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Guo JJ, Gong XW, Li XH, Zhang C, Duan CY, Lohbeck M, Sterck F, Hao GY. Coupled hydraulics and carbon economy underlie age-related growth decline and revitalisation of sand-fixing shrubs after crown removal. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38644635 DOI: 10.1111/pce.14923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 04/06/2024] [Accepted: 04/11/2024] [Indexed: 04/23/2024]
Abstract
Crown removal revitalises sand-fixing shrubs that show declining vigour with age in drought-prone environments; however, the underlying mechanisms are poorly understood. Here, we addressed this knowledge gap by comparing the growth performance, xylem hydraulics and plant carbon economy across different plant ages (10, 21 and 33 years) and treatments (control and crown removal) using a representative sand-fixing shrub (Caragana microphylla Lam.) in northern China. We found that growth decline with plant age was accompanied by simultaneous decreases in soil moisture, plant hydraulic efficiency and photosynthetic capacity, suggesting that these interconnected changes in plant water relations and carbon economy were responsible for this decline. Following crown removal, quick resprouting, involving remobilisation of root nonstructural carbohydrate reserves, contributed to the reconstruction of an efficient hydraulic system and improved plant carbon status, but this became less effective in older shrubs. These age-dependent effects of carbon economy and hydraulics on plant growth vigour provide a mechanistic explanation for the age-related decline and revitalisation of sand-fixing shrubs. This understanding is crucial for the development of suitable management strategies for shrub plantations constructed with species having the resprouting ability and contributes to the sustainability of ecological restoration projects in water-limited sandy lands.
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Affiliation(s)
- Jing-Jing Guo
- CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- Daqinggou Ecological Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Xue-Wei Gong
- CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- Daqinggou Ecological Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Xue-Hua Li
- CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Chi Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Chun-Yang Duan
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Madelon Lohbeck
- Forest Ecology and Management Group, Wageningen University & Research, AA Wageningen, the Netherlands
| | - Frank Sterck
- Forest Ecology and Management Group, Wageningen University & Research, AA Wageningen, the Netherlands
| | - Guang-You Hao
- CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- Daqinggou Ecological Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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2
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Potkay A, Feng X. Dynamically optimizing stomatal conductance for maximum turgor-driven growth over diel and seasonal cycles. AOB PLANTS 2023; 15:plad044. [PMID: 37899972 PMCID: PMC10601388 DOI: 10.1093/aobpla/plad044] [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: 12/22/2022] [Accepted: 07/04/2023] [Indexed: 10/31/2023]
Abstract
Stomata have recently been theorized to have evolved strategies that maximize turgor-driven growth over plants' lifetimes, finding support through steady-state solutions in which gas exchange, carbohydrate storage and growth have all reached equilibrium. However, plants do not operate near steady state as plant responses and environmental forcings vary diurnally and seasonally. It remains unclear how gas exchange, carbohydrate storage and growth should be dynamically coordinated for stomata to maximize growth. We simulated the gas exchange, carbohydrate storage and growth that dynamically maximize growth diurnally and annually. Additionally, we test whether the growth-optimization hypothesis explains nocturnal stomatal opening, particularly through diel changes in temperature, carbohydrate storage and demand. Year-long dynamic simulations captured realistic diurnal and seasonal patterns in gas exchange as well as realistic seasonal patterns in carbohydrate storage and growth, improving upon unrealistic carbohydrate responses in steady-state simulations. Diurnal patterns of carbohydrate storage and growth in day-long simulations were hindered by faulty modelling assumptions of cyclic carbohydrate storage over an individual day and synchronization of the expansive and hardening phases of growth, respectively. The growth-optimization hypothesis cannot currently explain nocturnal stomatal opening unless employing corrective 'fitness factors' or reframing the theory in a probabilistic manner, in which stomata adopt an inaccurate statistical 'memory' of night-time temperature. The growth-optimization hypothesis suggests that diurnal and seasonal patterns of stomatal conductance are driven by a dynamic carbon-use strategy that seeks to maintain homeostasis of carbohydrate reserves.
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Affiliation(s)
- Aaron Potkay
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, 500 Pillsbury Drive S.E., Minneapolis, MN 55455, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Twin Cities, 23rd Ave SE, Minneapolis, MN 55414, USA
| | - Xue Feng
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, 500 Pillsbury Drive S.E., Minneapolis, MN 55455, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Twin Cities, 23rd Ave SE, Minneapolis, MN 55414, USA
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3
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Martín-Gómez P, Rodríguez-Robles U, Ogée J, Wingate L, Sancho-Knapik D, Peguero-Pina J, Dos Santos Silva JV, Gil-Pelegrín E, Pemán J, Ferrio JP. Contrasting stem water uptake and storage dynamics of water-saver and water-spender species during drought and recovery. TREE PHYSIOLOGY 2023; 43:1290-1306. [PMID: 36930058 DOI: 10.1093/treephys/tpad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 03/01/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Drought is projected to occur more frequently and intensely in the coming decades, and the extent to which it will affect forest functioning will depend on species-specific responses to water stress. Aiming to understand the hydraulic traits and water dynamics behind water-saver and water-spender strategies in response to drought and recovery, we conducted a pot experiment with two species with contrasting physiological strategies, Scots pine (Pinus sylvestris L.) and Portuguese oak (Quercus faginea L.). We applied two cycles of soil drying and recovery and irrigated with isotopically different water to track fast changes in soil and stem water pools, while continuously measuring physiological status and xylem water content from twigs. Our results provide evidence for a tight link between the leaf-level response and the water uptake and storage patterns in the stem. The water-saver strategy of pines prevented stem dehydration by rapidly closing stomata which limited their water uptake during the early stages of drought and recovery. Conversely, oaks showed a less conservative strategy, maintaining transpiration and physiological activity under dry soil conditions, and consequently becoming more dehydrated at the stem level. We interpreted this dehydration as the release of water from elastic storage tissues as no major loss of hydraulic conductance occurred for this species. After soil rewetting, pines recovered pre-drought leaf water potential rapidly, but it took longer to replace the water from conductive tissues (slower labeling speed). In contrast, water-spender oaks were able to quickly replace xylem water during recovery (fast labeling speed), but it took longer to refill stem storage tissues, and hence to recover pre-drought leaf water potential. These different patterns in sap flow rates, speed and duration of the labeling reflected a combination of water-use and storage traits, linked to the leaf-level strategies in response to drought and recovery.
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Affiliation(s)
- Paula Martín-Gómez
- Joint Research Unit CTFC - AGROTECNIO - CERCA, Ctra de Sant Llorenç de Morunys, km 2, E-25280 Solsona, Lleida, Spain
| | - Ulises Rodríguez-Robles
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Av. Independencia Nacional 151, Autlán de Navarro, 48900 Jalisco, México
| | - Jérôme Ogée
- Atmosphere Plant Soil Interactions Research Unit (UMR ISPA), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), 71 Av. Edouard Bourlaux, F-33140 Villenave d'Ornon, France
| | - Lisa Wingate
- Atmosphere Plant Soil Interactions Research Unit (UMR ISPA), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), 71 Av. Edouard Bourlaux, F-33140 Villenave d'Ornon, France
| | - Domingo Sancho-Knapik
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - José Peguero-Pina
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - José Victor Dos Santos Silva
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - Eustaquio Gil-Pelegrín
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
| | - Jesús Pemán
- Department of Crop and Forest Sciences, Universitat de Lleida (UdL), Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Juan Pedro Ferrio
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda. Montañana 930, E-50059 Zaragoza, Spain
- Aragon Agency for Research and Development (ARAID), E-50018 Zaragoza, Spain
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4
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Blumstein M, Gersony J, Martínez-Vilalta J, Sala A. Global variation in nonstructural carbohydrate stores in response to climate. GLOBAL CHANGE BIOLOGY 2023; 29:1854-1869. [PMID: 36583374 DOI: 10.1111/gcb.16573] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/26/2022] [Indexed: 05/28/2023]
Abstract
Woody plant species store nonstructural carbohydrates (NSCs) for many functions. While known to buffer against fluctuations in photosynthetic supply, such as at night, NSC stores are also thought to buffer against environmental extremes, such as drought or freezing temperatures by serving as either back-up energy reserves or osmolytes. However, a clear picture of how NSCs are shaped by climate is still lacking. Here, we update and leverage a unique global database of seasonal NSC storage measurements to examine whether maximum total NSC stores and the amount of soluble sugars are associated with clinal patterns in low temperatures or aridity, indicating they may confer a benefit under freezing or drought conditions. We examine patterns using the average climate at each study site and the unique climatic conditions at the time and place in which the sample was taken. Altogether, our results support the idea that NSC stores act as critical osmolytes. Soluble Sugars increase with both colder and drier conditions in aboveground tissues, indicating they can plastically increase a plants' tolerance of cold or arid conditions. However, maximum total NSCs increased, rather than decreased, with average site temperature and had no relationship to average site aridity. This result suggests that the total amount of NSC a plant stores may be more strongly determined by its capacity to assimilate carbon than by environmental stress. Thus, NSCs are unlikely to serve as reservoir of energy. This study is the most comprehensive synthesis to date of global NSC variation in relation to climate and supports the idea that NSC stores likely serve as buffers against environmental stress. By clarifying their role in cold and drought tolerance, we improve our ability to predict plant response to environment.
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Affiliation(s)
- Meghan Blumstein
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jessica Gersony
- Department of Natural Resources, University of New Hampshire, Durham, New Hampshire, USA
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA
| | - Jordi Martínez-Vilalta
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Anna Sala
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA
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5
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Mantova M, Cochard H, Burlett R, Delzon S, King A, Rodriguez-Dominguez CM, Ahmed MA, Trueba S, Torres-Ruiz JM. On the path from xylem hydraulic failure to downstream cell death. THE NEW PHYTOLOGIST 2023; 237:793-806. [PMID: 36305207 DOI: 10.1111/nph.18578] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Xylem hydraulic failure (HF) has been identified as a ubiquitous factor in triggering drought-induced tree mortality through the damage induced by the progressive dehydration of plant living cells. However, fundamental evidence of the mechanistic link connecting xylem HF to cell death has not been identified yet. The main aim of this study was to evaluate, at the leaf level, the relationship between loss of hydraulic function due to cavitation and cell death under drought conditions and discern how this relationship varied across species with contrasting resistances to cavitation. Drought was induced by withholding water from potted seedlings, and their leaves were sampled to measure their relative water content (RWC) and cell mortality. Vulnerability curves to cavitation at the leaf level were constructed for each species. An increment in cavitation events occurrence precedes the onset of cell mortality. A variation in cells tolerance to dehydration was observed along with the resistance to cavitation. Overall, our results indicate that the onset of cellular mortality occurs at lower RWC than the one for cavitation indicating the role of cavitation in triggering cellular death. They also evidenced a critical RWC for cellular death varying across species with different cavitation resistance.
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Affiliation(s)
- Marylou Mantova
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Régis Burlett
- Université Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Sylvain Delzon
- Université Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Andrew King
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Gif-sur-Yvette cedex, France
| | - Celia M Rodriguez-Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, 41012, Sevilla, Spain
| | - Mutez A Ahmed
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany
- Department of Land, Air and Water Resources, University of California Davis, Davis, CA, 95616, USA
| | | | - José M Torres-Ruiz
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
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6
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Xu GQ, Chen TQ, Liu SS, Ma J, Li Y. Within-crown plasticity of hydraulic properties influence branch dieback patterns of two woody plants under experimental drought conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 854:158802. [PMID: 36115397 DOI: 10.1016/j.scitotenv.2022.158802] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/11/2022] [Accepted: 09/12/2022] [Indexed: 06/15/2023]
Abstract
In recent year, widespread declines of Populus bolleana Lauche trees (P. bolleana, which dieback from the top down) and Haloxylon ammodendron shrubs (H. ammodendron, which dieback starting from their outer canopy) have occurred. To investigate how both intra-canopy hydraulic changes and plasticity in hydraulic properties create differences in vulnerability between these two species, we conducted a drought simulation field experiment. We analyzed branch hydraulic vulnerability, leaf water potential (Ψ), photosynthesis (A), stomatal conductance (gs), non-structural carbohydrate (NSCs) contents and morphological traits of the plants as the plants underwent a partial canopy dieback. Our results showed that: (1) the hydraulic architecture was very different between the two life forms; (2) H. ammodendron exhibited a drought tolerance response with weak stomatal control, and thus a sharp decline in Ψ while P. bolleana showed a drought avoidance response with tighter stomatal control that maintained a relatively stable Ψ; (3) the Ψ of H. ammodendron showed relative consistent symptoms of drought stress with increasing plant stature, but the Ψ of P. bolleana showed greater drought stress in higher portions of the crown; (4) prolonged drought caused P. bolleana to consume and H. ammodendron to accumulate NSCs in the branches of their upper canopy. Thus, the prolonged drought caused the shoots of the upper canopy of P. bolleana to experience greater vulnerability leading to dieback of the upper branches first, while all the twigs of the outer canopy of H. ammodendron experienced nearly identical degrees of vulnerability, and thus dieback occurred uniformly. Our results indicate that intra-canopy hydraulic change and their plasticity under drought was the main cause of the observed canopy dieback patterns in both species. However, more work is needed to further establish that hydraulic limitation as a function of plant stature was the sole mechanism for causing the divergent canopy dieback patterns.
