- Division of Biological Sciences; The University of Montana; Missoula Montana 59812 USA
- CREAF; 08913 Cerdanyola del Vallès Spain
- Univ Autònoma Barcelona; 08913 Cerdanyola del Vallès Spain
| | | | - Francisco Lloret
- CREAF; 08913 Cerdanyola del Vallès Spain
- Univ Autònoma Barcelona; 08913 Cerdanyola del Vallès Spain
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23
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Epila J, De Baerdemaeker NJF, Vergeynst LL, Maes WH, Beeckman H, Steppe K. Capacitive water release and internal leaf water relocation delay drought-induced cavitation in African Maesopsis eminii. TREE PHYSIOLOGY 2017; 37:481-490. [PMID: 28062725 DOI: 10.1093/treephys/tpw128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 12/04/2016] [Indexed: 06/06/2023]
Abstract
The impact of drought on the hydraulic functioning of important African tree species, like Maesopsis eminii Engl., is poorly understood. To map the hydraulic response to drought-induced cavitation, sole reliance on the water potential at which 50% loss of xylem hydraulic conductivity (ψ50) occurs might be limiting and at times misleading as the value alone does not give a comprehensive overview of strategies evoked by M. eminii to cope with drought. This article therefore uses a methodological framework to study the different aspects of drought-induced cavitation and water relations in M. eminii. Hydraulic functioning of whole-branch segments was investigated during bench-top dehydration. Cumulative acoustic emissions and continuous weight measurements were used to quantify M. eminii's vulnerability to drought-induced cavitation and hydraulic capacitance. Wood structural traits, including wood density, vessel area, diameter and wall thickness, vessel grouping index, solitary vessel index and vessel wall reinforcement, were used to underpin observed physiological responses. On average, M. eminii's ψ50 (±SE) was -1.9 ± 0.1 MPa, portraying its xylem as drought vulnerable, just as one would expect for a common tropical pioneer. However, M. eminii additionally employed an interesting desiccation delay strategy, fuelled by internal relocation of leaf water, hydraulic capacitance and the presence of parenchyma around the xylem vessels. Our findings suggest that exclusive dependence on ψ50 would have misdirected our assessments of M. eminii's drought stress vulnerability. Hydraulic capacitance linked to anatomy and leaf-water relocation behaviour was equally important to better understand M. eminii's drought survival strategies. Because our study was conducted on branches of 3-year-old greenhouse-grown M. eminii seedlings, the findings cannot be simply extrapolated to adult M. eminii trees or their mature wood, because structural and physiological plant properties change with age. The techniques and methodological framework used in this study are, however, transferable to other species regardless of age.
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Affiliation(s)
- Jackie Epila
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
- CAVElab Computational & Applied Vegetation Ecology, Department of Applied Ecology and Environmental Biology, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - Niels J F De Baerdemaeker
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000Ghent, Belgium
| | - Lidewei L Vergeynst
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000Ghent, Belgium
| | - Wouter H Maes
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
- Remote Sensing, University of Technology Sydney (UTS), 745 Harris Str., Broadway 2007, NSW, Australia
| | - Hans Beeckman
- Laboratory for Wood Biology and Xylarium (Royal Museum for Central Africa), Leuvensesteenweg 13, B-3080 Tervuren, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000Ghent, Belgium
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Matheny AM, Mirfenderesgi G, Bohrer G. Trait-based representation of hydrological functional properties of plants in weather and ecosystem models. PLANT DIVERSITY 2017; 39:1-12. [PMID: 30159486 PMCID: PMC6112282 DOI: 10.1016/j.pld.2016.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 10/03/2016] [Accepted: 10/08/2016] [Indexed: 05/14/2023]
Abstract
Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types (PFTs) and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.
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Affiliation(s)
- Ashley M. Matheny
- Department of Civil, Environmental, and Geodetic Engineering, The Ohio State University, Columbus, OH, USA
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25
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Johnson DM, Wortemann R, McCulloh KA, Jordan-Meille L, Ward E, Warren JM, Palmroth S, Domec JC. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species. TREE PHYSIOLOGY 2016; 36:983-93. [PMID: 27146334 DOI: 10.1093/treephys/tpw031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/15/2016] [Indexed: 05/05/2023]
Abstract
Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better understand strategies of plant drought tolerance and the critical control points within the hydraulic pathway.
