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Nieves DJ, Reich PB, Stefanski A, Bermudez R, Beidler KV, Kennedy PG. Ectomycorrhizal fungal community response to warming and rainfall reduction differs between co-occurring temperate-boreal ecotonal Pinus saplings. MYCORRHIZA 2024:10.1007/s00572-024-01169-1. [PMID: 39382647 DOI: 10.1007/s00572-024-01169-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 09/25/2024] [Indexed: 10/10/2024]
Abstract
Understanding the responses of ectomycorrhizal (ECM) fungi and their tree hosts to warming and reduced soil water availability under realistic future climate scenarios is essential, yet few studies have investigated how combined global change stressors impact ECM fungal community richness and composition as well as host performance. In this study, we leveraged a long-term factorial warming (ambient, + 1.7 ºC, + 3.2 ºC) and rainfall reduction (ambient, 30% reduced rainfall) experiment in northern Minnesota, USA to investigate the responses of two congeneric hosts with varying drought tolerances and their associated ECM fungal communities to a gradient of soil moisture induced by a combination of warming and rainfall reduction. Soil drying had host-specific effects; the less drought tolerant Pinus strobus had decreased stem growth and lower ECM fungal community richness (fewer ECM fungal Operational Taxonomic Units, OTUs), while the more drought tolerant Pinus banksiana experienced no decline in stem growth but had an altered ECM fungal community composition under drier, warmer soils. Taken together, the results of this study suggest that the combined effects of warming and decreased precipitation will largely be additive in terms of their impact on host performance and ECM fungal community richness, but that drier and warmer soil conditions may also differentially impact specific ECM fungal genera independently of host performance.
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Affiliation(s)
- Dyonishia J Nieves
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN, USA
- Institute for Global Change Biology, School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, St. Paul, MN, USA
| | - Raimundo Bermudez
- Department of Forest Resources, University of Minnesota, St. Paul, MN, USA
| | - Katilyn V Beidler
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Ave, St. Paul, MN, 55108, USA
| | - Peter G Kennedy
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Ave, St. Paul, MN, 55108, USA.
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2
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Salomón RL, Camarero JJ. Stem Growth and Dehydration Responses of Mediterranean Tree Species to Atmospheric and Soil Drought. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39363554 DOI: 10.1111/pce.15177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 08/21/2024] [Accepted: 09/13/2024] [Indexed: 10/05/2024]
Abstract
Stem growth responses to soil and atmospheric drought are critical to forecasting the tree carbon sink strength. Yet, responses of drought-prone forests remain uncertain despite global aridification trends. Stem diameter variations at an hourly resolution were monitored in five Mediterranean tree species from a mesic and a xeric site for 6 and 12 years. Stem growth and dehydration responses to soil (REW) and atmospheric (VPD) drought were explored at different timescales. Annually, growth was determined by the number of growing days and hours. Seasonally, growth was bimodal (autumn growth ≈ 8%-18% of annual growth), varying among species and sites across the hydrometeorological space, while dehydration consistently responded to REW. Sub-daily, substantial growth occurred during daytime, with nighttime-to-daytime ratios ranging between 1.2 and 3.5 (Arbutus unedo ≈ Quercus faginea < Quercus ilex < Pinus halepensis in the mesic site, and Juniperus thurifera < P. halepensis in the xeric site). Overall, time windows favourable for growth were limited by soil (rather than atmospheric) drought, modulating annual and seasonal growth in Mediterranean species, and stems maintained non-negligible growth during daytime. These patterns contrast with observations from wetter or cooler biomes, demonstrating the growth plasticity of drought-prone species to more arid climate conditions.
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Affiliation(s)
- Roberto L Salomón
- Departamento de Sistemas y Recursos Naturales, Research Group FORESCENT, Universidad Politécnica de Madrid, Madrid, Spain
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3
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Restrepo-Acevedo AM, Guo JS, Kannenberg SA, Benson MC, Beverly D, Diaz R, Anderegg WRL, Johnson DM, Koch G, Konings AG, Lowman LEL, Martínez-Vilalta J, Poyatos R, Schenk HJ, Matheny AM, McCulloh KA, Nippert JB, Oliveira RS, Novick K. PSInet: a new global water potential network. TREE PHYSIOLOGY 2024; 44:tpae110. [PMID: 39190893 PMCID: PMC11447379 DOI: 10.1093/treephys/tpae110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 07/02/2024] [Accepted: 08/26/2024] [Indexed: 08/29/2024]
Abstract
Given the pressing challenges posed by climate change, it is crucial to develop a deeper understanding of the impacts of escalating drought and heat stress on terrestrial ecosystems and the vital services they offer. Soil and plant water potential play a pivotal role in governing the dynamics of water within ecosystems and exert direct control over plant function and mortality risk during periods of ecological stress. However, existing observations of water potential suffer from significant limitations, including their sporadic and discontinuous nature, inconsistent representation of relevant spatio-temporal scales and numerous methodological challenges. These limitations hinder the comprehensive and synthetic research needed to enhance our conceptual understanding and predictive models of plant function and survival under limited moisture availability. In this article, we present PSInet (PSI-for the Greek letter Ψ used to denote water potential), a novel collaborative network of researchers and data, designed to bridge the current critical information gap in water potential data. The primary objectives of PSInet are as follows. (i) Establishing the first openly accessible global database for time series of plant and soil water potential measurements, while providing important linkages with other relevant observation networks. (ii) Fostering an inclusive and diverse collaborative environment for all scientists studying water potential in various stages of their careers. (iii) Standardizing methodologies, processing and interpretation of water potential data through the engagement of a global community of scientists, facilitated by the dissemination of standardized protocols, best practices and early career training opportunities. (iv) Facilitating the use of the PSInet database for synthesizing knowledge and addressing prominent gaps in our understanding of plants' physiological responses to various environmental stressors. The PSInet initiative is integral to meeting the fundamental research challenge of discerning which plant species will thrive and which will be vulnerable in a world undergoing rapid warming and increasing aridification.
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Affiliation(s)
- Ana Maria Restrepo-Acevedo
- O'Neill School of Public & Environmental Affairs, Indiana University Bloomington, 702 N Walnut Grove St, Bloomington, IN 47405, USA
- Department of Biology, West Virginia University, Morgantown, VA 26506, USA
| | - Jessica S Guo
- Arizona Experiment Station, University of Arizona, 1140 E. South Campus Dr., Tucson, AZ 85721, USA
| | | | - Michael C Benson
- O'Neill School of Public & Environmental Affairs, Indiana University Bloomington, 702 N Walnut Grove St, Bloomington, IN 47405, USA
| | - Daniel Beverly
- O'Neill School of Public & Environmental Affairs, Indiana University Bloomington, 702 N Walnut Grove St, Bloomington, IN 47405, USA
| | - Renata Diaz
- Arizona Experiment Station, University of Arizona, 1140 E. South Campus Dr., Tucson, AZ 85721, USA
| | - William R L Anderegg
- School of Biological Sciences and Wilkes Center for Climate Science and Policy, University of Utah, Salt Lake City, UT 84112, USA
| | - Daniel M Johnson
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
| | - George Koch
- Center for Ecosystem Science and Society & Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Alexandra G Konings
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
| | - Lauren E L Lowman
- Department of Engineering, Wake Forest University, Winston-Salem, NC 27101, USA
| | - Jordi Martínez-Vilalta
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Rafael Poyatos
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - H Jochen Schenk
- Department of Biological Science, California State University, Fullerton, CA 92831, USA
| | - Ashley M Matheny
- Department of Earth and Planetary Sciences, Jackson School of Geological Sciences, University of Texas at Austin, Austin, TX 98705, USA
| | | | - Jesse B Nippert
- Division of Biology, Kansas State University, Manhattan, KA 66506, USA
| | - Rafael S Oliveira
- Department of Plant Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Kimberly Novick
- O'Neill School of Public & Environmental Affairs, Indiana University Bloomington, 702 N Walnut Grove St, Bloomington, IN 47405, USA
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Huang X, Hou ZL, Ma BL, Zhao H, Jiang ZM, Cai J. Seasonality in embolism resistance and hydraulic capacitance jointly mediate hydraulic safety in branches and leaves of oriental cork oak (Quercus variabilis Bl.). TREE PHYSIOLOGY 2024; 44:tpae109. [PMID: 39216110 DOI: 10.1093/treephys/tpae109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 05/31/2024] [Accepted: 08/29/2024] [Indexed: 09/04/2024]
Abstract
Seasonality in temperate regions is prominent during the era of increased climatic variability. A hydraulic trait that can adjust to seasonally changing climatic conditions is crucial for tree safety. However, little attention has been paid to the intraspecific seasonality of drought-related traits and hydraulic safety of keystone forest trees. We examined seasonal variations in the key morphological and physiological traits as well as multiple hydraulic safety margins (SMs) at the branch and leaf levels in oriental cork oak (Quercus variabilis Bl.), which is predominant in Chinese temperate forests. Pneumatic measurements indicated that, as seasons progressed, the water potential at which 50% of branch embolisms occur (P50_branch) decreased from -3.34 to -4.23 MPa, with a coefficient of variation (CV) of 9.08%. Sapwood capacitance ranged from 48.19 to 248.08 kg m-3 MPa-1, peaking in autumn and reaching minimum in winter (CV 60.58%). Rehydration kinetics confirmed higher leaf embolism vulnerability (P50_leaf) in spring and autumn than those in summer, with values ranging from -1.06 to -3.02 MPa (CV 39.85%). All leaf pressure-volume (PV) traits shifted with growth, with CVs ranging from 6.95% to 46.69%. Sapwood density had significant negative correlations with P50_branch and hydraulic capacitance for elastic water storage, whereas leaf mass per area was linearly associated with PV traits but not with P50_leaf. Furthermore, the branch typical SMs (difference between branch midday water potential and P50_branch) were consistently >1.84 MPa, and vulnerability segmentation was prevalent throughout, implying a plausible hydraulic foundation for the dominance of Q. variabilis. Diverse hydraulic response patterns existed across seasons, leading to positive SMs mediated by the aforementioned physiological traits. Although Q. variabilis exhibits a high level of hydraulic safety, its susceptibility to sudden summer droughts may increase due to global climate change.
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Affiliation(s)
- Xin Huang
- College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
| | - Zhuo-Liang Hou
- College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
| | - Bo-Long Ma
- College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
| | - Han Zhao
- College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
| | - Zai-Min Jiang
- College of Life, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
- Qinling National Forest Ecosystem Research Station, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
| | - Jing Cai
- College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
- Qinling National Forest Ecosystem Research Station, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China
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5
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Piña I, Garrido-Salinas M, Seguel O, Opazo I, Faúndez-Urbina C, Verdugo-Vásquez N, Villalobos-Soublett E. Coordination between water relations strategy and carbon investment in leaf and stem in six fruit tree species. FUNCTIONAL PLANT BIOLOGY : FPB 2024; 51:FP24008. [PMID: 39222466 DOI: 10.1071/fp24008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 08/02/2024] [Indexed: 09/04/2024]
Abstract
The water relation strategy is a key issue in climate change. Given the difficulty of determining water relations strategy, there is a need for simple traits with a solid theoretical basis to estimate it. Traits associated with resource allocation patterns along a 'fast-slow' plant economics spectrum are particularly compelling, reflecting trade-offs between growth rate and carbon allocation. Avocado (Persea americana ), fig tree (Ficus carica ), mandarin (Citrus reticulata ), olive (Olea europaea ), pomegranate (Punica granatum ), and grapevine (Vitis vinifera ) were characterised in terms of iso-anisohydric strategy through stomatal behaviour, water potential at the turgor loss point (TLP), and hydroscape area. Additionally, the association of these metrics with leaf mass per area (LMA) and wood density (WDen) was explored. We observed high coordination between LMA and WDen, and both traits were related to metrics of water relation strategy. More anisohydric species tended to invest more carbon per unit leaf area or unit stem volume, which has implications for hydraulic efficiency and water stress tolerance. WDen and TLP were the most powerful traits in estimating the water relation strategy for six fruit species. These traits are easy to measure, time-cost efficient, and appear central to coordinating multiple traits and behaviours along the water relations strategies.