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Affiliation(s)
- Gui-Qing Xu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang 831505, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Tu-Qiang 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, Chinese Academy of Sciences, Fukang 831505, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shen-Si 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, Chinese Academy of Sciences, Fukang 831505, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Ma
- 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, Chinese Academy of Sciences, Fukang 831505, China
| | - Yan Li
- State Key Lab of Subtropical Siviculture, Zhejiang A&F University, 666Wusu Street, Lin-An, Hangzhou 311300, China
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Haberstroh S, Werner C, Grün M, Kreuzwieser J, Seifert T, Schindler D, Christen A. Central European 2018 hot drought shifts scots pine forest to its tipping point. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1186-1197. [PMID: 35869655 DOI: 10.1111/plb.13455] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
The occurrence of hot drought, i.e. low water availability and simultaneous high air temperature, represents a severe threat to ecosystems. Here, we investigated how the 2018 hot drought in Central Europe caused a tipping point in tree and ecosystem functioning in a Scots pine (Pinus sylvestris L.) forest in southwest Germany. Measurements of stress indicators, such as needle water potential, carbon assimilation and volatile organic compound (VOC) emissions, of dominant P. sylvestris trees were deployed to evaluate tree functioning during hot drought. Ecosystem impact and recovery were assessed as ecosystem carbon exchange, normalized difference vegetation index (NDVI) from satellite data and tree mortality data. During summer 2018, needle water potentials of trees dropped to minimum values of -7.5 ± 0.2 MPa, which implied severe hydraulic impairment of P. sylvestris. Likewise, carbon assimilation and VOC emissions strongly declined after mid-July. Decreasing NDVI values from August 2018 onwards were detected, along with severe defoliation in P. sylvestris, impairing ecosystem carbon flux recovery in 2019, shifting the forest into a year-round carbon source. A total of 47% of all monitored trees (n = 368) died by September 2020. NDVI recovered to pre-2018 levels in 2019, likely caused by emerging broadleaved understorey species. The 2018 hot drought had severe negative impacts on P. sylvestris. The co-occurrence of unfavourable site-specific conditions with recurrent severe droughts resulted in accelerated mortality. Thus, the 2018 hot drought pushed the P. sylvestris stand towards its tipping point, with a subsequent vegetation shift to a broadleaf-dominated forest.
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Affiliation(s)
- S Haberstroh
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
| | - C Werner
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
| | - M Grün
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
| | - J Kreuzwieser
- Ecosystem Physiology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
| | - T Seifert
- Forest Growth and Dendroecology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
- Department of Forest and Wood Science, Stellenbosch University, Matieland, South Africa
| | - D Schindler
- Environmental Meteorology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
| | - A Christen
- Environmental Meteorology, Faculty of Environment and Natural Resources, University Freiburg, Freiburg, Germany
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Wang L, Dai Y, Zhang J, Meng P, Wan X. Xylem structure and hydraulic characteristics of deep roots, shallow roots and branches of walnut under seasonal drought. BMC PLANT BIOLOGY 2022; 22:440. [PMID: 36104814 PMCID: PMC9472371 DOI: 10.1186/s12870-022-03815-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Despite the importance of root hydraulics, there is little research on the in situ dynamic responses of embolism formation and embolism repair of roots distributed in different soil depths in response to different water regimes. RESULTS The vessel diameter, hydraulic conductivity, and vulnerability to cavitation were in the order of deep root > shallow root > branch. The midday PLC of shallow root was the highest in the dry season, while the midday PLC of deep root slightly higher than that of branch with no significant difference in the two seasons. The capacity of embolism repair of roots was significantly greater than that of branch both in dry season and wet season. The xylem pressure was in the order of deep roots > shallow root > branch, and it was negative in most of the time for the latter two in the dry season, but positive for both of the roots during the observation period in the wet season. The NSC and starch content in roots were significantly higher than those in branches, especially in the dry season. In contrast, roots had lower content of soluble sugar. CONCLUSIONS The relatively stable water condition in soil, especially in the deep layers, is favorable for the development of larger-diameter vessels in root xylem, however it cannot prevent the root from forming embolism. The mechanism of embolism repair may be different in different parts of plants. Deep roots mainly depend on root pressure to refill the embolized vessels, while branches mainly depend on starch hydrolysis to soluble sugars to do the work, with shallow roots shifted between the two mechanisms in different moisture regimes. There is theoretically an obvious trade-off between conducting efficiency and safety over deep roots, shallow roots and branches. But in natural conditions, roots do not necessarily suffer more severe embolism than branches, maybe due to their root pressure-driven embolism repair and relatively good water conditions.
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Affiliation(s)
- Lin Wang
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, 030801, People's Republic of China
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Yongxin Dai
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, 030801, People's Republic of China
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Jinsong Zhang
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Ping Meng
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Xianchong Wan
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China.
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9
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Gomez‐Gallego M, Galiano L, Martínez‐Vilalta J, Stenlid J, Capador‐Barreto HD, Elfstrand M, Camarero JJ, Oliva J. Interaction of drought- and pathogen-induced mortality in Norway spruce and Scots pine. PLANT, CELL & ENVIRONMENT 2022; 45:2292-2305. [PMID: 35598958 PMCID: PMC9546048 DOI: 10.1111/pce.14360] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
Pathogenic diseases frequently occur in drought-stressed trees. However, their contribution to the process of drought-induced mortality is poorly understood. We combined drought and stem inoculation treatments to study the physiological processes leading to drought-induced mortality in Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) saplings infected with Heterobasidion annosum s.s. We analysed the saplings' water status, gas exchange, nonstructural carbohydrates (NSCs) and defence responses, and how they related to mortality. Saplings were followed for two growing seasons, including an artificially induced 3-month dormancy period. The combined drought and pathogen treatment significantly increased spruce mortality; however, no interaction between these stressors was observed in pine, although individually each stressor caused mortality. Our results suggest that pathogen infection decreased carbon reserves in spruce, reducing the capacity of saplings to cope with drought, resulting in increased mortality rates. Defoliation, relative water content and the starch concentration of needles were predictors of mortality in both species under drought and pathogen infection. Infection and drought stress create conflicting needs for carbon to compartmentalize the pathogen and to avoid turgor loss, respectively. Heterobasidion annosum reduces the functional sapwood area and shifts NSC allocation patterns, reducing the capacity of trees to cope with drought.
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Affiliation(s)
- Mireia Gomez‐Gallego
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural SciencesUppsalaSweden
- Université de Lorraine, INRAE, IAMNancyFrance
| | - Lucia Galiano
- CREAF, Bellaterra (Cerdanyola del Vallès)CataloniaSpain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès)CataloniaSpain
| | - Jordi Martínez‐Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès)CataloniaSpain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès)CataloniaSpain
| | - Jan Stenlid
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural SciencesUppsalaSweden
| | - Hernán D. Capador‐Barreto
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural SciencesUppsalaSweden
| | - Malin Elfstrand
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural SciencesUppsalaSweden
| | | | - Jonàs Oliva
- Department of Crop and Forest SciencesUniversity of LleidaLleidaSpain
- Joint Research Unit CTFC‐AGROTECNIOLleidaSpain
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10
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Limousin JM, Roussel A, Rodríguez-Calcerrada J, Torres-Ruiz JM, Moreno M, Garcia de Jalon L, Ourcival JM, Simioni G, Cochard H, Martin-StPaul N. Drought acclimation of Quercus ilex leaves improves tolerance to moderate drought but not resistance to severe water stress. PLANT, CELL & ENVIRONMENT 2022; 45:1967-1984. [PMID: 35394675 DOI: 10.1111/pce.14326] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/12/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Increasing temperature and drought can result in leaf dehydration and defoliation even in drought-adapted tree species such as the Mediterranean evergreen Quercus ilex L. The stomatal regulation of leaf water potential plays a central role in avoiding this phenomenon and is constrained by a suite of leaf traits including hydraulic conductance and vulnerability, hydraulic capacitance, minimum conductance to water vapour, osmotic potential and cell wall elasticity. We investigated whether the plasticity in these traits may improve leaf tolerance to drought in two long-term rainfall exclusion experiments in Mediterranean forests. Osmotic adjustment was observed to lower the water potential at turgor loss in the rainfall-exclusion treatments, thus suggesting a stomatal closure at more negative water potentials and a more anisohydric behaviour in drier conditions. Conversely, leaf hydraulic conductance and vulnerability did not exhibit any plasticity between treatments so the hydraulic safety margins were narrower in the rainfall-exclusion treatments. The sequence of leaf responses to seasonal drought and dehydration was conserved among treatments and sites but trees were more likely to suffer losses of turgor and hydraulic functioning in the rainfall-exclusion treatments. We conclude that leaf plasticity might help the trees to tolerate moderate drought but not to resist severe water stress.
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Affiliation(s)
| | - Amélie Roussel
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Jesús Rodríguez-Calcerrada
- Departamento de Sistemas y Recursos Naturales, ETSI Montes, Forestal y del Medio Natural, Universidad Politécnica de Madrid Ciudad Universitaria, Madrid, Spain
| | | | - Myriam Moreno
- Unité Ecologie des Forêts Méditerranéennes (UR629), INRAE Avignon Cedex 9, Domaine Saint Paul, Site Agroparc, France
| | | | | | - Guillaume Simioni
- Unité Ecologie des Forêts Méditerranéennes (UR629), INRAE Avignon Cedex 9, Domaine Saint Paul, Site Agroparc, France
| | - Hervé Cochard
- PIAF, University Clermont-Auvergne, INRAE, Clermont-Ferrand, France
| | - Nicolas Martin-StPaul
- Unité Ecologie des Forêts Méditerranéennes (UR629), INRAE Avignon Cedex 9, Domaine Saint Paul, Site Agroparc, France
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11
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González de Andrés E, Gazol A, Querejeta JI, Igual JM, Colangelo M, Sánchez‐Salguero R, Linares JC, Camarero JJ. The role of nutritional impairment in carbon-water balance of silver fir drought-induced dieback. GLOBAL CHANGE BIOLOGY 2022; 28:4439-4458. [PMID: 35320604 PMCID: PMC9540818 DOI: 10.1111/gcb.16170] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/12/2022] [Indexed: 06/01/2023]
Abstract
Rear-edge populations at the xeric distribution limit of tree species are particularly vulnerable to forest dieback triggered by drought. This is the case of silver fir (Abies alba) forests located in Southwestern Europe. While silver fir drought-induced dieback patterns have been previously explored, information on the role played by nutritional impairment is lacking despite its potential interactions with tree carbon-water balances. We performed a comparative analysis of radial growth, intrinsic water-use efficiency (iWUE), oxygen isotopes (δ18 O) and nutrient concentrations in leaves of declining (DD) and non-declining (ND) trees in silver fir in four forests in the Spanish Pyrenees. We also evaluated the relationships among dieback predisposition, intraspecific trait variation (wood density and leaf traits) and rhizosphere soil physical-chemical properties. The onset of growth decline in DD trees occurred more than two decades ago, and they subsequently showed low growth resilience against droughts. The DD trees presented consistently lower foliar concentrations of nutrients such as P, K, Cu and Ni than ND trees. The strong effects of foliar nutrient status on growth resilience indices support the key role played by mineral nutrition in tree functioning and growth before, during and after drought. In contrast, variability in wood density and leaf morphological traits, as well as soil properties, showed weak relationships with tree nutritional status and drought performance. At the low elevation, warmer sites, DD trees showed stronger climate-growth relationships and lower δ18 O than ND trees. The uncoupling between iWUE and δ18 O, together with the positive correlations between P and K leaf concentrations and δ18 O, point to deeper soil/bedrock water sources and vertical decoupling between nutrient and water uptake in DD trees. This study provides novel insights into the mechanisms driving silver fir dieback and highlights the need to incorporate tree nutrition into forest dieback studies.
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Affiliation(s)
| | - Antonio Gazol
- Instituto Pirenaico de Ecología (IPE‐CSIC)ZaragozaSpain
| | | | - José M. Igual
- Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA‐CSIC)SalamancaSpain
| | - Michele Colangelo
- Instituto Pirenaico de Ecología (IPE‐CSIC)ZaragozaSpain
- Scuola di Scienze AgrarieForestaliAlimentarie AmbientaliUniversità della BasilicataPotenzaItaly
| | - Raúl Sánchez‐Salguero
- Instituto Pirenaico de Ecología (IPE‐CSIC)ZaragozaSpain
- Dpto. de Sistemas FísicosQuímicos y NaturalesUniversidad Pablo de OlavideSevillaSpain
| | - Juan Carlos Linares
- Dpto. de Sistemas FísicosQuímicos y NaturalesUniversidad Pablo de OlavideSevillaSpain
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12
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Mantova M, Herbette S, Cochard H, Torres-Ruiz JM. Hydraulic failure and tree mortality: from correlation to causation. TRENDS IN PLANT SCIENCE 2022; 27:335-345. [PMID: 34772610 DOI: 10.1016/j.tplants.2021.10.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 09/27/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
Xylem hydraulic failure has been recognized as a pervasive factor in the triggering of drought-induced tree mortality. However, foundational evidence of the mechanistic link connecting hydraulic failure with living cell damage and tree death has not been identified yet, compromising our ability to predict mortality events. Meristematic cells are involved in the recovery of trees from drought, and focusing on their vitality and functionality after a drought event could provide novel information on the mechanistic link between hydraulic failure and drought-induced tree mortality. In this Opinion, we focus on the cell's critical hydration status for tree recovery from drought and how it links with the membrane integrity of the meristems.