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Affiliation(s)
- Daniel M Johnson
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, 875 Perimeter Drive MS1133, Moscow, ID 83844, USA
| | - Remi Wortemann
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | | | | | - Eric Ward
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27607, USA
| | - Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sari Palmroth
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Jean-Christophe Domec
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA Bordeaux Sciences Agro, UMR INRA-ISPA 1391, 33195 Gradignan, France
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26
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Jupa R, Plavcová L, Gloser V, Jansen S. Linking xylem water storage with anatomical parameters in five temperate tree species. TREE PHYSIOLOGY 2016; 36:756-69. [PMID: 27083523 DOI: 10.1093/treephys/tpw020] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 02/28/2016] [Indexed: 05/26/2023]
Abstract
The release of water from storage compartments to the transpiration stream is an important functional mechanism that provides the buffering of sudden fluctuations in water potential. The ability of tissues to release water per change in water potential, referred to as hydraulic capacitance, is assumed to be associated with the anatomy of storage tissues. However, information about how specific anatomical parameters determine capacitance is limited. In this study, we measured sapwood capacitance (C) in terminal branches and roots of five temperate tree species (Fagus sylvatica L., Picea abies L., Quercus robur L., Robinia pseudoacacia L., Tilia cordata Mill.). Capacitance was calculated separately for water released mainly from capillary (CI; open vessels, tracheids, fibres, intercellular spaces and cracks) and elastic storage compartments (CII; living parenchyma cells), corresponding to two distinct phases of the moisture release curve. We found that C was generally higher in roots than branches, with CI being 3-11 times higher than CII Sapwood density and the ratio of dead to living xylem cells were most closely correlated with C In addition, the magnitude of CI was strongly correlated with fibre/tracheid lumen area, whereas CII was highly dependent on the thickness of axial parenchyma cell walls. Our results indicate that water released from capillary compartments predominates over water released from elastic storage in both branches and roots, suggesting the limited importance of parenchyma cells for water storage in juvenile xylem of temperate tree species. Contrary to intact organs, water released from open conduits in our small wood samples significantly increased CI at relatively high water potentials. Linking anatomical parameters with the hydraulic capacitance of a tissue contributes to a better understanding of water release mechanisms and their implications for plant hydraulics.
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Affiliation(s)
- Radek Jupa
- Faculty of Science, Department of Experimental Biology, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Lenka Plavcová
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 890 81 Ulm, Germany Faculty of Science, Department of Experimental Plant Biology, Charles University, Viničná 5, 128 44 Prague, Czech Republic
| | - Vít Gloser
- Faculty of Science, Department of Experimental Biology, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 890 81 Ulm, Germany
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Affiliation(s)
- Shi‐Dan Zhu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
- Guangdong Provincial Key Laboratory of Applied Botany South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
| | - Hui Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
- Guangdong Provincial Key Laboratory of Applied Botany South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
| | - Qiu‐Yuan Xu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
- University of Chinese Academy of Sciences Yuquan Road 19A Beijing 100049 China
| | - Kun‐Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources College of Forestry Guangxi University Nanning 530004 GuangxiChina
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
- Guangdong Provincial Key Laboratory of Applied Botany South China Botanical Garden Chinese Academy of Sciences Xingke Road 723, Tianhe District Guangzhou 510650 GuangdongChina
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28
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29
