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Ziegler C, Cochard H, Stahl C, Foltzer L, Gérard B, Goret JY, Heuret P, Levionnois S, Maillard P, Bonal D, Coste S. Residual water losses mediate the trade-off between growth and drought survival across saplings of 12 tropical rainforest tree species with contrasting hydraulic strategies. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4128-4147. [PMID: 38613495 DOI: 10.1093/jxb/erae159] [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: 07/31/2023] [Accepted: 04/12/2024] [Indexed: 04/15/2024]
Abstract
Knowledge of the physiological mechanisms underlying species vulnerability to drought is critical for better understanding patterns of tree mortality. Investigating plant adaptive strategies to drought should thus help to fill this knowledge gap, especially in tropical rainforests exhibiting high functional diversity. In a semi-controlled drought experiment using 12 rainforest tree species, we investigated the diversity in hydraulic strategies and whether they determined the ability of saplings to use stored non-structural carbohydrates during an extreme imposed drought. We further explored the importance of water- and carbon-use strategies in relation to drought survival through a modelling approach. Hydraulic strategies varied considerably across species with a continuum between dehydration tolerance and avoidance. During dehydration leading to hydraulic failure and irrespective of hydraulic strategies, species showed strong declines in whole-plant starch concentrations and maintenance, or even increases in soluble sugar concentrations, potentially favouring osmotic adjustments. Residual water losses mediated the trade-off between time to hydraulic failure and growth, indicating that dehydration avoidance is an effective drought-survival strategy linked to the 'fast-slow' continuum of plant performance at the sapling stage. Further investigations on residual water losses may be key to understanding the response of tropical rainforest tree communities to climate change.
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Affiliation(s)
- Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Louis Foltzer
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Bastien Gérard
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Jean-Yves Goret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Pascale Maillard
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Damien Bonal
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
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2
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Joshi RK, Gupta R, Mishra A, Garkoti SC. Seasonal variations of leaf ecophysiological traits and strategies of co-occurring evergreen and deciduous trees in white oak forest in the central Himalaya. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:634. [PMID: 38900402 DOI: 10.1007/s10661-024-12771-3] [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: 10/08/2023] [Accepted: 05/25/2024] [Indexed: 06/21/2024]
Abstract
The present study investigates the seasonal variations in leaf ecophysiological traits and strategies employed by co-occurring evergreen and deciduous tree species within a white oak forest (Quercus leucotrichophora A. Camus) ecosystem in the central Himalaya. Seasonal variations in physiological, morphological, and chemical traits were observed from leaf initiation until senescence in co-occurring deciduous and evergreen tree species. We compared various parameters, including net photosynthetic capacity (Aarea and Amass), leaf stomatal conductance (gswarea and gswmass), transpiration rate (Earea and Emass), specific leaf area (SLA), mid-day water potential (Ψmd), leaf nitrogen (N) and phosphorus (P) concentration, leaf total chlorophyll concentration, photosynthetic nitrogen- and phosphorus-use efficiency (PNUE and PPUE), and water use efficiency (WUE) across four evergreen and four deciduous tree species. Our findings reveal that evergreen and deciduous trees exhibit divergent strategies in coping with seasonal changes, which are crucial for their survival and growth. Deciduous trees consistently exhibited significantly higher photosynthetic rates, transpiration rates, mass-based N and P concentrations (Nmass and Pmass), mass-based chlorophyll concentration (Chlmass), SLA, and leaf Ψmd, while maintaining lower leaf structural investments throughout the year compared to evergreen trees. These findings indicate that deciduous trees achieve greater assimilation rates per unit mass and higher nutrient-use efficiency. Physiological, morphological, and leaf N and P concentrations were higher in the summer (fully expanded leaf) than in the fall (senesced leaf). These insights provide valuable contributions to our understanding of tree species coexistence and their ecological roles in temperate forest ecosystems, with implications for forest management and conservation in the Himalayan region.
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Affiliation(s)
- Rajendra Kr Joshi
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- Department of Environmental Sciences, Daulat Ram College, University of Delhi, New Delhi, 110007, India
| | - Rajman Gupta
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ambuj Mishra
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Satish Chandra Garkoti
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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3
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Waite PA, Kumar M, Link RM, Schuldt B. Coordinated hydraulic traits influence the two phases of time to hydraulic failure in five temperate tree species differing in stomatal stringency. TREE PHYSIOLOGY 2024; 44:tpae038. [PMID: 38606678 DOI: 10.1093/treephys/tpae038] [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: 07/05/2023] [Revised: 03/08/2024] [Accepted: 03/28/2024] [Indexed: 04/13/2024]
Abstract
Worldwide, forests are increasingly exposed to extreme droughts causing tree mortality. Because of the complex nature of the mechanisms involved, various traits have been linked to tree drought responses with contrasting results. This may be due to species-specific strategies in regulating water potential, a process that unfolds in two distinct phases: a first phase until stomatal closure, and a second phase until reaching lethal xylem hydraulic thresholds. We conducted dry-down experiments with five broadleaved temperate tree species differing in their degree of isohydry to estimate the time to stomatal closure (tsc) and subsequent time to critical hydraulic failure (tcrit). We measured various traits linked to tree drought responses, such as the water potentials at turgor loss point (Ptlp), stomatal closure (Pgs90), and 12%, 50% and 88% loss of xylem hydraulic conductance (P12, P50, P88), hydraulic capacitance (C), minimum leaf conductance (gmin), hydroscape area (HSA) and hydraulic safety margins (HSM). We found that Pgs90 followed previously recorded patterns of isohydry and was associated with HSA. Species ranked from more to less isohydric in the sequence Acer pseudoplatanus < Betula pendula < Tilia cordata < Sorbus aucuparia < Fagus sylvatica. Their degree of isohydry was associated with leaf safety (Ptlp and gmin), drought avoidance (C) and tsc, but decoupled from xylem safety (HSM and P88) and tcrit. Regardless of their stomatal stringency, species with wider HSM and lower P88 reached critical hydraulic failure later. We conclude that the duration of the first phase is determined by stomatal regulation, while the duration of the second phase is associated with xylem safety. Isohydry is thus linked to water use rather than to drought survival strategies, confirming the proposed use of HSA as a complement to HSM for describing plant drought responses before and after stomatal closure.
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Affiliation(s)
- Pierre-André Waite
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- Forest Botany, TUD Dresden University of Technology, Pienner Straße 7, 01737, Tharandt, Germany
- CIRAD, UPR AIDA, 34398 Montpellier, France
| | - Manish Kumar
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- ICAR - Central Soil Salinity Research Institute (CSSRI), Karnal, 132001, India
| | - Roman M Link
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- Forest Botany, TUD Dresden University of Technology, Pienner Straße 7, 01737, Tharandt, Germany
| | - Bernhard Schuldt
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- Forest Botany, TUD Dresden University of Technology, Pienner Straße 7, 01737, Tharandt, Germany
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4
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Sterck FJ, Song Y, Poorter L. Drought- and heat-induced mortality of conifer trees is explained by leaf and growth legacies. SCIENCE ADVANCES 2024; 10:eadl4800. [PMID: 38608026 PMCID: PMC11014445 DOI: 10.1126/sciadv.adl4800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/08/2024] [Indexed: 04/14/2024]
Abstract
An increased frequency and severity of droughts and heat waves have resulted in increased tree mortality and forest dieback across the world, but underlying mechanisms are poorly understood. We used a common garden experiment with 20 conifer tree species to quantify mortality after three consecutive hot, dry summers and tested whether mortality could be explained by putative underlying mechanisms, such as stem hydraulics and legacies affected by leaf life span and stem growth responses to previous droughts. Mortality varied from 0 to 79% across species and was not affected by hydraulic traits. Mortality increased with species' leaf life span probably because leaf damage caused crown dieback and contributed to carbon depletion and bark beetle damage. Mortality also increased with lower growth resilience, which may exacerbate the contribution of carbon depletion and bark beetle sensitivity to tree mortality. Our study highlights how ecological legacies at different time scales can explain tree mortality in response to hot, dry periods and climate change.
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Affiliation(s)
- Frank J. Sterck
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA Wageningen, Netherlands
| | - Yanjun Song
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA Wageningen, Netherlands
- School of Biological Sciences, Washington State University, P.O. Box 644236, Pullman, WA 99164-4236, USA
| | - Lourens Poorter
- Forest Ecology and Forest Management Group, Wageningen University and Research, P.O. Box 47, 6700 AA Wageningen, Netherlands
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5
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Ávila-Lovera E, Haro R, Choudhary M, Acosta-Rangel A, Pratt RB, Santiago LS. The benefits of woody plant stem photosynthesis extend to hydraulic function and drought survival in Parkinsonia florida. TREE PHYSIOLOGY 2024; 44:tpae013. [PMID: 38284819 PMCID: PMC10918054 DOI: 10.1093/treephys/tpae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/16/2024] [Accepted: 01/21/2024] [Indexed: 01/30/2024]
Abstract
As climate change exacerbates drought stress in many parts of the world, understanding plant physiological mechanisms for drought survival is critical to predicting ecosystem responses. Stem net photosynthesis, which is common in arid environments, may be a drought survival trait, but whether the additional carbon fixed by stems contributes to plant hydraulic function and drought survival in arid land plants is untested. We conducted a stem light-exclusion experiment on saplings of a widespread North American desert tree species, Parkinsonia florida L., and after shading acclimation, we then subjected half of the plants to a drought treatment to test the interaction between light exclusion and water limitation on growth, leaf and stem photosynthetic gas exchange, xylem embolism assessed with micro-computed tomography and gravimetric techniques, and survival. Growth, stem photosynthetic gas exchange, hydraulic function and survival all showed expected reductions in response to light exclusion. However, stem photosynthesis mitigated the drought-induced reductions in gas exchange, xylem embolism (percent loss of conductivity, PLC) and mortality. The highest mortality was in the combined light exclusion and drought treatment, and was related to stem PLC and native sapwood-specific hydraulic conductivity. This research highlights the integration of carbon economy and water transport. Our results show that additional carbon income by photosynthetic stems has an important role in the growth and survival of a widespread desert tree species during drought. This shift in function under conditions of increasing stress underscores the importance of considering stem photosynthesis for predicting drought-induced mortality not only for the additional supply of carbon, but also for its extended benefits for hydraulic function.
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Affiliation(s)
- Eleinis Ávila-Lovera
- School of Biological Sciences, The University of Utah, 257 S 1400 E, Salt Lake City, UT 84112, USA
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama, Republic of Panama
| | - Roxana Haro
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Manika Choudhary
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Aleyda Acosta-Rangel
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - R Brandon Pratt
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - Louis S Santiago
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama, Republic of Panama
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6
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Thompson RA. A neutral theory of plant carbon allocation. TREE PHYSIOLOGY 2024; 44:tpad151. [PMID: 38102767 DOI: 10.1093/treephys/tpad151] [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: 06/15/2023] [Accepted: 12/10/2023] [Indexed: 12/17/2023]
Abstract
How plants use the carbon they gain from photosynthesis remains a key area of study among plant ecologists. Although numerous theories have been presented throughout the years, the field lacks a clear null model. To fill this gap, I have developed the first null model, or neutral theory, of plant carbon allocation using probability theory, plant biochemistry and graph theory at the level of a leaf. Neutral theories have been used to establish a null hypothesis in molecular evolution and community assembly to describe how much of an ecological phenomenon can be described by chance alone. Here, the aim of a neutral theory of plant carbon allocation is to ask: how is carbon partitioned between sinks if one assumes plants do not prioritize certain sinks over others? Using the biochemical network of plant carbon metabolism, I show that, if allocation was strictly random, carbon is more likely to be allocated to storage, defense, respiration and finally growth. This 'neutral hierarchy' suggests that a sink's biochemical distance from photosynthesis plays an important role in carbon allocation patterns, highlighting the potentially adaptive role of this biochemical network for plant survival in variable environments. A brief simulation underscores that our ability to measure the carbon allocation from photosynthesis to a given sink is unreliable due to simple probabilistic rules. While neutral theory may not explain all patterns of carbon allocation, its utility is in the minimal assumptions and role as a null model against which future data should be tested.