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Affiliation(s)
- Marylou Mantova
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Stéphane Herbette
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - José M Torres-Ruiz
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France.
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13
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Vitali V, Martínez-Sancho E, Treydte K, Andreu-Hayles L, Dorado-Liñán I, Gutierrez E, Helle G, Leuenberger M, Loader NJ, Rinne-Garmston KT, Schleser GH, Allen S, Waterhouse JS, Saurer M, Lehmann MM. The unknown third - Hydrogen isotopes in tree-ring cellulose across Europe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 813:152281. [PMID: 34942249 DOI: 10.1016/j.scitotenv.2021.152281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/24/2021] [Accepted: 12/05/2021] [Indexed: 06/14/2023]
Abstract
This is the first Europe-wide comprehensive assessment of the climatological and physiological information recorded by hydrogen isotope ratios in tree-ring cellulose (δ2Hc) based on a unique collection of annually resolved 100-year tree-ring records of two genera (Pinus and Quercus) from 17 sites (36°N to 68°N). We observed that the high-frequency climate signals in the δ2Hc chronologies were weaker than those recorded in carbon (δ13Cc) and oxygen isotope signals (δ18Oc) but similar to the tree-ring width ones (TRW). The δ2Hc climate signal strength varied across the continent and was stronger and more consistent for Pinus than for Quercus. For both genera, years with extremely dry summer conditions caused a significant 2H-enrichment in tree-ring cellulose. The δ2Hc inter-annual variability was strongly site-specific, as a result of the imprinting of climate and hydrology, but also physiological mechanisms and tree growth. To differentiate between environmental and physiological signals in δ2Hc, we investigated its relationships with δ18Oc and TRW. We found significant negative relationships between δ2Hc and TRW (7 sites), and positive ones between δ2Hc and δ18Oc (10 sites). The strength of these relationships was nonlinearly related to temperature and precipitation. Mechanistic δ2Hc models performed well for both genera at continental scale simulating average values, but they failed on capturing year-to-year δ2Hc variations. Our results suggest that the information recorded by δ2Hc is significantly different from that of δ18Oc, and has a stronger physiological component independent from climate, possibly related to the use of carbohydrate reserves for growth. Advancements in the understanding of 2H-fractionations and their relationships with climate, physiology, and species-specific traits are needed to improve the modelling and interpretation accuracy of δ2Hc. Such advancements could lead to new insights into trees' carbon allocation mechanisms, and responses to abiotic and biotic stress conditions.
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Affiliation(s)
- V Vitali
- Stable Isotope Research Center (SIRC), Ecosystem Ecology, Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Forest Dynamics, CH-8903 Birmensdorf, Switzerland.
| | - E Martínez-Sancho
- Dendrosciences, Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Forest Dynamics, CH-8903 Birmensdorf, Switzerland
| | - K Treydte
- Dendrosciences, Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Forest Dynamics, CH-8903 Birmensdorf, Switzerland
| | - L Andreu-Hayles
- Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA; CREAF, Bellaterra (Cerdanyola del Vall.s), Barcelona, Spain; ICREA, Pg. Llu.s Companys 23, Barcelona, Spain
| | - I Dorado-Liñán
- Department of Systems and Natural Resources, Universidad Politécnica de Madrid, Madrid, Spain
| | - E Gutierrez
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Barcelona, Spain
| | - G Helle
- German Research Centre for Geosciences, Section 4.3 Climate Dynamics and Landscape Evolution, Telegrafenberg, 14473 Potsdam, Germany
| | - M Leuenberger
- Climate and Environmental Physics Division and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - N J Loader
- Department of Geography, Swansea University, Swansea, UK
| | | | - G H Schleser
- FZJ Research Center Jülich, Institute of Bio- and Geosciences, Agrosphere (IBG-3), 52425 Jülich, Germany
| | - S Allen
- Department of Natural Resources and Environmental Science, University of Nevada Reno, 1664 N Virginia St., Reno, NV 89557, USA
| | - J S Waterhouse
- School of Life Sciences, Anglia Ruskin University, Cambridge, UK
| | - M Saurer
- Stable Isotope Research Center (SIRC), Ecosystem Ecology, Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Forest Dynamics, CH-8903 Birmensdorf, Switzerland
| | - M M Lehmann
- Stable Isotope Research Center (SIRC), Ecosystem Ecology, Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Forest Dynamics, CH-8903 Birmensdorf, Switzerland
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14
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Lintunen A, Preisler Y, Oz I, Yakir D, Vesala T, Hölttä T. Bark Transpiration Rates Can Reach Needle Transpiration Rates Under Dry Conditions in a Semi-arid Forest. FRONTIERS IN PLANT SCIENCE 2021; 12:790684. [PMID: 34987535 PMCID: PMC8721219 DOI: 10.3389/fpls.2021.790684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/17/2021] [Indexed: 05/25/2023]
Abstract
Drought can cause tree mortality through hydraulic failure and carbon starvation. To prevent excess water loss, plants typically close their stomata before massive embolism formation occurs. However, unregulated water loss through leaf cuticles and bark continues after stomatal closure. Here, we studied the diurnal and seasonal dynamics of bark transpiration and how it is affected by tree water availability. We measured continuously for six months water loss and CO2 efflux from branch segments and needle-bearing shoots in Pinus halepensis growing in a control and an irrigation plot in a semi-arid forest in Israel. Our aim was to find out how much passive bark transpiration is affected by tree water status in comparison with shoot transpiration and bark CO2 emission that involve active plant processes, and what is the role of bark transpiration in total tree water use during dry summer conditions. Maximum daily water loss rate per bark area was 0.03-0.14 mmol m-2 s-1, which was typically ~76% of the shoot transpiration rate (on leaf area basis) but could even surpass the shoot transpiration rate during the highest evaporative demand in the control plot. Irrigation did not affect bark transpiration rate. Bark transpiration was estimated to account for 64-78% of total water loss in drought-stressed trees, but only for 6-11% of the irrigated trees, due to differences in stomatal control between the treatments. Water uptake through bark was observed during most nights, but it was not high enough to replenish the lost water during the day. Unlike bark transpiration, branch CO2 efflux decreased during drought due to decreased metabolic activity. Our results demonstrate that although bark transpiration represents a small fraction of the total water loss through transpiration from foliage in non-stressed trees, it may have a large impact during drought.
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Affiliation(s)
- Anna Lintunen
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Yakir Preisler
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot,Israel
| | - Itay Oz
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot,Israel
| | - Dan Yakir
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot,Israel
| | - Timo Vesala
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki, Finland
- Laboratory of Ecosystem-Atmospheric Interactions of Forest - Mire Complexes, Yugra State University, Khanty-Mansiysk, Russia
| | - Teemu Hölttä
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki, Finland
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15
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Hájíčková M, Plichta R, Urban J, Volařík D, Gebauer R. Low resistance but high resilience to drought of flushing Norway spruce seedlings. TREE PHYSIOLOGY 2021; 41:1848-1860. [PMID: 33822237 DOI: 10.1093/treephys/tpab043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
Spring drought episodes are becoming more frequent and intensive in European temperate forests. To study tree resilience to spring drought, Norway spruce seedlings were exposed to three levels of drought stress (well-watered (W), moderately stressed (M) and severely stressed (S)) for 42 days and then fully irrigated for 14 days. Drought strongly reduced gas exchange parameters for both M and S seedlings. After 42 days, stomatal conductance was lower by 83 and 97% in M and S, respectively, than in W seedlings. Respiration prevailed over photosynthesis in S seedlings at the end of the drought period. Drought mostly reduced longitudinal growth, especially in shoots and needles. Xylem growth reduction was caused mainly by a lower number of newly produced tracheids, not by changes in their size. Norway spruce seedlings showed good resilience to spring drought, as the observed physiological parameters started to recover after rewatering and seedlings started to sprout and form new tracheids. In M seedlings, all physiological traits recovered to the level of W seedlings during the 14-day irrigation period but the recovery took longer in S seedlings. Shoots and needles did not regrow in length but leaf mass per area increased during the recovery phase. To conclude, Norway spruce seedlings showed good resilience to spring single-drought event, but time necessary to full recovery from stress could make seedlings more vulnerable to recurrent drought events.
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Affiliation(s)
- Martina Hájíčková
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Roman Plichta
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Josef Urban
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
- Siberian Federal University, Svobodnyy Ave, 82A, 660041 Krasnoyarsk, Krasnoyarsk Krai, Russia
| | - Daniel Volařík
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Roman Gebauer
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
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16
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Ouyang SN, Gessler A, Saurer M, Hagedorn F, Gao DC, Wang XY, Schaub M, Li MH, Shen WJ, Schönbeck L. Root carbon and nutrient homeostasis determines downy oak sapling survival and recovery from drought. TREE PHYSIOLOGY 2021; 41:1400-1412. [PMID: 33595075 PMCID: PMC8436808 DOI: 10.1093/treephys/tpab019] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
The role of carbon (C) and nutrient uptake, allocation, storage and especially their interactions in survival and recovery of trees under increased frequencies and intensities of drought events is not well understood. A full factorial experiment with four soil water content regimes ranging from extreme drought to well-watered conditions and two fertilization levels was carried out. We aimed to investigate whether nutrient addition mitigates drought effects on downy oak (Quercus pubescens Willd.) and whether storage pools of non-structural carbohydrates (NSC) are modified to enhance survival after 2.5 years of drought and recovery after drought relief. Physiological traits, such as photosynthesis, predawn leaf water potential as well as tissue biomass together with pools and dynamics of NSC and nutrients at the whole-tree level were investigated. Our results showed that fertilization played a minor role in saplings' physiological processes to cope with drought and drought relief, but reduced sapling mortality during extreme drought. Irrespective of nutrient supply, Q. pubescens showed increased soluble sugar concentration in all tissues with increasing drought intensity, mostly because of starch degradation. After 28 days of drought relief, tissue sugar concentrations decreased, reaching comparable values to those of well-watered plants. Only during the recovery process from extreme drought, root NSC concentration strongly declined, leading to an almost complete NSC depletion after 28 days of rewetting, simultaneously with new leaves flushing. These findings suggest that extreme drought can lead to root C exhaustion. After drought relief, the repair and regrowth of organs can even exacerbate the root C depletion. We concluded that under future climate conditions with repeated drought events, the insufficient and lagged C replenishment in roots might eventually lead to C starvation and further mortality.
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Affiliation(s)
- Sheng-Nan Ouyang
- South China Botanical Garden, Chinese Academy of Sciences,723 XingKe Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Shijingshan District, Beijing 100049, China
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zürich, Ramistrasse 101, Zurich 8902, Switzerland
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
| | - Frank Hagedorn
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
| | - De-Cai Gao
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
- School of Geographical Sciences, Northeast Normal University, 5268 Renming Road, Nanguan District, Changchun 130024, China
| | - Xiao-Yu Wang
- Jiyang College, Zhejiang A&F University, 72 Puyang Road,Jiyang District, Zhuji 311800, China
| | - Marcus Schaub
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
| | - Mai-He Li
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
- School of Geographical Sciences, Northeast Normal University, 5268 Renming Road, Nanguan District, Changchun 130024, China
| | | | - Leonie Schönbeck
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zurcherstrasse 111, Birmensdorf 8903, Switzerland
- Plant Ecology Research Laboratory, School of Architecture, Civil and Environmental Engineering, EPFL, Route Cantonale, Lausanne 1015, Switzerland
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17
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Mantova M, Menezes-Silva PE, Badel E, Cochard H, Torres-Ruiz JM. The interplay of hydraulic failure and cell vitality explains tree capacity to recover from drought. PHYSIOLOGIA PLANTARUM 2021; 172:247-257. [PMID: 33432594 DOI: 10.1111/ppl.13331] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 12/16/2020] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
Global climatic models predict an increment in the frequency and intensity of drought events, which have important consequences on forest dieback. However, the mechanisms leading to tree mortality under drought conditions and the physiological thresholds for recovery are not totally understood yet. This study aimed to identify what are the key physiological traits that determine the tree capacity to recover from drought. Individuals of a conifer (Pseudotsuga menziesii M.) and an angiosperm (Prunus lusitanica L.) species were exposed to drought and their ability to recover after rehydration monitored. Results showed that the actual thresholds used for recovery from drought based on percentage loss of conductance (PLC) (i.e., 50% for conifers, 88% for angiosperms) do not provide accurate insights about the tree capacity for surviving extreme drought events. On the contrary, differences in stem relative water content (RWCStem ) and the level of electrolytes leakage (EL) were directly related to the capacity of the trees to recover from drought. This was the case for the conifer species, P. menziesii, for which higher RWCStem and lower EL values were related to the recovery capacity. Even if results showed a similar trend for the angiosperm P. lusitanica as for the conifers, differences between the two traits were much more subtle and did not allow an accurate differentiation between trees able to recover and those that were not. RWCStem and EL could work as indicators of tree capacity to recover from drought for conifers but more studies are required to confirm this observation for angiosperms.