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Knipfer T, Brodersen CR, Zedan A, Kluepfel DA, McElrone AJ. Patterns of drought-induced embolism formation and spread in living walnut saplings visualized using X-ray microtomography. TREE PHYSIOLOGY 2015; 35:744-55. [PMID: 26063708 DOI: 10.1093/treephys/tpv040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/27/2015] [Indexed: 05/23/2023]
Abstract
Embolism formation and spread are dependent on conduit structure and xylem network connectivity. Detailed spatial analysis has been limited due to a lack of non-destructive methods to visualize these processes in living plants. We used synchrotron X-ray computed tomography (microCT) to visualize these processes in vivo for Juglans microcarpa Berl. saplings subjected to drought, and also evaluated embolism repair capability after re-watering. Cavitation was not detected in vivo until stem water potentials (Ψ(stem)) reached -2.2 MPa, and loss of stem hydraulic conductivity as derived from microCT images predicted that 50% of conductivity was lost at Ψ(stem) of ∼ -3.5 MPa; xylem vulnerability as determined with the centrifuge method was comparable only in the range of Ψ(stem) from -2.5 to -3.5 MPa. MicroCT images showed that cavitation appeared initially in isolated vessels not connected to other air-filled conduits. Once embolized vessels were present, multiple vessels in close proximity cavitated, and 3-D analysis along the stem axis revealed some connections between cavitated vessels. A tomography-derived automated xylem network analysis found that only 36% of vessels had one or more connections to other vessels. Cavitation susceptibility was related to vessel diameter, with large diameter vessels (>40 μm, mean diameter 25-30 μm) cavitating mainly under moderate stress (Ψ(stem) > -3 MPa) and small diameter vessels (<30 μm) under severe stress. After re-watering there was no evidence for short or longer term vessel refilling over 2 weeks despite a rapid recovery of plant water status. The low embolism susceptibility in 1-year-old J. microcarpa may aid sapling survival during establishment.
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Affiliation(s)
- Thorsten Knipfer
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT 06511, USA
| | - Amr Zedan
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - Daniel A Kluepfel
- US Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA US Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
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30
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Huang Y, Lechowicz MJ, Price CA, Li L, Wang Y, Zhou D. The underlying basis for the trade‐off between leaf size and leafing intensity. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12491] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yingxin Huang
- Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China
| | - Martin J. Lechowicz
- Biology Department McGill University 1205 Dr. Penfield Avenue Montreal H3A 1B1 Canada
| | - Charles A. Price
- School of Plant Biology University of Western Australia Crawley Perth 6009 Australia
| | - Lei Li
- Center for Watershed Ecology Institute of Life Science Nanchang University Nanchang 330031 China
| | - Ying Wang
- Key Laboratory of Songliao Aquatic Environment Ministry of Education Jilin Jianzhu University Changchun 130118 China
| | - Daowei Zhou
- Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China
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31
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Law BE. Regional analysis of drought and heat impacts on forests: current and future science directions. GLOBAL CHANGE BIOLOGY 2014; 20:3595-3599. [PMID: 24909650 DOI: 10.1111/gcb.12651] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/06/2014] [Indexed: 06/03/2023]
Abstract
Accurate assessments of forest response to current and future climate and human actions are needed at regional scales. Predicting future impacts on forests will require improved analysis of species-level adaptation, resilience, and vulnerability to mortality. Land system models can be enhanced by creating trait-based groupings of species that better represent climate sensitivity, such as risk of hydraulic failure from drought. This emphasizes the need for more coordinated in situ and remote sensing observations to track changes in ecosystem function, and to improve model inputs, spatio-temporal diagnosis, and predictions of future conditions, including implications of actions to mitigate climate change.