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Affiliation(s)
- R Alex Thompson
- School of the Environment, Washington State University, Pullman, WA 99164, USA
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7
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Liu S, Xu G, Chen T, Wu X, Li Y. Quantifying the effects of precipitation exclusion and groundwater drawdown on functional traits of Haloxylon ammodendron - How does this xeric shrub survive the drought? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166945. [PMID: 37699482 DOI: 10.1016/j.scitotenv.2023.166945] [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: 06/12/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/14/2023]
Abstract
The increasing frequency of drought and decline in groundwater levels are causing ecophysiological changes in woody plants, particularly in desert ecosystems in arid regions. However, the combined effects of meteorological and hydrological droughts on perennial desert plants, especially phreatophytes, remain poorly understood. To address this knowledge gap, we conducted a 5-year precipitation exclusion experiment at two sites with contrasting groundwater depths in the Gurbantunggut Desert located in northwest China. Our study aimed to investigate the impacts of precipitation exclusion and groundwater depth decline on multiple traits of H. ammodendron. We found that long-term precipitation exclusion enhanced midday leaf water potential, stomatal conductance, chlorophyll content, root nonstructural carbohydrates concentration, leaf starch concentration, but decreased water use efficiency. Groundwater drawdown decreased predawn and midday leaf water potentials, maximum net photosynthetic rate, stomatal conductance, Huber value, stem water δ18O, but enhanced water use efficiency and branch nonstructural carbohydrates concentration. A combination of precipitation exclusion and groundwater depth decline reduced Huber value, but did not show exacerbated effects. The findings demonstrate that hydrological drought induced by groundwater depth decline poses a greater threat to the survival of H. ammodendron than future changes in precipitation.
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Affiliation(s)
- Shensi Liu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Fukang Station of Desert Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Fukang 831500, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guiqing Xu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Fukang Station of Desert Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Fukang 831500, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Tuqiang Chen
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Fukang Station of Desert Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Fukang 831500, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xue Wu
- College of Ecology and Environment, Xinjiang University, Urumqi 830046, China
| | - Yan Li
- Fukang Station of Desert Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Fukang 831500, China; University of Chinese Academy of Sciences, Beijing 100049, China
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8
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Wei Y, Chen YJ, Siddiq Z, Zhang JL, Zhang SB, Jansen S, Cao KF. Hydraulic traits and photosynthesis are coordinated with trunk sapwood capacitance in tropical tree species. TREE PHYSIOLOGY 2023; 43:2109-2120. [PMID: 37672225 DOI: 10.1093/treephys/tpad107] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 08/28/2023] [Indexed: 09/07/2023]
Abstract
Water stored in trunk sapwood is vital for the canopy to maintain its physiological function under high transpiration demands. Little is known regarding the anatomical properties that contribute to the hydraulic capacitance of tree trunks and whether trunk capacitance is correlated with the hydraulic and gas exchange traits of canopy branches. We examined sapwood capacitance, xylem anatomical characteristics of tree trunks, embolism resistance, the minimal xylem water potential of canopy branches, leaf photosynthesis and stomatal conductance in 22 species from a tropical seasonal rainforest and savanna. The results showed that the mean trunk sapwood capacitance did not differ between the two biomes. Capacitance was closely related to the fiber lumen fraction and fiber wall reinforcement and not to the axial and ray parenchyma fractions. Additionally, it was positively correlated with the theoretical hydraulic conductivity of a trunk and the specific hydraulic conductivity of branches, and showed a trade-off with branch embolism resistance. Species with a high trunk sapwood capacitance maintained less negative canopy water potentials in the dry season, but higher leaf photosynthetic rates and stomatal conductance in the wet season. This study provides a functional link among trunk sapwood capacitance, xylem anatomy, canopy hydraulics and photosynthesis in tropical trees.
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Affiliation(s)
- Yang Wei
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang 653300, Yunnan, China
| | - Zafar Siddiq
- Department of Botany, Government College University, Katchery Road, Lahore 54000, Punjab, Pakistan
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Steven Jansen
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Baden-Wurttemberg, Germany
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
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9
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Blackman CJ, Billon LM, Cartailler J, Torres-Ruiz JM, Cochard H. Key hydraulic traits control the dynamics of plant dehydration in four contrasting tree species during drought. TREE PHYSIOLOGY 2023; 43:1772-1783. [PMID: 37318310 PMCID: PMC10652334 DOI: 10.1093/treephys/tpad075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/07/2023] [Accepted: 06/08/2023] [Indexed: 06/16/2023]
Abstract
Trees are at risk of mortality during extreme drought, yet our understanding of the traits that govern the timing of drought-induced hydraulic failure remains limited. To address this, we tested SurEau, a trait-based soil-plant-atmosphere model designed to predict the dynamics of plant dehydration as represented by the changes in water potential against those observed in potted trees of four contrasting species (Pinus halepensis Mill., Populus nigra L., Quercus ilex L. and Cedrus atlantica (Endl.) Manetti ex Carriére) exposed to drought. SurEau was parameterized with a range of plant hydraulic and allometric traits, soil and climatic variables. We found a close correspondence between the predicted and observed plant water potential (in MPa) dynamics during the early phase drought, leading to stomatal closure, as well as during the latter phase of drought, leading to hydraulic failure in all four species. A global model's sensitivity analysis revealed that, for a common plant size (leaf area) and soil volume, dehydration time from full hydration to stomatal closure (Tclose) was most strongly controlled by the leaf osmotic potential (Pi0) and its influence on stomatal closure, in all four species, while the maximum stomatal conductance (gsmax) also contributed to Tclose in Q. ilex and C. atlantica. Dehydration times from stomatal closure to hydraulic failure (Tcav) was most strongly controlled by Pi0, the branch residual conductance (gres) and Q10a sensitivity of gres in the three evergreen species, while xylem embolism resistance (P50) was most influential in the deciduous species P. nigra. Our findings point to SurEau as a highly useful model for predicting changes in plant water status during drought and suggest that adjustments made in key hydraulic traits are potentially beneficial to delaying the onset of drought-induced hydraulic failure in trees.
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Affiliation(s)
- Chris J Blackman
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, School of Natural Sciences, University of Tasmania, Hobart 7001, Australia
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - Lise-Marie Billon
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - Julien Cartailler
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - José M Torres-Ruiz
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
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10
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Martínez-Vilalta J, García-Valdés R, Jump A, Vilà-Cabrera A, Mencuccini M. Accounting for trait variability and coordination in predictions of drought-induced range shifts in woody plants. THE NEW PHYTOLOGIST 2023; 240:23-40. [PMID: 37501525 DOI: 10.1111/nph.19138] [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: 03/03/2023] [Accepted: 06/20/2023] [Indexed: 07/29/2023]
Abstract
Functional traits offer a promising avenue to improve predictions of species range shifts under climate change, which will entail warmer and often drier conditions. Although the conceptual foundation linking traits with plant performance and range shifts appears solid, the predictive ability of individual traits remains generally low. In this review, we address this apparent paradox, emphasizing examples of woody plants and traits associated with drought responses at the species' rear edge. Low predictive ability reflects the fact not only that range dynamics tend to be complex and multifactorial, as well as uncertainty in the identification of relevant traits and limited data availability, but also that trait effects are scale- and context-dependent. The latter results from the complex interactions among traits (e.g. compensatory effects) and between them and the environment (e.g. exposure), which ultimately determine persistence and colonization capacity. To confront this complexity, a more balanced coverage of the main functional dimensions involved (stress tolerance, resource use, regeneration and dispersal) is needed, and modelling approaches must be developed that explicitly account for: trait coordination in a hierarchical context; trait variability in space and time and its relationship with exposure; and the effect of biotic interactions in an ecological community context.
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Affiliation(s)
- Jordi Martínez-Vilalta
- CREAF, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Raúl García-Valdés
- CREAF, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Forest Science and Technology Centre of Catalonia (CTFC), E25280, Solsona, Spain
- Department of Biology, Geology, Physics and Inorganic Chemistry, School of Experimental Sciences and Technology, Rey Juan Carlos University, E28933, Móstoles, Madrid, Spain
| | - Alistair Jump
- Biological and Environmental Sciences, University of Stirling, FK9 4LA, Stirling, UK
| | - Albert Vilà-Cabrera
- CREAF, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Biological and Environmental Sciences, University of Stirling, FK9 4LA, Stirling, UK
| | - Maurizio Mencuccini
- CREAF, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- ICREA, Pg. Lluís Companys 23, E08010, Barcelona, Spain
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11
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Schönbeck L, Arteaga M, Mirza H, Coleman M, Mitchell D, Huang X, Ortiz H, Santiago LS. Plant physiological indicators for optimizing conservation outcomes. CONSERVATION PHYSIOLOGY 2023; 11:coad073. [PMID: 37711583 PMCID: PMC10498484 DOI: 10.1093/conphys/coad073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 07/20/2023] [Accepted: 08/22/2023] [Indexed: 09/16/2023]
Abstract
Plant species of concern often occupy narrow habitat ranges, making climate change an outsized potential threat to their conservation and restoration. Understanding the physiological status of a species during stress has the potential to elucidate current risk and provide an outlook on population maintenance. However, the physiological status of a plant can be difficult to interpret without a reference point, such as the capacity to tolerate stress before loss of function, or mortality. We address the application of plant physiology to conservation biology by distinguishing between two physiological approaches that together determine plant status in relation to environmental conditions and evaluate the capacity to avoid stress-induced loss of function. Plant physiological status indices, such as instantaneous rates of photosynthetic gas exchange, describe the level of physiological activity in the plant and are indicative of physiological health. When such measurements are combined with a reference point that reflects the maximum value or environmental limits of a parameter, such as the temperature at which photosynthesis begins to decline due to high temperature stress, we can better diagnose the proximity to potentially damaging thresholds. Here, we review a collection of useful plant status and reference point measurements related to photosynthesis, water relations and mineral nutrition, which can contribute to plant conservation physiology. We propose that these measurements can serve as important additional information to more commonly used phenological and morphological parameters, as the proposed parameters will reveal early warning signals before they are visible. We discuss their implications in the context of changing temperature, water and nutrient supply.
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Affiliation(s)
- Leonie Schönbeck
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Marc Arteaga
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Humera Mirza
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Mitchell Coleman
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
- Tejon Ranch Conservancy, Frazier Park, CA 93225, USA
| | - Denise Mitchell
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Xinyi Huang
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Haile Ortiz
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Louis S Santiago
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092. Balboa, Ancon, Panama, Republic of Panama
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12
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Bei Z, Zhang X, Tian X. The Mechanism by Which Umbrella-Shaped Ratchet Trichomes on the Elaeagnus angustifolia Leaf Surface Collect Water and Reflect Light. BIOLOGY 2023; 12:1024. [PMID: 37508453 PMCID: PMC10376016 DOI: 10.3390/biology12071024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/18/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
Leaves are essential for plants, enabling photosynthesis and transpiration. In arid regions, water availability limits plant growth. Some plants, like Elaeagnus angustifolia, a sandy sub-tree species widely distributed in arid and semi-arid regions, have unique leaf structures to reduce water loss and solar radiation. Here, we describe the leaves of Elaeagnus angustifolia L., with special functioning trichomes. Through leaf submicroscopic structure observation, in situ water collection experiments, photosynthesis measurements, and reflection spectrum analysis, we investigated E. angustifolia leaves, focusing on their functioning trichomes. These trichomes capture water vapor, reflect UV and NIR light, and possess a 3D interface structure composed of 1D and 2D structures. The 1D conical structure captures water droplets, which are then gathered by the radial conical structure and guided towards the stomata through wedge-shaped grooves on the 2D umbrella structure. The trichomes also reflect sunlight, with micropapillae reflecting UV light and the umbrella structure reflecting NIR light. These mechanisms reduce leaf temperature, respiration, and water transpiration, protecting against solar radiation damage. This study provides insights into water collection and light-reflection mechanisms, revealing adaptive strategies of plants with large leaves in arid regions.