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Affiliation(s)
- Marylou Mantova
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, France
| | - Paulo E Menezes-Silva
- Laboratório de Fisiologia Vegetal, Instituto Federal de Educação, Ciência e Tecnologia Goiano, Goiânia, Brazil
| | - Eric Badel
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, France
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18
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Timofeeva G, Treydte K, Bugmann H, Salmon Y, Rigling A, Schaub M, Vollenweider P, Siegwolf R, Saurer M. How does varying water supply affect oxygen isotope variations in needles and tree rings of Scots pine? TREE PHYSIOLOGY 2020; 40:1366-1380. [PMID: 32589748 DOI: 10.1093/treephys/tpaa082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 04/01/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
In many regions, drought is suspected to be a cause of Scots pine decline and mortality, but the underlying physiological mechanisms remain unclear. Because of their relationship to ecohydrological processes, δ18O values in tree rings are potentially useful for deciphering long-term physiological responses and tree adaptation to increasing drought. We therefore analyzed both needle- and stem-level isotope fractionations in mature trees exposed to varying water supply. In a first experiment, we investigated seasonal δ18O variations in soil and needle water of Scots pine in a dry inner Alpine valley in Switzerland, comparing drought-stressed trees with trees that were irrigated for more than 10 years. In a second experiment, we analyzed twentieth-century δ18O variations in tree rings of the same forest, including a group of trees that had recently died. We observed less 18O enrichment in needle water of drought-stressed compared with irrigated trees. We applied different isotope fractionation models to explain these results, including the Péclet and the two-pool correction, which considers the ratio of unenriched xylem water in the needles to total needle water. Based on anatomical measurements, we found this ratio to be unchanged in drought-stressed needles, although they were shorter. The observed lower 18O enrichment in needles of stressed trees was therefore likely caused by increased effective path length for water movement within the leaf lamina. In the tree-ring study, we observed lower δ18O values in tree rings of dead trees compared with survivors during several decades prior to their death. These lower values in declining trees are consistent with the lower needle water 18O enrichment observed for drought-stressed compared with irrigated trees, suggesting that this needle-level signal is reflected in the tree rings, although changes in rooting depth could also play a role. Our study demonstrates that long-term effects of drought are reflected in the tree-ring δ18O values, which helps to provide a better understanding of past tree physiological changes of Scots pine.
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Affiliation(s)
- Galina Timofeeva
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen 5232, Switzerland
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
- Forest Ecology, Institute of Terrestrial Ecosystems, ETH Zurich, Zurich 8092, Switzerland
| | - Kerstin Treydte
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
| | - Harald Bugmann
- Forest Ecology, Institute of Terrestrial Ecosystems, ETH Zurich, Zurich 8092, Switzerland
| | - Yann Salmon
- Department of Physics, University of Helsinki, Helsinki 00014, Finland
- School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Andreas Rigling
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
| | - Marcus Schaub
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
| | - Pierre Vollenweider
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
| | - Rolf Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen 5232, Switzerland
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
| | - Matthias Saurer
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen 5232, Switzerland
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf 8903, Switzerland
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Rehschuh R, Cecilia A, Zuber M, Faragó T, Baumbach T, Hartmann H, Jansen S, Mayr S, Ruehr N. Drought-Induced Xylem Embolism Limits the Recovery of Leaf Gas Exchange in Scots Pine. PLANT PHYSIOLOGY 2020; 184:852-864. [PMID: 32820065 PMCID: PMC7536670 DOI: 10.1104/pp.20.00407] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/03/2020] [Indexed: 05/16/2023]
Abstract
Climate change increases the occurrence of prolonged drought periods with large implications for forest functioning. Scots pine (Pinus sylvestris) is one of the most abundant conifers worldwide, and evidence is rising that its resilience to severe drought is limited. However, we know little about its ability to recover from drought-induced embolism. To analyze postdrought hydraulic recovery, we investigated stress and recovery dynamics of leaf gas exchange, nonstructural carbohydrates, and hydraulic properties in 2.5-year-old Scots pine seedlings. We quantified the degree of xylem embolism by combining in vivo x-ray microtomography with intrusive techniques including measurements of hydraulic conductivity and dye staining during drought progression and short-term (2 d) and long-term (4 weeks) recovery. Seedlings were grown under controlled conditions, and irrigation was withheld until stomata closed and xylem water potential declined to -3.2 MPa on average, causing a 46% loss of stem hydraulic conductivity. Following drought release, we found a gradual recovery of leaf gas exchange to 50% to 60% of control values. This partial recovery indicates hydraulic limitations due to drought-induced damage. Whereas xylem water potential recovered close to control values within 2 d, both x-ray microtomography and intrusive measurements revealed no recovery of stem hydraulic conductivity. Moreover, we did not find indications for nonstructural carbohydrate reserves limiting hydraulic recovery. Our findings demonstrate that Scots pine is able to survive severe drought and to partially recover, although we assume that xylem development during the next growing season might compensate for some of the hydraulic impairment. Such drought-induced legacy effects are important when considering vegetation responses to extreme events.
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Affiliation(s)
- Romy Rehschuh
- Karlsruhe Institute of Technology, KIT Campus Alpin, Institute of Meteorology and Climate Research- Atmospheric Environmental Research, 82467 Garmisch-Partenkirchen, Germany
| | - Angelica Cecilia
- Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation, 76344 Eggenstein-Leopoldshafen, Germany
| | - Marcus Zuber
- Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation, 76344 Eggenstein-Leopoldshafen, Germany
| | - Tomáš Faragó
- Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation, 76344 Eggenstein-Leopoldshafen, Germany
| | - Tilo Baumbach
- Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation, 76344 Eggenstein-Leopoldshafen, Germany
| | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, Department of Biogeochemical Processes, 07745 Jena, Germany
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, 89081 Ulm, Germany
| | - Stefan Mayr
- University of Innsbruck, Institute of Botany, 6020 Innsbruck, Austria
| | - Nadine Ruehr
- Karlsruhe Institute of Technology, KIT Campus Alpin, Institute of Meteorology and Climate Research- Atmospheric Environmental Research, 82467 Garmisch-Partenkirchen, Germany
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20
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Du Q, Jiao X, Song X, Zhang J, Bai P, Ding J, Li J. The Response of Water Dynamics to Long-Term High Vapor Pressure Deficit Is Mediated by Anatomical Adaptations in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:758. [PMID: 32582267 PMCID: PMC7289962 DOI: 10.3389/fpls.2020.00758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Vapor pressure deficit (VPD) is the driver of water movement in plants. However, little is known about how anatomical adaptations determine the acclimation of plant water dynamics to elevated VPD, especially at the whole plant level. Here, we examined the responses of transpiration, stomatal conductance (gs), hydraulic partitioning, and anatomical traits in two tomato cultivars (Jinpeng and Zhongza) to long-term high (2.2-2.6 kPa) and low (1.1-1.5 kPa) VPD. Compared to plants growing under low VPD, no variation in gs was found for Jinpeng under high VPD conditions; however, high VPD induced an increase in whole plant hydraulic conductance (Kplant), which was responsible for the maintenance of high transpiration. In contrast, transpiration was not influenced by high VPD in Zhongza, which was primarily attributed to a coordinated decline in gs and Kplant. The changes in gs were closely related to stomatal density and size. Furthermore, high VPD altered hydraulic partitioning among the leaf, stem, and root for both cultivars via adjustments in anatomy. The increase in lumen area of vessels in veins and large roots in Jinpeng under high VPD conditions improved water transport efficiency in the leaf and root, thus resulting in a high Kplant. However, the decreased Kplant for Zhongza under high VPD was the result of a decline of water transport efficiency in the leaf that was caused by a reduction in vein density. Overall, we concluded that the tradeoff in anatomical acclimations among plant tissues results in different water relations in plants under high VPD conditions.
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Affiliation(s)
- Qingjie Du
- College of Horticulture, Northwest A&F University, Yangling, China
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Xiaocong Jiao
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Xiaoming Song
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Jiayu Zhang
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Ping Bai
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Juping Ding
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Jianming Li
- College of Horticulture, Northwest A&F University, Yangling, China
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21
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Retrospective Analysis of Tree Decline Based on Intrinsic Water-Use Efficiency in Semi-Arid Areas of North China. ATMOSPHERE 2020. [DOI: 10.3390/atmos11060577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-term tree growth is significantly affected by climate change, which have become a global concern. Tree-ring width and isotopic information can show how trees respond to climate change on a long-term scale and reveal some phenomena of tree decline or death. In this study, we used isotopic techniques and investigated annual changes in carbon isotope composition and tree-ring width of Populus simonii Carr. in Zhangbei, as well as trends in tree-ring carbon discrimination (Δ13C) and iWUE in normal, mildly declining and severely declining trees, in order to make a retrospective analysis and further understand the process of tree decline. We found that there were significant differences (p < 0.01 **) in δ13C, Δ13C, ci and iWUE at different decline stages, meaning that the δ13C and iWUE could be new indicators of tree health. The iWUE of all groups increased significantly, while the growth rate of declined P. simonii was much higher than that of normal growth P. simonii. According to the analysis, there may be a threshold of iWUE for healthy trees, which once the threshold value is exceeded, it indicates that trees are resistant to adversity and their growth is under stress. Similarly, the changing trend of BAI supports our conclusion with its changes showed that tree growth became slower and slower as degradation progressed. iWUE inferred from tree-ring stable carbon isotope composition is a strong modulator of adaptation capacity in response to environmental stressors under climate change. Elevated annual temperatures and increased groundwater depth are all contributing to the decline of P. simonii in north China.
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22
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Salmon Y, Lintunen A, Dayet A, Chan T, Dewar R, Vesala T, Hölttä T. Leaf carbon and water status control stomatal and nonstomatal limitations of photosynthesis in trees. THE NEW PHYTOLOGIST 2020; 226:690-703. [PMID: 31955422 DOI: 10.1111/nph.16436] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/18/2019] [Indexed: 05/22/2023]
Abstract
Photosynthetic rate is concurrently limited by stomatal limitations and nonstomatal limitations (NSLs). However, the controls on NSLs to photosynthesis and their coordination with stomatal control on different timescales remain poorly understood. According to a recent optimization hypothesis, NSLs depend on leaf osmotic or water status and are coordinated with stomatal control so as to maximize leaf photosynthesis. Drought and notching experiments were conducted on Pinus sylvestris, Picea abies, Betula Pendula and Populus tremula seedlings in glasshouse conditions to study the dependence of NSLs on leaf osmotic and water status, and their coordination with stomatal control, on timescales of minutes and weeks, to test the assumptions and predictions of the optimization hypothesis. Both NSLs and stomatal conductance followed power-law functions of leaf osmotic concentration and leaf water potential. Moreover, stomatal conductance was proportional to the square root of soil-to-leaf hydraulic conductance, as predicted by the optimization hypothesis. Though the detailed mechanisms underlying the dependence of NSLs on leaf osmotic or water status lie outside the scope of this study, our results support the hypothesis that NSLs and stomatal control are coordinated to maximize leaf photosynthesis and allow the effect of NSLs to be included in models of tree gas-exchange.
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Affiliation(s)
- Yann Salmon
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, Helsinki, 00014, Finland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, Helsinki, 00014, Finland
| | - Anna Lintunen
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, Helsinki, 00014, Finland
| | - Alexia Dayet
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, Helsinki, 00014, Finland
| | - Tommy Chan
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, Helsinki, 00014, Finland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, Helsinki, 00014, Finland
| | - Roderick Dewar
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, Helsinki, 00014, Finland
- Plant Sciences Division, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Timo Vesala
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, Helsinki, 00014, Finland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, Helsinki, 00014, Finland
| | - Teemu Hölttä
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, Helsinki, 00014, Finland
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23
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Measurement of Inner Bark and Leaf Osmolality. Methods Mol Biol 2020. [PMID: 31197792 DOI: 10.1007/978-1-4939-9562-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Sugar transport in the phloem is driven by turgor pressure gradients which are created by osmotic gradients resulting from sugars loaded to the phloem at the source tissue and unloaded at the sink tissue. Therefore, osmolality is a key parameter that can be used to evaluate sugar status and get an indication of the driving force for phloem transport. Here we describe how osmotic concentration measurements from inner bark (practically, the phloem) and needles of trees can be measured. This protocol presents the procedure used by Lintunen et al. (Front Plant Sci 7:726, 2016) and Paljakka et al. (Plant Cell Environ 40:2160-2173, 2017), extended by practical advice and discussion of potential errors and caveats. We describe how to implement this procedure for gymnosperm as well as angiosperm trees. This method uses mechanical sap extraction with a centrifuge from inner bark and leaf samples, which have gone through a deep freeze treatment and thawing. The osmotic potential of these samples is then analyzed with a freezing point or vapor pressure osmometer. The aim of these measurements is to study the spatial and temporal dynamics of phloem function.