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Affiliation(s)
- Beverly E Law
- Oregon State University, 328 Richardson Hall, Corvallis, OR, 97331-5752, USA
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32
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Moser G, Schuldt B, Hertel D, Horna V, Coners H, Barus H, Leuschner C. Replicated throughfall exclusion experiment in an Indonesian perhumid rainforest: wood production, litter fall and fine root growth under simulated drought. GLOBAL CHANGE BIOLOGY 2014; 20:1481-97. [PMID: 24115242 DOI: 10.1111/gcb.12424] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 08/28/2013] [Indexed: 05/25/2023]
Abstract
Climate change scenarios predict increases in the frequency and duration of ENSO-related droughts for parts of South-East Asia until the end of this century exposing the remaining rainforests to increasing drought risk. A pan-tropical review of recorded drought-related tree mortalities in more than 100 monitoring plots before, during and after drought events suggested a higher drought-vulnerability of trees in South-East Asian than in Amazonian forests. Here, we present the results of a replicated (n = 3 plots) throughfall exclusion experiment in a perhumid tropical rainforest in Sulawesi, Indonesia. In this first large-scale roof experiment outside semihumid eastern Amazonia, 60% of the throughfall was displaced during the first 8 months and 80% during the subsequent 17 months, exposing the forest to severe soil desiccation for about 17 months. In the experiment's second year, wood production decreased on average by 40% with largely different responses of the tree families (ranging from -100 to +100% change). Most sensitive were trees with high radial growth rates under moist conditions. In contrast, tree height was only a secondary factor and wood specific gravity had no influence on growth sensitivity. Fine root biomass was reduced by 35% after 25 months of soil desiccation while fine root necromass increased by 250% indicating elevated fine root mortality. Cumulative aboveground litter production was not significantly reduced in this period. The trees from this Indonesian perhumid rainforest revealed similar responses of wood and litter production and root dynamics as those in two semihumid Amazonian forests subjected to experimental drought. We conclude that trees from paleo- or neotropical forests growing in semihumid or perhumid climates may not differ systematically in their growth sensitivity and vitality under sublethal drought stress. Drought vulnerability may depend more on stem cambial activity in moist periods than on tree height or wood specific gravity.
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Affiliation(s)
- Gerald Moser
- Plant Ecology, University of Giessen, Heinrich-Buff-Ring 26-29, 35392, Giessen, Germany; Plant Ecology and Ecosystems Research, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
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Richards AE, Wright IJ, Lenz TI, Zanne AE. Sapwood capacitance is greater in evergreen sclerophyll species growing in high compared to low‐rainfall environments. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12193] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anna E. Richards
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Ian J. Wright
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Tanja I. Lenz
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Amy E. Zanne
- Department of Biological Sciences George Washington University Washington District of Columbia 20052 USA
- Center for Conservation and Sustainable Development Missouri Botanical GardenSt. Louis Missouri 63166 USA
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Carnicer J, Barbeta A, Sperlich D, Coll M, Peñuelas J. Contrasting trait syndromes in angiosperms and conifers are associated with different responses of tree growth to temperature on a large scale. FRONTIERS IN PLANT SCIENCE 2013; 4:409. [PMID: 24146668 PMCID: PMC3797994 DOI: 10.3389/fpls.2013.00409] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/26/2013] [Indexed: 05/18/2023]
Abstract
Recent large-scale studies of tree growth in the Iberian Peninsula reported contrasting positive and negative effects of temperature in Mediterranean angiosperms and conifers. Here we review the different hypotheses that may explain these trends and propose that the observed contrasting responses of tree growth to temperature in this region could be associated with a continuum of trait differences between angiosperms and conifers. Angiosperm and conifer trees differ in the effects of phenology in their productivity, in their growth allometry, and in their sensitivity to competition. Moreover, angiosperms and conifers significantly differ in hydraulic safety margins, sensitivity of stomatal conductance to vapor-pressure deficit (VPD), xylem recovery capacity or the rate of carbon transfer. These differences could be explained by key features of the xylem such as non-structural carbohydrate content (NSC), wood parenchymal fraction or wood capacitance. We suggest that the reviewed trait differences define two contrasting ecophysiological strategies that may determine qualitatively different growth responses to increased temperature and drought. Improved reciprocal common garden experiments along altitudinal or latitudinal gradients would be key to quantify the relative importance of the different hypotheses reviewed. Finally, we show that warming impacts in this area occur in an ecological context characterized by the advance of forest succession and increased dominance of angiosperm trees over extensive areas. In this context, we examined the empirical relationships between the responses of tree growth to temperature and hydraulic safety margins in angiosperm and coniferous trees. Our findings suggest a future scenario in Mediterranean forests characterized by contrasting demographic responses in conifer and angiosperm trees to both temperature and forest succession, with increased dominance of angiosperm trees, and particularly negative impacts in pines.