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Affiliation(s)
- Zhanlin Bei
- School of Life Sciences, Nanjing University, Nanjing 210023, China
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
| | - Xin Zhang
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
| | - Xingjun Tian
- School of Life Sciences, Nanjing University, Nanjing 210023, China
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13
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Belovitch MW, NeSmith JE, Nippert JB, Holdo RM. African savanna grasses outperform trees across the full spectrum of soil moisture availability. THE NEW PHYTOLOGIST 2023; 239:66-74. [PMID: 36967595 DOI: 10.1111/nph.18909] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/20/2023] [Indexed: 06/02/2023]
Abstract
Models of tree-grass coexistence in savannas make different assumptions about the relative performance of trees and grasses under wet vs dry conditions. We quantified transpiration and drought tolerance traits in 26 tree and 19 grass species from the African savanna biome across a gradient of soil water potentials to test for a trade-off between water use under wet conditions and drought tolerance. We measured whole-plant hourly transpiration in a growth chamber and quantified drought tolerance using leaf osmotic potential (Ψosm ). We also quantified whole-plant water-use efficiency (WUE) and relative growth rate (RGR) under well-watered conditions. Grasses transpired twice as much as trees on a leaf-mass basis across all soil water potentials. Grasses also had a lower Ψosm than trees, indicating higher drought tolerance in the former. Higher grass transpiration and WUE combined to largely explain the threefold RGR advantage in grasses. Our results suggest that grasses outperform trees under a wide range of conditions, and that there is no evidence for a trade-off in water-use patterns in wet vs dry soils. This work will help inform mechanistic models of water use in savanna ecosystems, providing much-needed whole-plant parameter estimates for African species.
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Affiliation(s)
| | | | - Jesse B Nippert
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Ricardo M Holdo
- Odum School of Ecology, University of Georgia, Athens, GA, 30601, USA
- School of Animal Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2050, South Africa
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14
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Blonder BW, Brodrick PG, Chadwick KD, Carroll E, Cruz-de Hoyos RM, Expósito-Alonso M, Hateley S, Moon M, Ray CA, Tran H, Walton JA. Climate lags and genetics determine phenology in quaking aspen (Populus tremuloides). THE NEW PHYTOLOGIST 2023; 238:2313-2328. [PMID: 36856334 DOI: 10.1111/nph.18850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 02/19/2023] [Indexed: 05/19/2023]
Abstract
Spatiotemporal patterns of phenology may be affected by mosaics of environmental and genetic variation. Environmental drivers may have temporally lagged impacts, but patterns and mechanisms remain poorly known. We combine multiple genomic, remotely sensed, and physically modeled datasets to determine the spatiotemporal patterns and drivers of canopy phenology in quaking aspen, a widespread clonal dioecious tree species with diploid and triploid cytotypes. We show that over 391 km2 of southwestern Colorado: greenup date, greendown date, and growing season length vary by weeks and differ across sexes, cytotypes, and genotypes; phenology has high phenotypic plasticity and heritabilities of 31-61% (interquartile range); and snowmelt date, soil moisture, and air temperature predict phenology, at temporal lags of up to 3 yr. Our study shows that lagged environmental effects are needed to explain phenological variation and that the effect of cytotype on phenology is obscured by its correlation with topography. Phenological patterns are consistent with responses to multiyear accumulation of carbon deficit or hydraulic damage.
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Affiliation(s)
- Benjamin W Blonder
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Philip G Brodrick
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - K Dana Chadwick
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Erin Carroll
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Roxanne M Cruz-de Hoyos
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | | | - Shannon Hateley
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Minkyu Moon
- Department of Earth & Environment, Boston University, Boston, MA, 02215, USA
| | - Courtenay A Ray
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Hoang Tran
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, 08540, USA
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - James A Walton
- Molecular Ecology Laboratory, Department of Wildland Resources, Utah State University, Logan, UT, 84322, USA
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15
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Yang D, Wang YSD, Wang Q, Ke Y, Zhang YB, Zhang SB, Zhang YJ, McDowell NG, Zhang JL. Physiological response and photosynthetic recovery to an extreme drought: Evidence from plants in a dry-hot valley savanna of Southwest China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161711. [PMID: 36682563 DOI: 10.1016/j.scitotenv.2023.161711] [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: 10/21/2022] [Revised: 01/15/2023] [Accepted: 01/15/2023] [Indexed: 06/17/2023]
Abstract
The frequency of extreme drought events has been rising worldwide, but due to its unpredictability, how plants will respond remains poorly understood. Here, we aimed to characterize how the hydraulics and photosynthesis of savanna plants respond to extreme drought, and tested whether they can subsequently recover photosynthesis after drought. There was an extreme drought in 2019 in Southwest (SW) China. We investigated photosynthetic gas exchange, leaf-, stem-, and whole-shoot hydraulic conductance of 18 plant species with diverse leaf habits (deciduous, semi-deciduous and evergreen) and growth forms (tree and shrub) from a dry-hot valley savanna in SW China for three rainy seasons from 2019 to 2021. We also compared photosynthetic gas exchange to those of a regular year (2014). We found that leaf stomatal and hydraulic conductance and maximum photosynthetic rate were significantly lower during the drought in 2019 than in the wetter years. In 2019, all studied plants maintained stomatal conductance at their minimum level observed, which could be related to high vapor pressure deficits (VPD, >2 kPa). However, no significant difference in stem and shoot hydraulic conductance was detected across years. The reductions in leaf hydraulic conductance and stomatal regulation under extreme drought might help keep the stem hydraulic function. Stomatal conductance and photosynthesis after drought (2020 and 2021) showed comparable or even higher values compared to that of 2014, suggesting high recovery of photosynthetic gas exchange. In addition, the response of hydraulic and photosynthetic traits to extreme drought was convergent across leaf habits and growth forms. Our results will help better understand the physiological mechanism underlying the response of savanna ecosystems to climate change.
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Affiliation(s)
- Da Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
| | - Yang-Si-Ding Wang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qin Wang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Ke
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yun-Bing Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME 04469, USA.
| | - Nate G McDowell
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA; School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China.
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16
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Chen Z, Li S, Wan X, Liu S. Strategies of tree species to adapt to drought from leaf stomatal regulation and stem embolism resistance to root properties. FRONTIERS IN PLANT SCIENCE 2022; 13:926535. [PMID: 36237513 PMCID: PMC9552884 DOI: 10.3389/fpls.2022.926535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Considerable evidences highlight the occurrence of increasing widespread tree mortality as a result of global climate change-associated droughts. However, knowledge about the mechanisms underlying divergent strategies of various tree species to adapt to drought has remained remarkably insufficient. Leaf stomatal regulation and embolism resistance of stem xylem serves as two important strategies for tree species to prevent hydraulic failure and carbon starvation, as comprising interconnected physiological mechanisms underlying drought-induced tree mortality. Hence, the physiological and anatomical determinants of leaf stomatal regulation and stems xylem embolism resistance are evaluated and discussed. In addition, root properties related to drought tolerance are also reviewed. Species with greater investment in leaves and stems tend to maintain stomatal opening and resist stem embolism under drought conditions. The coordination between stomatal regulation and stem embolism resistance are summarized and discussed. Previous studies showed that hydraulic safety margin (HSM, the difference between minimum water potential and that causing xylem dysfunction) is a significant predictor of tree species mortality under drought conditions. Compared with HSM, stomatal safety margin (the difference between water potential at stomatal closure and that causing xylem dysfunction) more directly merge stomatal regulation strategies with xylem hydraulic strategies, illustrating a comprehensive framework to characterize plant response to drought. A combination of plant traits reflecting species' response and adaptation to drought should be established in the future, and we propose four specific urgent issues as future research priorities.
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Affiliation(s)
- Zhicheng Chen
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
| | - Shan Li
- Department of Environmental Science and Ecology, School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi’an, China
| | - Xianchong Wan
- Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing, China
| | - Shirong Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
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17
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Yu J, Hou G, Zhou T, Shi P, Zong N, Sun J. Variation of plant CSR strategies across a precipitation gradient in the alpine grasslands on the northern Tibet Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156512. [PMID: 35679928 DOI: 10.1016/j.scitotenv.2022.156512] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/24/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
Identifying ecological strategies based on functional traits can help us better understand plants' adaptations and changes in ecological processes, and thus predict the impact of climate change on ecosystems, especially in the vulnerable alpine grasslands. Herein, we investigated the plant CSR strategies of four grassland types (alpine meadows, AM; alpine meadow steppes, AMS; alpine steppes, AS; and alpine desert steppes, ADS) and its functional groups (grasses, sedges, legumes, and forbs) along the east-to-west gradient of decreasing precipitation on the northern Tibetan grasslands by using Grime's CSR (C: competitor, S: stress tolerator, and R: ruderal) analysis. Although alpine grasslands were dominated by S-strategy, our results also indicated that AM with higher water, nitrogen (N) and phosphorus (P) availability had significantly lower S-strategy values and relatively higher C- and R-strategy values (C: S: R = 6: 63: 31 %) than those in AMS (C: S: R = 3: 94: 3 %,), AS (C: S: R = 3: 87: 10 %), and ADS (C: S: R = 1: 94: 5 %). The CSR strategy values of forbs and legumes showed greater variability compared with grasses and sedges in the environmental gradient. Furthermore, water variability on the precipitation gradient eventually affected plant traits and CSR strategies through soil N and P availability and pH. Our findings highlighted that plant CSR strategies were regulated by the availability of soil resources, and plants adopted more flexible adaptation strategies in relatively resource-rich environments. This study sheds light on the mechanisms of plant adaptation to the changing environment in the alpine grasslands.
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Affiliation(s)
- Jialuo Yu
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Ge Hou
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Tiancai Zhou
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Peili Shi
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China.
| | - Ning Zong
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jian Sun
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
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18
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Vicente E, Didion-Gency M, Morcillo L, Morin X, Vilagrosa A, Grossiord C. Aridity and cold temperatures drive divergent adjustments of European beech xylem anatomy, hydraulics and leaf physiological traits. TREE PHYSIOLOGY 2022; 42:1720-1735. [PMID: 35285500 DOI: 10.1093/treephys/tpac029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Understanding plant trait coordination and variance across climatic gradients is critical for assessing forests' adaptive potential to climate change. We measured 11 hydraulic, anatomical and leaf-level physiological traits in European beech (Fagus sylvatica L.) along a moisture and temperature gradient in the French Alps. We assessed how traits covaried, and how their population-level variances shifted along the gradient. The intrapopulation variances of vessel size and xylem-specific conductivity reduced in colder locations as narrow vessels were observed in response to low temperature. This decreased individual-level water transport capacity compared with the warmer and more xeric sites. Conversely, the maximum stomatal conductance and Huber value variances were constrained in the arid and warm locations, where trees showed restricted gas exchange and higher xylem-specific conductivity. The populations growing under drier and warmer conditions presented wide variance for the xylem anatomical and hydraulic traits. Our results suggest that short-term physiological acclimation to raising aridity and heat in southern beech populations may occur mainly at the leaf level. Furthermore, the wide variance of the xylem anatomical and hydraulic traits at these sites may be advantageous since more heterogeneous hydraulic conductivity could imply populations' greater tree-tree complementarity and resilience against climatic variability. Our study highlights that both intrapopulation trait variance and trait network analysis are key approaches for understanding species adaptation and the acclimation potential to a shifting environment.