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24
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Tree-Ring Analysis Reveals Density-Dependent Vulnerability to Drought in Planted Mongolian Pines. FORESTS 2020. [DOI: 10.3390/f11010098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Population density influences tree responses to environmental stresses, such as drought and high temperature. Prolonged drought negatively affects the health of Mongolian pines in forests planted by the Three-North Shelter Forest Program in North China. To understand the relationship between stand density and drought-induced forest decline, and to generate information regarding the development of future management strategies, we analyzed the vulnerability to drought of planted Mongolian pines at three stand densities. A tree-ring width index for trees from each density was established from tree-ring data covering the period 1988–2018 and was compared for differences in radial growth. Resistance (Rt), recovery (Rc), resilience (Rs), and relative resilience (RRs) in response to drought events were calculated from the smoothed basal area increment (BAI) curves. The high-density (HDT) group showed a consistently lower tree-ring width than the border trees (BT) and low-density (LDT) groups. The BAI curve of the HDT group started to decrease five years earlier than the LDT and BT groups. Pearson correlation analysis revealed that the radial growth of all of the groups was related to precipitation, relative humidity (RH), potential evapotranspiration (ET0), and standardized precipitation evapotranspiration index (SPEI) in the previous October and the most recent July, indicating that Mongolian pine trees of different densities had similar growth–climate relationships. Over the three decades, the trees experienced three severe drought events, each causing reduced tree-ring width and BAI. All of the groups showed similar Rc to each drought event, but the HDT group exhibited significantly lower Rt, Rs, and RRs than the BT group, suggesting that the HDT trees were more vulnerable to repeated drought stress. The RRs of the HDT group decreased progressively after each drought event and attained <0 after the third event. All of the groups showed similar trends regarding water consumption under varying weather conditions, but the HDT group showed significantly reduced whole-tree hydraulic capability compared with the other two groups. From these results, HDT trees exhibit ecophysiological memory effects from successive droughts, including sap flux dysfunction and higher competition index, which may prevent recovery of pre-drought growth rates. HDT trees may be at greater risk of mortality under future drought disturbance.
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25
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Torres-Ruiz JM, Kremer A, Carins-Murphy MR, Brodribb TJ, Lamarque LJ, Truffaut L, Bonne F, Ducousso A, Delzon S. Genetic differentiation in functional traits among European sessile oak populations. TREE PHYSIOLOGY 2019; 39:1736-1749. [PMID: 31553461 PMCID: PMC6954098 DOI: 10.1093/treephys/tpz090] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 07/23/2019] [Accepted: 08/15/2019] [Indexed: 05/25/2023]
Abstract
The vulnerability of forest species and tree populations to climate change is related to the exposure of the ecosystem to extreme climatic conditions and to the adaptive capacity of the population to cope with those conditions. Adaptive capacity is a relatively under-researched topic within the forest science community, and there is an urgent need to understand to what extent particular combinations of traits have been shaped by natural selection under climatic gradients, potentially resulting in adaptive multi-trait associations. Thus, our aim was to quantify genetic variation in several leaf and woody traits that may contribute to multi-trait associations in which intra-specific variation could represent a source for species adaptation to climate change. A multi-trait approach was performed using nine Quercus petraea provenances originating from different locations that cover most of the species' distribution range over Europe and that were grown in a common garden. Multiple adaptive differences were observed between oak provenances but also some evolutionary stasis. In addition, our results revealed higher genetic differentiation in traits related to phenology and growth than in those related to xylem anatomy, physiology and hydraulics, for which no genetic differentiation was observed. The multiple associations between those traits and climate variables resulting from multivariate and path analyses suggest a multi-trait association largely involving phenological and growth traits for Q. petraea.
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Affiliation(s)
- JM Torres-Ruiz
- Universite Clermont-Auvergne, INRA, PIAF, 63000, Clermont-Ferrand, France
| | - A Kremer
- Unité Mixte de Recherche Biodiversité Genes & Communautés (UMR 1202 BIOGECO), Institut National de la Recherche Agronomique (INRA) – Université de Bordeaux, 69 route d’Arcachon, Cestas F-33610, France
| | - MR Carins-Murphy
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - TJ Brodribb
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - LJ Lamarque
- Unité Mixte de Recherche Biodiversité Genes & Communautés (UMR 1202 BIOGECO), Institut National de la Recherche Agronomique (INRA) – Université de Bordeaux, 69 route d’Arcachon, Cestas F-33610, France
| | - L Truffaut
- Unité Mixte de Recherche Biodiversité Genes & Communautés (UMR 1202 BIOGECO), Institut National de la Recherche Agronomique (INRA) – Université de Bordeaux, 69 route d’Arcachon, Cestas F-33610, France
| | - F Bonne
- UMR SILVA, INRA, Nancy, France
| | - A Ducousso
- Unité Mixte de Recherche Biodiversité Genes & Communautés (UMR 1202 BIOGECO), Institut National de la Recherche Agronomique (INRA) – Université de Bordeaux, 69 route d’Arcachon, Cestas F-33610, France
| | - S Delzon
- Unité Mixte de Recherche Biodiversité Genes & Communautés (UMR 1202 BIOGECO), Institut National de la Recherche Agronomique (INRA) – Université de Bordeaux, 69 route d’Arcachon, Cestas F-33610, France
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26
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MacAllister S, Mencuccini M, Sommer U, Engel J, Hudson A, Salmon Y, Dexter KG. Drought-induced mortality in Scots pine: opening the metabolic black box. TREE PHYSIOLOGY 2019; 39:1358-1370. [PMID: 31038161 DOI: 10.1093/treephys/tpz049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 04/11/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
Forests are sensitive to droughts, which increase the mortality rate of tree species. Various processes have been proposed to underlie drought-induced tree mortality, including hydraulic failure, carbon starvation and increased susceptibility to natural enemies. To give insights into these processes, we assessed the metabolic effects of a mortality-inducing drought on seedlings of Pinus sylvestris L. (Scots Pine), a widespread and important Eurasian species. We found divergence over time in the foliar metabolic composition of droughted vs well-watered seedlings, with the former showing increased abundance of aromatic amino acids and decreases in secondary metabolism associated with defence. We observed no significant differences amongst provenances in these effects: seedlings from drought-prone areas showed the same foliar metabolic changes under drought as seedlings from moist environments, although morphological effects of drought varied by provenance. Overall, our results demonstrate how severe drought prior to death may target particular primary and secondary metabolic pathways, weakening defences against natural enemies and contributing to the risk of drought-induced mortality in P. sylvestris.
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Affiliation(s)
| | | | - Ulf Sommer
- NBAF-Birmingham, School of Biosciences, University of Birmingham, UK
| | - Jasper Engel
- NBAF-Birmingham, School of Biosciences, University of Birmingham, UK
| | - Andrew Hudson
- School of Biological Sciences, University of Edinburgh, UK
| | | | - Kyle G Dexter
- School of GeoSciences, University of Edinburgh, UK
- Royal Botanic Garden Edinburgh, UK
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27
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Ruehr NK, Grote R, Mayr S, Arneth A. Beyond the extreme: recovery of carbon and water relations in woody plants following heat and drought stress. TREE PHYSIOLOGY 2019; 39:1285-1299. [PMID: 30924906 PMCID: PMC6703153 DOI: 10.1093/treephys/tpz032] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 01/08/2019] [Accepted: 03/13/2019] [Indexed: 05/19/2023]
Abstract
Plant responses to drought and heat stress have been extensively studied, whereas post-stress recovery, which is fundamental to understanding stress resilience, has received much less attention. Here, we present a conceptual stress-recovery framework with respect to hydraulic and metabolic functioning in woody plants. We further synthesize results from controlled experimental studies following heat or drought events and highlight underlying mechanisms that drive post-stress recovery. We find that the pace of recovery differs among physiological processes. Leaf water potential and abscisic acid concentration typically recover within few days upon rewetting, while leaf gas exchange-related variables lag behind. Under increased drought severity as indicated by a loss in xylem hydraulic conductance, the time for stomatal conductance recovery increases markedly. Following heat stress release, a similar delay in leaf gas exchange recovery has been observed, but the reasons are most likely a slow reversal of photosynthetic impairment and other temperature-related leaf damages, which typically manifest at temperatures above 40 °C. Based thereon, we suggest that recovery of gas exchange is fast following mild stress, while recovery is slow and reliant on the efficiency of repair and regrowth when stress results in functional impairment and damage to critical plant processes. We further propose that increasing stress severity, particular after critical stress levels have been reached, increases the carbon cost involved in reestablishing functionality. This concept can guide future experimental research and provides a base for modeling post-stress recovery of carbon and water relations in trees.
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Affiliation(s)
- Nadine K Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research—Atmospheric Environmental Research (KIT/IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Rüdiger Grote
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research—Atmospheric Environmental Research (KIT/IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Almut Arneth
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research—Atmospheric Environmental Research (KIT/IMK-IFU), Garmisch-Partenkirchen, Germany
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28
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Savi T, Casolo V, Dal Borgo A, Rosner S, Torboli V, Stenni B, Bertoncin P, Martellos S, Pallavicini A, Nardini A. Drought-induced dieback of Pinus nigra: a tale of hydraulic failure and carbon starvation. CONSERVATION PHYSIOLOGY 2019; 7:coz012. [PMID: 31198559 PMCID: PMC6541882 DOI: 10.1093/conphys/coz012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/22/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Ongoing climate change is apparently increasing tree mortality rates, and understanding mechanisms of drought-induced tree decline can improve mortality projections. Differential drought impact on conspecific individuals within a population has been reported, but no clear mechanistic explanation for this pattern has emerged. Following a severe drought (summer 2012), we monitored over a 3-year period healthy (H) and declining (D) Pinus nigra trees co-occurring in a karstic woodland to highlight eventual individual-specific physiological differences underlying differential canopy dieback. We investigated differences in water and carbon metabolism, and xylem anatomy as a function of crown health status, as well as eventual genotypic basis of contrasting drought responses. H and D trees exploited the same water pools and relied on similar hydraulic strategies to cope with drought stress. Genetic analyses did not highlight differences between groups in terms of geographical provenance. Hydraulic and anatomical analyses showed conflicting results. The hydraulic tracheid diameter and theoretical hydraulic conductivity were similar, but D trees were characterized by lower water transport efficiency, greater vulnerability to xylem conduit implosion and reduced carbohydrate stores. Our results suggest that extreme drought events can have different impacts on conspecific individuals, with differential vulnerability to xylem embolism likely playing a major role in setting the fate of trees under climate change.
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Affiliation(s)
- Tadeja Savi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
- Division of Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad Lorenz Strasse 24, Tulln, Austria
| | - Valentino Casolo
- Dipartimento di Scienze Agro-Alimentari, Ambientali e Animali, Università di Udine, Via delle Scienze 91, Udine, Italia
| | - Anna Dal Borgo
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
| | - Sabine Rosner
- Institute of Botany, University of Natural Resources and Life Sciences, Gregor Mendel Strasse 33, Vienna, Austria
| | - Valentina Torboli
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
| | - Barbara Stenni
- Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca’ Foscari Venezia, Via Torino 155, Venezia Mestre, Italia
| | - Paolo Bertoncin
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
| | - Stefano Martellos
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
| | - Alberto Pallavicini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, Italia
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29
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Salmon Y, Dietrich L, Sevanto S, Hölttä T, Dannoura M, Epron D. Drought impacts on tree phloem: from cell-level responses to ecological significance. TREE PHYSIOLOGY 2019; 39:173-191. [PMID: 30726983 DOI: 10.1093/treephys/tpy153] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 12/03/2018] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Abstract
On-going climate change is increasing the risk of drought stress across large areas worldwide. Such drought events decrease ecosystem productivity and have been increasingly linked to tree mortality. Understanding how trees respond to water shortage is key to predicting the future of ecosystem functions. Phloem is at the core of the tree functions, moving resources such as non-structural carbohydrates, nutrients, and defence and information molecules across the whole plant. Phloem function and ability to transport resources is tightly controlled by the balance of carbon and water fluxes within the tree. As such, drought is expected to impact phloem function by decreasing the amount of available water and new photoassimilates. Yet, the effect of drought on the phloem has received surprisingly little attention in the last decades. Here we review existing knowledge on drought impacts on phloem transport from loading and unloading processes at cellular level to possible effects on long-distance transport and consequences to ecosystems via ecophysiological feedbacks. We also point to new research frontiers that need to be explored to improve our understanding of phloem function under drought. In particular, we show how phloem transport is affected differently by increasing drought intensity, from no response to a slowdown, and explore how severe drought might actually disrupt the phloem transport enough to threaten tree survival. Because transport of resources affects other organisms interacting with the tree, we also review the ecological consequences of phloem response to drought and especially predatory, mutualistic and competitive relations. Finally, as phloem is the main path for carbon from sources to sink, we show how drought can affect biogeochemical cycles through changes in phloem transport. Overall, existing knowledge is consistent with the hypotheses that phloem response to drought matters for understanding tree and ecosystem function. However, future research on a large range of species and ecosystems is urgently needed to gain a comprehensive understanding of the question.