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Affiliation(s)
- Ismael Piña
- Programa de Magister en Manejo de Suelo y Aguas, Escuela de Postgrado Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile
| | - Marco Garrido-Salinas
- Departamento de Agronomía, Facultad de Ciencias, Universidad de la Serena, Avenida La Paz 1108, Ovalle 1842646, Chile
| | - Oscar Seguel
- Departamento de Ingeniería y Suelos, Facultad de Ciencias Agronómicas, Universidad de Chile, Avenida Santa Rosa 11315, La Pintana, Santiago 8820808, Chile
| | - Ismael Opazo
- Plant Breeding Laboratory, Centro de Estudios Avanzados en Fruticultura (CEAF), Rengo 2940000, Chile
| | - Carlos Faúndez-Urbina
- Escuela de Agronomía, Facultad de Ciencias Agronómicas y de los Alimentos, Pontificia Universidad Católica de Valparaíso, San Francisco S/N, Quillota 2260000, Chile
| | - Nicolás Verdugo-Vásquez
- Instituto de Investigaciones Agropecuarias, INIA Intihuasi, Colina San Joaquín s/n, La Serena, Chile
| | - Emilio Villalobos-Soublett
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur, Universidad de Chile, Santiago, Chile
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6
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Liu J, Huang J, Peng S, Xiong D. Rewatering after drought: Unravelling the drought thresholds and function recovery-limiting factors in maize leaves. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39205650 DOI: 10.1111/pce.15080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 07/05/2024] [Accepted: 07/30/2024] [Indexed: 09/04/2024]
Abstract
Drought and subsequent rewatering are common in agriculture, where recovery from mild droughts is easier than from severe ones. The specific drought threshold and factors limiting recovery are under-researched. This study subjected maize plants to varying drought degrees before rewatering, and measuring plant water status, gas exchange, hydraulic conductance, hormone levels, and cellular damage throughout. We discovered that stomatal reopening in plants was inhibited with leaf water potentials below about -1.7 MPa, hindering postdrought photosynthetic recovery. Neither hydraulic loss nor abscisic acid (ABA) content was the factor inhibited stomatal reopening on the second day following moderate drought stress and rewatering. But stomatal reopening was significantly correlated to the interaction between hydraulic signals and ABA content under severe drought. Extended drought led to leaf death at about -2.8 MPa or 57% relative water content, influenced by reduced rehydration capacity, not hydraulic failure. The lethal threshold remained relatively constant across leaf stages, but the recoverable safety margin (RSM), that is, the water potential difference between stomatal closure and recovery capacity loss, significantly decreased with leaf aging due to delayed stomatal closure during drought. Our findings indicate hydraulic failure alone does not cause maize leaf death, highlighting the importance of RSM in future research.
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Affiliation(s)
- Junzhou Liu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MARA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jianliang Huang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MARA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shaobing Peng
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MARA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Dongliang Xiong
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MARA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Huazhong Agricultural University, Wuhan, Hubei, China
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7
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Augustine SP, McCulloh KA. Physiological trait coordination and variability across and within three Pinus species. THE NEW PHYTOLOGIST 2024. [PMID: 39205436 DOI: 10.1111/nph.19859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 04/21/2024] [Indexed: 09/04/2024]
Abstract
Studies have explored how traits separate plants ecologically and the trade-offs that underpin this separation. However, uncertainty remains as to the taxonomic scale at which traits can predictably separate species. We studied how physiological traits separated three Pinus (Pinus banksiana, Pinus resinosa, and Pinus strobus) species across three sites. We collected traits from four common leaf and branch measurements (light-response curves, CO2-response curves, pressure-volume curves, and hydraulic vulnerability curves) across each species and site. While common, these measurements are not typically measured together due to logistical constraints. Few traits varied across species and sites as expected given the ecological preferences of the species and environmental site characteristics. Some trait trade-offs present at broad taxonomic scales were observed across the three species, but most were absent within species. Certain trade-offs contrasted expectations observed at broader scales but followed expectations given the species' ecological preferences. We emphasize the need to both clarify why certain traits are being studied, as variation in unexpected but ecologically meaningful ways often occurs and certain traits might not vary substantially within a given lineage (e.g. hydraulic vulnerability in Pinus), highlighting the role a trait selection in trait ecology.
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Affiliation(s)
- Steven P Augustine
- Department of Botany, University of Wisconsin - Madison, Madison, WI, 53706, USA
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, 55108, USA
| | - Katherine A McCulloh
- Department of Botany, University of Wisconsin - Madison, Madison, WI, 53706, USA
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8
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Martius LR, Mencuccini M, Bittencourt PRL, Moraes Alves M, Binks O, Sanchez-Martinez P, da Costa ACL, Meir P. Towards accurate monitoring of water content in woody tissue across tropical forests and other biomes. TREE PHYSIOLOGY 2024; 44:tpae076. [PMID: 38952005 PMCID: PMC11299548 DOI: 10.1093/treephys/tpae076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 06/05/2024] [Accepted: 06/26/2024] [Indexed: 07/03/2024]
Abstract
Forest ecosystems face increasing drought exposure due to climate change, necessitating accurate measurements of vegetation water content to assess drought stress and tree mortality risks. Although Frequency Domain Reflectometry offers a viable method for monitoring stem water content by measuring dielectric permittivity, challenges arise from uncertainties in sensor calibration linked to wood properties and species variability, impeding its wider usage. We sampled tropical forest trees and palms in eastern Amazônia to evaluate how sensor output differences are controlled by wood density, temperature and taxonomic identity. Three individuals per species were felled and cut into segments within a diverse dataset comprising five dicotyledonous tree and three monocotyledonous palm species on a wide range of wood densities. Water content was estimated gravimetrically for each segment using a temporally explicit wet-up/dry-down approach and the relationship with the dielectric permittivity was examined. Woody tissue density had no significant impact on the calibration, but species identity and temperature significantly affected sensor readings. The temperature artefact was quantitatively important at large temperature differences, which may have led to significant bias of daily and seasonal water content dynamics in previous studies. We established the first tropical tree and palm calibration equation which performed well for estimating water content. Notably, we demonstrated that the sensitivity remained consistent across species, enabling the creation of a simplified one-slope calibration for accurate, species-independent measurements of relative water content. Our one-slope calibration serves as a general, species-independent standard calibration for assessing relative water content in woody tissue, offering a valuable tool for quantifying drought responses and stress in trees and forest ecosystems.
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Affiliation(s)
- Lion R Martius
- School of GeoSciences, University of Edinburgh, King's Buildings, Alexander Crum Brown Rd, Edinburgh EH9 3FF, United Kingdom
| | - Maurizio Mencuccini
- CREAF, Campus UAB, Cerdanyola del Vallés 08193, Spain
- ICREA, Barcelona 08193, Spain
| | - Paulo R L Bittencourt
- Geography, College of Life and Environmental Sciences, University of Exeter, Amory Building, Exeter EX4 4RJ, United Kingdom
| | - Moisés Moraes Alves
- Instituto de Geociências, Universidade Federal do Pará, Belém, PA 66075-110, Brazil
| | - Oliver Binks
- CREAF, Campus UAB, Cerdanyola del Vallés 08193, Spain
| | - Pablo Sanchez-Martinez
- School of GeoSciences, University of Edinburgh, King's Buildings, Alexander Crum Brown Rd, Edinburgh EH9 3FF, United Kingdom
| | - Antonio C L da Costa
- Instituto de Geociências, Universidade Federal do Pará, Belém, PA 66075-110, Brazil
- Museu Paraense Emílio Goeldi, Belém, PA 66040-170, Brazil
| | - Patrick Meir
- School of GeoSciences, University of Edinburgh, King's Buildings, Alexander Crum Brown Rd, Edinburgh EH9 3FF, United Kingdom
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Miranda MT, Pires GS, Pereira L, de Lima RF, da Silva SF, Mayer JLS, Azevedo FA, Machado EC, Jansen S, Ribeiro RV. Rootstocks affect the vulnerability to embolism and pit membrane thickness in Citrus scions. PLANT, CELL & ENVIRONMENT 2024; 47:3063-3075. [PMID: 38660960 DOI: 10.1111/pce.14924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 04/26/2024]
Abstract
Embolism resistance of xylem tissue varies among species and is an important trait related to drought resistance, with anatomical attributes like pit membrane thickness playing an important role in avoiding embolism spread. Grafted Citrus trees are commonly grown in orchards, with the rootstock being able to affect the drought resistance of the whole plant. Here, we evaluated how rootstocks affect the vulnerability to embolism resistance of the scion using several rootstock/scion combinations. Scions of 'Tahiti' acid lime, 'Hamlin', 'Pera' and 'Valencia' oranges grafted on a 'Rangpur' lime rootstock exhibit similar vulnerability to embolism. In field-grown trees, measurements of leaf water potential did not suggest significant embolism formation during the dry season, while stomata of Citrus trees presented an isohydric response to declining water availability. When 'Valencia' orange scions were grafted on 'Rangpur' lime, 'IAC 1710' citrandarin, 'Sunki Tropical' mandarin or 'Swingle' citrumelo rootstocks, variation in intervessel pit membrane thickness of the scion was found. The 'Rangpur' lime rootstock, which is known for its drought resistance, induced thicker pit membranes in the scion, resulting in higher embolism resistance than the other rootstocks. Similarly, the rootstock 'IAC 1710' citrandarin generated increased embolism resistance of the scion, which is highly relevant for citriculture.
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Affiliation(s)
- Marcela T Miranda
- Laboratory of Plant Physiology 'Coaracy M. Franco', Center of Agricultural and Post-Harvest Biosystems, Agronomic Institute (IAC), Campinas, SP, Brazil
- Institute of Botany, Ulm University, Ulm, Germany
| | - Gabriel S Pires
- Laboratory of Crop Physiology (LCroP), Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Rodrigo F de Lima
- Laboratory of Plant Anatomy, Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Simone F da Silva
- Laboratory of Crop Physiology (LCroP), Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Juliana L S Mayer
- Laboratory of Plant Anatomy, Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Fernando A Azevedo
- Center of Citriculture Sylvio Moreira, Agronomic Institute (IAC), Cordeirópolis, SP, Brazil
| | - Eduardo C Machado
- Laboratory of Plant Physiology 'Coaracy M. Franco', Center of Agricultural and Post-Harvest Biosystems, Agronomic Institute (IAC), Campinas, SP, Brazil
| | | | - Rafael V Ribeiro
- Laboratory of Crop Physiology (LCroP), Department of Plant Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
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10
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Chhajed SS, Wright IJ, Perez-Priego O. Theory and tests for coordination among hydraulic and photosynthetic traits in co-occurring woody species. THE NEW PHYTOLOGIST 2024. [PMID: 39044658 DOI: 10.1111/nph.19987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 05/30/2024] [Indexed: 07/25/2024]
Abstract
Co-occurring plants show wide variation in their hydraulic and photosynthetic traits. Here, we extended 'least-cost' optimality theory to derive predictions for how variation in key hydraulic traits potentially affects the cost of acquiring and using water in photosynthesis and how this, in turn, should drive variation in photosynthetic traits. We tested these ideas across 18 woody species at a temperate woodland in eastern Australia, focusing on hydraulic traits representing different aspects of plant water balance, that is storage (sapwood capacitance, CS), demand vs supply (branch leaf : sapwood area ratio, AL : AS and leaf : sapwood mass ratio and ML : MS), access to soil water (proxied by predawn leaf water potential, ΨPD) and physical strength (sapwood density, WD). Species with higher AL : AS had higher ratio of leaf-internal to ambient CO2 concentration during photosynthesis (ci : ca), a trait central to the least-cost theory framework. CS and the daily operating range of tissue water potential (∆Ψ) had an interactive effect on ci : ca. CS, WD and ΨPD were significantly correlated with each other. These results, along with those from multivariate analyses, underscored the pivotal role leaf : sapwood allocation (AL : AS), and water storage (CS) play in coordination between plant hydraulic and photosynthetic systems. This study uniquely explored the role of hydraulic traits in predicting species-specific photosynthetic variation based on optimality theory and highlights important mechanistic links within the plant carbon-water balance.