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Affiliation(s)
- Eduardo Vicente
- Department of Ecology, Faculty of Sciences, IMEM Ramón Margalef, University of Alicante, C. San Vicente del Raspeig, s/n, Alicante 03080, Spain
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, Alicante 03080, Spain
| | - Margaux Didion-Gency
- Ecosystem Ecology, Forest Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, Zürcherstrasse 111, Birmensdorf 8903, Switzerland
| | - Luna Morcillo
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, Alicante 03080, Spain
| | - Xavier Morin
- CEFE UMR 5175 (CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, IRD), 1919 Route de Mende, Montpellier Cedex 5 F-34293, France
| | - Alberto Vilagrosa
- CEAM Foundation, Joint Research Unit University of Alicante-CEAM, Department of Ecology, University of Alicante, PO Box 99, C. San Vicente del Raspeig, s/n, Alicante 03080, Spain
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, PO box 96, Lausanne CH-1015, Switzerland
- Functional Plant Ecology, Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSL, PO box 96, Lausanne CH-1015, Switzerland
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19
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Walker SL, Zinnert J. Whole plant traits of coastal dune vegetation and implications for interactions with dune dynamics. Ecosphere 2022. [DOI: 10.1002/ecs2.4065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Shannon L. Walker
- Department of Biology Virginia Commonwealth University Richmond Virginia USA
- Oak Ridge Institute for Science and Education (ORISE) Program, Research Participation Program with U.S. Army Corps of Engineers, Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC CHL) U.S. Department of Defense (DOD) Duck North Carolina USA
| | - Julie Zinnert
- Department of Biology Virginia Commonwealth University Richmond Virginia USA
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20
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Influence of Climate Change on Metabolism and Biological Characteristics in Perennial Woody Fruit Crops in the Mediterranean Environment. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8040273] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The changes in the state of the climate have a high impact on perennial fruit crops thus threatening food availability. Indeed, climatic factors affect several plant aspects, such as phenological stages, physiological processes, disease-pest frequency, yield, and qualitative composition of the plant tissues and derived products. To mitigate the effects of climatic parameters variability, plants implement several strategies of defense, by changing phenological trends, altering physiology, increasing carbon sequestration, and metabolites synthesis. This review was divided into two sections. The first provides data on climate change in the last years and a general consideration on their impact, mitigation, and resilience in the production of food crops. The second section reviews the consequences of climate change on the industry of two woody fruit crops models (evergreen and deciduous trees). The research focused on, citrus, olive, and loquat as evergreen trees examples; while grape, apple, pear, cherry, apricot, almond, peach, kiwi, fig, and persimmon as deciduous species. Perennial fruit crops originated by a complex of decisions valuable in a long period and involving economic and technical problems that farmers may quickly change in the case of annual crops. However, the low flexibility of woody crops is balanced by resilience in the long-life cycle.
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21
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Leuschner C, Schipka F, Backes K. Stomatal regulation and water potential variation in European beech: challenging the iso/anisohydry concept. TREE PHYSIOLOGY 2022; 42:365-378. [PMID: 34415347 DOI: 10.1093/treephys/tpab104] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
The iso/anisohydric continuum has been used to classify tree species' drought response strategies. The range over which stomata are regulating leaf water potential (ψl) before turgor loss occurs can be described with metrics such as the dependence of ψl on soil water potential (ψsoil) and the size of 'hydroscape area' (HA), but corresponding field data from adult trees are scarce. We examined the stomatal conductance (gs)-ψl relationship in its temporal (diurnal vs seasonal and interannual) and spatial (within-crown vs between-site) variation in European beech, using extensive ψl and gs measurements in the canopy of four beech stands across a precipitation gradient, and complemented the data set by published ψl and gs measurements in further Central European beech stands (including the extreme 2018 drought) in order to cover the full water potential operation space of the species. Both metrics characterize beech as a strictly anisohydric species with δψl/δψsoil >> 1 and HA = 4 MPa2. However, stomates close sensitively in response to increasing vapor pressure deficit, disproving the widely assumed dependence of large ψl variation on looser stomatal control. Characterizing the water status regulation mechanisms of trees requires separating diurnal from day-to-day variation in ψl and gs. The large diurnal and seasonal ψl variation in beech leaves is partly caused by a low leaf tissue elasticity, suggesting that a whole-plant perspective with consideration of osmotic and elastic tissue properties and stem and root hydraulics is needed for fully understanding ψl regulation and the drought tolerance strategy of trees.
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Affiliation(s)
| | - Florian Schipka
- Plant Ecology, University of Goettingen, 37073 Göttingen, Germany
| | - Katharina Backes
- Plant Ecology, University of Goettingen, 37073 Göttingen, Germany
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22
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Ávila-Lovera E, Goldsmith GR, Kay KM, Funk JL. Above- and below-ground functional trait coordination in the Neotropical understory genus Costus. AOB PLANTS 2022; 14:plab073. [PMID: 35035869 PMCID: PMC8757582 DOI: 10.1093/aobpla/plab073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
The study of plant functional traits and variation among and within species can help illuminate functional coordination and trade-offs in key processes that allow plants to grow, reproduce and survive. We studied 20 leaf, above-ground stem, below-ground stem and fine-root traits of 17 Costus species from forests in Costa Rica and Panama to answer the following questions: (i) Do congeneric species show above-ground and below-ground trait coordination and trade-offs consistent with theory of resource acquisition and conservation? (ii) Is there correlated evolution among traits? (iii) Given the diversity of habitats over which Costus occurs, what is the relative contribution of site and species to trait variation? We performed a principal components analysis (PCA) to assess for the existence of a spectrum of trait variation and found that the first two PCs accounted for 21.4 % and 17.8 % of the total trait variation, respectively, with the first axis of variation being consistent with a continuum of resource-acquisitive and resource-conservative traits in water acquisition and use, and the second axis of variation being related to the leaf economics spectrum. Stomatal conductance was negatively related to both above-ground stem and rhizome specific density, and these relationships became stronger after accounting for evolutionary relatedness, indicating correlated evolution. Despite elevation and climatic differences among sites, high trait variation was ascribed to individuals rather than to sites. We conclude that Costus species present trait coordination and trade-offs that allow species to be categorized as having a resource-acquisitive or resource-conservative functional strategy, consistent with a whole-plant functional strategy with evident coordination and trade-offs between above-ground and below-ground function. Our results also show that herbaceous species and species with rhizomes tend to agree with trade-offs found in more species-rich comparisons.
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Affiliation(s)
- Eleinis Ávila-Lovera
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Gregory R Goldsmith
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Kathleen M Kay
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Jennifer L Funk
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
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23
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Large variation in availability of Maya food plant sources during ancient droughts. Proc Natl Acad Sci U S A 2022; 119:2115657118. [PMID: 34969847 PMCID: PMC8740729 DOI: 10.1073/pnas.2115657118] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 11/24/2022] Open
Abstract
The disruption of Classic Maya society coincided with extended droughts, as suggested by numerous paleoclimatic studies. However, the role of drought in civil upheaval and demographic decline is complicated by the difficulty of linking relatively coarse estimates of meteorological drought with fine-scale plant processes that underpin agriculture. Our analysis of drought resistance across the historically documented, indigenous food plants of ethnographic Maya groups shows a broad range of foods gradually dwindling through droughts of increasing severity. This finding implies that short to moderate droughts could have caused agricultural disruption but not subsistence collapse. However, multiyear extreme drought is consistent with agricultural collapse and the specter of starvation, unless mitigated by food storage or trade from areas less affected by drought. Paleoclimatic evidence indicating a series of droughts in the Yucatan Peninsula during the Terminal Classic period suggests that climate change may have contributed to the disruption or collapse of Classic Maya polities. Although climate change cannot fully account for the multifaceted, political turmoil of the period, it is clear that droughts of strong magnitude could have limited food availability, potentially causing famine, migration, and societal decline. Maize was undoubtedly an important staple food of the ancient Maya, but a complete analysis of other food resources that would have been available during drought remains unresolved. Here, we assess drought resistance of all 497 indigenous food plant species documented in ethnographic, ethnobotanical, and botanical studies as having been used by the lowland Maya and classify the availability of these plant species and their edible components under various drought scenarios. Our analysis indicates availability of 83% of food plant species in short-term drought, but this percentage drops to 22% of food plant species available in moderate drought up to 1 y. During extreme drought, lasting several years, our analysis indicates availability of 11% of food plant species. Our results demonstrate a greater diversity of food sources beyond maize that would have been available to the Maya during climate disruption of the Terminal Classic period than has been previously acknowledged. While drought would have necessitated shifts in dietary patterns, the range of physiological drought responses for the available food plants would have allowed a continuing food supply under all but the most dire conditions.
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24
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Zhao H, Wang C, Lan H. A bHLH transcription factor from Chenopodium glaucum confers drought tolerance to transgenic maize by positive regulation of morphological and physiological performances and stress-responsive genes' expressions. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2021; 41:74. [PMID: 37309519 PMCID: PMC10236094 DOI: 10.1007/s11032-021-01267-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 11/15/2021] [Indexed: 06/14/2023]
Abstract
The basic helix-loop-helix (bHLH) transcription factor has been shown to play an important role in various physiological processes. However, its functions and mechanisms in drought tolerance still remain poorly understood. Here, we reported a bHLH transcription factor - CgbHLH001 - from Chenopodium glaucum, which was able to confer drought tolerance in maize. CgbHLH001-overexpressed maize lines exhibited drought-tolerant phenotype and improved ear traits by accumulating the contents of soluble sugar and proline and elevating the activities of antioxidant enzymes (SOD, POD, and CAT) under drought stress, accompanying with the upregulation of some stress-related genes, which may balance the redox and osmotic homeostasis compared with the non-transgenic and CgbHLH001-RNAi plants. These findings suggest that CgbHLH001 can confer drought tolerance and has the potential for utilization in improving drought resistance in maize breeding. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-021-01267-4.
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Affiliation(s)
- Haiju Zhao
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Changhai Wang
- Join Hope Seeds Industry Co., Ltd., Changji, 831199 China
| | - Haiyan Lan
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
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25
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Pivovaroff AL, McDowell NG, Rodrigues TB, Brodribb T, Cernusak LA, Choat B, Grossiord C, Ishida Y, Jardine KJ, Laurance S, Leff R, Li W, Liddell M, Mackay DS, Pacheco H, Peters J, de J Sampaio Filho I, Souza DC, Wang W, Zhang P, Chambers J. Stability of tropical forest tree carbon-water relations in a rainfall exclusion treatment through shifts in effective water uptake depth. GLOBAL CHANGE BIOLOGY 2021; 27:6454-6466. [PMID: 34469040 DOI: 10.1111/gcb.15869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Increasing severity and frequency of drought is predicted for large portions of the terrestrial biosphere, with major impacts already documented in wet tropical forests. Using a 4-year rainfall exclusion experiment in the Daintree Rainforest in northeast Australia, we examined canopy tree responses to reduced precipitation and soil water availability by quantifying seasonal changes in plant hydraulic and carbon traits for 11 tree species between control and drought treatments. Even with reduced soil volumetric water content in the upper 1 m of soil in the drought treatment, we found no significant difference between treatments for predawn and midday leaf water potential, photosynthesis, stomatal conductance, foliar stable carbon isotope composition, leaf mass per area, turgor loss point, xylem vessel anatomy, or leaf and stem nonstructural carbohydrates. While empirical measurements of aboveground traits revealed homeostatic maintenance of plant water status and traits in response to reduced soil moisture, modeled belowground dynamics revealed that trees in the drought treatment shifted the depth from which water was acquired to deeper soil layers. These findings reveal that belowground acclimation of tree water uptake depth may buffer tropical rainforests from more severe droughts that may arise in future with climate change.