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Affiliation(s)
- Yann Salmon
- Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, Gustaf Hällströmin katu 2b, University of Helsinki, Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Forest Sciences, Faculty of Agriculture and Forestry, Latokartanonkaari 7, University of Helsinki, Helsinki, Finland
| | - Lars Dietrich
- Department of Environmental Sciences, University of Basel, Schönbeinstrasse 6, Basel, Switzerland
| | - Sanna Sevanto
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, PO Box 1663 MA 495, Los Alamos, NM, USA
| | - Teemu Hölttä
- Institute for Atmospheric and Earth System Research/Forest Sciences, Faculty of Agriculture and Forestry, Latokartanonkaari 7, University of Helsinki, Helsinki, Finland
| | - Masako Dannoura
- Kyoto University, Laboratory of Ecosystem Production and Dynamics, Graduate School of Global Environmental Studies, Kyoto, Japan
- Kyoto University, Laboratory of Forest Utilization, Graduate School of Agriculture, Kyoto, Japan
| | - Daniel Epron
- Université de Lorraine, AgroParisTech, INRA, UMR Silva, Faculté des Sciences et Technologies, Nancy, France
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30
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Jin Y, Li J, Liu C, Liu Y, Zhang Y, Sha L, Wang Z, Song Q, Lin Y, Zhou R, Chen A, Li P, Fei X, Grace J. Carbohydrate dynamics of three dominant species in a Chinese savanna under precipitation exclusion. TREE PHYSIOLOGY 2018; 38:1371-1383. [PMID: 29474710 DOI: 10.1093/treephys/tpy017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
The potential impact of drought on the carbon balance in plants has gained great attention. Non-structural carbohydrate (NSC) dynamics have been suggested as an important trait reflecting carbon balance under drought conditions. However, NSC dynamics under drought and the response mechanisms of NSC to drought remain unclear, especially in water-limited savanna ecosystems. A precipitation exclusion experiment was performed to simulate different drought intensities in a savanna ecosystem in Yuanjiang valley in southwestern China. Growth, total NSC concentration and diurnal change of NSC were determined for the leaves and non-photosynthetic organs of three dominant species (Lannea coromandelica, Polyalthia cerasoides and Heteropogon contortus) throughout the growing season. Drought significantly reduced the growth of all the three species. Total NSC concentration averaged ~8.1%, varying with species, organ and sampling period, and did not significantly decrease under drought stress. By contrast, the diurnal change of NSC in these three species increased under drought stress. These results indicate that these three dominant species did not undergo carbon limitation. Thus, relative change in NSC is a more sensitive and effective indicator than carbon reserves in evaluation of plant carbon balance. These findings provide new insights for the understanding of carbon balance and the mechanisms of carbon starvation.
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Affiliation(s)
- Yanqiang Jin
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jing Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chenggang Liu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Yuntong Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Yiping Zhang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Liqing Sha
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Zhe Wang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, China
| | - Qinghai Song
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
| | - Youxing Lin
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruiwu Zhou
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Aiguo Chen
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, China
| | - Peiguang Li
- Yellow River Delta Ecological Research Station of Coastal Wetland, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Xuehai Fei
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - John Grace
- School of Geosciences, University of Edinburgh, Edinburgh, UK
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31
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Tiemuerbieke B, Min XJ, Zang YX, Xing P, Ma JY, Sun W. Water use patterns of co-occurring C 3 and C 4 shrubs in the Gurbantonggut desert in northwestern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 634:341-354. [PMID: 29627558 DOI: 10.1016/j.scitotenv.2018.03.307] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 03/24/2018] [Accepted: 03/24/2018] [Indexed: 06/08/2023]
Abstract
In water-limited ecosystems, spatial and temporal partitioning of water sources is an important mechanism that facilitates plant survival and lessens the competition intensity of co-existing plants. Insights into species-specific root functional plasticity and differences in the water sources of co-existing plants under changing water conditions can aid in accurate prediction of the response of desert ecosystems to future climate change. We used stable isotopes of soil water, groundwater and xylem water to determine the seasonal and inter- and intraspecific differences variations in the water sources of six C3 and C4 shrubs in the Gurbantonggut desert. We also measured the stem water potentials to determine the water stress levels of each species under varying water conditions. The studied shrubs exhibited similar seasonal water uptake patterns, i.e., all shrubs extracted shallow soil water recharged by snowmelt water during early spring and reverted to deeper water sources during dry summer periods, indicating that all of the studied shrubs have dimorphic root systems that enable them to obtain water sources that differ in space and time. Species in the C4 shrub community exhibited differences in seasonal water absorption and water status due to differences in topography and rooting depth, demonstrating divergent adaptations to water availability and water stress. Haloxylon ammodendron and T. ramosissima in the C3/C4 mixed community were similar in terms of seasonal water extraction but differed with respect to water potential, which indicated that plant water status is controlled by both root functioning and shoot eco-physiological traits. The two Tamarix species in the C3 shrub community were similar in terms of water uptake and water status, which suggests functional convergence of the root system and physiological performance under same soil water conditions. In different communities, Haloxylon ammodendron differed in terms of summer water extraction, which suggests that this species exhibits plasticity with respect to rooting depth under different soil water conditions. Shrubs in the Gurbantonggut desert displayed varying adaptations across species and communities through divergent root functioning and shoot eco-physiological traits.
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Affiliation(s)
- Bahejiayinaer Tiemuerbieke
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, No.19A, Yuquan Road, Shijingshan District, Beijing 10049, China
| | - Xiao-Jun Min
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, No.19A, Yuquan Road, Shijingshan District, Beijing 10049, China
| | - Yong-Xin Zang
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, No.19A, Yuquan Road, Shijingshan District, Beijing 10049, China
| | - Peng Xing
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, No.19A, Yuquan Road, Shijingshan District, Beijing 10049, China
| | - Jian-Ying Ma
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
| | - Wei Sun
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China.
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32
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Li X, Blackman CJ, Rymer PD, Quintans D, Duursma RA, Choat B, Medlyn BE, Tissue DT. Xylem embolism measured retrospectively is linked to canopy dieback in natural populations of Eucalyptus piperita following drought. TREE PHYSIOLOGY 2018; 38:1193-1199. [PMID: 29757423 DOI: 10.1093/treephys/tpy052] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/18/2018] [Indexed: 06/08/2023]
Abstract
Manipulative experiments have suggested that embolism-induced hydraulic impairment underpins widespread tree mortality during extreme drought, yet in situ evidence is rare. One month after drought-induced leaf and branch dieback was observed in field populations of Eucalyptus piperita Sm. in the Blue Mountains (Australia), we measured the level of native stem embolism and characterized the extent of leaf death in co-occurring dieback and healthy (non-dieback) trees. We found that canopy dieback-affected trees showed significantly higher levels of native embolism (26%) in tertiary order branchlets than healthy trees (11%). Furthermore, there was a significant positive correlation (R2 = 0.51) between the level of leaf death and the level of native embolism recorded in branchlets from dieback-affected trees. This retrospective study suggests that hydraulic failure was the primary mechanism of leaf and branch dieback in response to a natural drought event in the field. It also suggests that post-drought embolism refilling is minimal or absent in this species of eucalypt.
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Affiliation(s)
- Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Paul D Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Desi Quintans
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW, Australia
| | - Remko A Duursma
- 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
| | - 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
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33
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González-Muñoz N, Sterck F, Torres-Ruiz JM, Petit G, Cochard H, von Arx G, Lintunen A, Caldeira MC, Capdeville G, Copini P, Gebauer R, Grönlund L, Hölttä T, Lobo-do-Vale R, Peltoniemi M, Stritih A, Urban J, Delzon S. Quantifying in situ phenotypic variability in the hydraulic properties of four tree species across their distribution range in Europe. PLoS One 2018; 13:e0196075. [PMID: 29715289 PMCID: PMC5929519 DOI: 10.1371/journal.pone.0196075] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 04/05/2018] [Indexed: 01/29/2023] Open
Abstract
Many studies have reported that hydraulic properties vary considerably between tree species, but little is known about their intraspecific variation and, therefore, their capacity to adapt to a warmer and drier climate. Here, we quantify phenotypic divergence and clinal variation for embolism resistance, hydraulic conductivity and branch growth, in four tree species, two angiosperms (Betula pendula, Populus tremula) and two conifers (Picea abies, Pinus sylvestris), across their latitudinal distribution in Europe. Growth and hydraulic efficiency varied widely within species and between populations. The variability of embolism resistance was in general weaker than that of growth and hydraulic efficiency, and very low for all species but Populus tremula. In addition, no and weak support for a safety vs. efficiency trade-off was observed for the angiosperm and conifer species, respectively. The limited variability of embolism resistance observed here for all species except Populus tremula, suggests that forest populations will unlikely be able to adapt hydraulically to drier conditions through the evolution of embolism resistance.
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Affiliation(s)
| | - F. Sterck
- Forest Ecology and Forest Management Group, Wageningen University & Research, Wageningen, The Netherlands
| | | | - G. Petit
- Università degli Studi di Padova, Dep. TeSAF, Legnaro (PD), Italy
| | - H. Cochard
- PIAF, INRA, Université Clermont-Auvergne, Clermont-Ferrand, France
| | - G. von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Climatic Change and Climate Impacts, Institute for Environmental Sciences, Geneva, Switzerland
| | - A. Lintunen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - M. C. Caldeira
- Forest Research Centre, School of Agriculture, University of Lisbon, Tapada da Ajuda, Lisboa, Portugal
| | - G. Capdeville
- BIOGECO, INRA, Université de Bordeaux, Pessac, France
| | - P. Copini
- Forest Ecology and Forest Management Group, Wageningen University & Research, Wageningen, The Netherlands
- Wageningen Environmental Research (Alterra), Wageningen, The Netherlands
| | - R. Gebauer
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University, Zemědělská 3, Brno, Czech Republic
| | - L. Grönlund
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - T. Hölttä
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - R. Lobo-do-Vale
- Forest Research Centre, School of Agriculture, University of Lisbon, Tapada da Ajuda, Lisboa, Portugal
| | - M. Peltoniemi
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, Helsinki, Finland
| | - A. Stritih
- Swiss Federal Institute of Technology ETH, Planning of Landscape and Urban Systems, Zurich, Switzerland
| | - J. Urban
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University, Zemědělská 3, Brno, Czech Republic
| | - S. Delzon
- BIOGECO, INRA, Université de Bordeaux, Pessac, France
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34
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Hartmann H, Moura CF, Anderegg WRL, Ruehr NK, Salmon Y, Allen CD, Arndt SK, Breshears DD, Davi H, Galbraith D, Ruthrof KX, Wunder J, Adams HD, Bloemen J, Cailleret M, Cobb R, Gessler A, Grams TEE, Jansen S, Kautz M, Lloret F, O'Brien M. Research frontiers for improving our understanding of drought-induced tree and forest mortality. THE NEW PHYTOLOGIST 2018; 218:15-28. [PMID: 29488280 DOI: 10.1111/nph.15048] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 01/08/2018] [Indexed: 05/20/2023]
Abstract
Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit (VPD). Resulting forest die-off events have severe consequences for ecosystem services, biophysical and biogeochemical land-atmosphere processes. Despite advances in monitoring, modelling and experimental studies of the causes and consequences of tree death from individual tree to ecosystem and global scale, a general mechanistic understanding and realistic predictions of drought mortality under future climate conditions are still lacking. We update a global tree mortality map and present a roadmap to a more holistic understanding of forest mortality across scales. We highlight priority research frontiers that promote: (1) new avenues for research on key tree ecophysiological responses to drought; (2) scaling from the tree/plot level to the ecosystem and region; (3) improvements of mortality risk predictions based on both empirical and mechanistic insights; and (4) a global monitoring network of forest mortality. In light of recent and anticipated large forest die-off events such a research agenda is timely and needed to achieve scientific understanding for realistic predictions of drought-induced tree mortality. The implementation of a sustainable network will require support by stakeholders and political authorities at the international level.