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Affiliation(s)
- Shubham S Chhajed
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
- ARC Centre for Plant Success in Nature & Agriculture, Western Sydney University, Penrith, NSW, 2751, Australia
| | - Ian J Wright
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
- ARC Centre for Plant Success in Nature & Agriculture, Western Sydney University, Penrith, NSW, 2751, Australia
| | - Oscar Perez-Priego
- Department of Forest Engineering, University of Córdoba, Campus de Rabanales, Crta. N-IV km. 396, C.P. 14071, Córdoba, Spain
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11
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Gerolamo CS, Pereira L, Costa FRC, Jansen S, Angyalossy V, Nogueira A. Lianas in tropical dry seasonal forests have a high hydraulic efficiency but not always a higher embolism resistance than lianas in rainforests. ANNALS OF BOTANY 2024; 134:337-350. [PMID: 38721801 PMCID: PMC11232521 DOI: 10.1093/aob/mcae077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 05/07/2024] [Indexed: 07/10/2024]
Abstract
BACKGROUND AND AIMS Lianas have higher relative abundance and biomass in drier seasonal forests than in rainforests, but whether this difference is associated with their hydraulic strategies is unclear. Here, we investigate whether lianas of seasonally dry forests are safer and more efficient in water transport than rainforest lianas, explaining patterns of liana abundance. METHODS We measured hydraulic traits on five pairs of congeneric lianas of the tribe Bignonieae in two contrasting forest sites: the wet 'Dense Ombrophilous Forest' in Central Amazonia (~2 dry months) and the drier 'Semideciduous Seasonal Forest' in the inland Atlantic Forest (~6 dry months). We also gathered a broader database, including 197 trees and 58 liana species from different tropical forests, to compare hydraulic safety between habits and forest types. KEY RESULTS Bignonieae lianas from both forests had high and similar hydraulic efficiency but exhibited variability in resistance to embolism across forest types when phylogenetic relationships were taken into account. Three genera had higher hydraulic safety in the seasonal forest than in the rainforest, but species across both forests had similar positive hydraulic safety margins despite lower predawn water potential values of seasonal forest lianas. We did not find the safety-efficiency trade-off. Merging our results with previously published data revealed a high variability of resistance to embolism in both trees and lianas, independent of forest types. CONCLUSIONS The high hydraulic efficiency of lianas detected here probably favours their rapid growth across tropical forests, but differences in hydraulic safety highlight that some species are highly vulnerable and may rely on other mechanisms to cope with drought. Future research on the lethal dehydration threshold and the connection between hydraulic resistance strategies and liana abundance could offer further insights into tropical forest dynamics under climatic threats.
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Affiliation(s)
- Caian S Gerolamo
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, 05508-090, Brazil
| | - Luciano Pereira
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm D-89081, Germany
| | - Flavia R C Costa
- Instituto Nacional de Pesquisas da Amazônia - INPA, Manaus, AM, 69011-970, Brazil
| | - Steven Jansen
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm D-89081, Germany
| | - Veronica Angyalossy
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, 05508-090, Brazil
| | - Anselmo Nogueira
- Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do ABC, São Bernardo do Campo, SP, 09606-070, Brazil
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12
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Kongjarat W, Han L, Aritsara ANA, Zhang SB, Zhao GJ, Zhang YJ, Maenpuen P, Li YM, Zou YK, Li MY, Li XN, Tao LB, Chen YJ. Hydraulic properties and drought response of a tropical bamboo ( Cephalostachyum pergracile). PLANT DIVERSITY 2024; 46:406-415. [PMID: 38798721 PMCID: PMC11119542 DOI: 10.1016/j.pld.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 05/29/2024]
Abstract
Bamboo plants are an essential component of tropical ecosystems, yet their vulnerability to climate extremes, such as drought, is poorly understood due to limited knowledge of their hydraulic properties. Cephalostachyum pergracile, a commonly used tropical bamboo species, exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019, but the underlying mechanisms remain unclear. This study investigated the leaf and stem hydraulic traits related to drought responses, including leaf-stem embolism resistance (P50leaf; P50stem) estimated using optical and X-ray microtomography methods, leaf pressure-volume and water-releasing curves. Additionally, we investigated the seasonal water potentials, native embolism level (PLC) and xylem water source using stable isotope. We found that C. pergracile exhibited strong resistance to embolism, showing low P50leaf, P50stem, and turgor loss point, despite its rapid leaf water loss. Interestingly, its leaves displayed greater resistance to embolism than its stem, suggesting a lack of effective hydraulic vulnerability segmentation (HVS) to protect the stem from excessive xylem tension. During the dry season, approximately 49% of the water was absorbed from the upper 20-cm-deep soil layer. Consequently, significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87 ± 2.33% in the wet season to 12.87 ± 4.09% in the dry season were observed. In summary, this study demonstrated that the rapid leaf water loss, high reliance on surface water, and a lack of effective HVS in C. pergracile accelerated water depletion and increased xylem embolism even in the typical dry season, which may explain its high mortality rate during extreme drought events in 2019.
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Affiliation(s)
- Wanwalee Kongjarat
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Lu Han
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Amy Ny Aina Aritsara
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Gao-Juan Zhao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, USA
- Climate Change Institute, University of Maine, Orono, ME 04469, USA
| | - Phisamai Maenpuen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Mei Li
- School of Biological and Chemical Science, Pu’er University, Xueyuan Road, Yunnan 665000, China
| | - Yi-Ke Zou
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ming-Yi Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Xue-Nan Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- School of Ecology and Environment, Southwest Forestry University, Kunming, Yunnan 650224, China
| | - Lian-Bin Tao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan 653300, China
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13
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Andriantelomanana T, Améglio T, Delzon S, Cochard H, Herbette S. Unpacking the point of no return under drought in poplar: insight from stem diameter variation. THE NEW PHYTOLOGIST 2024; 242:466-478. [PMID: 38406847 DOI: 10.1111/nph.19615] [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: 11/15/2023] [Accepted: 02/02/2024] [Indexed: 02/27/2024]
Abstract
A specific, robust threshold for drought-induced tree mortality is needed to improve the prediction of forest dieback. Here, we tested the relevance of continuous measurements of stem diameter variations for identifying such a threshold, their relationship with hydraulic and cellular damage mechanisms, and the influence of growth conditions on these relationships. Poplar saplings were grown under well-watered, water-limited, or light-limited conditions and then submitted to a drought followed by rewatering. Stem diameter was continuously measured to investigate two parameters: the percentage loss of diameter (PLD) and the percentage of diameter recovery (DR) following rewatering. Water potentials, stomatal conductance, embolism, and electrolyte leakage were also measured, and light microscopy allowed investigating cell collapse induced by drought. The water release observed through loss of diameter occurred throughout the drought, regardless of growth conditions. Poplars did not recover from drought when PLD reached a threshold and this differed according to growth conditions but remained linked to cell resistance to damage and collapse. Our findings shed new light on the mechanisms of drought-induced tree mortality and indicate that PLD could be a relevant indicator of drought-induced tree mortality, regardless of the growth conditions.
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Affiliation(s)
| | - Thierry Améglio
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, 63000, France
| | - Sylvain Delzon
- Université Bordeaux, INRAE, BIOGECO, Pessac, 33615, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, 63000, France
| | - Stephane Herbette
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, 63000, France
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14
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Beckett HAA, Bryant C, Neeman T, Mencuccini M, Ball MC. Plasticity in branch water relations and stem hydraulic vulnerability enhances hydraulic safety in mangroves growing along a salinity gradient. PLANT, CELL & ENVIRONMENT 2024; 47:854-870. [PMID: 37975319 DOI: 10.1111/pce.14764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/05/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023]
Abstract
Coping with water stress depends on maintaining cellular function and hydraulic conductance. Yet measurements of vulnerability to drought and salinity do not often focus on capacitance in branch organs that buffer hydraulic function during water stress. The relationships between branch water relations, stem hydraulic vulnerability and stem anatomy were investigated in two co-occurring mangroves Aegiceras corniculatum and Rhizophora stylosa growing at low and high salinity. The dynamics of branch water release acted to conserve water content in the stem at the expense of the foliage during extended drying. Hydraulic redistribution from the foliage to the stem increased stem relative water content by up to 21%. The water potentials at which 12% and 50% loss of stem hydraulic conductivity occurred decreased by ~1.7 MPa in both species between low and high salinity sites. These coordinated tissue adjustments increased hydraulic safety despite declining turgor safety margins at higher salinity sites. Our results highlight the complex interplay of plasticity in organ-level water relations with hydraulic vulnerability in the maintenance of stem hydraulic function in mangroves distributed along salinity gradients. These results emphasise the importance of combining water relations and hydraulic vulnerability parameters to understand vulnerability to water stress across the whole plant.
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Affiliation(s)
- Holly A A Beckett
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
| | - Callum Bryant
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
| | - Teresa Neeman
- Biological Data Science Institute, Australian National University, Canberra, Australia
| | - Maurizio Mencuccini
- Ecological and Forestry Applications Research Centre (CREAF), Barcelona, Bellaterra, Spain
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
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15
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Liu YY, Chao L, Li ZG, Ma L, Hu BQ, Zhu SD, Cao KF. Water storage capacity is inversely associated with xylem embolism resistance in tropical karst tree species. TREE PHYSIOLOGY 2024; 44:tpae017. [PMID: 38281245 DOI: 10.1093/treephys/tpae017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/21/2024] [Indexed: 01/30/2024]
Abstract
Tropical karst habitats are characterized by limited and patchy soil, large rocky outcrops and porous substrates, resulting in high habitat heterogeneity and soil moisture fluctuations. Xylem hydraulic efficiency and safety can determine the drought adaptation and spatial distribution of woody plants growing in karst environments. In this study, we measured sapwood-specific hydraulic conductivity (Ks), vulnerability to embolism, wood density, saturated water content, and vessel and pit anatomical characteristics in the branch stems of 12 evergreen tree species in a tropical karst seasonal rainforest in southwestern China. We aimed to characterize the effects of structural characteristics on hydraulic efficiency and safety. Our results showed that there was no significant correlation between Ks and hydraulic safety across the tropical karst woody species. Ks was correlated with hydraulic vessel diameter (r = 0.80, P < 0.05) and vessel density (r = -0.60, P < 0.05), while the stem water potential at 50 and 88% loss of hydraulic conductivity (P50 and P88) were both significantly correlated with wood density (P < 0.05) and saturated water content (P = 0.052 and P < 0.05, respectively). High stem water storage capacity was associated with low cavitation resistance possibly because of its buffering the moisture fluctuations in karst environments. However, both Ks and P50/P88 were decoupled from the anatomical traits of pit and pit membranes. This may explain the lack of tradeoff between hydraulic safety and efficiency in tropical karst evergreen tree species. Our results suggest that diverse hydraulic trait combination may facilitate species coexistence in karst environments with high spatial heterogeneity.
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Affiliation(s)
- Yan-Yan Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, Guangxi, China
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation, Nanning Normal University, Nanning 530001, China
| | - Lin Chao
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation, Nanning Normal University, Nanning 530001, China
| | - Zhong-Guo Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, Guangxi, China
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang 532600, Guangxi, China
| | - Lin Ma
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation, Nanning Normal University, Nanning 530001, China
| | - Bao-Qing Hu
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation, Nanning Normal University, Nanning 530001, China
| | - Shi-Dan Zhu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, Guangxi, China
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, Guangxi, China
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16
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Ávila-Lovera E, Haro R, Choudhary M, Acosta-Rangel A, Pratt RB, Santiago LS. The benefits of woody plant stem photosynthesis extend to hydraulic function and drought survival in Parkinsonia florida. TREE PHYSIOLOGY 2024; 44:tpae013. [PMID: 38284819 PMCID: PMC10918054 DOI: 10.1093/treephys/tpae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/16/2024] [Accepted: 01/21/2024] [Indexed: 01/30/2024]
Abstract
As climate change exacerbates drought stress in many parts of the world, understanding plant physiological mechanisms for drought survival is critical to predicting ecosystem responses. Stem net photosynthesis, which is common in arid environments, may be a drought survival trait, but whether the additional carbon fixed by stems contributes to plant hydraulic function and drought survival in arid land plants is untested. We conducted a stem light-exclusion experiment on saplings of a widespread North American desert tree species, Parkinsonia florida L., and after shading acclimation, we then subjected half of the plants to a drought treatment to test the interaction between light exclusion and water limitation on growth, leaf and stem photosynthetic gas exchange, xylem embolism assessed with micro-computed tomography and gravimetric techniques, and survival. Growth, stem photosynthetic gas exchange, hydraulic function and survival all showed expected reductions in response to light exclusion. However, stem photosynthesis mitigated the drought-induced reductions in gas exchange, xylem embolism (percent loss of conductivity, PLC) and mortality. The highest mortality was in the combined light exclusion and drought treatment, and was related to stem PLC and native sapwood-specific hydraulic conductivity. This research highlights the integration of carbon economy and water transport. Our results show that additional carbon income by photosynthetic stems has an important role in the growth and survival of a widespread desert tree species during drought. This shift in function under conditions of increasing stress underscores the importance of considering stem photosynthesis for predicting drought-induced mortality not only for the additional supply of carbon, but also for its extended benefits for hydraulic function.
