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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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2
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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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3
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Flo V, Joshi J, Sabot M, Sandoval D, Prentice IC. Incorporating photosynthetic acclimation improves stomatal optimisation models. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38589983 DOI: 10.1111/pce.14891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/04/2024] [Accepted: 03/08/2024] [Indexed: 04/10/2024]
Abstract
Stomatal opening in plant leaves is regulated through a balance of carbon and water exchange under different environmental conditions. Accurate estimation of stomatal regulation is crucial for understanding how plants respond to changing environmental conditions, particularly under climate change. A new generation of optimality-based modelling schemes determines instantaneous stomatal responses from a balance of trade-offs between carbon gains and hydraulic costs, but most such schemes do not account for biochemical acclimation in response to drought. Here, we compare the performance of six instantaneous stomatal optimisation models with and without accounting for photosynthetic acclimation. Using experimental data from 37 plant species, we found that accounting for photosynthetic acclimation improves the prediction of carbon assimilation in a majority of the tested models. Photosynthetic acclimation contributed significantly to the reduction of photosynthesis under drought conditions in all tested models. Drought effects on photosynthesis could not accurately be explained by the hydraulic impairment functions embedded in the stomatal models alone, indicating that photosynthetic acclimation must be considered to improve estimates of carbon assimilation during drought.
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Affiliation(s)
- Victor Flo
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Ascot, UK
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Univ Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Jaideep Joshi
- Department of Geosciences, Institute of Geography, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, Faculty of Science, University of Bern, Bern, Switzerland
- Advancing Systems Analysis Program, International Institute for Applied Systems Analysis, Laxenburg, Austria
- Complexity Science and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan
| | - Manon Sabot
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia
- Department of Biogeochemical Signals, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - David Sandoval
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Ascot, UK
| | - Iain Colin Prentice
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Ascot, UK
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4
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O'Keefe K, Nippert JB, Keen RM, McCulloh KA. Contrasting shrub and grass hydraulic responses to experimental drought. Oecologia 2024; 204:931-941. [PMID: 38607552 DOI: 10.1007/s00442-024-05543-w] [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: 08/23/2023] [Accepted: 03/07/2024] [Indexed: 04/13/2024]
Abstract
Whole-plant hydraulics provide important information about responses to water limitation and can be used to understand how plant communities may change in a drier climate when measured on multiple species. Here, we measured above- and belowground hydraulic traits in Cornus drummondii, an encroaching shrub within North American tallgrass prairies, and Andropogon gerardii, a dominant C4 grass, to assess the potential hydraulic responses to future drought as this region undergoes woody expansion. Shelters that reduced precipitation by 50% and 0% were built over shrubs and grasses growing in sites that are burned at 1-year and 4-year frequencies. We then measured aboveground (Kshoot), belowground (Kroot), and whole-plant maximum hydraulic conductance (Kplant) in C. drummondii and Kroot in A. gerardii. We also measured vulnerability to embolism (P50) in C. drummondii stems. Overall, we show that: (1) A. gerardii had substantially greater Kroot than C. drummondii; (2) belowground hydraulic functioning was linked with aboveground processes; (3) above- and belowground C. drummondii hydraulics were not negatively impacted by the rainfall reductions imposed here. These results suggest that a multi-year drought will not ameliorate rates of woody expansion and highlight key differences in aboveground and belowground hydraulics for dominant species within the same ecosystem.
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Affiliation(s)
- Kimberly O'Keefe
- Department of Biological Sciences, St. Edward's University, Austin, TX, 78704, USA.
- Department of Botany, University of Wisconsin, Madison, WI, 53706, USA.
| | - Jesse B Nippert
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Rachel M Keen
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Department of Ecology and Evolutionary Biology, Kansas Biological Survey, The University of Kansas, Lawrence, KS, 66047, USA
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5
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Shekhar A, Hörtnagl L, Paul-Limoges E, Etzold S, Zweifel R, Buchmann N, Gharun M. Contrasting impact of extreme soil and atmospheric dryness on the functioning of trees and forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:169931. [PMID: 38199368 DOI: 10.1016/j.scitotenv.2024.169931] [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: 08/12/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/12/2024]
Abstract
Recent studies indicate an increase in the frequency of extreme compound dryness days (days with both extreme soil AND air dryness) across central Europe in the future, with little information on their impact on the functioning of trees and forests. This study aims to quantify and assess the impact of extreme soil dryness, extreme air dryness, and extreme compound dryness on the functioning of trees and forests. For this, >15 years of ecosystem-level (carbon dioxide and water vapor fluxes) and 6-10 years of tree-level measurements (transpiration and growth) each from a montane mixed deciduous forest (CH-Lae) and a subalpine evergreen coniferous forest (CH-Dav) in Switzerland, is used. The results showed extreme air dryness limitation on CO2 fluxes and extreme soil dryness limitations on water vapor fluxes. Additionally, CH-Dav was mainly affected by extreme air dryness whereas CH-Lae was affected by both extreme soil dryness and extreme air dryness. The impact of extreme compound dryness on net CO2 uptake (about 75 % decrease) was more due to higher increased ecosystem respiration (40 % and 70 % increase at CH-Dav and CH-Lae, respectively) than decreased gross primary productivity (10 % and 40 % decrease at CH-Dav and CH-Lae, respectively). A significant negative impact on evapotranspiration and transpiration was only observed at CH-Lae during extreme soil and compound dryness (about 25 % decrease). Furthermore, with some differences, the tree-level impact on tree water deficit, transpiration, and growth were consistent with the ecosystem-level impact on carbon uptake and evapotranspiration. Finally, the impact of extreme dryness showed no significant relationship with tree allometry (diameter and height) but across different tree species. The projected future is likely to expose these forest areas to more extreme and frequent dryness conditions, thus compromising the functioning of trees and forests, thereby calling for management interventions to increase the adaptive capacity and resistance of these forests.
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Affiliation(s)
- Ankit Shekhar
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland.
| | - Lukas Hörtnagl
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Eugénie Paul-Limoges
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Mana Gharun
- Faculty of Geosciences, University of Münster, 48149 Münster, Germany
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6
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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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7
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Lamour J, Souza DC, Gimenez BO, Higuchi N, Chave J, Chambers J, Rogers A. Wood-density has no effect on stomatal control of leaf-level water use efficiency in an Amazonian forest. PLANT, CELL & ENVIRONMENT 2023; 46:3806-3821. [PMID: 37635450 DOI: 10.1111/pce.14704] [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: 03/24/2023] [Revised: 07/20/2023] [Accepted: 08/16/2023] [Indexed: 08/29/2023]
Abstract
Forest disturbances increase the proportion of fast-growing tree species compared to slow-growing ones. To understand their relative capacity for carbon uptake and their vulnerability to climate change, and to represent those differences in Earth system models, it is necessary to characterise the physiological differences in their leaf-level control of water use efficiency and carbon assimilation. We used wood density as a proxy for the fast-slow growth spectrum and tested the assumption that trees with a low wood density (LWD) have a lower water-use efficiency than trees with a high wood density (HWD). We selected 5 LWD tree species and 5 HWD tree species growing in the same location in an Amazonian tropical forest and measured in situ steady-state gas exchange on top-of-canopy leaves with parallel sampling and measurement of leaf mass area and leaf nitrogen content. We found that LWD species invested more nitrogen in photosynthetic capacity than HWD species, had higher photosynthetic rates and higher stomatal conductance. However, contrary to expectations, we showed that the stomatal control of the balance between transpiration and carbon assimilation was similar in LWD and HWD species and that they had the same dark respiration rates.
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Affiliation(s)
- Julien Lamour
- Department of Environmental & Climate Sciences, Brookhaven National Laboratory, Upton, New York, USA
- Evolution and Biological Diversity (EDB), CNRS/IRD/UPS, Toulouse, France
| | - Daisy C Souza
- National Institute of Amazonian Research (INPA), Forest Management Laboratory (LMF), Manaus, Amazonas, Brazil
| | - Bruno O Gimenez
- National Institute of Amazonian Research (INPA), Forest Management Laboratory (LMF), Manaus, Amazonas, Brazil
- Department of Geography, University of California, Berkeley, California, USA
| | - Niro Higuchi
- National Institute of Amazonian Research (INPA), Forest Management Laboratory (LMF), Manaus, Amazonas, Brazil
| | - Jérôme Chave
- Evolution and Biological Diversity (EDB), CNRS/IRD/UPS, Toulouse, France
| | - Jeffrey Chambers
- Department of Geography, University of California, Berkeley, California, USA
| | - Alistair Rogers
- Department of Environmental & Climate Sciences, Brookhaven National Laboratory, Upton, New York, USA
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8
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Cai G, Carminati A, Gleason SM, Javaux M, Ahmed MA. Soil-plant hydraulics explain stomatal efficiency-safety tradeoff. PLANT, CELL & ENVIRONMENT 2023; 46:3120-3127. [PMID: 36609853 DOI: 10.1111/pce.14536] [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: 07/24/2022] [Revised: 12/10/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
The efficiency-safety tradeoff has been thoroughly investigated in plants, especially concerning their capacity to transport water and avoid embolism. Stomatal regulation is a vital plant behaviour to respond to soil and atmospheric water limitation. Recently, a stomatal efficiency-safety tradeoff was reported where plants with higher maximum stomatal conductance (gmax ) exhibited greater sensitivity to stomatal closure during soil drying, that is, less negative leaf water potential at 50% gmax (ψgs50 ). However, the underlying mechanism of this gmax -ψgs50 tradeoff remains unknown. Here, we utilized a soil-plant hydraulic model, in which stomatal closure is triggered by nonlinearity in soil-plant hydraulics, to investigate such tradeoff. Our simulations show that increasing gmax is aligned with less negative ψgs50 . Plants with higher gmax (also higher transpiration) require larger quantities of water to be moved across the rhizosphere, which results in a precipitous decrease in water potential at the soil-root interface, and therefore in the leaves. We demonstrated that the gmax -ψgs50 tradeoff can be predicted based on soil-plant hydraulics, and is impacted by plant hydraulic properties, such as plant hydraulic conductance, active root length and embolism resistance. We conclude that plants may therefore adjust their growth and/or their hydraulic properties to adapt to contrasting habitats and climate conditions.