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Affiliation(s)
- Henrik Hartmann
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, 07745, Jena, Germany
| | - Catarina F Moura
- Max-Planck Institute for Biogeochemistry, Hans Knöll Str. 10, 07745, Jena, Germany
- Faculty of Sciences and Technology, NOVA University of Lisbon, Campus da Caparica, 2829-516, Caparica, Portugal
- Centre for Functional Ecology, Department of Life Sciences, Universilty of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | | | - Nadine K Ruehr
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany
| | - Yann Salmon
- School of Geosciences, University of Edinburgh, Crew Building, The Kings Buildings, Alexander Crum Brown Road, Edinburgh, EH9 3FF, UK
- Faculty of Science, Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, PO Box 68, Gustaf Hällströmin katu 2b, 00014, Helsinki, Finland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Latokartanonkaari 7, PO Box 27, 00014, Helsinki, Finland
| | - Craig D Allen
- US Geological Survey, Fort Collins Science Centre, New Mexico Landscapes Field Station, Los Alamos, NM, 87544, USA
| | - Stefan K Arndt
- School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, 3121, Vic., Australia
| | - David D Breshears
- School of Natural Resources and the Environment and Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
| | - Hendrik Davi
- INRA, URFM Ecologie des Forest Méditerranéennes, Domaine Saint Paul, Site Agroparc, 84914, Avignon Cedex 9, France
| | - David Galbraith
- School of Geography, University of Leeds, Leeds, LS2 9JT, UK
| | - Katinka X Ruthrof
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA, 6150, Australia
- Botanic Gardens and Parks Authority, Fraser Avenue, Kings Park, WA, 6005, Australia
| | - Jan Wunder
- Insubric Ecosystems Research Group, Community Ecology, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, a Ramèl 18, CH-6593, Cadenazzo, Switzerland
- Tree-Ring Laboratory, School of Environment, University of Auckland, Auckland, 1142, New Zealand
| | - Henry D Adams
- Department of Plant Biology, Ecology, and Evolution, 301 Physical Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jasper Bloemen
- Institute of Ecology, University of Innsbruck, Sternwartestraße 15, 6020, Innsbruck, Austria
- Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium
| | - Maxime Cailleret
- Forest Ecology, Department of Environmental Sciences, ETH Zürich. ETH-Zentrum, CHN G77, Universitätstrasse 16, CH-8092, Zürich, Switzerland
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Richard Cobb
- Department of Natural Resources and Environmental Science, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
| | - Arthur Gessler
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technical University of Munich, Von-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Markus Kautz
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany
| | - Francisco Lloret
- CREAF - Centre for Ecological Research and Applied Forestry, Cerdanyola del Vallès, Barcelona, Spain
- Unitat d'Ecologia, Department of Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma Barcelona, Edifici C, Campus UAB, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Michael O'Brien
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Carretera de Sacramento s/n, E-04120 La Cañada, Almería, Spain
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35
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Martínez-Sancho E, Dorado-Liñán I, Gutiérrez Merino E, Matiu M, Helle G, Heinrich I, Menzel A. Increased water-use efficiency translates into contrasting growth patterns of Scots pine and sessile oak at their southern distribution limits. GLOBAL CHANGE BIOLOGY 2018; 24:1012-1028. [PMID: 29030903 DOI: 10.1111/gcb.13937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 08/26/2017] [Indexed: 05/08/2023]
Abstract
In forests, the increase in atmospheric CO2 concentrations (Ca ) has been related to enhanced tree growth and intrinsic water-use efficiency (iWUE). However, in drought-prone areas such as the Mediterranean Basin, it is not yet clear to what extent this "fertilizing" effect may compensate for drought-induced growth reduction. We investigated tree growth and physiological responses at five Scots pine (Pinus sylvestris L.) and five sessile oak (Quercus petraea (Matt.) Liebl.) sites located at their southernmost distribution limits in Europe for the period 1960-2012 using annually resolved tree-ring width and δ13 C data to track ecophysiological processes. Results indicated that all 10 natural stands significantly increased their leaf intercellular CO2 concentration (Ci ), and consequently iWUE. Different trends in the theoretical gas-exchange scenarios as a response to increasing Ca were found: generally, Ci tended to increase proportionally to Ca , except for trees at the driest sites in which Ci remained constant. Ci from the oak sites displaying higher water availability tended to increase at a comparable rate to Ca . Multiple linear models fitted at site level to predict basal area increment (BAI) using iWUE and climatic variables better explained tree growth in pines (31.9%-71.4%) than in oak stands (15.8%-46.8%). iWUE was negatively linked to pine growth, whereas its effect on growth of oak differed across sites. Tree growth in the western and central oak stands was negatively related to iWUE, whereas BAI from the easternmost stand was positively associated with iWUE. Thus, some Q. petraea stands might have partially benefited from the "fertilizing" effect of rising Ca , whereas P. sylvestris stands due to their strict closure of stomata did not profit from increased iWUE and consequently showed in general growth reductions across sites. Additionally, the inter-annual variability of BAI and iWUE displayed a geographical polarity in the Mediterranean.
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Affiliation(s)
- Elisabet Martínez-Sancho
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität München, Freising, Germany
| | - Isabel Dorado-Liñán
- Departamento de Silvicultura y Gestión de los Sistemas Forestales, CIFOR-INIA, Madrid, Spain
| | - Emilia Gutiérrez Merino
- Departament of Biological Evolution, Ecology and Environmental Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Michael Matiu
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität München, Freising, Germany
| | - Gerhard Helle
- Climate Dynamics and Landscape Evolution, GFZ - German Research Centre for Geosciences, Potsdam, Germany
| | - Ingo Heinrich
- Climate Dynamics and Landscape Evolution, GFZ - German Research Centre for Geosciences, Potsdam, Germany
| | - Annette Menzel
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität München, Freising, Germany
- Institute for Advanced Study, Technische Universität München, Garching, Germany
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36
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Dai Y, Wang L, Wan X. Relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality caused by drought. AOB PLANTS 2018; 10:plx069. [PMID: 29367873 PMCID: PMC5774510 DOI: 10.1093/aobpla/plx069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 11/30/2017] [Indexed: 05/29/2023]
Abstract
Drought-induced tree mortality has been observed worldwide. Nevertheless, the physiological mechanisms underlying this phenomenon are still being debated. Potted Robinia pseudoacacia and Platycladus orientalis saplings were subjected to drought and their hydraulic failure and carbon starvation responses were studied. They underwent simulated fast drought (FD) and slow drought (SD) until death. The dynamics of their growth, photosynthesis, water relations and carbohydrate concentration were measured. The results showed that during drought, growth and photosynthesis of all saplings were significantly reduced in both species. The predawn water potential in both species was ~ -8 MPa at mortality. The percentage loss of conductivity (PLC) was at a maximum at mortality under both FD and SD. For R. pseudoacacia and P. orientalis, they were >95 and ~45 %, respectively. At complete defoliation, the PLC of R. pseudoacacia was ~90 % but the trees continued to survive for around 46 days. The non-structural carbohydrate (NSC) concentrations in the stems and roots of both FD and SD R. pseudoacacia declined to a very low level near death. In contrast, the NSC concentrations in the needles, stems and roots of P. orientalis at mortality under FD did not significantly differ from those of the control, whereas the NSC concentrations in SD P. orientalis stems and roots at death were significantly lower than those of the control. These results suggest that the duration of the drought affected NSC at mortality in P. orientalis. In addition, the differences in NSC between FD and SD P. orientalis did not alter mortality thresholds associated with hydraulic failure. The drought-induced death of R. pseudoacacia occurred at 95 % PLC for both FD and SD, indicating that hydraulic failure played an important role in mortality. Nevertheless, the consistent decline in NSC in R. pseudoacacia saplings following drought-induced defoliation may have also contributed to its mortality.
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Affiliation(s)
- Yongxin Dai
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, P.R. China
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, P.R. China
| | - Lin Wang
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, P.R. China
| | - Xianchong Wan
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, P.R. China
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37
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Martín-Gómez P, Aguilera M, Pemán J, Gil-Pelegrín E, Ferrio JP. Contrasting ecophysiological strategies related to drought: the case of a mixed stand of Scots pine (Pinus sylvestris) and a submediterranean oak (Quercus subpyrenaica). TREE PHYSIOLOGY 2017; 37:1478-1492. [PMID: 29040771 DOI: 10.1093/treephys/tpx101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 08/04/2017] [Indexed: 06/07/2023]
Abstract
Submediterranean forests are considered an ecotone between Mediterranean and Eurosiberian ecosystems, and are very sensitive to global change. A decline of Scots pine (Pinus sylvestris L.) and a related expansion of oak species (Quercus spp.) have been reported in the Spanish Pre-Pyrenees. Although this has been associated with increasing drought stress, the underlying mechanisms are not fully understood, and suitable monitoring protocols are lacking. The aim of this study is to bring insight into the physiological mechanisms anticipating selective decline of the pines, with particular focus on carbon and water relations. For this purpose, we performed a sampling campaign covering two growing seasons in a mixed stand of P. sylvestris and Quercus subpyrenaica E.H del Villar. We sampled seasonally twig xylem and soil for water isotope composition (δ18O and δ2H), leaves for carbon isotope composition (δ13C) and stems to quantify non-structural carbohydrates (NSC) concentration, and measured water potential and leaf gas exchange. The first summer drought was severe for both species, reaching low predawn water potential (-2.2 MPa), very low stomatal conductance (12 ± 1.0 mmol m-2 s-1) and near-zero or even negative net photosynthesis, particularly in P. sylvestris (-0.6 ± 0.34 μmol m-2 s-1 in oaks, -1.3 ± 0.16 μmol m-2 s-1 in pines). Hence, the tighter stomatal control and more isohydric strategy of P. sylvestris resulted in larger limitations on carbon assimilation, and this was also reflected in carbon storage, showing twofold larger total NSC concentration in oaks than in pines (7.8 ± 2.4% and 4.0 ± 1.3%, respectively). We observed a faster recovery of predawn water potential after summer drought in Q. subpyrenaica than in P. sylvestris (-0.8 MPa and -1.1 MPa, respectively). As supported by the isotopic data, this was probably associated with a deeper and more reliable water supply in Q. subpyrenaica. In line with these short-term observations, we found a more pronounced negative effect of steadily increasing drought stress on long-term growth in pines compared with oaks. All these observations confer evidence of early warning of P. sylvestris decline and indicate the adaptive advantage of Q. subpyrenaica in the area.
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Affiliation(s)
- Paula Martín-Gómez
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Mònica Aguilera
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Jesús Pemán
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
| | - Eustaquio Gil-Pelegrín
- Unidad de Recursos Forestales, CITA de Aragón, Av. Montañana, 930, 50059 Zaragoza, Spain
| | - Juan Pedro Ferrio
- Department of Crop and Forest Sciences-AGROTECNIO, Universitat de Lleida, Av. Alcalde Rovira Roure 191, 25198 Lleida, Spain
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, 4030000 Concepción, Chile
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Paljakka T, Jyske T, Lintunen A, Aaltonen H, Nikinmaa E, Hölttä T. Gradients and dynamics of inner bark and needle osmotic potentials in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst). PLANT, CELL & ENVIRONMENT 2017; 40:2160-2173. [PMID: 28671720 DOI: 10.1111/pce.13017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Preconditions of phloem transport in conifers are relatively unknown. We studied the variation of needle and inner bark axial osmotic gradients and xylem water potential in Scots pine and Norway spruce by measuring needle and inner bark osmolality in saplings and mature trees over several periods within a growing season. The needle and inner bark osmolality was strongly related to xylem water potential in all studied trees. Sugar concentrations were measured in Scots pine, and they had similar dynamics to inner bark osmolality. The sucrose quantity remained fairly constant over time and position, whereas the other sugars exhibited a larger change with time and position. A small osmotic gradient existed from branch to stem base under pre-dawn conditions, and the osmotic gradient between upper stem and stem base was close to zero. The turgor in branches was significantly driven by xylem water potential, and the turgor loss point in branches was relatively close to daily minimum needle water potentials typically reported for Scots pine. Our results imply that xylem water potential considerably impacts the turgor pressure gradient driving phloem transport and that gravitation has a relatively large role in phloem transport in the stems of mature Scots pine trees.
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Affiliation(s)
- Teemu Paljakka
- Department of Forest Sciences, University of Helsinki, Helsinki, FI-00014, Finland
| | - Tuula Jyske
- Natural Resources Institute Finland (Luke), FI-02150, Espoo, Finland
| | - Anna Lintunen
- Department of Forest Sciences, University of Helsinki, Helsinki, FI-00014, Finland
| | - Heidi Aaltonen
- Department of Forest Sciences, University of Helsinki, Helsinki, FI-00014, Finland
| | - Eero Nikinmaa
- Department of Forest Sciences, University of Helsinki, Helsinki, FI-00014, Finland
| | - Teemu Hölttä
- Department of Forest Sciences, University of Helsinki, Helsinki, FI-00014, Finland
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Galiano L, Timofeeva G, Saurer M, Siegwolf R, Martínez-Vilalta J, Hommel R, Gessler A. The fate of recently fixed carbon after drought release: towards unravelling C storage regulation in Tilia platyphyllos and Pinus sylvestris. PLANT, CELL & ENVIRONMENT 2017; 40:1711-1724. [PMID: 28432768 DOI: 10.1111/pce.12972] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 04/04/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Carbon reserves are important for maintaining tree function during and after stress. Increasing tree mortality driven by drought globally has renewed the interest in how plants regulate allocation of recently fixed C to reserve formation. Three-year-old seedlings of two species (Tilia platyphyllos and Pinus sylvestris) were exposed to two intensities of experimental drought during ~10 weeks, and 13 C pulse labelling was subsequently applied with rewetting. Tracking the 13 C label across different organs and C compounds (soluble sugars, starch, myo-inositol, lipids and cellulose), together with the monitoring of gas exchange and C mass balances over time, allowed for the identification of variations in C allocation priorities and tree C balances that are associated with drought effects and subsequent drought release. The results demonstrate that soluble sugars accumulated in P. sylvestris under drought conditions independently of growth trends; thus, non-structural carbohydrates (NSC) formation cannot be simply considered a passive overflow process in this species. Once drought ceased, C allocation to storage was still prioritized at the expense of growth, which suggested the presence of 'drought memory effects', possibly to ensure future growth and survival. On the contrary, NSC and growth dynamics in T. platyphyllos were consistent with a passive (overflow) view of NSC formation.