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Affiliation(s)
- Eleinis Ávila-Lovera
- School of Biological Sciences, The University of Utah, 257 S 1400 E, Salt Lake City, UT 84112, USA
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama, Republic of Panama
| | - Roxana Haro
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Manika Choudhary
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Aleyda Acosta-Rangel
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - R Brandon Pratt
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - Louis S Santiago
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama, Republic of Panama
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17
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Mas E, Cochard H, Deluigi J, Didion-Gency M, Martin-StPaul N, Morcillo L, Valladares F, Vilagrosa A, Grossiord C. Interactions between beech and oak seedlings can modify the effects of hotter droughts and the onset of hydraulic failure. THE NEW PHYTOLOGIST 2024; 241:1021-1034. [PMID: 37897156 DOI: 10.1111/nph.19358] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023]
Abstract
Mixing species with contrasting resource use strategies could reduce forest vulnerability to extreme events. Yet, how species diversity affects seedling hydraulic responses to heat and drought, including mortality risk, is largely unknown. Using open-top chambers, we assessed how, over several years, species interactions (monocultures vs mixtures) modulate heat and drought impacts on the hydraulic traits of juvenile European beech and pubescent oak. Using modeling, we estimated species interaction effects on timing to drought-induced mortality and the underlying mechanisms driving these impacts. We show that mixtures mitigate adverse heat and drought impacts for oak (less negative leaf water potential, higher stomatal conductance, and delayed stomatal closure) but enhance them for beech (lower water potential and stomatal conductance, narrower leaf safety margins, faster tree mortality). Potential underlying mechanisms include oak's larger canopy and higher transpiration, allowing for quicker exhaustion of soil water in mixtures. Our findings highlight that diversity has the potential to alter the effects of extreme events, which would ensure that some species persist even if others remain sensitive. Among the many processes driving diversity effects, differences in canopy size and transpiration associated with the stomatal regulation strategy seem the primary mechanisms driving mortality vulnerability in mixed seedling plantations.
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Affiliation(s)
- Eugénie Mas
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Janisse Deluigi
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Margaux Didion-Gency
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Nicolas Martin-StPaul
- Unité Ecologie des Forêts Méditerranéennes (UR629), INRAE, DomaineSaint Paul, Site Agroparc, 84914, Avignon Cedex 9, France
| | - Luna Morcillo
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, 03080, Alicante, Spain
| | - Fernando Valladares
- Depto de Biogeografía y Cambio Global, LINCGlobal, Museo Nacional de Ciencias Naturales (MNCN-CSIC), 28006, Madrid, Spain
- Área de Biodiversidad y Conservación, Univ. Rey Juan Carlos, Móstoles, 28933, Madrid, Spain
| | - Alberto Vilagrosa
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, 03080, Alicante, Spain
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory (PERL), School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanne, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
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18
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Li Y, Wang J, Wang L. Seasonal variations in C/N/P/K stoichiometric characteristics in different plant organs in the various forest types of Sygera Mountain. FRONTIERS IN PLANT SCIENCE 2024; 15:1293934. [PMID: 38362445 PMCID: PMC10867192 DOI: 10.3389/fpls.2024.1293934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/18/2024] [Indexed: 02/17/2024]
Abstract
We explored the resource acquisition and growth strategies of plants adapting to different environments, focusing on the typical forest types of Sygera Mountain: Pinus armandii, Picea likiangensis var. Linzhiensis, Abies georgei var. Smithii, and Juniperus saltuaria. Then, we analyzed the nutrient content and stoichiometric ratios of C, N, P, and K in different plant organs (leaves, branches, trunks, and roots) to examine the stoichiometric characteristics and nutrient balance mechanisms in these forests. Results show that within the same forest type, different plant organs exhibit high C and low N, P, and K levels. N content in all organs followed the order leaves > branches > roots > trunks. During the growth phase, the concentrations of P and K in PLL and AGS follow the order branches > leaves > roots > trunks. In the dormant phase, the distribution in different organs had the order leaves > branches > roots > trunks. C content remained relatively stable over time. In the same organ across different forest types, increase in nitrogen content in plant leaves is an active adaptation of JS plants, indicating that JS has a conservative growth strategy and can adapt to environmental stress. Owing to the influence of seasons, the evolution process of N and P content fluctuates, allocating nutrients to supporting and transporting organs for resource optimization and allocation. The N and P content were lower in the growth phase than in the dormant phase. Seasonal variations in the C/N, C/P, and C/K ratios in different forests were inversely correlated with changes in N, P, and K content in plant organs, supporting the "growth rate hypothesis." Stoichiometric analysis suggests that different limiting elements exist in organs across various forest types. Principal component analysis indicates that the seasonal patterns of stoichiometric ratios in the organs of different forest types show species-specific characteristics, reflecting the evolutionary nutrient utilization strategies of plant genera. In summary, plant growth in different Sygera Mountain forest types is limited by N and P, with a high tendency toward nitrogen limitation. The nutrient utilization and distribution differences among various organs during different growth stages are primarily influenced by the limited availability of environmental nutrients and inherent physiological characteristics of the plants.
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Affiliation(s)
- Yueyao Li
- Institute of Tibet Plateau Ecology, Tibet Agricultural & Animal Husbandry University, Nyingchi, China
| | - Jiaxiang Wang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, China
| | - Luqi Wang
- Anhui Agricultural University, Anhui, China
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19
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Tiemuerbieke B, Ma JY, Sun W. Differential eco-physiological performance to declining groundwater depth in Central Asian C 3 and C 4 shrubs in the Gurbantunggut Desert. FRONTIERS IN PLANT SCIENCE 2024; 14:1244555. [PMID: 38312360 PMCID: PMC10835802 DOI: 10.3389/fpls.2023.1244555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 12/22/2023] [Indexed: 02/06/2024]
Abstract
Resources in water-limited ecosystems are highly variable and unpredictable, and the maintenance of functional diversity among coexisting species is a crucial ecological strategy through which plants mitigate environmental stress. The comparison of differential eco-physiological responses among co-occurring plants in harsh environments could help provide deep insights into the coexistence mechanisms of competing species. Two coexisting desert shrubs with different photosynthetic pathways (Haloxylon ammodendron and Tamarix ramosissima) were selected in the Gurbantunggut Desert located in northwest China. This study detected variations in the water sources, photosynthetic parameters, stem water status, and non-structural carbohydrates of the two shrubs at three sites with different groundwater table depths during the growing seasons of 2015 and 2016 to identify distinct eco-physiological performances in coexisting plants with different functional types under fluctuating water conditions. The water sources of H. ammodendron shifted from soil water to groundwater, while T. ramosissima extracted water mainly from deep soil layers at both sites. Significant reductions in carbon assimilation and stomatal conductance in H. ammodendron with deeper groundwater table depth were detected during most drought periods, but no significant decreases in transpiration rate were detected with declining groundwater table depth. For T. ramosissima, all of these gas exchange parameters decreased with the progression of summer drought, and their relative reduction rates were larger compared with those of H. ammodendron. The stem water status of H. ammodendron deteriorated, and the relative reduction rates of water potential increased with deeper groundwater, whereas those of T. ramosissima did not differ with greater groundwater depth. These findings indicated that prolonged drought would intensify the impact of declining groundwater depth on the eco-physiology of both shrubs, but the extent to which the shrubs would respond differed. The two shrubs were segregated along the water-carbon balance continuum: the C3 shrub T. ramosissima maximized its carbon fixation at an enormous cost of water, while greater carbon fixation was achieved with far greater water economy for H. ammodendron. These results demonstrated that the two shrubs prioritized carbon gain and water loss differently when faced with limited water sources. These mechanisms might mitigate competitive stress and enable their coexistence.
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Affiliation(s)
- Bahejiayinaer Tiemuerbieke
- Xinjiang Key Laboratory of Oasis Ecology, College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi, China
| | - Jian-Ying Ma
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Wei Sun
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
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20
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Liu J, Hochberg U, Ding R, Xiong D, Dai Z, Zhao Q, Chen J, Ji S, Kang S. Elevated CO2 concentration increases maize growth under water deficit or soil salinity but with a higher risk of hydraulic failure. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:422-437. [PMID: 37715996 DOI: 10.1093/jxb/erad365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/15/2023] [Indexed: 09/18/2023]
Abstract
Climate change presents a challenge for plants to acclimate their water relations under changing environmental conditions, and may increase the risks of hydraulic failure under stress. In this study, maize plants were acclimated to two different CO2 concentrations ([CO2]; 400 ppm and 700 ppm) while under either water stress (WS) or soil salinity (SS) treatments, and their growth and hydraulic traits were examined in detail. Both WS and SS inhibited growth and had significant impacts on hydraulic traits. In particular, the water potential at 50% loss of stem hydraulic conductance (P50) decreased by 1 MPa in both treatments at 400 ppm. When subjected to elevated [CO2], the plants under both WS and SS showed improved growth by 7-23%. Elevated [CO2] also significantly increased xylem vulnerability (measured as loss of conductivity with decreasing xylem pressure), resulting in smaller hydraulic safety margins. According to the plant desiccation model, the critical desiccation degree (time×vapor pressure deficit) that the plants could tolerate under drought was reduced by 43-64% under elevated [CO2]. In addition, sensitivity analysis showed that P50 was the most important trait in determining the critical desiccation degree. Thus, our results demonstrated that whilst elevated [CO2] benefited plant growth under WS or SS, it also interfered with hydraulic acclimation, thereby potentially placing the plants at a higher risk of hydraulic failure and increased mortality.
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Affiliation(s)
- Junzhou Liu
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Uri Hochberg
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization Volcani Center, Bet Dagan, 7505101, Israel
| | - Risheng Ding
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Dongliang Xiong
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhanwu Dai
- Beijing Key Laboratory of Grape Science and Enology and Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Qing Zhao
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Jinliang Chen
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Shasha Ji
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Shaozhong Kang
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
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21
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Roth-Nebelsick A, Konrad W. Modeling and Analyzing Xylem Vulnerability to Embolism as an Epidemic Process. Methods Mol Biol 2024; 2722:17-34. [PMID: 37897597 DOI: 10.1007/978-1-0716-3477-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
Xylem vulnerability to embolism can be quantified by "vulnerability curves" (VC) that are obtained by subjecting wood samples to increasingly negative water potential and monitoring the progressive loss of hydraulic conductivity. VC are typically sigmoidal, and various approaches are used to fit the experimentally obtained VC data for extracting benchmark data of vulnerability to embolism. In addition to such empirical methods, mechanistic approaches to calculate embolism propagation are epidemic modeling and network theory. Both describe the transmission of "objects" (in this case, the transmission of gas) between interconnected elements. In network theory, a population of interconnected elements is described by graphs in which objects are represented by vertices or nodes and connections between these objections as edges linking the vertices. A graph showing a population of interconnected xylem conduits represents an "individual" wood sample that allows spatial tracking of embolism propagation. In contrast, in epidemic modeling, the transmission dynamics for a population that is subdivided into infection-relevant groups is calculated by an equation system. For this, embolized conduits are considered to be "infected," and the "infection" is the transmission of gas from embolized conduits to their still water-filled neighbors. Both approaches allow for a mechanistic simulation of embolism propagation.
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Affiliation(s)
| | - Wilfried Konrad
- Department of Geosciences, University of Tübingen, Tübingen, Germany.
- Institute of Botany, Technical University of Dresden, Dresden, Germany.