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Affiliation(s)
- Jofre Carnicer
- Community and Conservation Ecology Group, Centre for Ecological and Evolutionary Studies, University of GroningenGroningen, Netherlands
- CREAFBarcelona, Spain
- Global Ecology Unit, Consejo Superior de Investigaciones Científicas, CREAF-CEAB-CSIC-UABBarcelona, Spain
| | - Adrià Barbeta
- CREAFBarcelona, Spain
- Global Ecology Unit, Consejo Superior de Investigaciones Científicas, CREAF-CEAB-CSIC-UABBarcelona, Spain
| | - Dominik Sperlich
- CREAFBarcelona, Spain
- Global Ecology Unit, Consejo Superior de Investigaciones Científicas, CREAF-CEAB-CSIC-UABBarcelona, Spain
- Department of Ecology, University of BarcelonaBarcelona, Spain
| | - Marta Coll
- CREAFBarcelona, Spain
- Global Ecology Unit, Consejo Superior de Investigaciones Científicas, CREAF-CEAB-CSIC-UABBarcelona, Spain
| | - Josep Peñuelas
- CREAFBarcelona, Spain
- Global Ecology Unit, Consejo Superior de Investigaciones Científicas, CREAF-CEAB-CSIC-UABBarcelona, Spain
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35
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Rowland L, Malhi Y, Silva-Espejo JE, Farfán-Amézquita F, Halladay K, Doughty CE, Meir P, Phillips OL. The sensitivity of wood production to seasonal and interannual variations in climate in a lowland Amazonian rainforest. Oecologia 2013; 174:295-306. [PMID: 24026500 DOI: 10.1007/s00442-013-2766-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022]
Abstract
Understanding climatic controls on tropical forest productivity is key to developing more reliable models for predicting how tropical biomes may respond to climate change. Currently there is no consensus on which factors control seasonal changes in tropical forest tree growth. This study reports the first comprehensive plot-level description of the seasonality of growth in a Peruvian tropical forest. We test whether seasonal and interannual variations in climate are correlated with changes in biomass increment, and whether such relationships differ among trees with different functional traits. We found that biomass increments, measured every 3 months on the two plots, were reduced by between 40 and 55% in the peak dry season (July-September) relative to peak wet season (January-March). The seasonal patterns of biomass accumulation are significantly (p < 0.01) associated with seasonal patterns of rainfall and soil water content; however, this may reflect a synchrony of seasonal cycles rather than direct physiological controls on tree growth rates. The strength of the growth seasonality response among trees is significantly correlated to functional traits: consistent with a hypothesised trade-off between maximum potential growth rate and hydraulic safety, tall and fast-growing trees with broad stems had the most strongly seasonal biomass accumulation, suggesting that they are more productive in the wet season, but more vulnerable to water limitation in the dry season.
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Affiliation(s)
- Lucy Rowland
- School of Geosciences, The University of Edinburgh, Edinburgh, UK,
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36
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Zhu SD, Song JJ, Li RH, Ye Q. Plant hydraulics and photosynthesis of 34 woody species from different successional stages of subtropical forests. PLANT, CELL & ENVIRONMENT 2013; 36:879-91. [PMID: 23057774 DOI: 10.1111/pce.12024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
It is important to understand the ecophysiological characters of plants when exploring mechanisms underlying species substitution in the process of plant succession. In the present study, we selected 34 woody species from different stages of secondary succession in subtropical forests of southern China, and measured their hydraulic conductivity, gas exchange rates, leaf nutrients and drought-tolerance traits such as xylem resistance to cavitation, turgor loss point and carbon isotope ratio. Principal component analysis revealed that early-, mid- and late-successional species were significantly separated along axis 1, which was strongly associated with hydraulic-photosynthetic coordination. In contrast to species distributed in late-successional forest, early-successional species had the highest hydraulic conductivity, net photosynthetic rates, photosynthetic nitrogen and phosphorus use efficiencies, but had the lowest photosynthetic water-use efficiency. However, changes of the measured drought-tolerance traits of the 34 species along the succession did not demonstrate a clear trend - no significant correlations between these traits and plant successional stages were found. Moreover, the trade-off between hydraulic efficiency and safety was not identified. Taken together, our results suggested that hydraulic efficiency and photosynthetic function, rather than drought tolerance, play an important role in species distributions along plant succession in subtropical forests.