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Affiliation(s)
- Alexandria L Pivovaroff
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Nate G McDowell
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Tayana Barrozo Rodrigues
- Forest Management Laboratory, National Institute of Amazonian Research, Manaus, Amazonas, Brazil
| | - Tim Brodribb
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Brendan Choat
- University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales, Australia
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
- Functional Plant Ecology, Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Lausanne, Switzerland
| | - Yoko Ishida
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Kolby J Jardine
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Susan Laurance
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Riley Leff
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Weibin Li
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
- State Key Laboratory of Grassland and Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Michael Liddell
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - D Scott Mackay
- Department of Geography and Department of Environment & Sustainability, University at Buffalo, Buffalo, New York, USA
| | - Heather Pacheco
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Jennifer Peters
- University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales, Australia
- Oak Ridge National Laboratory, Climate Change Science Institute & Environmental Science Division, Oak Ridge, Tennessee, USA
| | | | - Daisy C Souza
- Forest Management Laboratory, National Institute of Amazonian Research, Manaus, Amazonas, Brazil
| | - Wenzhi Wang
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Peipei Zhang
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Jeff Chambers
- Climate Sciences Department, Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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26
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Chen YJ, Choat B, Sterck F, Maenpuen P, Katabuchi M, Zhang SB, Tomlinson KW, Oliveira RS, Zhang YJ, Shen JX, Cao KF, Jansen S. Hydraulic prediction of drought-induced plant dieback and top-kill depends on leaf habit and growth form. Ecol Lett 2021; 24:2350-2363. [PMID: 34409716 DOI: 10.1111/ele.13856] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 04/19/2021] [Accepted: 07/11/2021] [Indexed: 01/05/2023]
Abstract
Hydraulic failure caused by severe drought contributes to aboveground dieback and whole-plant death. The extent to which dieback or whole-plant death can be predicted by plant hydraulic traits has rarely been tested among species with different leaf habits and/or growth forms. We investigated 19 hydraulic traits in 40 woody species in a tropical savanna and their potential correlations with drought response during an extreme drought event during the El Niño-Southern Oscillation in 2015. Plant hydraulic trait variation was partitioned substantially by leaf habit but not growth form along a trade-off axis between traits that support drought tolerance versus avoidance. Semi-deciduous species and shrubs had the highest branch dieback and top-kill (complete aboveground death) among the leaf habits or growth forms. Dieback and top-kill were well explained by combining hydraulic traits with leaf habit and growth form, suggesting integrating life history traits with hydraulic traits will yield better predictions.
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Affiliation(s)
- Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Yunnan, China.,Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan, China.,Forest Ecology and Forest Management Group, Wageningen University and Research, Wageningen, the Netherlands
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Frank Sterck
- Forest Ecology and Forest Management Group, Wageningen University and Research, Wageningen, the Netherlands
| | - Phisamai Maenpuen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Masatoshi Katabuchi
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan, China
| | - Kyle W Tomlinson
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, CP6109, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, Maine, USA
| | - Jing-Xian Shen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan, China
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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27
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Peters JMR, López R, Nolf M, Hutley LB, Wardlaw T, Cernusak LA, Choat B. Living on the edge: A continental-scale assessment of forest vulnerability to drought. GLOBAL CHANGE BIOLOGY 2021; 27:3620-3641. [PMID: 33852767 DOI: 10.1111/gcb.15641] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Globally, forests are facing an increasing risk of mass tree mortality events associated with extreme droughts and higher temperatures. Hydraulic dysfunction is considered a key mechanism of drought-triggered dieback. By leveraging the climate breadth of the Australian landscape and a national network of research sites (Terrestrial Ecosystem Research Network), we conducted a continental-scale study of physiological and hydraulic traits of 33 native tree species from contrasting environments to disentangle the complexities of plant response to drought across communities. We found strong relationships between key plant hydraulic traits and site aridity. Leaf turgor loss point and xylem embolism resistance were correlated with minimum water potential experienced by each species. Across the data set, there was a strong coordination between hydraulic traits, including those linked to hydraulic safety, stomatal regulation and the cost of carbon investment into woody tissue. These results illustrate that aridity has acted as a strong selective pressure, shaping hydraulic traits of tree species across the Australian landscape. Hydraulic safety margins were constrained across sites, with species from wetter sites tending to have smaller safety margin compared with species at drier sites, suggesting trees are operating close to their hydraulic thresholds and forest biomes across the spectrum may be susceptible to shifts in climate that result in the intensification of drought.
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Affiliation(s)
- Jennifer M R Peters
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Rosana López
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Markus Nolf
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Lindsay B Hutley
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia
| | - Tim Wardlaw
- ARC Centre for Forest Value, University of Tasmania, Hobart, Tas, Australia
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Qld, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
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28
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Christmann T, Rosado BHP, Delhaye G, Matos IS, Drummond JS, Roland HL, Moraes YC, Oliveras Menor I. Functional assembly of tropical montane tree islands in the Atlantic Forest is shaped by stress tolerance, bamboo presence, and facilitation. Ecol Evol 2021; 11:10164-10177. [PMID: 34367567 PMCID: PMC8328411 DOI: 10.1002/ece3.7824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/02/2021] [Accepted: 06/06/2021] [Indexed: 11/18/2022] Open
Abstract
AIMS Amidst the Campos de Altitude (Highland Grasslands) in the Brazilian Atlantic Forest, woody communities grow either clustered in tree islands or interspersed within the herbaceous matrix. The functional ecology, diversity, and biotic processes shaping these plant communities are largely unstudied. We characterized the functional assembly and diversity of these tropical montane woody communities and investigated how they fit within Grime's CSR (C-competitor, S-stress-tolerant, R-ruderal) scheme, what functional trade-offs they exhibit, and how traits and functional diversity vary in response to bamboo presence/absence. METHODS To characterize the functional composition of the community, we sampled five leaf traits and wood density along transects covering the woody communities both inside tree islands and outside (i.e., isolated woody plants in the grasslands community). Then, we used Mann-Whitney test, t test, and variation partitioning to determine the effects of inside versus outside tree island and bamboo presence on community-weighted means, woody species diversity, and functional diversity. RESULTS We found a general SC/S strategy with drought-related functional trade-offs. Woody plants in tree islands had more acquisitive traits than those within the grasslands. Trait variation was mostly taxonomically than spatially driven, and species composition varied between inside and outside tree islands. Leaf thickness, wood density, and foliar water uptake were unrelated to CSR strategies, suggesting independent trait dimensions and multiple drought-coping strategies within the predominant S strategy. Islands with bamboo presence showed lower Simpson diversity, lower functional dispersion, lower foliar water uptake, and greater leaf thickness than in tree islands without bamboo. CONCLUSIONS The observed functional assembly hints toward large-scale environmental abiotic filtering shaping a stress-tolerant community strategy, and small-scale biotic interactions driving small-scale trait variation. We recommend experimental studies with fire, facilitation treatments, ecophysiological and recruitment traits to elucidate on future tree island expansion and community response to climate change.
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Affiliation(s)
- Tina Christmann
- School of Geography and the EnvironmentUniversity of OxfordOxfordUK
| | - Bruno H. P. Rosado
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
| | | | - Ilaíne S. Matos
- Macrosystems Ecology LaboratoryUniversity of California BerkeleyBerkeleyCAUSA
| | - Julia S. Drummond
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
| | - Helena L. Roland
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
| | - Yan C. Moraes
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
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29
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Bhusal N, Lee M, Lee H, Adhikari A, Han AR, Han A, Kim HS. Evaluation of morphological, physiological, and biochemical traits for assessing drought resistance in eleven tree species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146466. [PMID: 33744562 DOI: 10.1016/j.scitotenv.2021.146466] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 05/27/2023]
Abstract
The frequency and severity of drought are expected to increase due to climate change; therefore, selection of tree species for afforestation should consider drought resistance of the species for maximum survival and conservation of natural habitats. In this study, three soil moisture regimes: control (100% precipitation), mild drought (40% reduction in precipitation), and severe drought (80% reduction in precipitation) were applied to six gymnosperm and five angiosperm species for two consecutive years. We quantified the drought resistance index based on the root collar diameter and assessed the correlation between species drought resistance and other morphological, physiological, and biochemical traits by regression analysis. The prolonged drought stress altered the morphological, physiological, and biochemical traits, but the responses were species-specific. The species with high drought resistance had high leaf mass per area (LMA), photosynthetic rate (Pn), and midday leaf water potential (ΨMD), and low carbon isotopic discrimination (δ13C), flavonoid and polyphenol content, superoxide dismutase and DPPH radical scavenging activity. The highly drought-resistant species had a relatively less decrease in leaf size, Pn, and predawn leaf water potential (ΨPD), and less increase in δ13C, abscisic acid and sucrose content, and LMA compared to the control. The interannual variation in drought resistance (∆Rd) was positively correlated with the species hydroscopic slope (isohydric and anisohydric). Korean pine was highly resistant, sawtooth oak, hinoki cypress, East Asian white birch, East Asian ash, and mono maple were highly susceptible, and Korean red pine, Japanese larch, Sargent cherry, needle fir, and black pine were moderate in drought resistance under long-term drought. These findings will help species selection for afforestation programs and establishment of sustainable forests, especially of drought-tolerant species, under increased frequency and intensity of spring and summer droughts.
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Affiliation(s)
- Narayan Bhusal
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea; Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Minsu Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea
| | - Hojin Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea; Interdisciplinary Program in Agricultural and Forest Meteorology, Seoul National University, Seoul 08826, Republic of Korea
| | - Arjun Adhikari
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Ah Reum Han
- Division of Basic Research, National Institute of Ecology, Seocheon-gun 33657, Republic of Korea
| | - Areum Han
- Division of Basic Research, National Institute of Ecology, Seocheon-gun 33657, Republic of Korea
| | - Hyun Seok Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea; Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Interdisciplinary Program in Agricultural and Forest Meteorology, Seoul National University, Seoul 08826, Republic of Korea; National Center for Agro Meteorology, Seoul 08826, Republic of Korea.
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30
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Pivovaroff AL, Wolfe BT, McDowell N, Christoffersen B, Davies S, Dickman LT, Grossiord C, Leff RT, Rogers A, Serbin SP, Wright SJ, Wu J, Xu C, Chambers JQ. Hydraulic architecture explains species moisture dependency but not mortality rates across a tropical rainfall gradient. Biotropica 2021. [DOI: 10.1111/btp.12964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Alexandria L. Pivovaroff
- Atmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland WA USA
| | - Brett T. Wolfe
- Smithsonian Tropical Research Institute Balboa Republic of Panama
- School of Renewable Natural Resources Louisiana State University Baton Rouge LA USA
| | - Nate McDowell
- Atmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland WA USA
| | | | - Stuart Davies
- Smithsonian Tropical Research Institute Balboa Republic of Panama
| | - L. Turin Dickman
- Earth and Environmental Sciences Division Los Alamos National Laboratory Los Alamos NM USA
| | - Charlotte Grossiord
- Functional Plant Ecology Community Ecology Unit Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) Lausanne Switzerland
- School of Architecture Civil and Environmental Engineering ENAC Plant Ecology Research Laboratory – PERL EPFL Lausanne Switzerland
| | - Riley T. Leff
- Atmospheric Science and Global Change Division Pacific Northwest National Laboratory Richland WA USA
| | - Alistair Rogers
- Brookhaven National Laboratory, Environmental and Climate Sciences Upton NY USA
| | - Shawn P. Serbin
- Brookhaven National Laboratory, Environmental and Climate Sciences Upton NY USA
| | - S. Joseph Wright
- Smithsonian Tropical Research Institute Balboa Republic of Panama
| | - Jin Wu
- Brookhaven National Laboratory, Environmental and Climate Sciences Upton NY USA
- School of Biological Sciences The University of Hong Kong Hong Kong Hong Kong
| | - Chonggang Xu
- Earth and Environmental Sciences Division Los Alamos National Laboratory Los Alamos NM USA
| | - Jeffrey Q. Chambers
- Lawrence Berkeley National Laboratory Earth and Environmental Science Area Berkeley CA USA
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31
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Acheritobehere LM, Orellana IA, Raffaele E. The vulnerability of native and invasive conifer seedlings to simulated warming in north‐western Patagonia. AUSTRAL ECOL 2021. [DOI: 10.1111/aec.13051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laura M. Acheritobehere
- Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB) Ruta Nacional N° 259 km 16,41 Esquel Chubut 9200 Argentina
| | - Ivonne A. Orellana
- Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB) Ruta Nacional N° 259 km 16,41 Esquel Chubut 9200 Argentina
| | - Estela Raffaele
- Laboratorio Ecotono INIBIOMA (UNCO‐CONICET) Bariloche, Rio Negro Argentina
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32
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López R, Cano FJ, Martin-StPaul NK, Cochard H, Choat B. Coordination of stem and leaf traits define different strategies to regulate water loss and tolerance ranges to aridity. THE NEW PHYTOLOGIST 2021; 230:497-509. [PMID: 33452823 DOI: 10.1111/nph.17185] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/31/2020] [Indexed: 06/12/2023]
Abstract
Adaptation to drought involves complex interactions of traits that vary within and among species. To date, few data are available to quantify within-species variation in functional traits and they are rarely integrated into mechanistic models to improve predictions of species response to climate change. We quantified intraspecific variation in functional traits of two Hakea species growing along an aridity gradient in southeastern Australia. Measured traits were later used to parameterise the model SurEau to simulate a transplantation experiment to identify the limits of drought tolerance. Embolism resistance varied between species but not across populations. Instead, populations adjusted to drier conditions via contrasting sets of trait trade-offs that facilitated homeostasis of plant water status. The species from relatively mesic climate, Hakea dactyloides, relied on tight stomatal control whereas the species from xeric climate, Hakea leucoptera dramatically increased Huber value and leaf mass per area, while leaf area index (LAI) and epidermal conductance (gmin ) decreased. With trait variability, SurEau predicts the plasticity of LAI and gmin buffers the impact of increasing aridity on population persistence. Knowledge of within-species variability in multiple drought tolerance traits will be crucial to accurately predict species distributional limits.