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22
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Preisler Y, Grünzweig JM, Ahiman O, Amer M, Oz I, Feng X, Muller JD, Ruehr N, Rotenberg E, Birami B, Yakir D. Vapour pressure deficit was not a primary limiting factor for gas exchange in an irrigated, mature dryland Aleppo pine forest. PLANT, CELL & ENVIRONMENT 2023; 46:3775-3790. [PMID: 37680062 DOI: 10.1111/pce.14712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/23/2023] [Indexed: 09/09/2023]
Abstract
Climate change is often associated with increasing vapour pressure deficit (VPD) and changes in soil moisture (SM). While atmospheric and soil drying often co-occur, their differential effects on plant functioning and productivity remain uncertain. We investigated the divergent effects and underlying mechanisms of soil and atmospheric drought based on continuous, in situ measurements of branch gas exchange with automated chambers in a mature semiarid Aleppo pine forest. We investigated the response of control trees exposed to combined soil-atmospheric drought (low SM, high VPD) during the rainless Mediterranean summer and that of trees experimentally unconstrained by soil dryness (high SM; using supplementary dry season water supply) but subjected to atmospheric drought (high VPD). During the seasonal dry period, branch conductance (gbr ), transpiration rate (E) and net photosynthesis (Anet ) decreased in low-SM trees but greatly increased in high-SM trees. The response of E and gbr to the massive rise in VPD (to 7 kPa) was negative in low-SM trees and positive in high-SM trees. These observations were consistent with predictions based on a simple plant hydraulic model showing the importance of plant water potential in the gbr and E response to VPD. These results demonstrate that avoiding drought on the supply side (SM) and relying on plant hydraulic regulation constrains the effects of atmospheric drought (VPD) as a stressor on canopy gas exchange in mature pine trees under field conditions.
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Affiliation(s)
- Yakir Preisler
- Department of Earth and Planetary Science, Weizmann Institute of Science, Rehovot, Israel
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - José M Grünzweig
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Ori Ahiman
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- Institute of Soil, Water and Environmental Sciences, ARO Volcani Center, Beit Dagan, Israel
| | - Madi Amer
- Department of Earth and Planetary Science, Weizmann Institute of Science, Rehovot, Israel
| | - Itai Oz
- Department of Earth and Planetary Science, Weizmann Institute of Science, Rehovot, Israel
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Xue Feng
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jonathan D Muller
- Department of Earth and Planetary Science, Weizmann Institute of Science, Rehovot, Israel
- School for Climate Studies, Stellenbosch University, Stellenbosch, South Africa
| | - Nadine Ruehr
- Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), KIT-Campus Alpin, Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany
| | - Eyal Rotenberg
- Department of Earth and Planetary Science, Weizmann Institute of Science, Rehovot, Israel
| | - Benjamin Birami
- Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), KIT-Campus Alpin, Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany
| | - Dan Yakir
- Department of Earth and Planetary Science, Weizmann Institute of Science, Rehovot, Israel
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23
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Paligi SS, Link RM, Isasa E, Bittencourt P, Cabral JS, Jansen S, Oliveira RS, Pereira L, Schuldt B. Assessing the agreement between the pneumatic and the flow-centrifuge method for estimating xylem safety in temperate diffuse-porous tree species. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:1171-1185. [PMID: 37703535 DOI: 10.1111/plb.13573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/06/2023] [Indexed: 09/15/2023]
Abstract
The increasing frequency of global change-type droughts has created a need for fast, accurate and widely applicable techniques for estimating xylem embolism resistance to improve forecasts of future forest changes. We used data from 12 diffuse-porous temperate tree species covering a wide range of xylem safety to compare the pneumatic and flow-centrifuge method, two rapid methods used for constructing xylem vulnerability curves. We evaluated the agreement between parameters estimated with both methods and the sensitivity of pneumatic measurements to the duration of air discharge (AD) measurements. There was close agreement between xylem water potentials at 50% air discharged (PAD), estimated with the Pneumatron, and 50% loss of hydraulic conductivity (PLC), estimated with the flow-centrifuge method (mean signed deviation: 0.12 MPa, Pearson correlation: 0.96 after 15 s of gas extraction). However, the relationship between the estimated slopes was more variable, resulting in lower agreement in the xylem water potential at 12% and 88% PAD/PLC. The agreement between the two methods was not affected by species-specific vessel length distributions. All pneumatic parameters were sensitive to AD time. Overall agreement was highest at relatively short AD times, with an optimum at 16 s. Our results highlight the value of the Pneumatron as an easy and reliable tool to estimate 50% embolism thresholds for a wide range of diffuse-porous temperate angiosperms. Further, our study provides a set of useful metrics for methodological comparisons of vulnerability curves in terms of systematic and random deviations, as well as overall agreement.
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Affiliation(s)
- S S Paligi
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - R M Link
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| | - E Isasa
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - P Bittencourt
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - J S Cabral
- Ecosystem Modeling Group, Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - S Jansen
- Institute of Botany, Ulm University, Ulm, Germany
| | - R S Oliveira
- Department of Plant Biology, Instituto de Biologia, University of Campinas, Campinas, SP, Brazil
| | - L Pereira
- Institute of Botany, Ulm University, Ulm, Germany
| | - B Schuldt
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
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24
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Giardina F, Gentine P, Konings AG, Seneviratne SI, Stocker BD. Diagnosing evapotranspiration responses to water deficit across biomes using deep learning. THE NEW PHYTOLOGIST 2023; 240:968-983. [PMID: 37621238 DOI: 10.1111/nph.19197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/23/2023] [Indexed: 08/26/2023]
Abstract
Accounting for water limitation is key to determining vegetation sensitivity to drought. Quantifying water limitation effects on evapotranspiration (ET) is challenged by the heterogeneity of vegetation types, climate zones and vertically along the rooting zone. Here, we train deep neural networks using flux measurements to study ET responses to progressing drought conditions. We determine a water stress factor (fET) that isolates ET reductions from effects of atmospheric aridity and other covarying drivers. We regress fET against the cumulative water deficit, which reveals the control of whole-column moisture availability. We find a variety of ET responses to water stress. Responses range from rapid declines of fET to 10% of its water-unlimited rate at several savannah and grassland sites, to mild fET reductions in most forests, despite substantial water deficits. Most sensitive responses are found at the most arid and warm sites. A combination of regulation of stomatal and hydraulic conductance and access to belowground water reservoirs, whether in groundwater or deep soil moisture, could explain the different behaviors observed across sites. This variety of responses is not captured by a standard land surface model, likely reflecting simplifications in its representation of belowground water storage.
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Affiliation(s)
- Francesco Giardina
- Institute of Agricultural Sciences, Department of Environmental Systems Science, ETH Zürich, Zürich, CH-8092, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Pierre Gentine
- Department of Earth and Environmental Engineering, Columbia University, New York, NY, 10027, USA
- Center for Learning the Earth with Artificial Intelligence and Physics (LEAP), Columbia University, New York, NY, 10027, USA
| | - Alexandra G Konings
- Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA
| | - Sonia I Seneviratne
- Institute for Atmospheric and Climate Science, Department of Environmental Systems Science, ETH Zurich, Zürich, CH-8092, Switzerland
| | - Benjamin D Stocker
- Institute of Agricultural Sciences, Department of Environmental Systems Science, ETH Zürich, Zürich, CH-8092, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
- Institute of Geography, University of Bern, Hallerstrasse 12, Bern, 3012, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Falkenplatz 16, Bern, 3012, Switzerland
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25
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Ribeiro AT, Teodoro GS, da Silva KC, Pereira-Matos YC, Batista BL, Lobato AKS. 24-Epibrassinolide alleviates drought effects in young Carapa guianensis plants, improving the hydraulic safety margin, gas exchange and antioxidant defence. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:924-934. [PMID: 37549227 DOI: 10.1111/plb.13563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/12/2023] [Indexed: 08/09/2023]
Abstract
Climate change is increasing the frequency of extreme events such as droughts, limiting plant growth and productivity. Exogenous application of plant growth regulators, such as 24-epibrassinolide (EBR), might be a solution as this molecule is organic, eco-friendly, and biodegradable. This is the first research to examine possible roles of EBR on the hydraulic safety margin, physiological behaviour, and metabolism in Carapa guianensis Aubl. (Meliaceae) exposed to drought. C. guianensis is a widely distributed tree in tropical forests of the Amazon. The objective was to determine whether EBR can improve tolerance to water deficit in young C. guianensis by measuring hydraulic traits, nutritional, biochemical and physiological responses, and biomass. The experiment had four randomized treatments: two water conditions (control and water deficit) and two concentrations of EBR (0 and 100 nM EBR). EBR increased the water potential and hydraulic safety margin, increased CO2 fixation, and improved stomatal performance. EBR also stimulated antioxidant defences (SOD, CAT, APX, and POX). Overall, tretreatment with EBR improved drought tolerance of young C. guianensis plants.
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Affiliation(s)
- A T Ribeiro
- Programa de Pós-Graduação em Botânica, Coordenação de Botânica, Museu Paraense Emílio Goeldi, Belém, Pará, Brazil
| | - G S Teodoro
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil
| | - K C da Silva
- Programa de Pós-Graduação em Botânica, Coordenação de Botânica, Museu Paraense Emílio Goeldi, Belém, Pará, Brazil
| | - Y C Pereira-Matos
- Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amazônia, Paragominas, Pará, Brazil
| | - B L Batista
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, São Paulo, Brazil
| | - A K S Lobato
- Núcleo de Pesquisa Vegetal Básica e Aplicada, Universidade Federal Rural da Amazônia, Paragominas, Pará, Brazil
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26
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Sevanto S, Gehring CA, Ryan MG, Patterson A, Losko AS, Vogel SC, Carter KR, Dickman LT, Espy MA, Kuske CR. Benefits of symbiotic ectomycorrhizal fungi to plant water relations depend on plant genotype in pinyon pine. Sci Rep 2023; 13:14424. [PMID: 37660169 PMCID: PMC10475095 DOI: 10.1038/s41598-023-41191-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 08/23/2023] [Indexed: 09/04/2023] Open
Abstract
Rhizosphere microbes, such as root-associated fungi, can improve plant access to soil resources, affecting plant health, productivity, and stress tolerance. While mycorrhizal associations are ubiquitous, plant-microbe interactions can be species specific. Here we show that the specificity of the effects of microbial symbionts on plant function can go beyond species level: colonization of roots by ectomycorrhizal fungi (EMF) of the genus Geopora has opposite effects on water uptake, and stomatal control of desiccation in drought tolerant and intolerant genotypes of pinyon pine (Pinus edulis Engelm.). These results demonstrate, for the first time, that microorganisms can have significant and opposite effects on important plant functional traits like stomatal control of desiccation that are associated with differential mortality and growth in nature. They also highlight that appropriate pairing of plant genotypes and microbial associates will be important for mitigating climate change impacts on vegetation.
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Affiliation(s)
- Sanna Sevanto
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, MS J495, PO Box 1663, Los Alamos, NM, 87545, USA.
| | - Catherine A Gehring
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Max G Ryan
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, MS J495, PO Box 1663, Los Alamos, NM, 87545, USA
- Integral Ecology Group, Duncan, BC, V9L 6H1, Canada
| | - Adair Patterson
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Adrian S Losko
- Material Sciences and Technology Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Forschungs-Neutronenquelle Heinz Maier-Leibnitz, 85748, Garching, Germany
| | - Sven C Vogel
- Material Sciences and Technology Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Kelsey R Carter
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, MS J495, PO Box 1663, Los Alamos, NM, 87545, USA
| | - L Turin Dickman
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, MS J495, PO Box 1663, Los Alamos, NM, 87545, USA
| | - Michelle A Espy
- Engineering Technology and Design Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Cheryl R Kuske
- Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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27
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Franklin O, Fransson P, Hofhansl F, Jansen S, Joshi J. Optimal balancing of xylem efficiency and safety explains plant vulnerability to drought. Ecol Lett 2023; 26:1485-1496. [PMID: 37330625 DOI: 10.1111/ele.14270] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 06/19/2023]
Abstract
In vast areas of the world, forests and vegetation are water limited and plant survival depends on the ability to avoid catastrophic hydraulic failure. Therefore, it is remarkable that plants take hydraulic risks by operating at water potentials (ψ) that induce partial failure of the water conduits (xylem). Here we present an eco-evolutionary optimality principle for xylem conduit design that explains this phenomenon based on the hypothesis that conductive efficiency and safety are optimally co-adapted to the environment. The model explains the relationship between the tolerance to negative water potential (ψ50 ) and the environmentally dependent minimum ψ (ψmin ) across a large number of species, and along the xylem pathway within individuals of two species studied. The wider hydraulic safety margin in gymnosperms compared to angiosperms can be explained as an adaptation to a higher susceptibility to accumulation of embolism. The model provides a novel optimality-based perspective on the relationship between xylem safety and efficiency.