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Affiliation(s)
- Gaochao Cai
- School of Agriculture, Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Andrea Carminati
- Physics of Soils and Terrestrial Ecosystems, Institute of Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zürich, Zurich, Switzerland
| | - Sean M Gleason
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Mathieu Javaux
- Earth and Life Institute-Environmental Science, Universite catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Mutez Ali Ahmed
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
- Department of Land, Air and Water Resources, College of Agricultural and Environmental Sciences, University of California Davis, Davis, California, USA
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9
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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: 0] [Impact Index Per Article: 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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10
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Quetin GR, Anderegg LDL, Boving I, Anderegg WRL, Trugman AT. Observed forest trait velocities have not kept pace with hydraulic stress from climate change. GLOBAL CHANGE BIOLOGY 2023; 29:5415-5428. [PMID: 37421154 DOI: 10.1111/gcb.16847] [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: 03/24/2023] [Accepted: 05/25/2023] [Indexed: 07/09/2023]
Abstract
The extent to which future climate change will increase forest stress and the amount to which species and forest ecosystems can acclimate or adapt to increased stress is a major unknown. We used high-resolution maps of hydraulic traits representing the diversity in tree drought tolerance across the United States, a hydraulically enabled tree model, and forest inventory observations of demographic shifts to quantify the ability for within-species acclimation and between-species range shifts to mediate climate stress. We found that forests are likely to experience increases in both acute and chronic hydraulic stress with climate change. Based on current species distributions, regional hydraulic trait diversity was sufficient to buffer against increased stress in 88% of forested areas. However, observed trait velocities in 81% of forested areas are not keeping up with the rate required to ameliorate projected future stress without leaf area acclimation.
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Affiliation(s)
- G R Quetin
- Department of Geography, University of California, Santa Barbara, California, USA
| | - L D L Anderegg
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, USA
| | - I Boving
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, USA
| | - W R L Anderegg
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA
| | - A T Trugman
- Department of Geography, University of California, Santa Barbara, California, USA
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11
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Peters RL, Steppe K, Pappas C, Zweifel R, Babst F, Dietrich L, von Arx G, Poyatos R, Fonti M, Fonti P, Grossiord C, Gharun M, Buchmann N, Steger DN, Kahmen A. Daytime stomatal regulation in mature temperate trees prioritizes stem rehydration at night. THE NEW PHYTOLOGIST 2023. [PMID: 37235688 DOI: 10.1111/nph.18964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/16/2023] [Indexed: 05/28/2023]
Abstract
Trees remain sufficiently hydrated during drought by closing stomata and reducing canopy conductance (Gc ) in response to variations in atmospheric water demand and soil water availability. Thresholds that control the reduction of Gc are proposed to optimize hydraulic safety against carbon assimilation efficiency. However, the link between Gc and the ability of stem tissues to rehydrate at night remains unclear. We investigated whether species-specific Gc responses aim to prevent branch embolisms, or enable night-time stem rehydration, which is critical for turgor-dependent growth. For this, we used a unique combination of concurrent dendrometer, sap flow and leaf water potential measurements and collected branch-vulnerability curves of six common European tree species. Species-specific Gc reduction was weakly related to the water potentials at which 50% of branch xylem conductivity is lost (P50 ). Instead, we found a stronger relationship with stem rehydration. Species with a stronger Gc control were less effective at refilling stem-water storage as the soil dries, which appeared related to their xylem architecture. Our findings highlight the importance of stem rehydration for water-use regulation in mature trees, which likely relates to the maintenance of adequate stem turgor. We thus conclude that stem rehydration must complement the widely accepted safety-efficiency stomatal control paradigm.
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Affiliation(s)
- Richard L Peters
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Forest is Life, TERRA Teaching and Research Centre, Gembloux Agro Bio-Tech, University of Liège, Passage des Déportés 2, 5030, Gembloux, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
| | - Christoforos Pappas
- Department of Civil Engineering, University of Patras, Rio, Patras, 26504, Greece
| | - Roman Zweifel
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Flurin Babst
- School of Natural Resources and the Environment, University of Arizona, East Lowell Street 1064, Tucson, AZ, 85721, USA
- Laboratory of Tree-Ring Research, University of Arizona, East Lowell Street 1215, Tucson, AZ, 857121, USA
| | - Lars Dietrich
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Georg von Arx
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, 3012, Bern, Switzerland
| | - Rafael Poyatos
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Marina Fonti
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Patrick Fonti
- Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School for Architecture, Civil and Environmental Engineering, EPFL, CH-1015, Lausanna, Switzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, CH-1015, Lausanne, Switzerland
| | - Mana Gharun
- Department of Environmental Systems Science, ETH Zurich, Universitatstrasse 2, CH-8092, Zurich, Switzerland
- Department of Geosciences, University of Münster, Heisenbergstrasse 2, 48149, Münster, Germany
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zurich, Universitatstrasse 2, CH-8092, Zurich, Switzerland
| | - David N Steger
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
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12
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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: 1] [Impact Index Per Article: 1.0] [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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13
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Davidson KJ, Lamour J, Rogers A, Ely KS, Li Q, McDowell NG, Pivovaroff AL, Wolfe BT, Wright SJ, Zambrano A, Serbin SP. Short-term variation in leaf-level water use efficiency in a tropical forest. THE NEW PHYTOLOGIST 2023; 237:2069-2087. [PMID: 36527230 DOI: 10.1111/nph.18684] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
The representation of stomatal regulation of transpiration and CO2 assimilation is key to forecasting terrestrial ecosystem responses to global change. Given its importance in determining the relationship between forest productivity and climate, accurate and mechanistic model representation of the relationship between stomatal conductance (gs ) and assimilation is crucial. We assess possible physiological and mechanistic controls on the estimation of the g1 (stomatal slope, inversely proportional to water use efficiency) and g0 (stomatal intercept) parameters, using diurnal gas exchange surveys and leaf-level response curves of six tropical broadleaf evergreen tree species. g1 estimated from ex situ response curves averaged 50% less than g1 estimated from survey data. While g0 and g1 varied between leaves of different phenological stages, the trend was not consistent among species. We identified a diurnal trend associated with g1 and g0 that significantly improved model projections of diurnal trends in transpiration. The accuracy of modeled gs can be improved by accounting for variation in stomatal behavior across diurnal periods, and between measurement approaches, rather than focusing on phenological variation in stomatal behavior. Additional investigation into the primary mechanisms responsible for diurnal variation in g1 will be required to account for this phenomenon in land-surface models.
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Affiliation(s)
- Kenneth J Davidson
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Building 490A, Upton, NY, 11973, USA
- Department of Ecology and Evolution, Stony Brook University, 650 Life Sciences Building, Stony Brook, NY, 11794, USA
| | - Julien Lamour
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Building 490A, Upton, NY, 11973, USA
| | - Alistair Rogers
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Building 490A, Upton, NY, 11973, USA
| | - Kim S Ely
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Building 490A, Upton, NY, 11973, USA
| | - Qianyu Li
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Building 490A, Upton, NY, 11973, USA
| | - Nate G McDowell
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, PO Box 999, Richland, WA, 99352, USA
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA, 99164-4236, USA
| | | | - Brett T Wolfe
- School of Renewable Natural Resources, Louisiana State University, Room 227, Renewable Natural Resources Bldg, Baton Rouge, LA, 70803, USA
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Panama
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Panama
| | - Alfonso Zambrano
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Panama
| | - Shawn P Serbin
- Department of Environmental and Climate Sciences, Brookhaven National Laboratory, Building 490A, Upton, NY, 11973, USA
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14
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Knüver T, Bär A, Ganthaler A, Gebhardt T, Grams TEE, Häberle K, Hesse BD, Losso A, Tomedi I, Mayr S, Beikircher B. Recovery after long-term summer drought: Hydraulic measurements reveal legacy effects in trunks of Picea abies but not in Fagus sylvatica. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1240-1253. [PMID: 35611757 PMCID: PMC10084041 DOI: 10.1111/plb.13444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Climate change is expected to increase the frequency and intensity of summer droughts. Sufficient drought resistance, the ability to acclimate to and/or recover after drought, is thus crucial for forest tree species. However, studies on the hydraulics of mature trees during and after drought in natura are scarce. In this study, we analysed trunk water content (electrical resistivity: ER) and further hydraulic (water potential, sap flow density, specific hydraulic conductivity, vulnerability to embolism) as well as wood anatomical traits (tree ring width, conduit diameter, conduit wall reinforcement) of drought-stressed (artificially induced summer drought via throughfall-exclusion) and unstressed Picea abies and Fagus sylvatica trees. In P. abies, ER indicated a strong reduction in trunk water content after 5 years of summer drought, corresponding to significantly lower pre-dawn leaf water potential and xylem sap flow density. Vulnerability to embolism tended to be higher in drought-stressed trees. In F. sylvatica, only small differences between drought-stressed and control trees were observed. Re-watering led to a rapid increase in water potentials and xylem sap flow of both drought-stressed trees, and to increased growth rates in the next growing season. ER analyses revealed lower trunk water content in P. abies trees growing on throughfall-exclusion plots even 1 year after re-watering, indicating a limited capacity to restore internal water reserves. Results demonstrated that P. abies is more susceptible to recurrent summer drought than F. sylvatica, and can exhibit long-lasting and pronounced legacy effects in trunk water reserves.
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Affiliation(s)
- T. Knüver
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - A. Bär
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - A. Ganthaler
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - T. Gebhardt
- Technical University of MunichSchool of Life SciencesProfessorship for Land Surface‐Atmosphere Interactions AG Ecophysiology of PlantsFreisingGermany
| | - T. E. E. Grams
- Technical University of MunichSchool of Life SciencesProfessorship for Land Surface‐Atmosphere Interactions AG Ecophysiology of PlantsFreisingGermany
| | - K.‐H. Häberle
- Technical University of MunichSchool of Life SciencesChair of Restoration EcologyFreisingGermany
| | - B. D. Hesse
- Technical University of MunichSchool of Life SciencesProfessorship for Land Surface‐Atmosphere Interactions AG Ecophysiology of PlantsFreisingGermany
| | - A. Losso
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondAustralia
| | - I. Tomedi
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - S. Mayr
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - B. Beikircher
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
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15
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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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16
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Joshi J, Stocker BD, Hofhansl F, Zhou S, Dieckmann U, Prentice IC. Towards a unified theory of plant photosynthesis and hydraulics. NATURE PLANTS 2022; 8:1304-1316. [PMID: 36303010 PMCID: PMC9663302 DOI: 10.1038/s41477-022-01244-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 08/04/2022] [Indexed: 06/01/2023]
Abstract
The global carbon and water cycles are governed by the coupling of CO2 and water vapour exchanges through the leaves of terrestrial plants, controlled by plant adaptations to balance carbon gains and hydraulic risks. We introduce a trait-based optimality theory that unifies the treatment of stomatal responses and biochemical acclimation of plants to environments changing on multiple timescales. Tested with experimental data from 18 species, our model successfully predicts the simultaneous decline in carbon assimilation rate, stomatal conductance and photosynthetic capacity during progressive soil drought. It also correctly predicts the dependencies of gas exchange on atmospheric vapour pressure deficit, temperature and CO2. Model predictions are also consistent with widely observed empirical patterns, such as the distribution of hydraulic strategies. Our unified theory opens new avenues for reliably modelling the interactive effects of drying soil and rising atmospheric CO2 on global photosynthesis and transpiration.
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Affiliation(s)
- Jaideep Joshi
- Advancing Systems Analysis Program, International Institute for Applied Systems Analysis, Laxenburg, Austria.
- Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru, India.
- Complexity Science and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
| | - Benjamin D Stocker
- Department of Environmental Systems Science, ETH, Universitätsstrasse 2, Zürich, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Florian Hofhansl
- Biodiversity and Natural Resources Program, International Institute for Applied Systems Analysis, Laxenburg, Austria
| | - Shuangxi Zhou
- Department of Biological Sciences, Macquarie University, Macquarie Park, Australia
- CSIRO Agriculture and Food, Glen Osmond, South Australia, Australia
| | - Ulf Dieckmann
- Advancing Systems Analysis Program, International Institute for Applied Systems Analysis, Laxenburg, Austria
- Complexity Science and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
- Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa, Japan
| | - Iain Colin Prentice
- Department of Biological Sciences, Macquarie University, Macquarie Park, Australia
- Department of Life Sciences, Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Ascot, UK
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, China
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17
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Feng X, Lu Y, Jiang M, Katul G, Manzoni S, Mrad A, Vico G. Instantaneous stomatal optimization results in suboptimal carbon gain due to legacy effects. PLANT, CELL & ENVIRONMENT 2022; 45:3189-3204. [PMID: 36030546 DOI: 10.1111/pce.14427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/15/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Xue Feng
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, Minnesota, USA
| | - Yaojie Lu
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Gabriel Katul
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina, USA
| | - Stefano Manzoni
- Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| | - Assaad Mrad
- Department of Civil and Environmental Engineering, University of California, Irvine, California, USA
- Department of Engineering, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Giulia Vico
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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18
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Lee EH, Andersen CP, Beedlow PA, Tingey DT, Koike S, Dubois JJ, Kaylor SD, Novak K, Rice RB, Neufeld HS, Herrick JD. Ozone exposure-response relationships parametrized for sixteen tree species with varying sensitivity in the United States. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2022; 284:1-16. [PMID: 35775067 PMCID: PMC9237886 DOI: 10.1016/j.atmosenv.2022.119191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
It is well known that exposure to ambient O3 can decrease growth in many tree species in the United States (US). Our study reports experimental data from outdoor open-top chamber (OTC) studies that quantify total biomass response changes for seedlings of 16 species native to western and eastern North America, which were exposed to several levels of elevated O3 for one or more years. The primary objective of this study is to establish a reference set of parameters for these seedling exposure-response relationships using a 3-month (92 day) 12-hr W126 O3 metric used by US Environmental Protection Agency and other agencies to assess risk to trees from O3 exposure. We classified the 16 species according to their sensitivity, based on the biomass loss response functions to protect from a 5% biomass loss. The three-month 12-h W126 estimated to result in a 5% biomass loss was 2.5-9.2 ppm-h for sensitive species, 20.8-25.2 ppm-h for intermediate species, and > 28.7 ppm-h for insensitive species. The most sensitive tree species include black cherry, ponderosa pine, quaking aspen, red alder, American sycamore, tulip poplar and winged sumac. These species are ecologically important and widespread across US. The effects of O3 on whole-plant biomass depended on exposure duration and dynamics and on the number of successive years of exposure. These species-specific exposure-response relationships will allow US agencies and other groups to better estimate biomass losses based on ozone exposures in North America and can be used in risk assessment and scenario analyses.
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Affiliation(s)
- E Henry Lee
- US Environmental Protection Agency, 200 SW 35 Street, Corvallis, OR 97333
| | | | - Peter A Beedlow
- US Environmental Protection Agency, 200 SW 35 Street, Corvallis, OR 97333
| | - David T Tingey
- US Environmental Protection Agency, 200 SW 35 Street, Corvallis, OR 97333 (Retired)
| | - Seiji Koike
- Oak Ridge Associated Universities, 200 SW 35 Street, Corvallis, OR 97333
| | | | - S Douglas Kaylor
- US Environmental Protection Agency, 109 T.W. Alexander Drive, RTP, NC 27711
| | - Kristopher Novak
- US Environmental Protection Agency, 109 T.W. Alexander Drive, RTP, NC 27711
| | - R Byron Rice
- US Environmental Protection Agency, 109 T.W. Alexander Drive, RTP, NC 27711
| | - Howard S Neufeld
- Department of Biology, Appalachian State University, 572 Rivers Street, Boone, NC 28608
| | - Jeffrey D Herrick
- US Environmental Protection Agency, 109 T.W. Alexander Drive, RTP, NC 27711
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19
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Haberstroh S, Lobo‐do‐Vale R, Caldeira MC, Dubbert M, Cuntz M, Werner C. Plant invasion modifies isohydricity in Mediterranean tree species. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Simon Haberstroh
- Ecosystem Physiology, Faculty of Environment and Natural Resources University Freiburg 79110 Freiburg Germany
- Forest Research Centre School of Agriculture University of Lisbon, 1349‐017 Lisbon Portugal
| | - Raquel Lobo‐do‐Vale
- Forest Research Centre School of Agriculture University of Lisbon, 1349‐017 Lisbon Portugal
| | - Maria C. Caldeira
- Forest Research Centre School of Agriculture University of Lisbon, 1349‐017 Lisbon Portugal
| | - Maren Dubbert
- Ecosystem Physiology, Faculty of Environment and Natural Resources University Freiburg 79110 Freiburg Germany
- Leibniz Centre for Agricultural Landscape Research (ZALF), Isotope Biogeochemistry and Gas Fluxes, 15374 Müncheberg Germany
| | - Matthias Cuntz
- Université de Lorraine AgroParisTech, INRAE, UMR Silva, 54000 Nancy France
| | - Christiane Werner
- Ecosystem Physiology, Faculty of Environment and Natural Resources University Freiburg 79110 Freiburg Germany
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20
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Geng X, Yu Z, Zhang D, Li C, Yuan Y, Wang X. The influence of local background climate on the dominant factors and threshold-size of the cooling effect of urban parks. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 823:153806. [PMID: 35150695 DOI: 10.1016/j.scitotenv.2022.153806] [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: 10/25/2021] [Revised: 01/25/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Urban parks can mitigate the urban heat island (UHI) by creating microclimates that lower in temperature than their surroundings, which are known as park cooling effect (PCE). The local background climate has a significant impact on the PCE, however the dominant factors and threshold value of efficiency (TVoE) of the PCE under different local background climates are still uncertain. Here, we selected 207 urban parks in 27 cities in East China with four different local background climates, warm temperate sub-humid monsoon (WTC), northern subtropical sub-humid monsoon (NSC), northern subtropical humid monsoon (NHC), and middle subtropical humid monsoon climate (MSC), for comparative studies. The relative contributions of multi-influencing factors to the PCE and TVoE of urban parks were quantified through a multivariate stepwise regression model and curve fitting. The results show that: (1) PCE increases from WTC, NSC, NHC to MSC, and urban parks at low latitudes have a greater cooling effect in general than those at high latitudes; (2) the area of the park is the dominant factor of PCE under four different local background climates (the explanation rate exceeds 50%) and water bodies within urban parks play a more significant role in the cooling effect in high latitudes, dry areas; (3) the TVoE of park on WTC, NSC, NHC, and MSC are 0.81, 0.71, 0.70, and 0.66 ha, respectively, revealing that the background climate significantly affects the TVoE. These findings are essential to decision-makers and can provide actionable knowledge for climate adaptation planning on a regional (climate) scale.
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Affiliation(s)
- Xiaolei Geng
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China
| | - Zhaowu Yu
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China
| | - Dou Zhang
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China
| | - Chengwei Li
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China
| | - Yuan Yuan
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China
| | - Xiangrong Wang
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China.
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21
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Schönbeck L, Grossiord C, Gessler A, Gisler J, Meusburger K, D'Odorico P, Rigling A, Salmon Y, Stocker BD, Zweifel R, Schaub M. Photosynthetic acclimation and sensitivity to short- and long-term environmental changes in a drought-prone forest. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2576-2588. [PMID: 35134157 DOI: 10.1093/jxb/erac033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Future climate will be characterized by an increase in frequency and duration of drought and warming that exacerbates atmospheric evaporative demand. How trees acclimate to long-term soil moisture changes and whether these long-term changes alter trees' sensitivity to short-term (day to months) variations of vapor pressure deficit (VPD) and soil moisture is largely unknown. Leaf gas exchange measurements were performed within a long-term (17 years) irrigation experiment in a drought-prone Scots pine-dominated forest in one of Switzerland's driest areas on trees in naturally dry (control), irrigated, and 'irrigation-stop' (after 11 years of irrigation) conditions. Seventeen years of irrigation increased photosynthesis (A) and stomatal conductance (gs) and reduced gs sensitivity to increasing VPD and soil drying. Following irrigation-stop, gas exchange decreased only after 3 years. After 5 years, maximum carboxylation (Vcmax) and electron transport (Jmax) rates in irrigation-stop recovered to similar levels as to before the irrigation-stop. These results suggest that long-term release from soil drought reduces the sensitivity to VPD and that atmospheric constraints may play an increasingly important role in combination with soil drought. Moreover, our study indicates that structural adjustments lead to an attenuation of initially strong leaf-level acclimation to strong multiple-year drought.
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Affiliation(s)
- Leonie Schönbeck
- Plant Ecology Research Laboratory, School of Architecture, Civil and Environmental Engineering, EPFL, Station 2, 1015 Lausanne, Switzerland
- Functional Plant Ecology, Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Station 2, 1015 Lausanne, Switzerland
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory, School of Architecture, Civil and Environmental Engineering, EPFL, Station 2, 1015 Lausanne, Switzerland
- Functional Plant Ecology, Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Station 2, 1015 Lausanne, Switzerland
| | - Arthur Gessler
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - Jonas Gisler
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Katrin Meusburger
- Biogeochemistry Unit, Swiss Federal Research Institute for Forest, Snow and Landscape research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Petra D'Odorico
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Andreas Rigling
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - Yann Salmon
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, PO Box 27, 00014 University of Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, 00014 University of Helsinki, Finland
| | - Benjamin D Stocker
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - Roman Zweifel
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Marcus Schaub
- Forest Dynamics Research Unit, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
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22
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Saunders A, Drew DM. Stomatal responses of Eucalyptus spp. under drought can be predicted with a gain-risk optimization model. TREE PHYSIOLOGY 2022; 42:815-830. [PMID: 34791492 DOI: 10.1093/treephys/tpab145] [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: 09/10/2021] [Accepted: 11/05/2021] [Indexed: 06/13/2023]
Abstract
The frequency and severity of drought events are expected to increase due to climate change, with optimal environmental conditions for forestry likely to shift. Modeling plant responses to a changing climate is therefore vital. We tested the process-based gain-risk model to predict stomatal responses to drought of two Eucalyptus hybrids. The process-based gain-risk model has the advantage that all the parameters used within the model are based on measurable plant traits. The gain-risk model proposes that plants optimize photosynthetic gain while minimizing a hydraulic cost. Previous versions of the model used hydraulic risk as a cost function; however, they did not account for delayed or reduced hydraulic recovery rates from embolism post-drought. Hydraulic recovery has been seen in many species, however it is still unclear how this inclusion of a partial or delayed hydraulic recovery would affect the predictive power of the gain-risk model. Many hydraulic parameters required by the model are also difficult to measure and are not freely available. We therefore tested a simplified gain-risk model that includes a delayed or reduced hydraulic recovery component post-drought. The simplified gain-risk model performed well at predicting stomatal responses in both Eucalyptus grandis × camaldulensis (GC) and Eucalyptus urophylla × grandis (UG). In this study two distinct strategies were seen between GC and UG, with GC being more resistant to embolism formation, however it could not recover hydraulic conductance compared with UG. The inclusion of a delayed or reduced hydraulic recovery component slightly improved model predictions for GC, however not for UG, which can be related to UG being able to recover lost hydraulic conductance and therefore can maintain stomatal conductance regardless of hydraulic risk. Even though the gain-risk model shows promise in predicting plant responses, more information is needed regarding hydraulic recovery after drought.