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Affiliation(s)
- Rosana López
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Madrid, 28040, Spain
| | - Francisco Javier Cano
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | | | - Hervé Cochard
- Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, 63000, France
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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Ávila-Lovera E, Blanco H, Móvil O, Santiago LS, Tezara W. Shade tree species affect gas exchange and hydraulic conductivity of cacao cultivars in an agroforestry system. TREE PHYSIOLOGY 2021; 41:240-253. [PMID: 33313911 DOI: 10.1093/treephys/tpaa119] [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: 03/31/2020] [Accepted: 09/16/2020] [Indexed: 06/12/2023]
Abstract
Shade tolerance is a widespread strategy of rainforest understory plants. Many understory species have green young stems that may assimilate CO2 and contribute to whole-plant carbon balance. Cacao commonly grows in the shaded understory and recent emphasis has been placed on diversifying the types of trees used to shade cacao plants to achieve additional ecosystem services. We studied three agricultural cacao cultivars growing in the shade of four timber species (Cedrela odorata L., Cordia thaisiana Agostini, Swietenia macrophylla King and Tabebuia rosea (Bertol) A.D.C.) in an agroforestry system to (i) evaluate the timber species for their effect on the physiological performance of three cacao cultivars; (ii) assess the role of green stems on the carbon economy of cacao; and (iii) examine coordination between stem hydraulic conductivity and stem photosynthesis in cacao. Green young stem photosynthetic CO2 assimilation rate was positive and double leaf CO2 assimilation rate, indicating a positive contribution of green stems to the carbon economy of cacao; however, green stem area is smaller than leaf area and its relative contribution is low. Timber species showed a significant effect on leaf gas exchange traits and on stomatal conductance of cacao, and stem water-use efficiency varied among cultivars. There were no significant differences in leaf-specific hydraulic conductivity among cacao cultivars, but sapwood-specific hydraulic conductivity varied significantly among cultivars and there was an interactive effect of cacao cultivar × timber species. Hydraulic efficiency was coordinated with stem-stomatal conductance, but not with leaf-stomatal conductance or any measure of photosynthesis. We conclude that different shade regimes determined by timber species and the interaction with cacao cultivar had an important effect on most of the physiological traits and growth variables of three cacao cultivars growing in an agroforestry system. Results suggested that C. odorata is the best timber species to provide partial shade for cacao cultivars in the Barlovento region in Venezuela, regardless of cultivar origin.
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Affiliation(s)
- Eleinis Ávila-Lovera
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado 47114, Caracas 1041-A, Venezuela
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Héctor Blanco
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado 47114, Caracas 1041-A, Venezuela
| | - Olga Móvil
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado 47114, Caracas 1041-A, Venezuela
| | - Louis S Santiago
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Wilmer Tezara
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado 47114, Caracas 1041-A, Venezuela
- Facultad de Ciencias Agropecuarias, Universidad Técnica Luis Vargas Torres, Estación Experimental Mutile, Código postal 080150, Esmeraldas, Ecuador
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De Guzman ME, Acosta-Rangel A, Winter K, Meinzer FC, Bonal D, Santiago LS. Hydraulic traits of Neotropical canopy liana and tree species across a broad range of wood density: implications for predicting drought mortality with models. TREE PHYSIOLOGY 2021; 41:24-34. [PMID: 32803244 DOI: 10.1093/treephys/tpaa106] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 07/07/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Wood density (WD) is often used as a proxy for hydraulic traits such as vulnerability to drought-induced xylem cavitation and maximum water transport capacity, with dense-wooded species generally being more resistant to drought-induced xylem cavitation, having lower rates of maximum water transport and lower sapwood capacitance than light-wooded species. However, relationships between WD and the hydraulic traits that they aim to predict have not been well established in tropical forests, where modeling is necessary to predict drought responses for a high diversity of unmeasured species. We evaluated WD and relationships with stem xylem vulnerability by measuring cavitation curves, sapwood water release curves and minimum seasonal water potential (Ψmin) on upper canopy branches of six tree species and three liana species from a single wet tropical forest site in Panama. The objective was to better understand coordination and trade-offs among hydraulic traits and the potential utility of these relationships for modeling purposes. We found that parameters from sapwood water release curves such as capacitance, saturated water content and sapwood turgor loss point (Ψtlp,x) were related to WD, whereas stem vulnerability curve parameters were not. However, the water potential corresponding to 50% loss of hydraulic conductivity (P50) was related to Ψtlp,x and sapwood osmotic potential at full turgor (πo,x). Furthermore, species with lower Ψmin showed lower P50, Ψtlp,x and πo,x suggesting greater drought resistance. Our results indicate that WD is a good easy-to-measure proxy for some traits related to drought resistance, but not others. The ability of hydraulic traits such as P50 and Ψtlp,x to predict mortality must be carefully examined if WD values are to be used to predict drought responses in species without detailed physiological measurements.
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Affiliation(s)
- Mark E De Guzman
- Department of Botany & Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Aleyda Acosta-Rangel
- Department of Botany & Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Balboa, Ancón, Panamá 0843-03092, Republic of Panamá
| | - Frederick C Meinzer
- Pacific Northwest Station, USDA Forest Service, Corvallis, 3200 SW Jefferson Way, OR 97331, USA
| | - Damien Bonal
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, 14 Rue Girardet, 54000 Nancy, France
| | - Louis S Santiago
- Department of Botany & Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Balboa, Ancón, Panamá 0843-03092, Republic of Panamá
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Pratt RB, Tobin MF, Jacobsen AL, Traugh CA, De Guzman ME, Hayes CC, Toschi HS, MacKinnon ED, Percolla MI, Clem ME, Smith PT. Starch storage capacity of sapwood is related to dehydration avoidance during drought. AMERICAN JOURNAL OF BOTANY 2021; 108:91-101. [PMID: 33349932 DOI: 10.1002/ajb2.1586] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/22/2020] [Indexed: 05/26/2023]
Abstract
PREMISE The xylem tissue of plants performs three principal functions: transport of water, support of the plant body, and nutrient storage. Tradeoffs may arise because different structural requirements are associated with different functions or because suites of traits are under selection that relate to resource acquisition, use, and turnover. The structural and functional basis of xylem storage is not well established. We hypothesized that greater starch storage would be associated with greater sapwood parenchyma and reduced fibers, which would compromise resistance to xylem tensions during dehydration. METHODS We measured cavitation resistance, minimum water potential, starch content, and sapwood parenchyma and fiber area in 30 species of southern California chaparral shrubs (evergreen and deciduous). RESULTS We found that species storing greater starch within their xylem tended to avoid dehydration and were less cavitation resistant, and this was supported by phylogenetic independent contrasts. Greater sapwood starch was associated with greater parenchyma area and reduced fiber area. For species without living fibers, the associations with parenchyma were stronger, suggesting that living fibers may expand starch storage capacity while also contributing to the support function of the vascular tissue. Drought-deciduous species were associated with greater dehydration avoidance than evergreens. CONCLUSIONS Evolutionary forces have led to an association between starch storage and dehydration resistance as part of an adaptive suite of traits. We found evidence for a tradeoff between tissue mechanical traits and starch storage; moreover, the evolution of novel strategies, such as starch-storing living fibers, may mitigate the strength of this tradeoff.
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Affiliation(s)
- R Brandon Pratt
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Michael F Tobin
- University of Houston-Downtown, Department of Natural Sciences, One Main Street, Houston, Texas, 77002, USA
| | - Anna L Jacobsen
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Courtney A Traugh
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Mark E De Guzman
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Christine C Hayes
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Hayden S Toschi
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Evan D MacKinnon
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Marta I Percolla
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Michael E Clem
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Paul T Smith
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
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Zhang Q, Zhu S, Jansen S, Cao K. Topography strongly affects drought stress and xylem embolism resistance in woody plants from a karst forest in Southwest China. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13731] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Qi‐Wei Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation College of Forestry Guangxi University Nanning China
| | - Shi‐Dan Zhu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation College of Forestry Guangxi University Nanning China
| | - Steven Jansen
- Institute of Systematic Botany and Ecology Ulm University Ulm Germany
| | - Kun‐Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐Bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation College of Forestry Guangxi University Nanning China
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Levionnois S, Ziegler C, Jansen S, Calvet E, Coste S, Stahl C, Salmon C, Delzon S, Guichard C, Heuret P. Vulnerability and hydraulic segmentations at the stem-leaf transition: coordination across Neotropical trees. THE NEW PHYTOLOGIST 2020; 228:512-524. [PMID: 32496575 DOI: 10.1111/nph.16723] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/18/2020] [Indexed: 05/23/2023]
Abstract
Hydraulic segmentation at the stem-leaf transition predicts higher hydraulic resistance in leaves than in stems. Vulnerability segmentation, however, predicts lower embolism resistance in leaves. Both mechanisms should theoretically favour runaway embolism in leaves to preserve expensive organs such as stems, and should be tested for any potential coordination. We investigated the theoretical leaf-specific conductivity based on an anatomical approach to quantify the degree of hydraulic segmentation across 21 tropical rainforest tree species. Xylem resistance to embolism in stems (flow-centrifugation technique) and leaves (optical visualization method) was quantified to assess vulnerability segmentation. We found a pervasive hydraulic segmentation across species, but with a strong variability in the degree of segmentation. Despite a clear continuum in the degree of vulnerability segmentation, eight species showed a positive vulnerability segmentation (leaves less resistant to embolism than stems), whereas the remaining species studied exhibited a negative or no vulnerability segmentation. The degree of vulnerability segmentation was positively related to the degree of hydraulic segmentation, such that segmented species promote both mechanisms to hydraulically decouple leaf xylem from stem xylem. To what extent hydraulic and vulnerability segmentation determine drought resistance requires further integration of the leaf-stem transition at the whole-plant level, including both xylem and outer xylem tissue.