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Affiliation(s)
- Oskar Franklin
- International Institute for Applied Systems Analysis, Laxenburg, Austria
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Peter Fransson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany
| | - Florian Hofhansl
- International Institute for Applied Systems Analysis, Laxenburg, Austria
| | | | - Jaideep Joshi
- International Institute for Applied Systems Analysis, Laxenburg, Austria
- Institute of Geography, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
- Complexity Science and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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28
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Fernández-de-Uña L, Martínez-Vilalta J, Poyatos R, Mencuccini M, McDowell NG. The role of height-driven constraints and compensations on tree vulnerability to drought. THE NEW PHYTOLOGIST 2023; 239:2083-2098. [PMID: 37485545 DOI: 10.1111/nph.19130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/07/2023] [Indexed: 07/25/2023]
Abstract
Frequent observations of higher mortality in larger trees than in smaller ones during droughts have sparked an increasing interest in size-dependent drought-induced mortality. However, the underlying physiological mechanisms are not well understood, with height-associated hydraulic constraints often being implied as the potential mechanism driving increased drought vulnerability. We performed a quantitative synthesis on how key traits that drive plant water and carbon economy change with tree height within species and assessed the implications that the different constraints and compensations may have on the interacting mechanisms (hydraulic failure, carbon starvation and/or biotic-agent attacks) affecting tree vulnerability to drought. While xylem tension increases with tree height, taller trees present a range of structural and functional adjustments, including more efficient water use and transport and greater water uptake and storage capacity, that mitigate the path-length-associated drop in water potential. These adaptations allow taller trees to withstand episodic water stress. Conclusive evidence for height-dependent increased vulnerability to hydraulic failure and carbon starvation, and their coupling to defence mechanisms and pest and pathogen dynamics, is still lacking. Further research is needed, particularly at the intraspecific level, to ascertain the specific conditions and thresholds above which height hinders tree survival under drought.
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Affiliation(s)
- Laura Fernández-de-Uña
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
| | - Rafael Poyatos
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
| | - Maurizio Mencuccini
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- ICREA, Barcelona, 08010, Spain
| | - Nate G McDowell
- Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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Martínez-Vilalta J, Poyatos R. Connecting the dots: concurrent assessment of water flows and pools to better understand plant responses to drought. TREE PHYSIOLOGY 2023; 43:1285-1289. [PMID: 37341378 DOI: 10.1093/treephys/tpad076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/08/2023] [Accepted: 06/15/2023] [Indexed: 06/22/2023]
Affiliation(s)
- Jordi Martínez-Vilalta
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Rafael Poyatos
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
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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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31
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Byrt CS, Zhang RY, Magrath I, Chan KX, De Rosa A, McGaughey S. Exploring aquaporin functions during changes in leaf water potential. FRONTIERS IN PLANT SCIENCE 2023; 14:1213454. [PMID: 37615024 PMCID: PMC10442719 DOI: 10.3389/fpls.2023.1213454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/04/2023] [Indexed: 08/25/2023]
Abstract
Maintenance of optimal leaf tissue humidity is important for plant productivity and food security. Leaf humidity is influenced by soil and atmospheric water availability, by transpiration and by the coordination of water flux across cell membranes throughout the plant. Flux of water and solutes across plant cell membranes is influenced by the function of aquaporin proteins. Plants have numerous aquaporin proteins required for a multitude of physiological roles in various plant tissues and the membrane flux contribution of each aquaporin can be regulated by changes in protein abundance, gating, localisation, post-translational modifications, protein:protein interactions and aquaporin stoichiometry. Resolving which aquaporins are candidates for influencing leaf humidity and determining how their regulation impacts changes in leaf cell solute flux and leaf cavity humidity is challenging. This challenge involves resolving the dynamics of the cell membrane aquaporin abundance, aquaporin sub-cellular localisation and location-specific post-translational regulation of aquaporins in membranes of leaf cells during plant responses to changes in water availability and determining the influence of cell signalling on aquaporin permeability to a range of relevant solutes, as well as determining aquaporin influence on cell signalling. Here we review recent developments, current challenges and suggest open opportunities for assessing the role of aquaporins in leaf substomatal cavity humidity regulation.
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32
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Rowland L, Ramírez-Valiente JA, Hartley IP, Mencuccini M. How woody plants adjust above- and below-ground traits in response to sustained drought. THE NEW PHYTOLOGIST 2023. [PMID: 37306017 DOI: 10.1111/nph.19000] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/01/2023] [Indexed: 06/13/2023]
Abstract
Future increases in drought severity and frequency are predicted to have substantial impacts on plant function and survival. However, there is considerable uncertainty concerning what drought adjustment is and whether plants can adjust to sustained drought. This review focuses on woody plants and synthesises the evidence for drought adjustment in a selection of key above-ground and below-ground plant traits. We assess whether evaluating the drought adjustment of single traits, or selections of traits that operate on the same plant functional axis (e.g. photosynthetic traits) is sufficient, or whether a multi-trait approach, integrating across multiple axes, is required. We conclude that studies on drought adjustments in woody plants might overestimate the capacity for adjustment to drier environments if spatial studies along gradients are used, without complementary experimental approaches. We provide evidence that drought adjustment is common in above-ground and below-ground traits; however, whether this is adaptive and sufficient to respond to future droughts remains uncertain for most species. To address this uncertainty, we must move towards studying trait integration within and across multiple axes of plant function (e.g. above-ground and below-ground) to gain a holistic view of drought adjustments at the whole-plant scale and how these influence plant survival.
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Affiliation(s)
- Lucy Rowland
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RJ, UK
| | | | - Iain P Hartley
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RJ, UK
| | - Maurizio Mencuccini
- CREAF, Campus de Bellaterra (UAB), Cerdanyola del Vallés, Barcelona, 08193, Spain
- ICREA, Barcelona, 08010, Spain
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33
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Kim A, Sevanto S, Moore ER, Lubbers N. Latent Dirichlet Allocation modeling of environmental microbiomes. PLoS Comput Biol 2023; 19:e1011075. [PMID: 37289841 PMCID: PMC10249879 DOI: 10.1371/journal.pcbi.1011075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 04/05/2023] [Indexed: 06/10/2023] Open
Abstract
Interactions between stressed organisms and their microbiome environments may provide new routes for understanding and controlling biological systems. However, microbiomes are a form of high-dimensional data, with thousands of taxa present in any given sample, which makes untangling the interaction between an organism and its microbial environment a challenge. Here we apply Latent Dirichlet Allocation (LDA), a technique for language modeling, which decomposes the microbial communities into a set of topics (non-mutually-exclusive sub-communities) that compactly represent the distribution of full communities. LDA provides a lens into the microbiome at broad and fine-grained taxonomic levels, which we show on two datasets. In the first dataset, from the literature, we show how LDA topics succinctly recapitulate many results from a previous study on diseased coral species. We then apply LDA to a new dataset of maize soil microbiomes under drought, and find a large number of significant associations between the microbiome topics and plant traits as well as associations between the microbiome and the experimental factors, e.g. watering level. This yields new information on the plant-microbial interactions in maize and shows that LDA technique is useful for studying the coupling between microbiomes and stressed organisms.
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Affiliation(s)
- Anastasiia Kim
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Sanna Sevanto
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Eric R. Moore
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Nicholas Lubbers
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
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34
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Potkay A, Feng X. Do stomata optimize turgor-driven growth? A new framework for integrating stomata response with whole-plant hydraulics and carbon balance. THE NEW PHYTOLOGIST 2023; 238:506-528. [PMID: 36377138 DOI: 10.1111/nph.18620] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Every existing optimal stomatal model uses photosynthetic carbon assimilation as a proxy for plant evolutionary fitness. However, assimilation and growth are often decoupled, making assimilation less ideal for representing fitness when optimizing stomatal conductance to water vapor and carbon dioxide. Instead, growth should be considered a closer proxy for fitness. We hypothesize stomata have evolved to maximize turgor-driven growth, instead of assimilation, over entire plants' lifetimes, improving their abilities to compete and reproduce. We develop a stomata model that dynamically maximizes whole-stem growth following principles from turgor-driven growth models. Stomata open to assimilate carbohydrates that supply growth and osmotically generate turgor, while stomata close to prevent losses of turgor and growth due to negative water potentials. In steady state, the growth optimization model captures realistic stomatal, growth, and carbohydrate responses to environmental cues, reconciles conflicting interpretations within existing stomatal optimization theories, and explains patterns of carbohydrate storage and xylem conductance observed during and after drought. Our growth optimization hypothesis introduces a new paradigm for stomatal optimization models, elevates the role of whole-plant carbon use and carbon storage in stomatal functioning, and has the potential to simultaneously predict gross productivity, net productivity, and plant mortality through a single, consistent modeling framework.
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Affiliation(s)
- Aaron Potkay
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
| | - Xue Feng
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
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35
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Losada JM, Blanco-Moure N, Fonollá A, Martínez-Ferrí E, Hormaza JI. Hydraulic trade-offs underlie enhanced performance of polyploid trees under soil water deficit. PLANT PHYSIOLOGY 2023:kiad204. [PMID: 37002827 DOI: 10.1093/plphys/kiad204] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 03/03/2023] [Accepted: 03/30/2023] [Indexed: 06/19/2023]
Abstract
The relationships between aerial organ morpho-anatomy of woody polyploid plants with their functional hydraulics under water stress remain largely understudied. We evaluated growth-associated traits, aerial organ xylem anatomy, and physiological parameters of diploid, triploid, and tetraploid genotypes of atemoyas (Annona cherimola x Annona squamosa), which belong to the woody perennial genus Annona (Annonaceae), testing their performance under long-term soil water reduction. The contrasting phenotypes of vigorous triploids and dwarf tetraploids consistently showed stomatal size-density trade-off. The vessel elements in aerial organs were ∼1.5 times wider in polyploids compared with diploids, and triploids displayed the lowest vessel density. Plant hydraulic conductance was higher in well-irrigated diploids while their tolerance to drought was lower. The phenotypic disparity of atemoya polyploids associated with contrasting leaf and stem xylem porosity traits that coordinate to regulate water balances between the trees and the belowground and aboveground environments. Polyploid trees displayed better performance under soil water scarcity, presenting as more sustainable agricultural and forestry genotypes to cope with water stress.
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Affiliation(s)
- Juan M Losada
- Department of Subtropical Fruit Crops. Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM La Mayora - CSIC - UMA. Av. Dr. Wienberg s/n. Algarrobo-Costa, 29750, Málaga, Spain
| | - Nuria Blanco-Moure
- Department of Subtropical Fruit Crops. Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM La Mayora - CSIC - UMA. Av. Dr. Wienberg s/n. Algarrobo-Costa, 29750, Málaga, Spain
| | - Andrés Fonollá
- Department of Subtropical Fruit Crops. Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM La Mayora - CSIC - UMA. Av. Dr. Wienberg s/n. Algarrobo-Costa, 29750, Málaga, Spain
| | - Elsa Martínez-Ferrí
- Fruticultura Subtropical y Mediterránea, IFAPA, JA, Associated Unit to CSIC by IHSM and IAS. Department of Natural and Forest Resources (IFAPA). Cortijo de la Cruz, 29140, Málaga, Spain
| | - José I Hormaza
- Department of Subtropical Fruit Crops. Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM La Mayora - CSIC - UMA. Av. Dr. Wienberg s/n. Algarrobo-Costa, 29750, Málaga, Spain
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36
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Buckley TN, Frehner EH, Bailey BN. Kinetic factors of physiology and the dynamic light environment influence the economic landscape of short-term hydraulic risk. THE NEW PHYTOLOGIST 2023; 238:529-548. [PMID: 36650668 DOI: 10.1111/nph.18739] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
Optimality-based models of stomatal conductance unify biophysical and evolutionary constraints and can improve predictions of land-atmosphere carbon and water exchange. Recent models incorporate hydraulic constraints by penalizing excessive stomatal opening in relation to hydraulic damage caused by low water potentials. We used simulation models to test whether penalties based solely on vulnerability curves adequately represent the optimality hypothesis, given that they exclude the effects of kinetic factors on stomatal behavior and integrated carbon balance. To quantify the effects of nonsteady-state phenomena on the landscape of short-term hydraulic risk, we simulated diurnal dynamics of leaf physiology for 10 000 patches of leaf in a canopy and used a ray-tracing model, Helios, to simulate realistic variation in sunfleck dynamics. Our simulations demonstrated that kinetic parameters of leaf physiology and sunfleck properties influence the economic landscape of short-term hydraulic risk, as characterized by the effect of stomatal strategy (gauged by the water potential causing a 50% hydraulic penalty) on both aggregated carbon gain and the aggregated carbon cost of short-term hydraulic risk. Hydraulic penalties in optimization models should be generalized to allow their parameters to account for kinetic factors, in addition to parameters of hydraulic vulnerability.