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Affiliation(s)
- Shi-Dan Zhu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
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37
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Plavcová L, Hacke UG. Phenotypic and developmental plasticity of xylem in hybrid poplar saplings subjected to experimental drought, nitrogen fertilization, and shading. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:6481-91. [PMID: 23095999 PMCID: PMC3504499 DOI: 10.1093/jxb/ers303] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Variation in xylem structure and function has been extensively studied across different species with a wide taxonomic, geographical, and ecological coverage. In contrast, our understanding of how xylem of a single species can adjust to different growing condition remains limited. Here phenotypic and developmental plasticity in xylem traits of hybrid poplar (Populus trichocarpa×deltoides) was studied. Clonally propagated saplings were grown under experimental drought, nitrogen fertilization, and shade for >30 d. Xylem hydraulic and anatomical traits were subsequently examined in stem segments taken from two different vertical positions along the plant's main axis. The experimental treatments affected growth and development and induced changes in xylem phenotype. Across all treatments, the amount of leaf area supported by stem segments (A(L)) scaled linearly with stem native hydraulic conductivity (K (native)), suggesting that the area of assimilating leaves is constrained by the xylem transport capacity. In turn, K (native) was mainly driven by the size of xylem cross-sectional area (A(X)). Moreover, the structural and functional properties of xylem varied significantly. Vulnerability to cavitation, measured as the xylem pressure inducing 50% loss of conductivity (P50), ranged from -1.71 MPa to -0.15 MPa in saplings subjected to drought and nitrogen fertilization, respectively. Across all treatments and stem segment positions, P50 was tightly correlated with wood density. In contrast, no relationship between P50 and xylem-specific conductivity (K (S)) was observed. The results of this study enhance our knowledge of plant hydraulic acclimation and provide insights into common trade-offs that exist in xylem structure and function.
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Affiliation(s)
- Lenka Plavcová
- University of Alberta, Department of Renewable Resources, 4-42 Earth Sciences Building, Edmonton, AB, Canada, T6G 2E3.
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Johnson DM, McCulloh KA, Woodruff DR, Meinzer FC. Hydraulic safety margins and embolism reversal in stems and leaves: why are conifers and angiosperms so different? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 195:48-53. [PMID: 22920998 DOI: 10.1016/j.plantsci.2012.06.010] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 05/05/2023]
Abstract
Angiosperm and coniferous tree species utilize a continuum of hydraulic strategies. Hydraulic safety margins (defined as differences between naturally occurring xylem pressures and pressures that would cause hydraulic dysfunction, or differences between pressures resulting in loss of hydraulic function in adjacent organs (e.g., stems vs. leaves) tend to be much greater in conifers than angiosperms and serve to prevent stem embolism. However, conifers tend to experience embolism more frequently in leaves and roots than angiosperms. Embolism repair is thought to occur by active transport of sugars into empty conduits followed by passive water movement. The most likely source of sugar for refilling is from nonstructural carbohydrate depolymerization in nearby parenchyma cells. Compared to angiosperms, conifers tend to have little parenchyma or nonstructural carbohydrates in their wood. The ability to rapidly repair embolisms may rely on having nearby parenchyma cells, which could explain the need for greater safety margins in conifer wood as compared to angiosperms. The frequent embolisms that occur in the distal portions of conifers are readily repaired, perhaps due to the abundant parenchyma in leaves and roots, and these distal tissues may act as hydraulic circuit breakers that prevent tension-induced embolisms in the attached stems. Frequent embolisms in conifer leaves may also be due to weaker stomatal response to changes in ambient humidity. Although there is a continuum of hydraulic strategies among woody plants, there appear to be two distinct 'behaviors' at the extremes: (1) embolism prevention and (2) embolism occurrence and subsequent repair.
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Affiliation(s)
- Daniel M Johnson
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
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