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Affiliation(s)
- Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- UMR SILVA, INRAE , Université de Lorraine, Nancy, 54000, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, D-89081, Germany
| | - Emma Calvet
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Camille Salmon
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Sylvain Delzon
- Univ. Bordeaux , INRAE, BIOGECO, Pessac, F-33615, France
| | - Charlotte Guichard
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
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Li Q, Zhao M, Wang N, Liu S, Wang J, Zhang W, Yang N, Fan P, Wang R, Wang H, Du N. Water use strategies and drought intensity define the relative contributions of hydraulic failure and carbohydrate depletion during seedling mortality. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 153:106-118. [PMID: 32485615 DOI: 10.1016/j.plaphy.2020.05.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 05/08/2023]
Abstract
COMBINING HYDRAULIC: and carbon-related measurements can help elucidate drought-induced plant mortality. To study drought mortality mechanisms, seedlings of two woody species, including the anisohydric Robinia pseudoacacia and isohydric Quercus acutissima, were cultivated in a greenhouse and subjected to intense drought by withholding water and mild drought by adding half of the amount of daily water lost. Patterns of leaf and root gas exchange, leaf surface areas, growth, leaf and stem hydraulics, and carbohydrate dynamics were determined in drought-stressed and control seedlings. We detected a complete loss of hydraulic conductivity and partial depletion of total nonstructural carbohydrates contents (TNC) in the dead seedlings. We also found that intense drought triggered a more rapid decrease in plant water potential and a faster drop in net photosynthesis below zero, and a greater TNC loss in dead seedlings than mild drought. Additionally, anisohydric R. pseudoacacia suffered a rapider death than the isohydric Q. acutissima. Based on these findings, we propose that hydraulic conductivity loss and carbon limitation jointly contributed to drought-induced death, while the relative contributions could be altered by drought intensity. We thus believe that it is important to illustrate the mechanistic relationships between stress intensity and carbon-hydraulics coupling in the context of isohydric vs. anisohydric hydraulic strategies.
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Affiliation(s)
- Qiang Li
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China
| | - Mingming Zhao
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China
| | - Ning Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China
| | - Shuna Liu
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China
| | - Jingwen Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China
| | - Wenxin Zhang
- Shandong Academy of Forestry, 42 Wenhuadong Road, Jinan, 250014, China
| | - Ning Yang
- Qingdao Forestry Station, 106 Yan'an'yi Road, Qingdao, 266003, China
| | - Peixian Fan
- Qingdao Forestry Station, 106 Yan'an'yi Road, Qingdao, 266003, China
| | - Renqing Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China
| | - Hui Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China.
| | - Ning Du
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao, 266237, China; Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, 72 Binhai Road, Qingdao, 266237, China.
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Drought-modulated allometric patterns of trees in semi-arid forests. Commun Biol 2020; 3:405. [PMID: 32733028 PMCID: PMC7393108 DOI: 10.1038/s42003-020-01144-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 07/09/2020] [Indexed: 11/09/2022] Open
Abstract
Tree allometry in semi-arid forests is characterized by short height but large canopy. This pattern may be important for maintaining water-use efficiency and carbon sequestration simultaneously, but still lacks quantification. Here we use terrestrial laser scanning to quantify allometry variations of Quercus mongolica in semi-arid forests. With tree height (Height) declining, canopy area (CA) decreases with substantial variations. The theoretical CA-Height relationship in dynamic global vegetation models (DGVMs) matches only the 5th percentile of our results because of CA underestimation and Height overestimation by breast height diameter (DBH). Water supply determines Height variation (P = 0.000) but not CA (P = 0.2 in partial correlation). The decoupled functions of stem, hydraulic conductance and leaf spatial arrangement, may explain the inconsistency, which may further ensure hydraulic safety and carbon assimilation, avoiding forest dieback. Works on tree allometry pattern and determinant will effectively supply tree drought tolerance studying and support DGVM improvements.
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Ripullone F, Camarero JJ, Colangelo M, Voltas J. Variation in the access to deep soil water pools explains tree-to-tree differences in drought-triggered dieback of Mediterranean oaks. TREE PHYSIOLOGY 2020; 40:591-604. [PMID: 32159804 DOI: 10.1093/treephys/tpaa026] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/01/2020] [Indexed: 06/10/2023]
Abstract
Individual differences in the access to deep soil water pools may explain the differential damage among coexisting, conspecific trees as a consequence of drought-induced dieback. We addressed this issue by comparing the responses to a severe drought of three Mediterranean oak species with different drought tolerance, Quercus pubescens L. and Quercus frainetto Ten., mainly thriving at xeric and mesic sites, respectively, and Quercus cerris L., which dominates at intermediate sites. For each species, we compared coexisting declining (D) and non-declining (ND) trees. The stable isotope composition (δ2H, δ18O) of xylem and soil water was used to infer a differential use of soil water sources. We also measured tree size and radial growth to quantify the long-term divergence of wood production between D and ND trees and non-structural carbohydrates (NSCs) in sapwood to evaluate if D trees presented lower NSC values. The ND trees had access to deeper soil water than D trees except in Q. frainetto, as indicated by significantly more depleted xylem water values. However, a strong δ2H offset between soil and xylem water isotopes observed in peak summer could suggest that both tree types were not physiologically active under extreme drought conditions. Alternative processes causing deuterium fractionation, however, could not be ruled out. Tree height and recent (last 15-25 years) growth rates in all species studied were lower in D than in ND trees by 22 and 44%, respectively. Lastly, there was not a consistent pattern of NSC sapwood concentration; in Q. pubescens, it was higher in ND trees while in Q. frainetto, the D trees were the ones exhibiting the higher NSC concentration. We conclude that the vulnerability to drought among conspecific Mediterranean oaks depends on the differential access to deep soil water pools, which may be related to differences in rooting depth, tree size and growth rate.
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Affiliation(s)
- Francesco Ripullone
- School of Agricultural, Forest, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano 10, Potenza I-85100, Italy
| | - J Julio Camarero
- Instituto Pirenaico de Ecología (IPE-CSIC), Avda Montañana 1005, Zaragoza E-50059, Spain
| | - Michele Colangelo
- School of Agricultural, Forest, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano 10, Potenza I-85100, Italy
- Instituto Pirenaico de Ecología (IPE-CSIC), Avda Montañana 1005, Zaragoza E-50059, Spain
| | - Jordi Voltas
- Joint Research Unit CTFC-AGROTECNIO, Av. Alcalde Rovira Roure 191, Lleida 25198, Spain
- Department of Crop and Forest Sciences, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida 25198, Spain
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Väänänen PJ, Osem Y, Cohen S, Grünzweig JM. Differential drought resistance strategies of co-existing woodland species enduring the long rainless Eastern Mediterranean summer. TREE PHYSIOLOGY 2020; 40:305-320. [PMID: 31860712 DOI: 10.1093/treephys/tpz130] [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: 07/01/2019] [Revised: 08/28/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
In anticipation of a drier climate and to project future changes in forest dynamics, it is imperative to understand species-specific differences in drought resistance. The objectives of this study were to form a comprehensive understanding of the drought resistance strategies adopted by Eastern Mediterranean woodland species, and to elaborate specific ecophysiological traits that can explain the observed variation in survival among these species. We examined leaf water potential (𝛹), gas exchange and stem hydraulics during 2-3 years in mature individuals of the key woody species Phillyrea latifolia L., Pistacia lentiscus L. and Quercus calliprinos Webb that co-exist in a dry woodland experiencing ~ 6 rainless summer months. As compared with the other two similarly functioning species, Phillyrea displayed considerably lower 𝛹 (minimum 𝛹 of -8.7 MPa in Phillyrea vs -4.2 MPa in Pistacia and Quercus), lower 𝛹 at stomatal closure and lower leaf turgor loss point (𝛹TLP ), but reduced hydraulic vulnerability and wider safety margins. Notably, Phillyrea allowed 𝛹 to drop below 𝛹TLP under severe drought, whereas the other two species maintained positive turgor. These results indicate that Phillyrea adopted a more anisohydric drought resistance strategy, while Pistacia and Quercus exhibited a more isohydric strategy and probably relied on deeper water reserves. Unlike the two relatively isohydric species, Phillyrea reached complete stomatal closure at the end of the dry summer. Despite assessing a large number of physiological traits, none of them could be directly related to tree mortality. Higher mortality was observed for Quercus than for the other two species, which may result from higher water consumption due to its 2.5-10 times larger crown volume. The observed patterns suggest that similar levels of drought resistance in terms of survival can be achieved via different drought resistance strategies. Conversely, similar resistance strategies in terms of isohydricity can lead to different levels of vulnerability to extreme drought.
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Affiliation(s)
- Päivi J Väänänen
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
- Department of Natural Resources, Agricultural Research Organization, Volcani Center, Bet-Dagan 50250, Israel
| | - Yagil Osem
- Department of Natural Resources, Agricultural Research Organization, Volcani Center, Bet-Dagan 50250, Israel
| | - Shabtai Cohen
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, Bet-Dagan 50250, Israel
| | - José M Grünzweig
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
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Santiago LS. Going underground: new approaches to assess dynamic root behaviour during drought. THE NEW PHYTOLOGIST 2020; 225:599-600. [PMID: 31721227 DOI: 10.1111/nph.16278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Louis S Santiago
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA, 92521, USA
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Ramirez AR, De Guzman ME, Dawson TE, Ackerly DD. Plant hydraulic traits reveal islands as refugia from worsening drought. CONSERVATION PHYSIOLOGY 2020; 8:coz115. [PMID: 32015878 PMCID: PMC6988607 DOI: 10.1093/conphys/coz115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 12/05/2019] [Accepted: 12/31/2019] [Indexed: 05/14/2023]
Abstract
Relatively mesic environments within arid regions may be important conservation targets as 'climate change refugia' for species persistence in the face of worsening drought conditions. Semi-arid southern California and the relatively mesic environments of California's Channel Islands provide a model system for examining drought responses of plants in potential climate change refugia. Most methods for detecting refugia are focused on 'exposure' of organisms to certain abiotic conditions, which fail to assess how local adaptation or acclimation of plant traits (i.e. 'sensitivity') contribute to or offset the benefits of reduced exposure. Here, we use a comparative plant hydraulics approach to characterize the vulnerability of plants to drought, providing a framework for identifying the locations and trait patterns that underlie functioning climate change refugia. Seasonal water relations, xylem hydraulic traits and remotely sensed vegetation indices of matched island and mainland field sites were used to compare the response of native plants from contrasting island and mainland sites to hotter droughts in the early 21st century. Island plants experienced more favorable water relations and resilience to recent drought. However, island plants displayed low plasticity/adaptation of hydraulic traits to local conditions, which indicates that relatively conserved traits of island plants underlie greater hydraulic safety and localized buffering from regional drought conditions. Our results provide an explanation for how California's Channel Islands function as a regional climate refugia during past and current climate change and demonstrate a physiology-based approach for detecting potential climate change refugia in other systems.