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Affiliation(s)
- Alta Saunders
- Department of Forest and Wood Science, Stellenbosch University, Paul Sauer Building, Bosman St, Stellenbosch Central, Stellenbosch, 7599, South Africa
| | - David M Drew
- Department of Forest and Wood Science, Stellenbosch University, Paul Sauer Building, Bosman St, Stellenbosch Central, Stellenbosch, 7599, South Africa
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23
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Challis A, Blackman C, Ahrens C, Medlyn B, Rymer P, Tissue D. Adaptive plasticity in plant traits increases time to hydraulic failure under drought in a foundation tree. TREE PHYSIOLOGY 2022; 42:708-721. [PMID: 34312674 DOI: 10.1093/treephys/tpab096] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The viability of forest trees, in response to climate change-associated drought, will depend on their capacity to survive through genetic adaptation and phenotypic plasticity in drought tolerance traits. Genotypes with enhanced plasticity for drought tolerance (adaptive plasticity) will have a greater ability to persist and delay the onset of hydraulic failure. By examining populations from different climate-origins grown under contrasting soil water availability, we tested for genotype (G), environment (E) and genotype-by-environment (G × E) effects on traits that determine the time it takes for saplings to desiccate from stomatal closure to 88% loss of stem hydraulic conductance (time to hydraulic failure, THF). Specifically, we hypothesized that: (i) THF is dependent on a G × E interaction, with longer THF for warm, dry climate populations in response to chronic water deficit treatment compared with cool, wet populations, and (ii) hydraulic and allometric traits explain the observed patterns in THF. Corymbia calophylla saplings from two populations originating from contrasting climates (warm-dry or cool-wet) were grown under well-watered and chronic soil water deficit treatments in large containers. Hydraulic and allometric traits were measured and then saplings were dried-down to critical levels of drought stress to estimate THF. Significant plasticity was detected in the warm-dry population in response to water-deficit, with enhanced drought tolerance compared with the cool-wet population. Projected leaf area and total plant water storage showed treatment variation, and minimum conductance showed significant population differences driving longer THF in trees from warm-dry origins grown in water-limited conditions. Our findings contribute information on intraspecific variation in key drought traits, including hydraulic and allometric determinants of THF. It highlights the need to quantify adaptive capacity in populations of forest trees in climate change-type drought to improve predictions of forest die-back.
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Affiliation(s)
- Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Chris Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- School of Biological Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Collin Ahrens
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Belinda Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Paul Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
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24
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Preisler Y, Hölttä T, Grünzweig JM, Oz I, Tatarinov F, Ruehr NK, Rotenberg E, Yakir D. The importance of tree internal water storage under drought conditions. TREE PHYSIOLOGY 2022; 42:771-783. [PMID: 34726242 DOI: 10.1093/treephys/tpab144] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Global warming and drying trends, as well as the increase in frequency and intensity of droughts, may have unprecedented impacts on various forest ecosystems. We assessed the role of internal water storage (WS) in drought resistance of mature pine trees in the semi-arid Yatir Forest. Transpiration (T), soil moisture and sap flow (SF) were measured continuously, accompanied by periodical measurements of leaf and branch water potential (Ψleaf) and water content (WC). The data were used to parameterize a tree hydraulics model to examine the impact of WS capacitance on the tree water relations. The results of the continuous measurements showed a 5-h time lag between T and SF in the dry season, which peaked in the early morning and early afternoon, respectively. A good fit between model results and observations was only obtained when the empirically estimated WS capacitance was included in the model. Without WS during the dry season, Ψleaf would drop below a threshold known to cause hydraulic failure and cessation of gas exchange in the studied tree species. Our results indicate that tree WS capacitance is a key drought resistance trait that could enhance tree survival in a drying climate, contributing up to 45% of the total daily transpiration during the dry season.
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Affiliation(s)
- Yakir Preisler
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street POB 12, Rehovot 7610001, Israel
| | - Teemu Hölttä
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, 3 Yliopistonkatu st, 0001 Helsinki, Finland
| | - José M Grünzweig
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street POB 12, Rehovot 7610001, Israel
| | - Itay Oz
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street POB 12, Rehovot 7610001, Israel
| | - Fedor Tatarinov
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
| | - Nadine K Ruehr
- Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen 82467, Germany
| | - Eyal Rotenberg
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
| | - Dan Yakir
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
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25
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Rao K, Williams AP, Diffenbaugh NS, Yebra M, Konings AG. Plant-water sensitivity regulates wildfire vulnerability. Nat Ecol Evol 2022; 6:332-339. [PMID: 35132185 PMCID: PMC8913365 DOI: 10.1038/s41559-021-01654-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/17/2021] [Indexed: 11/16/2022]
Abstract
Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2 = 0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50% faster during 1990–2010 than in other wildland–urban interfaces and because VPD has risen most rapidly in these vulnerable areas. As plant-water sensitivity is strongly linked to wildfire vulnerability, accounting for ecophysiological controls should improve wildfire forecasts. If recent trends in VPD and demographic shifts continue, human wildfire risk will probably continue to increase. The authors show that an ecosystem’s sensitivity to drought, measured as the amount of change in vegetation moisture content for a given change in background moisture, predicts the fire hazard in that location.
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26
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Characteristic of Stomatal Conductance and Optimal Stomatal Behaviour in an Arid Oasis of Northwestern China. SUSTAINABILITY 2022. [DOI: 10.3390/su14020968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Stomatal conductance (gs), the process that governs plant carbon uptake and water loss, is fundamental to most Land Surface Models (LSMs). With global change accelerating, more attention should be paid to investigating stomatal behavior, especially in extremely arid areas. In this study, gas exchange measurements and environmental/biological variables observations during growing seasons in 2016 and 2017 were combined to investigate diurnal and seasonal characteristics of gs and the applicability of the optimal stomatal conductance model in a desert oasis vineyard. The results showed that the responses of gs to environmental factors (photosynthesis active radiation, PAR; vapor pressure deficit, VPD; and temperature, T) formed hysteresis loops in the daytime. The stomatal conductance slope, g1, a parameter in the unified stomatal optimal model, varied in different growing seasons and correlated with the soil-to-leaf hydraulic conductance (KL). These results indicated the potential bias when using a constant g1 value to simulate gs and highlighted that the water-use strategy of oasis plants might not be consistent throughout the entire growing season. Our findings further help to achieve a better understanding of stomata behavior in responding to climate change and encourage future efforts toward a more accurate parameterization of gs to improve the modeling of LSMs.
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27
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Dewar R, Hölttä T, Salmon Y. Exploring optimal stomatal control under alternative hypotheses for the regulation of plant sources and sinks. THE NEW PHYTOLOGIST 2022; 233:639-654. [PMID: 34637543 DOI: 10.1111/nph.17795] [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: 05/13/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
Experimental evidence that nonstomatal limitations to photosynthesis (NSLs) correlate with leaf sugar and/or leaf water status suggests the possibility that stomata adjust to maximise photosynthesis through a trade-off between leaf CO2 supply and NSLs, potentially involving source-sink interactions. However, the mechanisms regulating NSLs and sink strength, as well as their implications for stomatal control, remain uncertain. We used an analytically solvable model to explore optimal stomatal control under alternative hypotheses for source and sink regulation. We assumed that either leaf sugar concentration or leaf water potential regulates NSLs, and that either phloem turgor pressure or phloem sugar concentration regulates sink phloem unloading. All hypotheses led to realistic stomatal responses to light, CO2 and air humidity, including conservative behaviour for the intercellular-to-atmospheric CO2 concentration ratio. Sugar-regulated and water-regulated NSLs are distinguished by the presence/absence of a stomatal closure response to changing sink strength. Turgor-regulated and sugar-regulated phloem unloading are distinguished by the presence/absence of stomatal closure under drought and avoidance/occurrence of negative phloem turgor. Results from girdling and drought experiments on Pinus sylvestris, Betula pendula, Populus tremula and Picea abies saplings are consistent with optimal stomatal control under sugar-regulated NSLs and turgor-regulated unloading. Our analytical results provide a simple representation of stomatal responses to above-ground and below-ground environmental factors and sink activity.
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Affiliation(s)
- Roderick Dewar
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, Helsinki, 00014, Finland
- Plant Sciences Division, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Teemu Hölttä
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, PO Box 27, Latokartanonkaari 7, Helsinki, 00014, Finland
| | - Yann Salmon
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, Helsinki, 00014, Finland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, PO Box 27, Latokartanonkaari 7, Helsinki, 00014, Finland
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28
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Kannenberg SA, Guo JS, Novick KA, Anderegg WRL, Feng X, Kennedy D, Konings AG, Martínez‐Vilalta J, Matheny AM. Opportunities, challenges and pitfalls in characterizing plant water‐use strategies. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13945] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Jessica S. Guo
- Department of Geology and Geophysics University of Utah Salt Lake City UT USA
- Arizona Experiment Station, College of Agriculture and Life Sciences University of Arizona Tucson AZ USA
| | - Kimberly A. Novick
- O’Neill School of Public and Environmental Affairs Indiana University Bloomington IN USA
| | | | - Xue Feng
- Department of Civil, Environmental, and Geo‐Engineering University of Minnesota Minneapolis MN USA
- Saint Anthony Falls Laboratory University of Minnesota Minneapolis MN USA
| | | | | | - Jordi Martínez‐Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès) Catalonia Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès) Catalonia Spain
| | - Ashley M. Matheny
- Department of Geological Sciences Jackson School of Geosciences University of Texas Austin TX USA
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29
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McAdam SAM, Chater CCC, Shpak ED, Raissig MT, Dow GJ. Editorial: Linking Stomatal Development and Physiology: From Stomatal Models to Non-model Species and Crops. FRONTIERS IN PLANT SCIENCE 2021; 12:743964. [PMID: 34659313 PMCID: PMC8516402 DOI: 10.3389/fpls.2021.743964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Scott A. M. McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | | | - Elena D. Shpak
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Michael T. Raissig
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Graham J. Dow
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland
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30
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Harrison SP, Cramer W, Franklin O, Prentice IC, Wang H, Brännström Å, de Boer H, Dieckmann U, Joshi J, Keenan TF, Lavergne A, Manzoni S, Mengoli G, Morfopoulos C, Peñuelas J, Pietsch S, Rebel KT, Ryu Y, Smith NG, Stocker BD, Wright IJ. Eco-evolutionary optimality as a means to improve vegetation and land-surface models. THE NEW PHYTOLOGIST 2021; 231:2125-2141. [PMID: 34131932 DOI: 10.1111/nph.17558] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
Global vegetation and land-surface models embody interdisciplinary scientific understanding of the behaviour of plants and ecosystems, and are indispensable to project the impacts of environmental change on vegetation and the interactions between vegetation and climate. However, systematic errors and persistently large differences among carbon and water cycle projections by different models highlight the limitations of current process formulations. In this review, focusing on core plant functions in the terrestrial carbon and water cycles, we show how unifying hypotheses derived from eco-evolutionary optimality (EEO) principles can provide novel, parameter-sparse representations of plant and vegetation processes. We present case studies that demonstrate how EEO generates parsimonious representations of core, leaf-level processes that are individually testable and supported by evidence. EEO approaches to photosynthesis and primary production, dark respiration and stomatal behaviour are ripe for implementation in global models. EEO approaches to other important traits, including the leaf economics spectrum and applications of EEO at the community level are active research areas. Independently tested modules emerging from EEO studies could profitably be integrated into modelling frameworks that account for the multiple time scales on which plants and plant communities adjust to environmental change.