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Affiliation(s)
- Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, Davis, CA, 95616, USA
| | - Ethan H Frehner
- Department of Plant Sciences, University of California, Davis, Davis, CA, 95616, USA
| | - Brian N Bailey
- Department of Plant Sciences, University of California, Davis, Davis, CA, 95616, USA
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37
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Haworth M, Marino G, Materassi A, Raschi A, Scutt CP, Centritto M. The functional significance of the stomatal size to density relationship: Interaction with atmospheric [CO 2] and role in plant physiological behaviour. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 863:160908. [PMID: 36535478 DOI: 10.1016/j.scitotenv.2022.160908] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/08/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
The limits for stomatal conductance are set by stomatal size (SS) and density (SD). An inverse relationship between SS and SD has been observed in fossil and living plants. This has led to hypotheses proposing that the ratio of SS to SD influences the diffusion pathway for CO2 and degree of physiological stomatal control. However, conclusive evidence supportive of a functional role of the SS-SD relationship is not evident, and patterns in SS-SD may simply reflect geometric constraints in stomatal spacing over a leaf surface. We examine published and new data to investigate the potential functional significance of the relationship between SS and SD to atmospheric [CO2] in multiple generation adaptive responses and short-term acclamatory adjustment of stomatal morphology. Consistent patterns in SS and SD were not evident in fossil and living plants adapted to high [CO2] over many generations. However, evolutionary adaptation to [CO2] strongly affected SS and SD responses to elevated [CO2], with plants adapted to the 'low' [CO2] of the past 10 million years (Myr) showing adjustment of SS-SD, while members of the same species adapted to 'high' [CO2] showed no response. This may suggest that SS and SD responses to future [CO2] will likely constrain the stimulatory effect of 'CO2-fertilisation' on photosynthesis. Angiosperms generally possessed higher densities of smaller stomata that corresponded to a greater degree of physiological stomatal control consistent with selective pressures induced by declining [CO2] over the past 90 Myr. Atmospheric [CO2] has likely shaped stomatal size and density relationships alongside the interaction with stomatal physiological behaviour. The rate and predicted extent of future increases in [CO2] will have profound impacts on the selective pressures shaping SS and SD. Understanding the trade-offs involved in SS-SD and the interaction with [CO2], will be central to the development of more productive climate resilient crops.
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Affiliation(s)
- Matthew Haworth
- Institute for Sustainable Plant Protection, National Research Council of Italy (CNR-IPSP), Via Madonna del Piano 10 Sesto Fiorentino, 50019 Firenze, Italy.
| | - Giovanni Marino
- Institute for Sustainable Plant Protection, National Research Council of Italy (CNR-IPSP), Via Madonna del Piano 10 Sesto Fiorentino, 50019 Firenze, Italy
| | - Alessandro Materassi
- The Institute of BioEconomy, National Research Council of Italy (CNR-IBE), Via Giovanni Caproni 8, 50145 Firenze, Italy
| | - Antonio Raschi
- The Institute of BioEconomy, National Research Council of Italy (CNR-IBE), Via Giovanni Caproni 8, 50145 Firenze, Italy
| | - Charles P Scutt
- Laboratoire de Reproduction et Développement des Plantes, UMR5667, CNRS, INRA, Université de Lyon, Ecole Normale Supérieure de Lyon, Lyon Cedex 07, France
| | - Mauro Centritto
- Institute for Sustainable Plant Protection, National Research Council of Italy (CNR-IPSP), Via Madonna del Piano 10 Sesto Fiorentino, 50019 Firenze, Italy
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38
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Mantova M, Cochard H, Burlett R, Delzon S, King A, Rodriguez-Dominguez CM, Ahmed MA, Trueba S, Torres-Ruiz JM. On the path from xylem hydraulic failure to downstream cell death. THE NEW PHYTOLOGIST 2023; 237:793-806. [PMID: 36305207 DOI: 10.1111/nph.18578] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Xylem hydraulic failure (HF) has been identified as a ubiquitous factor in triggering drought-induced tree mortality through the damage induced by the progressive dehydration of plant living cells. However, fundamental evidence of the mechanistic link connecting xylem HF to cell death has not been identified yet. The main aim of this study was to evaluate, at the leaf level, the relationship between loss of hydraulic function due to cavitation and cell death under drought conditions and discern how this relationship varied across species with contrasting resistances to cavitation. Drought was induced by withholding water from potted seedlings, and their leaves were sampled to measure their relative water content (RWC) and cell mortality. Vulnerability curves to cavitation at the leaf level were constructed for each species. An increment in cavitation events occurrence precedes the onset of cell mortality. A variation in cells tolerance to dehydration was observed along with the resistance to cavitation. Overall, our results indicate that the onset of cellular mortality occurs at lower RWC than the one for cavitation indicating the role of cavitation in triggering cellular death. They also evidenced a critical RWC for cellular death varying across species with different cavitation resistance.
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Affiliation(s)
- Marylou Mantova
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Régis Burlett
- Université Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Sylvain Delzon
- Université Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Andrew King
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Gif-sur-Yvette cedex, France
| | - Celia M Rodriguez-Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, 41012, Sevilla, Spain
| | - Mutez A Ahmed
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany
- Department of Land, Air and Water Resources, University of California Davis, Davis, CA, 95616, USA
| | | | - José M Torres-Ruiz
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
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39
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Zhang YJ, Hochberg U, Rockwell FE, Ponomarenko A, Chen YJ, Manandhar A, Graham AC, Holbrook NM. Xylem conduit deformation across vascular plants: an evolutionary spandrel or protective valve? THE NEW PHYTOLOGIST 2023; 237:1242-1255. [PMID: 36307967 DOI: 10.1111/nph.18584] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
The hydraulic system of vascular plants and its integrity is essential for plant survival. To transport water under tension, the walls of xylem conduits must approximate rigid pipes. Against this expectation, conduit deformation has been reported in the leaves of a few species and hypothesized to function as a 'circuit breaker' against embolism. Experimental evidence is lacking, and its generality is unknown. We demonstrated the role of conduit deformation in protecting the upstream xylem from embolism through experiments on three species and surveyed a diverse selection of vascular plants for conduit deformation in leaves. Conduit deformation in minor veins occurred before embolism during slow dehydration. When leaves were exposed to transient increases in transpiration, conduit deformation was accompanied by large water potential differences from leaf to stem and minimal embolism in the upstream xylem. In the three species tested, collapsible vein endings provided clear protection of upstream xylem from embolism during transient increases in transpiration. We found conduit deformation in diverse vascular plants, including 11 eudicots, ginkgo, a cycad, a fern, a bamboo, and a grass species, but not in two bamboo and a palm species, demonstrating that the potential for 'circuit breaker' functionality may be widespread across vascular plants.
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Affiliation(s)
- Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Climate Change Institute, University of Maine, Orono, ME, 04469, USA
| | - Uri Hochberg
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- ARO Volcani Center, Institute of Soil, Water and Environmental Sciences, Rishon Lezion, 7505101, Israel
| | - Fulton E Rockwell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Alexandre Ponomarenko
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Anju Manandhar
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Adam C Graham
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, 02138, USA
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
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40
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Brum M, Pereira L, Ribeiro RV, Jansen S, Bittencourt PRL, Oliveira RS, Saleska SR. Reconciling discrepancies in measurements of vulnerability to xylem embolism with the pneumatic method: A comment on Chen et al. (2021) 'Quantifying vulnerability to embolism in tropical trees and lianas using five methods: can discrepancies be explained by xylem structural traits?': A comment on Chen et al. (2021) 'Quantifying vulnerability to embolism in tropical trees and lianas using five methods: can discrepancies be explained by xylem structural traits?'. THE NEW PHYTOLOGIST 2023; 237:374-383. [PMID: 36537303 DOI: 10.1111/nph.18531] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/11/2022] [Indexed: 05/12/2023]
Affiliation(s)
- Mauro Brum
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Luciano Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Rafael Vasconcelos Ribeiro
- Laboratory of Crop Physiology, Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), PO Box 6109, 13083-970, Campinas, SP, Brazil
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Paulo R L Bittencourt
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, UNICAMP, PO Box 6109, 13083-970, Campinas, SP, Brazil
| | - Scott R Saleska
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, USA
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41
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Kahmen A, Basler D, Hoch G, Link RM, Schuldt B, Zahnd C, Arend M. Root water uptake depth determines the hydraulic vulnerability of temperate European tree species during the extreme 2018 drought. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1224-1239. [PMID: 36219537 DOI: 10.1111/plb.13476] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
We took advantage of the European 2018 drought and assessed the mechanisms causing differences in drought vulnerability among mature individuals of nine co-occurring tree species at the Swiss Canopy Crane II site in Switzerland. Throughout the drought we monitored leaf water status and determined native embolism formation in the canopy of the trees as indicators of drought vulnerability. We also determined hydraulic vulnerability thresholds (Ψ12 -, Ψ50 - and Ψ88 -values), corresponding hydraulic safety margins (HSMs) and carbohydrate reserves for all species as well as total average leaf area per tree, and used stable isotopes to assess differences in root water uptake depth among the nine species as variables predicting differences in drought vulnerability among species. Marked differences in drought vulnerability were observed among the nine tree species. Six species maintained their water potentials above hydraulic thresholds, while three species, Fagus sylvatica, Carpinus betulus and Picea abies, were pushed beyond their hydraulic thresholds and showed loss of hydraulic conductivity in their canopies at the end of the drought. Embolism resistance thresholds and associated HSMs did not explain why the co-existing species differed in their drought vulnerability, neither did their degree of isohydry, nor their regulation of carbohydrate reserves. Instead, differences in structural-morphological traits, in particular root water uptake depth, were associated with the risk of reaching hydraulic vulnerability thresholds and embolism formation among the nine species. Our study shows that structural-morphological traits, such as root water uptake depth, determine how quickly different species approach hydraulic vulnerability thresholds during a drought event and can thus explain species differences in drought vulnerability among mature field-grown trees.
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Affiliation(s)
- A Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
| | - D Basler
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - G Hoch
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
| | - R M Link
- Ecophysiology and Vegetation Ecology, Universität Würzburg, Würzburg, Germany
| | - B Schuldt
- Ecophysiology and Vegetation Ecology, Universität Würzburg, Würzburg, Germany
| | - C Zahnd
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
| | - M Arend
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
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42
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Guan X, Werner J, Cao KF, Pereira L, Kaack L, McAdam SAM, Jansen S. Stem and leaf xylem of angiosperm trees experiences minimal embolism in temperate forests during two consecutive summers with moderate drought. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1208-1223. [PMID: 34990084 DOI: 10.1111/plb.13384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
Drought events may increase the likelihood that the plant water transport system becomes interrupted by embolism. Yet our knowledge about the temporal frequency of xylem embolism in the field is frequently lacking, as it requires detailed, long-term measurements. We measured xylem embolism resistance and midday xylem water potentials during the consecutive summers of 2019 and 2020 to estimate maximum levels of embolism in leaf and stem xylem of ten temperate angiosperm tree species. We also studied vessel and pit membrane characteristics based on light and electron microscopy to corroborate potential differences in embolism resistance between leaves and stems. Apart from A. pseudoplatanus and Q. petraea, eight species experienced minimum xylem water potentials that were close to or below those required to initiate embolism. Water potentials corresponding to ca. 12% loss of hydraulic conductivity (PLC) could occur in six species, while considerable levels of embolism around 50% PLC were limited to B. pendula and C. avellana. There was a general agreement in embolism resistance between stems and leaves, with leaves being equally or more resistant than stems. Also, xylem embolism resistance was significantly correlated to intervessel pit membrane thickness (TPM ) for stems, but not to vessel diameter and total intervessel pit membrane surface area of a vessel. Our data indicate that low amounts of embolism occur in most species during moderate summer drought, and that considerable levels of embolism are uncommon. Moreover, our experimental and TPM data show that leaf xylem is generally no more vulnerable than stem xylem.