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Affiliation(s)
- Aaron R Ramirez
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building #3140 Berkeley CA 94720-3200, USA
- Department of Biology & Environmental Studies, Reed College, Portland, 33203 Southeast Woodstock Blvd., Portland, Oregon 97202-8199, USA
- Corresponding author: Department of Biology & Environmental Studies, Reed College, Portland, 33203 Southeast Woodstock Blvd., Portland, Oregon 97202-8199, USA. Tel: +(503) 517-4101.
| | - Mark E De Guzman
- Department of Biology & Environmental Studies, Reed College, Portland, 33203 Southeast Woodstock Blvd., Portland, Oregon 97202-8199, USA
- Department of Botany & Plant Sciences, University of California, Riverside, 900 University Ave., Riverside CA 92521, USA
| | - Todd E Dawson
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building #3140 Berkeley CA 94720-3200, USA
- Department of Environmental Science, Policy, and Management, University of California, 130 Mulford Hall #3114, Berkeley, CA 94720-3114, USA
| | - David D Ackerly
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building #3140 Berkeley CA 94720-3200, USA
- Department of Environmental Science, Policy, and Management, University of California, 130 Mulford Hall #3114, Berkeley, CA 94720-3114, USA
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Comparison of Branch Water Relations in Two Riparian Species: Populus euphratica and Tamarix ramosissima. SUSTAINABILITY 2019. [DOI: 10.3390/su11195461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Water relations in plants maintain healthy tree branches and drought conditions during plant growth may affect water relations, but the mechanisms are poorly known. In our study, we determined the stomatal conductance, hydraulic conductance, water potential and ion concentration of xylem sap to increase the understanding of changes in water relations in branches of Populus euphratica (P. euphratica) and Tamarix ramosissima (T. ramosissima), which are the dominant plant species in the lower reaches of the Heihe River Basin in China. The results showed that both species responded to vapor pressure deficit (VPD) during the growing season by adjusting stomatal conductance to achieve homeostasis in leaf water potentials. The leaf-specific hydraulic conductance (LSC) of the branch was determined using water status in the branch, and the LSC of the leaf was determined using water status in the leaf. Because of homeostasis in leaf water potentials, hydraulic conductance in leaves remained stable. As a result, branch dieback, which might be induced by deficits in water supply, could rarely be seen in T. ramosissima owing to the homeostasis in branch and leaf water status. The ion sensitivity of xylem hydraulic conductance in P. euphratica induced an increase in hydraulic conductance caused by the deficits in the water supply which might lead to branch dieback. The evaluation of water relations provides a further understanding of the internal mechanisms of drought acclimation for riparian plants.
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Ávila-Lovera E, Urich R, Coronel I, Tezara W. Seasonal gas exchange and resource-use efficiency in evergreen versus deciduous species from a tropical dry forest. TREE PHYSIOLOGY 2019; 39:1561-1571. [PMID: 31135926 DOI: 10.1093/treephys/tpz060] [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: 12/12/2018] [Revised: 03/12/2019] [Accepted: 05/12/2019] [Indexed: 06/09/2023]
Abstract
Tropical dry forests (TDFs) experience a long dry season in which plant species are subject to several months of water deficit. However, TDFs maintain a diverse group of plant life forms, growth forms and leaf phenology, and it is not clear how they vary in their mechanisms for coping with seasonal drought. We studied seasonal changes in leaf water potential (Ψleaf), gas exchange, photochemical activity and functional traits in evergreen and drought-deciduous species from a TDF to determine if leaf phenology mediates plant responses to drought. We found seasonal decreases in Ψleaf, stomatal conductance (gs) and transpiration rate (E), and increases in both intrinsic and instantaneous water-use efficiency. We did not find seasonal differences in photosynthetic rate (Aarea) and carbon isotope composition (δ13C); however, these traits differed between leaf phenology groups, with drought-deciduous plants having higher Aarea and δ13C than evergreen plants. We also found that plants with high leaf nitrogen concentration (Narea) also had low mass-based photosynthetic rate (Amass), photosynthetic-nitrogen-use efficiency and specific leaf area, contrary to the expected relationships given by the leaf economics spectrum. Despite higher Narea, sclerophyllous leaves maintained lower Amass, and this increased structural toughness of leaves may be imposing a stronger limitation for CO2 diffusion and hence photosynthesis. Overall, we found more water-conservative traits in deciduous than in evergreen plants, contrary to what is known about these two leaf phenology groups in other seasonal sites both at tropical and temperate latitudes.
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Affiliation(s)
- Eleinis Ávila-Lovera
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado, Caracas, Venezuela
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA
| | - Rosa Urich
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado, Caracas, Venezuela
| | - Ilsa Coronel
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado, Caracas, Venezuela
| | - Wilmer Tezara
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Apartado, Caracas, Venezuela
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Dória LC, Meijs C, Podadera DS, Del Arco M, Smets E, Delzon S, Lens F. Embolism resistance in stems of herbaceous Brassicaceae and Asteraceae is linked to differences in woodiness and precipitation. ANNALS OF BOTANY 2019; 124:1-14. [PMID: 30590483 PMCID: PMC6676380 DOI: 10.1093/aob/mcy233] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 12/05/2018] [Indexed: 05/16/2023]
Abstract
BACKGROUND AND AIMS Plant survival under extreme drought events has been associated with xylem vulnerability to embolism (the disruption of water transport due to air bubbles in conduits). Despite the ecological and economic importance of herbaceous species, studies focusing on hydraulic failure in herbs remain scarce. Here, we assess the vulnerability to embolism and anatomical adaptations in stems of seven herbaceous Brassicaceae species occurring in different vegetation zones of the island of Tenerife, Canary Islands, and merged them with a similar hydraulic-anatomical data set for herbaceous Asteraceae from Tenerife. METHODS Measurements of vulnerability to xylem embolism using the in situ flow centrifuge technique along with light and transmission electron microscope observations were performed in stems of the herbaceous species. We also assessed the link between embolism resistance vs. mean annual precipitation and anatomical stem characters. KEY RESULTS The herbaceous species show a 2-fold variation in stem P50 from -2.1 MPa to -4.9 MPa. Within Hirschfeldia incana and Sisymbrium orientale, there is also a significant stem P50 difference between populations growing in contrasting environments. Variation in stem P50 is mainly explained by mean annual precipitation as well as by the variation in the degree of woodiness (calculated as the proportion of lignified area per total stem area) and to a lesser extent by the thickness of intervessel pit membranes. Moreover, mean annual precipitation explains the total variance in embolism resistance and stem anatomical traits. CONCLUSIONS The degree of woodiness and thickness of intervessel pit membranes are good predictors of embolism resistance in the herbaceous Brassicaceae and Asteraceae species studied. Differences in mean annual precipitation across the sampling sites affect embolism resistance and stem anatomical characters, both being important characters determining survival and distribution of the herbaceous eudicots.
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Affiliation(s)
| | - Cynthia Meijs
- Naturalis Biodiversity Center, Leiden University, RA Leiden, The Netherlands
| | | | - Marcelino Del Arco
- Department of Plant Biology (Botany), La Laguna University, La Laguna, Tenerife, Spain
| | - Erik Smets
- Naturalis Biodiversity Center, Leiden University, RA Leiden, The Netherlands
| | | | - Frederic Lens
- Naturalis Biodiversity Center, Leiden University, RA Leiden, The Netherlands
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48
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Chen Z, Li S, Luan J, Zhang Y, Zhu S, Wan X, Liu S. Prediction of temperate broadleaf tree species mortality in arid limestone habitats with stomatal safety margins. TREE PHYSIOLOGY 2019; 39:1428-1437. [PMID: 30977822 DOI: 10.1093/treephys/tpz045] [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: 01/28/2019] [Revised: 03/24/2019] [Accepted: 04/04/2019] [Indexed: 06/09/2023]
Abstract
A growing body of evidence highlights the occurrence of increased widespread tree mortality during climate change-associated severe droughts; however, in situ long-term drought experiments with multispecies communities for the prediction of tree mortality and exploration of related mechanisms are rather limited in natural environments. We conducted a 7-year afforestation trial with 20 drought-resistant broadleaf tree species in an arid limestone habitat in northern China, where the species displayed a broad range of survival rates. The stomatal and xylem hydraulic traits of all the species were measured. We found that species' stomatal closure points were strongly related to their xylem embolism resistance and xylem minimum water potential but not to their survival rates. Hydraulic failure of the vascular system appeared to be the main cause of tree mortality, and the stomatal safety margin was a better predictor of tree mortality than the traditionally considered xylem embolism resistance and hydraulic safety margin. We recommend the stomatal safety margin as the indicator for predicting drought-induced tree mortality and for selecting tree species in future forest restorations in arid regions.
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Affiliation(s)
- Zhicheng Chen
- Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, China
| | - Shan Li
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, China
| | - Junwei Luan
- Institute for Resources and Environment, International Centre for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, National Forestry and Grassland Administration, Beijing, China
- Department of Natural Resource Sciences, Macdonald Campus, McGill University, Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, Canada
| | - Yongtao Zhang
- Mountain Tai Forest Ecosystem Research Station of National Forestry and Grassland Administration, Forestry College of Shandong Agricultural University, Taian, China
| | - Shidan Zhu
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Xianchong Wan
- Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, China
| | - Shirong Liu
- Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
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49
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Blackman CJ, Creek D, Maier C, Aspinwall MJ, Drake JE, Pfautsch S, O'Grady A, Delzon S, Medlyn BE, Tissue DT, Choat B. Drought response strategies and hydraulic traits contribute to mechanistic understanding of plant dry-down to hydraulic failure. TREE PHYSIOLOGY 2019; 39:910-924. [PMID: 30865274 DOI: 10.1093/treephys/tpz016] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/01/2019] [Indexed: 05/17/2023]
Abstract
Drought-induced tree mortality alters forest structure and function, yet our ability to predict when and how different species die during drought remains limited. Here, we explore how stomatal control and drought tolerance traits influence the duration of drought stress leading to critical levels of hydraulic failure. We examined the growth and physiological responses of four woody plant species (three angiosperms and one conifer) representing a range of water-use and drought tolerance traits over the course of two controlled drought-recovery cycles followed by an extended dry-down. At the end of the final dry-down phase, we measured changes in biomass ratios and leaf carbohydrates. During the first and second drought phases, plants of all species closed their stomata in response to decreasing water potential, but only the conifer species avoided water potentials associated with xylem embolism as a result of early stomatal closure relative to thresholds of hydraulic dysfunction. The time it took plants to reach critical levels of water stress during the final dry-down was similar among the angiosperms (ranging from 39 to 57 days to stemP88) and longer in the conifer (156 days to stemP50). Plant dry-down time was influenced by a number of factors including species stomatal-hydraulic safety margin (gsP90 - stemP50), as well as leaf succulence and minimum stomatal conductance. Leaf carbohydrate reserves (starch) were not depleted at the end of the final dry-down in any species, irrespective of the duration of drought. These findings highlight the need to consider multiple structural and functional traits when predicting the timing of hydraulic failure in plants.
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Affiliation(s)
- Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Danielle Creek
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Chelsea Maier
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Michael J Aspinwall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, USA
| | - John E Drake
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- Forest and Natural Resources Management, SUNY-ESF, 1 Forestry Drive, Syracuse, NY, USA
| | - Sebastian Pfautsch
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
- School of Social Science and Psychology (Urban Studies), Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
| | | | | | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
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50
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Siddiq Z, Zhang YJ, Zhu SD, Cao KF. Canopy water status and photosynthesis of tropical trees are associated with trunk sapwood hydraulic properties. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 139:724-730. [PMID: 31055133 DOI: 10.1016/j.plaphy.2019.04.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/21/2019] [Accepted: 04/23/2019] [Indexed: 06/09/2023]
Abstract
Tree trunks not only provide physical support for canopy leaves but also supply and store water for transpiration. However, the relationships between trunk hydraulic properties and canopy leaf physiology in tropical trees are not well-understood. In this study we concurrently measured morning and midday canopy leaf photosynthesis (A), stomatal conductance (gs), and leaf water potentials (ΨL) in 40 tropical trees representing 14 species at the beginning of the rainy season in Xishuangbanna, Southwest China. We also measured trunk sapwood capacitance (C), wood density, and sap flux density to assess their association with canopy leaf physiology. Among the 14 studied species, only three and four species did not show a significant midday reduction in A and gs respectively. The diurnally maximum A and gs were significantly positively related to sapwood hydraulic capacitance, maximum sap flux density (midday), and sap flux density at 11:00. Those species with lower wood density and higher C showed a lower reduction in ΨL at midday, whereas, species with high C, and large values of maximum sap flux density also showed high carbon assimilation at midday. Our results provide new insights into the close coordination between canopy physiology and trunk sapwood hydraulic properties in tropical trees.
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Affiliation(s)
- Zafar Siddiq
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, 666303, China; Department of Botany, Government College University, Lahore, 54000, Pakistan; University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
| | - Shi-Dan Zhu
- Plant Ecophysiology and Evolution Group, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, and Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, 530005, China
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, and Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, 530005, China.
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