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Affiliation(s)
- Sandy P Harrison
- Department of Geography and Environmental Science, University of Reading, Reading, RG6 6AB, UK
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Wolfgang Cramer
- Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale, Aix Marseille Université, CNRS, IRD, Avignon Université, Technopôle Arbois-Méditerranée, Aix-en-Provence Cedex 04, F-13545, France
| | - Oskar Franklin
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, 90183, Sweden
| | - Iain Colin Prentice
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Han Wang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Åke Brännström
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- Department of Mathematics and Mathematical Statistics, Umeå University, Umeå, 901 87, Sweden
| | - Hugo de Boer
- Copernicus Institute of Sustainable Development, Environmental Sciences, Faculty of Geosciences, Utrecht University, Vening Meinesz Building, Princetonlaan 8a, Utrecht, 3584 CB, the Netherlands
| | - Ulf Dieckmann
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa, 240-0193, Japan
| | - Jaideep Joshi
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
| | - Trevor F Keenan
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Aliénor Lavergne
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Stefano Manzoni
- Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Giulia Mengoli
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Catherine Morfopoulos
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Josep Peñuelas
- CSIC, Global Ecology, CREAF-CSIC-UAB, Bellaterra, Barcelona, Catalonia, 08193, Spain
- CREAF, Cerdanyola del Valles, Barcelona, Catalonia, 08193, Spain
| | - Stephan Pietsch
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- BOKU - University of Life Sciences and Natural Resources, Gregor-Medel-Strasse 33, Vienna, 1180, Austria
| | - Karin T Rebel
- Copernicus Institute of Sustainable Development, Environmental Sciences, Faculty of Geosciences, Utrecht University, Vening Meinesz Building, Princetonlaan 8a, Utrecht, 3584 CB, the Netherlands
| | - Youngryel Ryu
- Department of Landscape Architecture and Rural Systems Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Nicholas G Smith
- Department of Biological Sciences, Texas Tech University, 2901 Main Street, Lubbock, TX, 79409, USA
| | - Benjamin D Stocker
- Department of Environmental System Science, ETH, Universitätstrasse 2, Zürich, CH-8092, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zrcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
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31
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Kerr KL, Zenes N, Trugman AT, Anderegg WRL. Testing the effects of species interactions and water limitation on tree seedling biomass allocation and physiology. TREE PHYSIOLOGY 2021; 41:1323-1335. [PMID: 33555334 DOI: 10.1093/treephys/tpab005] [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: 03/08/2020] [Revised: 08/25/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Species interactions mediate tree responses to water limitation because competition and/or facilitation alter plant physiology and growth. However, because it is difficult to isolate the effects of plant-plant interactions and water limitation from other environmental factors, the mechanisms underlying tree physiology and growth in coexisting plants under drought are poorly understood. We investigated how species interactions and water limitation impact the physiology and growth of trembling aspen (Populus tremuloides), narrowleaf cottonwood (Populus angustifolia) and ponderosa pine (Pinus ponderosa) seedlings in a controlled environment growth chamber, using aspen as a focal species. Seedlings were grown in pots alone or with a con- or hetero-specific seedling, and were subjected to a water limitation treatment. Growth, water status and physiological traits were measured before, during and after the treatment. Under well-watered conditions, the presence of another seedling affected growth or biomass allocation in all species, but did not impact the physiological traits we measured. Under water limitation, the presence of a competing seedling had a marginal impact on seedling growth and physiological traits in all species. Throughout the study, the magnitude and direction of seedling responses were complex and often species-specific. Our study serves as an important step toward testing how species' interactions modify physiological responses and growth in well-watered and water-limited periods.
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Affiliation(s)
- Kelly L Kerr
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT 84111, USA
| | - Nicole Zenes
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT 84111, USA
| | - Anna T Trugman
- Department of Geography, University of California Santa Barbara, 1832 Ellison Hall, UC Santa Barbara, Santa Barbara, CA 93106, USA
| | - William R L Anderegg
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT 84111, USA
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Bassiouni M, Vico G. Parsimony vs predictive and functional performance of three stomatal optimization principles in a big-leaf framework. THE NEW PHYTOLOGIST 2021; 231:586-600. [PMID: 33864268 DOI: 10.1111/nph.17392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
Stomatal optimization models can improve estimates of water and carbon fluxes with relatively low complexity, yet there is no consensus on which formulations are most appropriate for ecosystem-scale applications. We implemented three existing analytical equations for stomatal conductance, based on different water penalty functions, in a big-leaf comparison framework, and determined which optimization principles were most consistent with flux tower observations from different biomes. We used information theory to dissect controls of soil water supply and atmospheric demand on evapotranspiration in wet to dry conditions and to quantify missing or inadequate information in model variants. We ranked stomatal optimization principles based on parameter uncertainty, parsimony, predictive accuracy, and functional accuracy of the interactions between soil moisture, vapor pressure deficit, and evapotranspiration. Performance was high for all model variants. Water penalty functions with explicit representation of plant hydraulics did not substantially improve predictive or functional accuracy of ecosystem-scale evapotranspiration estimates, and parameterizations were more uncertain, despite having physiological underpinnings at the plant level. Stomatal optimization based on water use efficiency thus provided more information about ecosystem-scale evapotranspiration compared to those based on xylem vulnerability and proved more useful in improving ecosystem-scale models with less complexity.
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Affiliation(s)
- Maoya Bassiouni
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, 750 07, Sweden
| | - Giulia Vico
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, 750 07, Sweden
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33
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Importance of hydraulic strategy trade-offs in structuring response of canopy trees to extreme drought in central Amazon. Oecologia 2021; 197:13-24. [PMID: 33948691 DOI: 10.1007/s00442-021-04924-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
Plant ecophysiological trade-offs between different strategies for tolerating stresses are widely theorized to shape forest functional diversity and vulnerability to climate change. However, trade-offs between hydraulic and stomatal regulation during natural droughts remain under-studied, especially in tropical forests. We investigated eleven mature forest canopy trees in central Amazonia during the strong 2015 El Niño. We found greater xylem embolism resistance ([Formula: see text] = - 3.3 ± 0.8 MPa) and hydraulic safety margin (HSM = 2.12 ± 0.57 MPa) than previously observed in more precipitation-seasonal rainforests of eastern Amazonia and central America. We also discovered that taller trees exhibited lower embolism resistance and greater stomatal sensitivity, a height-structured trade-off between hydraulic resistance and active stomatal regulation. Such active regulation of tree water status, triggered by the onset of stem embolism, acted as a feedback to avoid further increases in embolism, and also explained declines in photosynthesis and transpiration. These results suggest that canopy trees exhibit a conservative hydraulic strategy to endure drought, with trade-offs between investment in xylem to reduce vulnerability to hydraulic failure, and active stomatal regulation to protect against low water potentials. These findings improve our understanding of strategies in tropical forest canopies and contribute to more accurate prediction of drought responses.
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Restrepo-Coupe N, Albert LP, Longo M, Baker I, Levine NM, Mercado LM, da Araujo AC, Christoffersen BO, Costa MH, Fitzjarrald DR, Galbraith D, Imbuzeiro H, Malhi Y, von Randow C, Zeng X, Moorcroft P, Saleska SR. Understanding water and energy fluxes in the Amazonia: Lessons from an observation-model intercomparison. GLOBAL CHANGE BIOLOGY 2021; 27:1802-1819. [PMID: 33565692 DOI: 10.1111/gcb.15555] [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: 08/10/2020] [Revised: 01/18/2021] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
Tropical forests are an important part of global water and energy cycles, but the mechanisms that drive seasonality of their land-atmosphere exchanges have proven challenging to capture in models. Here, we (1) report the seasonality of fluxes of latent heat (LE), sensible heat (H), and outgoing short and longwave radiation at four diverse tropical forest sites across Amazonia-along the equator from the Caxiuanã and Tapajós National Forests in the eastern Amazon to a forest near Manaus, and from the equatorial zone to the southern forest in Reserva Jaru; (2) investigate how vegetation and climate influence these fluxes; and (3) evaluate land surface model performance by comparing simulations to observations. We found that previously identified failure of models to capture observed dry-season increases in evapotranspiration (ET) was associated with model overestimations of (1) magnitude and seasonality of Bowen ratios (relative to aseasonal observations in which sensible was only 20%-30% of the latent heat flux) indicating model exaggerated water limitation, (2) canopy emissivity and reflectance (albedo was only 10%-15% of incoming solar radiation, compared to 0.15%-0.22% simulated), and (3) vegetation temperatures (due to underestimation of dry-season ET and associated cooling). These partially compensating model-observation discrepancies (e.g., higher temperatures expected from excess Bowen ratios were partially ameliorated by brighter leaves and more interception/evaporation) significantly biased seasonal model estimates of net radiation (Rn ), the key driver of water and energy fluxes (LE ~ 0.6 Rn and H ~ 0.15 Rn ), though these biases varied among sites and models. A better representation of energy-related parameters associated with dynamic phenology (e.g., leaf optical properties, canopy interception, and skin temperature) could improve simulations and benchmarking of current vegetation-atmosphere exchange and reduce uncertainty of regional and global biogeochemical models.