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Affiliation(s)
- X Guan
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - J Werner
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - K-F Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilisation of Subtropical Agro-Bioresources, Guangxi University, Nanning, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, China
| | - L Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - L Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - S A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - S Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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43
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Fan DY, Dang QL, Yang XF, Liu XM, Wang JY, Zhang SR. Nitrogen deposition increases xylem hydraulic sensitivity but decreases stomatal sensitivity to water potential in two temperate deciduous tree species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157840. [PMID: 35934026 DOI: 10.1016/j.scitotenv.2022.157840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/22/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Although the effects of nitrogen deposition on tree water relations are studied extensively, its impact on the relative sensitivities of stomatal and xylem hydraulic conductance to vapor pressure deficit and water potential is still poorly understood. This study investigated the effects of a 7-year N deposition treatment on the responses of leaf water relations and sensitivity of canopy stomatal conductance to vapor pressure deficit (VPD) and water potential, as well as the sensitivity of branch hydraulic conductance to water potential in a dominant tree species (Quercus wutaishanica) and an associated tree species (Acer mono) in a temperate forest. It was found that the N deposition increased stomatal sensitivity to VPD, decreased stomatal sensitivity to water potential, and increased the vulnerability of the hydraulic system to cavitation in both species. The standardized stomatal sensitivity to VPD, however, was not affected by the N deposition, indicating that the stomata maintained the ability to regulate the water balance under nitrogen deposition condition. Although the increased stomatal sensitivity to VPD could compensate the decreased stomatal sensitivity to water potential to some extent, the combined response would increase the percentage loss of hydraulic conductivity (PLC) when 50 % loss in stomatal conductance occurred, particularly in the dominant species Q. wutaishanica. The result indicates that N deposition would increase the risk of hydraulic failure in those species if the soil and/or air becomes drier under future climate change scenarios. The results of the study can have significant implications on the modelling of ecosystem vulnerability to drought under the scenario of atmospheric nitrogen deposition.
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Affiliation(s)
- Da-Yong Fan
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China.
| | - Qing-Lai Dang
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada
| | - Xiao-Fang Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100096, China
| | - Xiao-Ming Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100096, China
| | - Jia-Yi Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China
| | - Shou-Ren Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100096, China.
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Brown A, Butler DW, Radford‐Smith J, Dwyer JM. Changes in trait covariance along an orographic moisture gradient reveal the relative importance of light- and moisture-driven trade-offs in subtropical rainforest communities. THE NEW PHYTOLOGIST 2022; 236:839-851. [PMID: 35922934 PMCID: PMC9804723 DOI: 10.1111/nph.18418] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
A range of functional trait-based approaches have been developed to investigate community assembly processes, but most ignore how traits covary within communities. We combined existing approaches - community-weighted means (CWMs) and functional dispersion (FDis) - with a metric of trait covariance to examine assembly processes in five angiosperm assemblages along a moisture gradient in Australia's subtropics. In addition to testing hypotheses about habitat filtering along the gradient, we hypothesized that trait covariance would be strongest at both ends of the moisture gradient and weakest in the middle, reflecting trade-offs associated with light capture in productive sites and moisture stress in dry sites. CWMs revealed evidence of climatic filtering, but FDis patterns were less clear. As hypothesized, trait covariance was weakest in the middle of the gradient but unexpectedly peaked at the second driest site due to the emergence of a clear drought tolerance-drought avoidance spectrum. At the driest site, the same spectrum was truncated at the 'avoider' end, revealing important information about habitat filtering in this system. Our focus on trait covariance revealed the nature and strength of trade-offs imposed by light and moisture availability, complementing insights gained about community assembly from existing trait-based approaches.
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Affiliation(s)
- Alison Brown
- School of Biological SciencesThe University of QueenslandSt LuciaQld4072Australia
| | - Donald W. Butler
- College of LawAustralian National UniversityCanberraACT2600Australia
| | - Julian Radford‐Smith
- School of Biological SciencesThe University of QueenslandSt LuciaQld4072Australia
| | - John M. Dwyer
- School of Biological SciencesThe University of QueenslandSt LuciaQld4072Australia
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45
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Huo J, Shi Y, Chen J, Zhang H, Feng L, Zhao Y, Zhang Z. Hydraulic trade-off and coordination strategies mediated by leaf functional traits of desert shrubs. FRONTIERS IN PLANT SCIENCE 2022; 13:938758. [PMID: 36388496 PMCID: PMC9662791 DOI: 10.3389/fpls.2022.938758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Desert shrubs play important roles in desertification control and vegetation restoration, which are particularly affected by droughts caused by climate change. However, the hydraulic strategies associated with hydraulic functional traits of desert shrubs remain unclear. Here, eight desert shrub species with different life forms and morphologies were selected for a common garden experiment at the southeast edge of the Tengger Desert in northern China to study the hydraulic strategies mediated by leaf hydraulic functional traits. Diurnal leaf water potential change, leaf hydraulic efficiency and safety, hydraulic safety margin, hydraulic capacitance, and water potential and relative water content at the turgor loss point were observed to significantly differ among species, suggesting that leaf hydraulic functional traits were strongly associated with species even when living in the same environment. Additionally, shrubs with greater leaf hydraulic efficiency had lower midday leaf water potential and leaf hydraulic safety, suggesting that leaf hydraulic efficiency had a strong trade-off with hydraulic safety and minimum leaf water potential, whereas there was also a coordination between leaf hydraulic safety and the leaf minimal water potential. Moreover, shrubs with higher leaf hydraulic capacitance had greater hydraulic safety margins, indicating coordination between leaf hydraulic capacitance and hydraulic safety margin. Overall, this study indicated that minimal daily leaf water potential, as an easily measured parameter, may be used preliminarily to predict leaf hydraulic conductivity and the resistance to embolism of desert shrubs, providing critical insights into hydraulic trade-off and coordination strategies for native shrubs as priority species in desert vegetation restoration and reconstruction.
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Affiliation(s)
- Jianqiang Huo
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yafei Shi
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jiajia Chen
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hongxia Zhang
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Li Feng
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Yang Zhao
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Zhishan Zhang
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
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46
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Xu GQ, Kandlikar GS, Vaz MC. Evolutionary lability underlies drought adaptation of Australian shrubs along aridity gradients. FRONTIERS IN PLANT SCIENCE 2022; 13:949531. [PMID: 36275606 PMCID: PMC9585297 DOI: 10.3389/fpls.2022.949531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Leaf drought tolerance traits influence plant survival in water deficit conditions, and these traits are influenced by both the plant's evolutionary history and the environment in which the plant is currently growing. However, due to the substantial phenotypic plasticity in leaf traits, we still do not know to what degree variation in leaf traits is governed by species' phylogenetic history or by their environment. To explore this question, we re-examined a drought tolerance dataset from 37 native Australian shrub species with varying climate origins growing in a common garden located in Melbourne, Australia. We previously measured seven leaf morphophysiological traits, and here, we estimated how phylogenetically conserved these traits are. We quantified phylogeny and the strength of correlation between the morphological traits and physiological traits before and after accounting for shared phylogenetic history. We also evaluated the relationship between species' leaf traits and the climate of their native ranges. We present three main findings: (a) most leaf drought tolerance traits had weak phylogenetic signals, which is consistent with the convergent evolution of these traits. (b) There is weak but consistent coordination between distinct leaf drought tolerance traits, which can be masked due to species' phylogenetic histories. (c) Leaf drought tolerance traits show strong correlations with the climate of species' origins, and this relationship is only weakly impacted by phylogenetic signals. Therefore, the role of phylogeny on the coordination among leaf functional traits and their links to climate were limited. A better understanding of trait-environment relationships might be more pivotal than understanding the evolution of these traits for improving the predictions of species' response to climate change-type drought, especially for shrub species that span substantial aridity gradients.
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Affiliation(s)
- Gui-Qing Xu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Gaurav S. Kandlikar
- Division of Biological Sciences and Division of Plant Sciences, University of Missouri, Columbia, MO, United States
| | - Marcel C. Vaz
- Wilkes University, Institute for Environmental Science and Sustainability, Wilkes-Barre, PA, United States
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47
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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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48
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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: 7] [Impact Index Per Article: 3.5] [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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49
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Levionnois S, Kaack L, Heuret P, Abel N, Ziegler C, Coste S, Stahl C, Jansen S. Pit characters determine drought-induced embolism resistance of leaf xylem across 18 Neotropical tree species. PLANT PHYSIOLOGY 2022; 190:371-386. [PMID: 35567500 PMCID: PMC9434246 DOI: 10.1093/plphys/kiac223] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/19/2022] [Indexed: 05/16/2023]
Abstract
Embolism spreading in xylem is an important component of plant drought resistance. Since embolism resistance has been shown to be mechanistically linked to pit membrane characters in stem xylem, we speculate that similar mechanisms account for leaf xylem. We conducted transmission electron microscopy to investigate pit membrane characters in leaf xylem across 18 Neotropical tree species. We also conducted gold perfusion and polar lipid detection experiments on three species covering the full range of leaf embolism resistance. We then related these observations to previously published data on embolism resistance of leaf xylem. We also incorporated previously published data on stem embolism resistance and stem xylem pit membranes to investigate the link between vulnerability segmentation (i.e. difference in embolism resistance) and leaf-stem anatomical variation. Maximum pit membrane thickness (Tpm,max) and the pit membrane thickness-to-diameter ratio (Tpm,max/Dpm) were predictive of leaf embolism resistance, especially when vestured pits were taken into account. Variation in Tpm,max/Dpm was the only trait predictive of vulnerability segmentation between leaves and stems. Gold particles of 5- and 10-nm infiltrated pit membranes in three species, while the entry of 50-nm particles was blocked. Moreover, polar lipids were associated with inner conduit walls and pits. Our results suggest that mechanisms related to embolism spreading are determined by Tpm, pore constrictions (i.e. the narrowest bottlenecks along pore pathways), and lipid surfactants, which are largely similar between leaf and stem xylem and between temperate and tropical trees. However, our mechanistic understanding of embolism propagation and the functional relevance of Tpm,max/Dpm remains elusive.
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Affiliation(s)
| | - Lucian Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Ulm D-89081, Germany
| | | | - Nina Abel
- Institute of Systematic Botany and Ecology, Ulm University, Ulm D-89081, Germany
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, Nancy 54000, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
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50
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Duan H, Wang D, Zhao N, Huang G, Resco de Dios V, Tissue DT. Limited hydraulic recovery in seedlings of six tree species with contrasting leaf habits in subtropical China. FRONTIERS IN PLANT SCIENCE 2022; 13:967187. [PMID: 36035730 PMCID: PMC9403191 DOI: 10.3389/fpls.2022.967187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Subtropical tree species may experience severe drought stress due to variable rainfall under future climates. However, the capacity to restore hydraulic function post-drought might differ among co-occurring species with contrasting leaf habits (e.g., evergreen and deciduous) and have implications for future forest composition. Moreover, the links between hydraulic recovery and physiological and morphological traits related to water-carbon availability are still not well understood. Here, potted seedlings of six tree species (four evergreen and two deciduous) were grown outdoors under a rainout shelter. They grew under favorable water conditions until they were experimentally subjected to a soil water deficit leading to losses of ca. 50% of hydraulic conductivity, and then soils were re-watered to field capacity. Traits related to carbon and water relations were measured. There were differences in drought responses and recovery between species, but not as a function of evergreen or deciduous groups. Sapindus mukorossi exhibited the most rapid drought response, which was associated with a suite of physiological and morphological traits (larger plant size, the lowest hydraulic capacitance (C branch), higher minimum conductance (g min) and lower HV (Huber value)). Upon re-watering, xylem water potential exhibited fast recovery in 1-3 days among species, while photosynthesis at saturating light (A sat) and stomatal conductance (g s) recovery lagged behind water potential recovery depending on species, with g s recovery being more delayed than A sat in most species. Furthermore, none of the six species exhibited significant hydraulic recovery during the 7 days re-watering period, indicating that xylem refilling was apparently limited; in addition, NSC availability had a minimal role in facilitating hydraulic recovery during this short-term period. Collectively, if water supply is limited by insignificant hydraulic recovery post-drought, the observed carbon assimilation recovery of seedlings may not be sustained over the longer term, potentially altering seedling regeneration and shifting forest species composition in subtropical China under climate change.
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Affiliation(s)
- Honglang Duan
- Institute for Forest Resources and Environment of Guizhou, Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, College of Forestry, Guizhou University, Guiyang, China
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Defu Wang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Nan Zhao
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Guomin Huang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA Center, Lleida, Spain
| | - David T. Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Richmond, NSW, Australia
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