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Affiliation(s)
- Natalia Restrepo-Coupe
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia
| | - Loren P Albert
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
- Biology Department, West Virginia University, Morgantown, WV, USA
| | - Marcos Longo
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Ian Baker
- Colorado State University, Atmospheric Science, Fort Collins, CO, USA
| | - Naomi M Levine
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- College of Letters, Arts, and Science, University of Southern California, Los Angeles, CA, USA
| | - Lina M Mercado
- University of Exeter, College of Life and Environmental Sciences, Exeter, Devon, UK
- Centre for Ecology and Hydrology, Wallingford, Oxfordshire, UK
| | - Alessandro C da Araujo
- Embrapa Amazônia Oriental, Belém, Pará, Brazil
- Programa LBA, Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brazil
| | - Bradley O'Donnell Christoffersen
- Department of Biology, University of Texas Rio Grande Valley, Edinburg, TX, USA
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Marcos H Costa
- Department of Agricultural Engineering, Federal University of Vicosa, Vicosa, Mato Grosso, Brazil
| | | | | | - Hewlley Imbuzeiro
- Department of Agricultural Engineering, Federal University of Vicosa, Vicosa, Mato Grosso, Brazil
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Celso von Randow
- National Institute for Space Research (INPE), Center for Earth Systems Science, São José dos Campos, São Pablo, Brazil
| | - Xubin Zeng
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Paul Moorcroft
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Scott R Saleska
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
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35
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Olson ME, Anfodillo T, Rosell JA, Martínez-Méndez N. Across climates and species, higher vapour pressure deficit is associated with wider vessels for plants of the same height. PLANT, CELL & ENVIRONMENT 2020; 43:3068-3080. [PMID: 32909290 DOI: 10.1111/pce.13884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/23/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
While plant height is the main driver of variation in mean vessel diameter at the stem base (VD) across angiosperms, climate, specifically temperature, does play an explanatory role, with vessels being wider with warmer temperature for plants of the same height. Using a comparative approach sampling 537 species of angiosperms across 19 communities, we rejected selection favouring freezing-induced embolism resistance as being able to account for wider vessels for a given height in warmer climates. Instead, we give reason to suspect that higher vapour pressure deficit (VPD) accounts for the positive scaling of height-standardized VD (and potential xylem conductance) with temperature. Selection likely favours conductive systems that are able to meet the higher transpirational demand of warmer climates, which have higher VPD, resulting in wider vessels for a given height. At the same time, wider vessels are likely more vulnerable to dysfunction. With future climates likely to experience ever greater extremes of VPD, future forests could be increasingly vulnerable.
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Affiliation(s)
- Mark E Olson
- Instituto de Biología, Departamento de Botánica, Universidad Nacional Autónoma de México, Tercer Circuito sn de Ciudad Universitaria, Ciudad de México, Mexico
| | - Tommaso Anfodillo
- Department Territorio e Sistemi Agro-Forestali, University of Padova, Padova, Italy
| | - Julieta A Rosell
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Norberto Martínez-Méndez
- Laboratorio de Bioconservación y Manejo, Departamento de Zoología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Unidad Profesional Lázaro Cárdenas, Ciudad de México, Mexico
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36
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Lavergne A, Sandoval D, Hare VJ, Graven H, Prentice IC. Impacts of soil water stress on the acclimated stomatal limitation of photosynthesis: Insights from stable carbon isotope data. GLOBAL CHANGE BIOLOGY 2020; 26:7158-7172. [PMID: 32970907 DOI: 10.1111/gcb.15364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/15/2020] [Indexed: 05/08/2023]
Abstract
Atmospheric aridity and drought both influence physiological function in plant leaves, but their relative contributions to changes in the ratio of leaf internal to ambient partial pressure of CO2 (χ) - an index of adjustments in both stomatal conductance and photosynthetic rate to environmental conditions - are difficult to disentangle. Many stomatal models predicting χ include the influence of only one of these drivers. In particular, the least-cost optimality hypothesis considers the effect of atmospheric demand for water on χ but does not predict how soils with reduced water further influence χ, potentially leading to an overestimation of χ under dry conditions. Here, we use a large network of stable carbon isotope measurements in C3 woody plants to examine the acclimated response of χ to soil water stress. We estimate the ratio of cost factors for carboxylation and transpiration (β) expected from the theory to explain the variance in the data, and investigate the responses of β (and thus χ) to soil water content and suction across seed plant groups, leaf phenological types and regions. Overall, β decreases linearly with soil drying, implying that the cost of water transport along the soil-plant-atmosphere continuum increases as water available in the soil decreases. However, despite contrasting hydraulic strategies, the stomatal responses of angiosperms and gymnosperms to soil water tend to converge, consistent with the optimality theory. The prediction of β as a simple, empirical function of soil water significantly improves χ predictions by up to 6.3 ± 2.3% (mean ± SD of adjusted-R2 ) over 1980-2018 and results in a reduction of around 2% of mean χ values across the globe. Our results highlight the importance of soil water status on stomatal functions and plant water-use efficiency, and suggest the implementation of trait-based hydraulic functions into the model to account for soil water stress.
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Affiliation(s)
- Aliénor Lavergne
- Carbon Cycle Research Group, Space and Atmospheric Physics, Department of Physics, Imperial College London, London, UK
| | - David Sandoval
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - Vincent J Hare
- Carbon Cycle Research Group, Space and Atmospheric Physics, Department of Physics, Imperial College London, London, UK
- Stable Light Isotope Laboratory, University of Cape Town, Cape Town, South Africa
| | - Heather Graven
- Carbon Cycle Research Group, Space and Atmospheric Physics, Department of Physics, Imperial College London, London, UK
- Grantham Institute - Climate Change and the Environment, Imperial College London, London, UK
| | - Iain Colin Prentice
- Department of Life Sciences, Imperial College London, Ascot, UK
- Grantham Institute - Climate Change and the Environment, Imperial College London, London, UK
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
- Department of Earth System Science, Tsinghua University, Beijing, China
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37
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Bartholomew DC, Bittencourt PRL, da Costa ACL, Banin LF, de Britto Costa P, Coughlin SI, Domingues TF, Ferreira LV, Giles A, Mencuccini M, Mercado L, Miatto RC, Oliveira A, Oliveira R, Meir P, Rowland L. Small tropical forest trees have a greater capacity to adjust carbon metabolism to long-term drought than large canopy trees. PLANT, CELL & ENVIRONMENT 2020; 43:2380-2393. [PMID: 32643169 DOI: 10.1111/pce.13838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
The response of small understory trees to long-term drought is vital in determining the future composition, carbon stocks and dynamics of tropical forests. Long-term drought is, however, also likely to expose understory trees to increased light availability driven by drought-induced mortality. Relatively little is known about the potential for understory trees to adjust their physiology to both decreasing water and increasing light availability. We analysed data on maximum photosynthetic capacity (Jmax , Vcmax ), leaf respiration (Rleaf ), leaf mass per area (LMA), leaf thickness and leaf nitrogen and phosphorus concentrations from 66 small trees across 12 common genera at the world's longest running tropical rainfall exclusion experiment and compared responses to those from 61 surviving canopy trees. Small trees increased Jmax , Vcmax , Rleaf and LMA (71, 29, 32, 15% respectively) in response to the drought treatment, but leaf thickness and leaf nutrient concentrations did not change. Small trees were significantly more responsive than large canopy trees to the drought treatment, suggesting greater phenotypic plasticity and resilience to prolonged drought, although differences among taxa were observed. Our results highlight that small tropical trees have greater capacity to respond to ecosystem level changes and have the potential to regenerate resilient forests following future droughts.
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Affiliation(s)
- David C Bartholomew
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Paulo R L Bittencourt
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | | | | | | | - Sarah I Coughlin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Tomas F Domingues
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - André Giles
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Maurizio Mencuccini
- ICREA, Barcelona, Spain
- CREAF, Universidad Autonoma de Barcelona, Barcelona, Spain
| | - Lina Mercado
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- UK Centre for Ecology and Hydrology, Wallingford, UK
| | - Raquel C Miatto
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Rafael Oliveira
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Patrick Meir
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Lucy Rowland
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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38
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Carminati A, Javaux M. Soil Rather Than Xylem Vulnerability Controls Stomatal Response to Drought. TRENDS IN PLANT SCIENCE 2020; 25:868-880. [PMID: 32376085 DOI: 10.1016/j.tplants.2020.04.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 05/12/2023]
Abstract
The current trend towards linking stomata regulation to plant hydraulics emphasizes the role of xylem vulnerability. Using a soil-plant hydraulic model, we show that xylem vulnerability does not trigger stomatal closure in medium-wet to dry soils and we propose that soil hydraulic conductivity loss is the primary driver of stomatal closure. This finding has two key implications: transpiration response to drought cannot be derived from plant traits only and is related to soil-root hydraulics in a predictable way; roots and their interface with the soil, the rhizosphere, are key hydraulic regions that plants can alter to efficiently adapt to water limitations. We conclude that connecting below- and aboveground hydraulics is necessary to fully comprehend plant responses to drought.
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Affiliation(s)
- Andrea Carminati
- University of Bayreuth, Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), Universitätstrasse 30, D-95447 Bayreuth, Germany
| | - Mathieu Javaux
- Université Catholique de Louvain, Earth and Life Institute, Croix du Sud L7.05.02, B-1348 Louvain-la-Neuve, Belgium; Agrosphere, Forschungszentrum Juelich GmbH, D-52425, Juelich, Germany.
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39
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Resco de Dios V, Anderegg WR, Li X, Tissue DT, Bahn M, Landais D, Milcu A, Yao Y, Nolan RH, Roy J, Gessler A. Circadian Regulation Does Not Optimize Stomatal Behaviour. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1091. [PMID: 32854373 PMCID: PMC7570086 DOI: 10.3390/plants9091091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/13/2020] [Accepted: 08/21/2020] [Indexed: 02/05/2023]
Abstract
The circadian clock is a molecular timer of metabolism that affects the diurnal pattern of stomatal conductance (gs), amongst other processes, in a broad array of plant species. The function of circadian gs regulation remains unknown and here, we test whether circadian regulation helps to optimize diurnal variations in stomatal conductance. We subjected bean (Phaseolus vulgaris) and cotton (Gossypium hirsutum) canopies to fixed, continuous environmental conditions of photosynthetically active radiation, temperature, and vapour pressure deficit (free-running conditions) over 48 h. We modelled gs variations in free-running conditions to test for two possible optimizations of stomatal behaviour under circadian regulation: (i) that stomata operate to maintain constant marginal water use efficiency; or (ii) that stomata maximize C net gain minus the costs or risks of hydraulic damage. We observed that both optimization models predicted gs poorly under free-running conditions, indicating that circadian regulation does not directly lead to stomatal optimization. We also demonstrate that failure to account for circadian variation in gs could potentially lead to biased parameter estimates during calibrations of stomatal models. More broadly, our results add to the emerging field of plant circadian ecology, where circadian controls may partially explain leaf-level patterns observed in the field.
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Affiliation(s)
- Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China;
- Department of Crop and Forest Sciences-AGROTECNIO Center, University of Lleida, 25198 Lleida, Spain
| | | | - Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia; (X.L.); (D.T.T.); (R.H.N.)
| | - David T. Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia; (X.L.); (D.T.T.); (R.H.N.)
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, 6020 Innsbruck, Austria;
| | - Damien Landais
- Ecotron Européen de Montpellier, CNRS, 34980 Montferrier-sur-Lez, France; (D.L.); (A.M.); (J.R.)
| | - Alexandru Milcu
- Ecotron Européen de Montpellier, CNRS, 34980 Montferrier-sur-Lez, France; (D.L.); (A.M.); (J.R.)
- Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), CNRS, UMR 5175, Université de Montpellier, Université Paul Valéry, EPHE, IRD, 34293 Montpellier, France
| | - Yinan Yao
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China;
| | - Rachael H. Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia; (X.L.); (D.T.T.); (R.H.N.)
| | - Jacques Roy
- Ecotron Européen de Montpellier, CNRS, 34980 Montferrier-sur-Lez, France; (D.L.); (A.M.); (J.R.)
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland;
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
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40
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Wang Y, Sperry JS, Anderegg WRL, Venturas MD, Trugman AT. A theoretical and empirical assessment of stomatal optimization modeling. THE NEW PHYTOLOGIST 2020; 227:311-325. [PMID: 32248532 DOI: 10.1111/nph.16572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/09/2020] [Indexed: 05/13/2023]
Abstract
Optimal stomatal control models have shown great potential in predicting stomatal behavior and improving carbon cycle modeling. Basic stomatal optimality theory posits that stomatal regulation maximizes the carbon gain relative to a penalty of stomatal opening. All models take a similar approach to calculate instantaneous carbon gain from stomatal opening (the gain function). Where the models diverge is in how they calculate the corresponding penalty (the penalty function). In this review, we compare and evaluate 10 different optimization models in how they quantify the penalty and how well they predict stomatal responses to the environment. We evaluate models in two ways. First, we compare their penalty functions against seven criteria that ensure a unique and qualitatively realistic solution. Second, we quantitatively test model against multiple leaf gas-exchange datasets. The optimization models with better predictive skills have penalty functions that meet our seven criteria and use fitting parameters that are both few in number and physiology based. The most skilled models are those with a penalty function based on stress-induced hydraulic failure. We conclude by proposing a new model that has a hydraulics-based penalty function that meets all seven criteria and demonstrates a highly predictive skill against our test datasets.
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Affiliation(s)
- Yujie Wang
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - John S Sperry
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - William R L Anderegg
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Anna T Trugman
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
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41
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Li X, Piao S, Wang K, Wang X, Wang T, Ciais P, Chen A, Lian X, Peng S, Peñuelas J. Temporal trade-off between gymnosperm resistance and resilience increases forest sensitivity to extreme drought. Nat Ecol Evol 2020; 4:1075-1083. [DOI: 10.1038/s41559-020-1217-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 05/05/2020] [Indexed: 01/15/2023]
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42
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Anderegg WRL, Venturas MD. Plant hydraulics play a critical role in Earth system fluxes. THE NEW PHYTOLOGIST 2020; 226:1535-1538. [PMID: 32259286 DOI: 10.1111/nph.16548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- William R L Anderegg
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
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43
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Eller CB, Rowland L, Mencuccini M, Rosas T, Williams K, Harper A, Medlyn BE, Wagner Y, Klein T, Teodoro GS, Oliveira RS, Matos IS, Rosado BHP, Fuchs K, Wohlfahrt G, Montagnani L, Meir P, Sitch S, Cox PM. Stomatal optimization based on xylem hydraulics (SOX) improves land surface model simulation of vegetation responses to climate. THE NEW PHYTOLOGIST 2020; 226:1622-1637. [PMID: 31916258 PMCID: PMC7318565 DOI: 10.1111/nph.16419] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/03/2020] [Indexed: 05/23/2023]
Abstract
Land surface models (LSMs) typically use empirical functions to represent vegetation responses to soil drought. These functions largely neglect recent advances in plant ecophysiology that link xylem hydraulic functioning with stomatal responses to climate. We developed an analytical stomatal optimization model based on xylem hydraulics (SOX) to predict plant responses to drought. Coupling SOX to the Joint UK Land Environment Simulator (JULES) LSM, we conducted a global evaluation of SOX against leaf- and ecosystem-level observations. SOX simulates leaf stomatal conductance responses to climate for woody plants more accurately and parsimoniously than the existing JULES stomatal conductance model. An ecosystem-level evaluation at 70 eddy flux sites shows that SOX decreases the sensitivity of gross primary productivity (GPP) to soil moisture, which improves the model agreement with observations and increases the predicted annual GPP by 30% in relation to JULES. SOX decreases JULES root-mean-square error in GPP by up to 45% in evergreen tropical forests, and can simulate realistic patterns of canopy water potential and soil water dynamics at the studied sites. SOX provides a parsimonious way to incorporate recent advances in plant hydraulics and optimality theory into LSMs, and an alternative to empirical stress factors.
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Affiliation(s)
- Cleiton B. Eller
- College of Life and Environmental SciencesUniversity of ExeterExeterEX4 4QFUK
- Department of Plant BiologyUniversity of CampinasCampinas13083‐862Brazil
| | - Lucy Rowland
- College of Life and Environmental SciencesUniversity of ExeterExeterEX4 4QFUK
| | - Maurizio Mencuccini
- CREAFBellaterra08193BarcelonaSpain
- ICREAPg. Lluís Companys 2308010BarcelonaSpain
| | - Teresa Rosas
- CREAFBellaterra08193BarcelonaSpain
- ICREAPg. Lluís Companys 2308010BarcelonaSpain
| | | | - Anna Harper
- College of Engineering, Mathematics and Physical SciencesUniversity of ExeterExeterEX4 4QFUK
| | - Belinda E. Medlyn
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
| | - Yael Wagner
- Department of Plant & Environmental SciencesWeizmann Institute of Science76100RehovotIsrael
| | - Tamir Klein
- Department of Plant & Environmental SciencesWeizmann Institute of Science76100RehovotIsrael
| | | | - Rafael S. Oliveira
- Department of Plant BiologyUniversity of CampinasCampinas13083‐862Brazil
| | - Ilaine S. Matos
- Department of Ecology – IBRAGRio de Janeiro State University (UERJ)Rio de Janeiro20550‐013Brazil
| | - Bruno H. P. Rosado
- Department of Ecology – IBRAGRio de Janeiro State University (UERJ)Rio de Janeiro20550‐013Brazil
| | - Kathrin Fuchs
- Department of Environmental Systems ScienceETH ZurichUniversitätstrasse 28092ZurichSwitzerland
| | - Georg Wohlfahrt
- Department of EcologyUniversity of InnsbruckInnsbruck6020Austria
| | - Leonardo Montagnani
- Forest ServicesAutonomous Province of BolzanoVia Brennero 639100BolzanoItaly
| | - Patrick Meir
- Research School of BiologyThe Australian National UniversityActonACT2601Australia
- School of GeosciencesUniversity of EdinburghEdinburghEH9 3FFUK
| | - Stephen Sitch
- College of Life and Environmental SciencesUniversity of ExeterExeterEX4 4QFUK
| | - Peter M. Cox
- College of Engineering, Mathematics and Physical SciencesUniversity of ExeterExeterEX4 4QFUK
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44
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Aparecido LMT, Woo S, Suazo C, Hultine KR, Blonder B. High water use in desert plants exposed to extreme heat. Ecol Lett 2020; 23:1189-1200. [PMID: 32436365 DOI: 10.1111/ele.13516] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 03/22/2020] [Accepted: 03/25/2020] [Indexed: 01/06/2023]
Abstract
Many plant water use models predict leaves maximize carbon assimilation while minimizing water loss via transpiration. Alternate scenarios may occur at high temperature, including heat avoidance, where leaves increase water loss to evaporatively cool regardless of carbon uptake; or heat failure, where leaves non-adaptively lose water also regardless of carbon uptake. We hypothesized that these alternative scenarios are common in species exposed to hot environments, with heat avoidance more common in species with high construction cost leaves. Diurnal measurements of leaf temperature and gas exchange for 11 Sonoran Desert species revealed that 37% of these species increased transpiration in the absence of increased carbon uptake. High leaf mass per area partially predicted this behaviour (r2 = 0.39). These data are consistent with heat avoidance and heat failure, but failure is less likely given the ecological dominance of the focal species. These behaviours are not yet captured in any extant plant water use model.
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Affiliation(s)
- Luiza M T Aparecido
- School of Life Sciences, Arizona State University, 427 E Tyler Mall, Tempe, AZ, 85821, USA
| | - Sabrina Woo
- School of Life Sciences, Arizona State University, 427 E Tyler Mall, Tempe, AZ, 85821, USA
| | - Crystal Suazo
- School of Life Sciences, Arizona State University, 427 E Tyler Mall, Tempe, AZ, 85821, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 N. Galvin Parkway, Phoenix, AZ, 85008, USA
| | - Benjamin Blonder
- School of Life Sciences, Arizona State University, 427 E Tyler Mall, Tempe, AZ, 85821, USA.,Environmental Change Institute, School of Geography and the Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK.,Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, 94720, USA
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45
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Zenes N, Kerr KL, Trugman AT, Anderegg WRL. Competition and Drought Alter Optimal Stomatal Strategy in Tree Seedlings. FRONTIERS IN PLANT SCIENCE 2020; 11:478. [PMID: 32457769 PMCID: PMC7227391 DOI: 10.3389/fpls.2020.00478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/31/2020] [Indexed: 05/17/2023]
Abstract
A better understanding of plant stomatal strategies holds strong promise for improving predictions of vegetation responses to drought because stomata are the primary mechanism through which plants mitigate water stress. It has been assumed that plants regulate stomata to maintain a constant marginal water use efficiency and forego carbon gain when water is scarce. However, recent hypotheses pose that plants maximize carbon assimilation while also accounting for the risk of hydraulic damage via cavitation and hydraulic failure. This "gain-risk" framework incorporates competition in stomatal regulation because it takes into account that neighboring plants can "steal" unused water. This study utilizes stomatal models representing both the water use efficiency and carbon-maximization frameworks, and empirical data from three species in a potted growth chamber experiment, to investigate the effects of drought and competition on seedling stomatal strategy. We found that drought and competition responses in the empirical data were best explained by the carbon-maximization hypothesis and that both drought and competition affected stomatal strategy. Interestingly, stomatal responses differed substantially by species, with seedlings employing a riskier strategy when planted with a high water use competitor, and seedlings employing a more conservative strategy when planted with a low water use competitor. Lower water users in general had less stomatal sensitivity to decreasing Ψ L compared to moderate to high water users. Repeated water stress also resulted in legacy effects on plant stomatal behavior, increasing stomatal sensitivity (i.e., conservative behavior) even when the seedling was returned to well-watered conditions. These results indicate that stomatal strategies are dynamic and change with climate and competition stressors. Therefore, incorporating mechanisms that allow for stomatal behavioral changes in response to water limitation may be an important step to improving carbon cycle projections in coupled climate-Earth system models.
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Affiliation(s)
- Nicole Zenes
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
- *Correspondence: Nicole Zenes, ;
| | - Kelly L. Kerr
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
| | - Anna T. Trugman
- School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
- Department of Geography, University of California, Santa Barbara, Santa Barbara, CA, United States
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46
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Granda E, Baumgarten F, Gessler A, Gil-Pelegrin E, Peguero-Pina JJ, Sancho-Knapik D, Zimmerman NE, Resco de Dios V. Day length regulates seasonal patterns of stomatal conductance in Quercus species. PLANT, CELL & ENVIRONMENT 2020; 43:28-39. [PMID: 31677177 DOI: 10.1111/pce.13665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Vapour pressure deficit is a major driver of seasonal changes in transpiration, but photoperiod also modulates leaf responses. Climate warming might enhance transpiration by increasing atmospheric water demand and the length of the growing season, but photoperiod-sensitive species could show dampened responses. Here, we document that day length is a significant driver of the seasonal variation in stomatal conductance. We performed weekly gas exchange measurements across a common garden experiment with 12 oak species from contrasting geographical origins, and we observed that the influence of day length was of similar strength to that of vapour pressure deficit in driving the seasonal pattern. We then examined the generality of our findings by incorporating day-length regulation into well-known stomatal models. For both angiosperm and gymnosperm species, the models improved significantly when adding day-length dependences. Photoperiod control over stomatal conductance could play a large yet underexplored role on the plant and ecosystem water balances.
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Affiliation(s)
- Elena Granda
- Department of Crop and Forest Sciences-AGROTECNIO Center, Universitat de Lleida, Lleida, 25198, Spain
- Department of Life Sciences, University of Alcalá, Alcalá de Henares, E-28805, Spain
| | - Frederik Baumgarten
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, CH-8903, Switzerland
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, CH-8903, Switzerland
| | - Eustaquio Gil-Pelegrin
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, Zaragoza, 50059, Spain
| | - Jose Javier Peguero-Pina
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, Zaragoza, 50059, Spain
| | - Domingo Sancho-Knapik
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, Zaragoza, 50059, Spain
| | - Niklaus E Zimmerman
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, CH-8903, Switzerland
| | - Víctor Resco de Dios
- Department of Crop and Forest Sciences-AGROTECNIO Center, Universitat de Lleida, Lleida, 25198, Spain
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China
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47
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Sun P, Wu Y, Xiao J, Hui J, Hu J, Zhao F, Qiu L, Liu S. Remote sensing and modeling fusion for investigating the ecosystem water-carbon coupling processes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134064. [PMID: 31476506 DOI: 10.1016/j.scitotenv.2019.134064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 07/20/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
The water and carbon cycles are tightly linked and play a key role in the material and energy flows between terrestrial ecosystems and the atmosphere, but the interactions of water and carbon cycles are not quite clear. The global climate change and intensive human activities could also complicate the water and carbon coupling processes. Better understanding the coupled water-carbon cycles and their spatiotemporal evolution can inform management and decision-making efforts regarding carbon uptake, food production, water resources, and climate change. The integration of remote sensing and numeric modeling is an attractive approach to address the challenge. Remote sensing can provide extensive data for a number of variables at regional scale and support models, whereas process-based modeling can facilitate investigating the processes that remote sensing cannot well handle (e.g., below-ground and lateral material movement) and backcast/forecast the impacts of environmental change. Over the past twenty years, an increasing number of studies using a variety of remote sensing products together with numeric models have examined the water-carbon interactions. This article reviewed the methodologies for integrating remote sensing data into these models and the modeling of water-carbon coupling processes. We first summarized the major remote sensing datasets and models used for studying the coupled water-carbon cycles. We then provided an overview of the methods for integrating remote sensing data into water-carbon models, and discussed their strengths and challenges. We also prospected the development of potential new remote sensing datasets, modeling methods, and their potential applications in the field of eco-hydrology.
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Affiliation(s)
- Pengcheng Sun
- Department of Earth & Environmental Science, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China; Key Laboratory of Degraded and Unused Land Consolidation Engineering, The Ministry of Natural Resources of China, Xi'an, Shaanxi Province 710075, China
| | - Yiping Wu
- Department of Earth & Environmental Science, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China.
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Jinyu Hui
- Department of Earth & Environmental Science, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China
| | - Jingyi Hu
- Department of Earth & Environmental Science, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China
| | - Fubo Zhao
- Department of Earth & Environmental Science, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China
| | - Linjing Qiu
- Department of Earth & Environmental Science, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China
| | - Shuguang Liu
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha, Hunan Province 410004, China
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48
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Sperry JS, Venturas MD, Todd HN, Trugman AT, Anderegg WRL, Wang Y, Tai X. The impact of rising CO 2 and acclimation on the response of US forests to global warming. Proc Natl Acad Sci U S A 2019; 116:25734-25744. [PMID: 31767760 PMCID: PMC6926066 DOI: 10.1073/pnas.1913072116] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The response of forests to climate change depends in part on whether the photosynthetic benefit from increased atmospheric CO2 (∆Ca = future minus historic CO2) compensates for increased physiological stresses from higher temperature (∆T). We predicted the outcome of these competing responses by using optimization theory and a mechanistic model of tree water transport and photosynthesis. We simulated current and future productivity, stress, and mortality in mature monospecific stands with soil, species, and climate sampled from 20 continental US locations. We modeled stands with and without acclimation to ∆Ca and ∆T, where acclimated forests adjusted leaf area, photosynthetic capacity, and stand density to maximize productivity while avoiding stress. Without acclimation, the ∆Ca-driven boost in net primary productivity (NPP) was compromised by ∆T-driven stress and mortality associated with vascular failure. With acclimation, the ∆Ca-driven boost in NPP and stand biomass (C storage) was accentuated for cooler futures but negated for warmer futures by a ∆T-driven reduction in NPP and biomass. Thus, hotter futures reduced forest biomass through either mortality or acclimation. Forest outcomes depended on whether projected climatic ∆Ca/∆T ratios were above or below physiological thresholds that neutralized the negative impacts of warming. Critically, if forests do not acclimate, the ∆Ca/∆T must be above ca 89 ppm⋅°C-1 to avoid chronic stress, a threshold met by 55% of climate projections. If forests do acclimate, the ∆Ca/∆T must rise above ca 67 ppm⋅°C-1 for NPP and biomass to increase, a lower threshold met by 71% of projections.
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Affiliation(s)
- John S Sperry
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112;
| | - Henry N Todd
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Anna T Trugman
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
- Department of Geography, University of California, Santa Barbara, CA 93106
| | | | - Yujie Wang
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Xiaonan Tai
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112
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49
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Trugman AT, Anderegg LDL, Sperry JS, Wang Y, Venturas M, Anderegg WRL. Leveraging plant hydraulics to yield predictive and dynamic plant leaf allocation in vegetation models with climate change. GLOBAL CHANGE BIOLOGY 2019; 25:4008-4021. [PMID: 31465580 DOI: 10.1111/gcb.14814] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Plant functional traits provide a link in process-based vegetation models between plant-level physiology and ecosystem-level responses. Recent advances in physiological understanding and computational efficiency have allowed for the incorporation of plant hydraulic processes in large-scale vegetation models. However, a more mechanistic representation of water limitation that determines ecosystem responses to plant water stress necessitates a re-evaluation of trait-based constraints for plant carbon allocation, particularly allocation to leaf area. In this review, we examine model representations of plant allocation to leaves, which is often empirically set by plant functional type-specific allometric relationships. We analyze the evolution of the representation of leaf allocation in models of different scales and complexities. We show the impacts of leaf allocation strategy on plant carbon uptake in the context of recent advancements in modeling hydraulic processes. Finally, we posit that deriving allometry from first principles using mechanistic hydraulic processes is possible and should become standard practice, rather than using prescribed allometries. The representation of allocation as an emergent property of scarce resource constraints is likely to be critical to representing how global change processes impact future ecosystem dynamics and carbon fluxes and may reduce the number of poorly constrained parameters in vegetation models.
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Affiliation(s)
- Anna T Trugman
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA, USA
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Leander D L Anderegg
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
| | - John S Sperry
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Yujie Wang
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Martin Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
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50
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Perri S, Katul GG, Molini A. Xylem-phloem hydraulic coupling explains multiple osmoregulatory responses to salt stress. THE NEW PHYTOLOGIST 2019; 224:644-662. [PMID: 31349369 DOI: 10.1111/nph.16072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/11/2019] [Indexed: 06/10/2023]
Abstract
Salinity is known to affect plant productivity by limiting leaf-level carbon exchange, root water uptake, and carbohydrates transport in the phloem. However, the mechanisms through which plants respond to salt exposure by adjusting leaf gas exchange and xylem-phloem flow are still mostly unexplored. A physically based model coupling xylem, leaf, and phloem flows is here developed to explain different osmoregulation patterns across species. Hydraulic coupling is controlled by leaf water potential, ψl , and determined under four different maximization hypotheses: water uptake (1), carbon assimilation (2), sucrose transport (3), or (4) profit function - i.e. carbon gain minus hydraulic risk. All four hypotheses assume that finite transpiration occurs, providing a further constraint on ψl . With increasing salinity, the model captures different transpiration patterns observed in halophytes (nonmonotonic) and glycophytes (monotonically decreasing) by reproducing the species-specific strength of xylem-leaf-phloem coupling. Salt tolerance thus emerges as plant's capability of differentiating between salt- and drought-induced hydraulic risk, and to regulate internal flows and osmolytes accordingly. Results are shown to be consistent across optimization schemes (1-3) for both halophytes and glycophytes. In halophytes, however, profit-maximization (4) predicts systematically higher ψl than (1-3), pointing to the need of an updated definition of hydraulic cost for halophytes under saline conditions.
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Affiliation(s)
- Saverio Perri
- Masdar Institute, Khalifa University of Science and Technology, PO Box 54224, Abu Dhabi, United Arab Emirates
- Department of Civil Infrastructure and Environmental Engineering, Khalifa University of Science and Technology, PO Box 127788, Abu Dhabi, United Arab Emirates
| | - Gabriel G Katul
- Nicholas School of the Environment, Duke University, Durham, NC, 27710, USA
- Department of Civil and Environmental Engineering, Duke University, Durham, NC, 27708, USA
| | - Annalisa Molini
- Masdar Institute, Khalifa University of Science and Technology, PO Box 54224, Abu Dhabi, United Arab Emirates
- Department of Civil Infrastructure and Environmental Engineering, Khalifa University of Science and Technology, PO Box 127788, Abu Dhabi, United Arab Emirates
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