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Affiliation(s)
- Lucía Galiano
- Swiss Federal Research Institute WSL, Birmensdorf, CH-8903, Switzerland
- Institute of Hydrology, University of Freiburg, Freiburg, D-79098, Germany
| | - Galina Timofeeva
- Swiss Federal Research Institute WSL, Birmensdorf, CH-8903, Switzerland
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute PSI, Villigen, CH-5232, Switzerland
- Forest Ecology, Department of Environmental Systems Science, Institute of Terrestrial Ecosystems, ETH Zürich, Zürich, CH-8092, Switzerland
| | - Matthias Saurer
- Swiss Federal Research Institute WSL, Birmensdorf, CH-8903, Switzerland
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute PSI, Villigen, CH-5232, Switzerland
| | - Rolf Siegwolf
- Swiss Federal Research Institute WSL, Birmensdorf, CH-8903, Switzerland
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute PSI, Villigen, CH-5232, Switzerland
| | - Jordi Martínez-Vilalta
- CREAF, Cerdanyola del Vallès, E-08193, Spain
- Autonomous University of Barcelona UAB, Cerdanyola del Vallès, E-08193, Spain
| | - Robert Hommel
- Eberswalde University of Sustainable Development, Schicklerstraße 5, 16225, Eberswalde, Germany
| | - Arthur Gessler
- Swiss Federal Research Institute WSL, Birmensdorf, CH-8903, Switzerland
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Torres-Ruiz JM, Cochard H, Choat B, Jansen S, López R, Tomášková I, Padilla-Díaz CM, Badel E, Burlett R, King A, Lenoir N, Martin-StPaul NK, Delzon S. Xylem resistance to embolism: presenting a simple diagnostic test for the open vessel artefact. THE NEW PHYTOLOGIST 2017; 215:489-499. [PMID: 28467616 DOI: 10.1111/nph.14589] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/28/2017] [Indexed: 05/21/2023]
Abstract
Xylem vulnerability to embolism represents an essential trait for the evaluation of the impact of hydraulics in plant function and ecology. The standard centrifuge technique is widely used for the construction of vulnerability curves, although its accuracy when applied to species with long vessels remains under debate. We developed a simple diagnostic test to determine whether the open-vessel artefact influences centrifuge estimates of embolism resistance. Xylem samples from three species with differing vessel lengths were exposed to less negative xylem pressures via centrifugation than the minimum pressure the sample had previously experienced. Additional calibration was obtained from non-invasive measurement of embolism on intact olive plants by X-ray microtomography. Results showed artefactual decreases in hydraulic conductance (k) for samples with open vessels when exposed to a less negative xylem pressure than the minimum pressure they had previously experienced. X-Ray microtomography indicated that most of the embolism formation in olive occurs at xylem pressures below -4.0 MPa, reaching 50% loss of hydraulic conductivity at -5.3 MPa. The artefactual reductions in k induced by centrifugation underestimate embolism resistance data of species with long vessels. A simple test is suggested to avoid this open vessel artefact and to ensure the reliability of this technique in future studies.
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Affiliation(s)
| | - Hervé Cochard
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
| | - Brendan Choat
- Western Sydney University, Hawkesbury Institute for the Environment, Richmond, NSW, 2753, Australia
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Rosana López
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
- Western Sydney University, Hawkesbury Institute for the Environment, Richmond, NSW, 2753, Australia
| | - Ivana Tomášková
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, 165 00, Praha 6 - Suchdol, Czech Republic
| | - Carmen M Padilla-Díaz
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, 41012, Sevilla, Spain
| | - Eric Badel
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
| | - Regis Burlett
- BIOGECO, INRA, University of Bordeaux, 33615, Pessac, France
| | - Andrew King
- Synchrotron SOLEIL, L'Orme de Merisiers, 91190 Saint-Aubin - BP48, Gif-sur-Yvette Cedex, France
| | - Nicolas Lenoir
- CNRS, University of Bordeaux, UMS 3626 Placamat, F-33608, Pessac, France
| | | | - Sylvain Delzon
- BIOGECO, INRA, University of Bordeaux, 33615, Pessac, France
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Saiki ST, Ishida A, Yoshimura K, Yazaki K. Physiological mechanisms of drought-induced tree die-off in relation to carbon, hydraulic and respiratory stress in a drought-tolerant woody plant. Sci Rep 2017; 7:2995. [PMID: 28592804 PMCID: PMC5462810 DOI: 10.1038/s41598-017-03162-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 04/12/2017] [Indexed: 11/09/2022] Open
Abstract
Drought-induced tree die-off related to climate change is occurring worldwide and affects the carbon stocks and biodiversity in forest ecosystems. Hydraulic failure and carbon starvation are two commonly proposed mechanisms for drought-induced tree die-off. Here, we show that inhibited branchlet respiration and soil-to-leaf hydraulic conductance, likely caused by cell damage, occur prior to hydraulic failure (xylem embolism) and carbon starvation (exhaustion of stored carbon in sapwood) in a drought-tolerant woody species, Rhaphiolepis wrightiana Maxim. The ratio of the total leaf area to the twig sap area was used as a health indicator after drought damage. Six adult trees with different levels of tree health and one dead adult tree were selected. Two individuals having the worst and second worst health among the six live trees died three months after our study was conducted. Soil-to-leaf hydraulic conductance and leaf gas exchange rates decreased linearly as tree health declined, whereas xylem cavitation and total non-structural carbon remained unchanged in the branchlets except in the dead and most unhealthy trees. Respiration rates and the number of living cells in the sapwood decreased linearly as tree health declined. This study is the first report on the importance of dehydration tolerance and respiration maintenance in living cells.
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Affiliation(s)
- Shin-Taro Saiki
- Center for Ecological Research, Kyoto University, Otsu, Shiga, 520-2113, Japan.
| | - Atsushi Ishida
- Center for Ecological Research, Kyoto University, Otsu, Shiga, 520-2113, Japan.
| | - Kenichi Yoshimura
- Faculty of Agriculture, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Kenichi Yazaki
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, 305-8687, Japan
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Torres-Ruiz JM, Cochard H, Fonseca E, Badel E, Gazarini L, Vaz M. Differences in functional and xylem anatomical features allow Cistus species to co-occur and cope differently with drought in the Mediterranean region. TREE PHYSIOLOGY 2017; 37:755-766. [PMID: 28338840 DOI: 10.1093/treephys/tpx013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/08/2017] [Indexed: 05/21/2023]
Abstract
A significant increase in drought events frequency is predicted for the next decades induced by climate change, potentially affecting plant species mortality rates and distributions worldwide. The main trigger of plant mortality is xylem hydraulic failure due to embolism and induced by the low pressures at which water is transported through xylem. As the Mediterranean basin will be severely affected by climate change, the aim of this study was to provide novel information about drought resistance and tolerance of one of its most widely distributed and common genera as a case study: the genus Cistus. Different functional and anatomical traits were evaluated in four co-occurring Cistus species in the Mediterranean Montado ecosystem. Soil water availability for each species was also assessed to evaluate if they show different ecological niches within the area. Results showed physiological and xylem anatomical differences between the four co-occurring species, as well as in the soil water availability of the sites they occupy. Despite the significant differences in embolism resistance across species, no trade-off between hydraulic safety and efficiency was observed. Interestingly, species with narrower vessels showed lower resistance to embolism than those with higher proportions of large conduits. No correlation, however, was observed between resistance to embolism and wood density. The four species showed different water-use and drought-tolerance strategies, occupying different ecological niches that would make them cope differently with drought. These results will allow us to improve the predictions about the expected changes in vegetation dynamics in this area due to ongoing climate change.
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Affiliation(s)
| | | | - Elsa Fonseca
- Departamento de Biologia, Escola de Ciências e Tecnologia, ICAAM-Instituto de Ciências Agrarias e Ambientais Mediterrânicas, Universidade de Evora, Evora, Portugal
| | - Eric Badel
- INRA, UCA, PIAF, 63000 Clermont-Ferrand, France
| | - Luiz Gazarini
- Departamento de Biologia, Escola de Ciências e Tecnologia, ICAAM-Instituto de Ciências Agrarias e Ambientais Mediterrânicas, Universidade de Evora, Evora, Portugal
| | - Margarida Vaz
- Departamento de Biologia, Escola de Ciências e Tecnologia, ICAAM-Instituto de Ciências Agrarias e Ambientais Mediterrânicas, Universidade de Evora, Evora, Portugal
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43
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The Deep Root System of Fagus sylvatica on Sandy Soil: Structure and Variation Across a Precipitation Gradient. Ecosystems 2017. [DOI: 10.1007/s10021-017-0148-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wang L, Liu Y, Feng S, Yang J, Li D, Zhang J. Roles of Plasmalemma Aquaporin Gene StPIP1 in Enhancing Drought Tolerance in Potato. FRONTIERS IN PLANT SCIENCE 2017; 8:616. [PMID: 28487712 PMCID: PMC5403905 DOI: 10.3389/fpls.2017.00616] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/05/2017] [Indexed: 05/23/2023]
Abstract
Survival and mortality of plants in response to severe drought may be related to carbon starvation, but little is known about how plasma membrane intrinsic proteins may help alleviate the drought-induced damage. Here, we determined the roles of plasmalemma aquaporin gene in improving plant water status, maintaining carbon accumulation, and thereby enhancing drought tolerance. Seven StPIP1 transformed potato (Solanum tuberosum L.) lines (namely T1, T2…T7) were compared with non-transgenic control plant at molecule and whole-plant levels. The relative expression of StPIP1 gene was found in leaves, stems and roots, with the most abundant expression being in the roots. The transgenic lines T6 and T7 had the highest StPIP1 expression, averaging 7.2 times that of the control and the greatest differences occurred 48 h after mannitol osmotic stress treatment. Using an evaluation index to quantifying the degree of drought tolerance, we found that the StPIP1 transgenic lines T6 and T7 had the highest drought tolerance, averaging 8.5 times that of the control. Measured at 30 days in drought stress treatment, the control plant decreased net photosynthetic rate by 33 and 56%, respectively, under moderate and severe stresses; also decreased stomatal conductance by 39 and 65%; and lowered transpiration rate by 49 and 69%, compared to the no-stress treatment, whereas the transgenic lines T6 and T7 maintained a relatively stable level with slight decreases in these properties. The constitutive overexpression of StPIP1 in potato improved plant water use efficiency and increased nonstructural carbohydrate concentration, which helped alleviate carbon starvation and minimized the loss of biomass and tuber yield due to drought stress. We conclude that the expression of StPIPs improves overall water relations in the plant and helps maintain photosynthesis and stomatal conductance; these help minimize carbon starvation and enhance the whole plant tolerance to drought stress.
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Affiliation(s)
- Li Wang
- Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural UniversityLanzhou, China
- Department of Plant Biotechnology, College of Life Science and Technology, Gansu Agricultural UniversityLanzhou, China
| | - Yuhui Liu
- Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural UniversityLanzhou, China
| | - Shoujiang Feng
- Institute of Soil, Fertilizer and Water-saving Agriculture, Gansu Academy of Agricultural SciencesLanzhou, China
| | - Jiangwei Yang
- Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural UniversityLanzhou, China
- Department of Plant Biotechnology, College of Life Science and Technology, Gansu Agricultural UniversityLanzhou, China
| | - Dan Li
- Department of Agronomy, Longdong UniversityLanzhou, China
| | - Junlian Zhang
- Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural UniversityLanzhou, China
- Department of Olericulture, College of Horticulture, Gansu Agricultural UniversityLanzhou, China
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Martínez-Sancho E, Dorado-Liñán I, Hacke UG, Seidel H, Menzel A. Contrasting Hydraulic Architectures of Scots Pine and Sessile Oak at Their Southernmost Distribution Limits. FRONTIERS IN PLANT SCIENCE 2017; 8:598. [PMID: 28473841 PMCID: PMC5397420 DOI: 10.3389/fpls.2017.00598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/03/2017] [Indexed: 05/05/2023]
Abstract
Many temperate European tree species have their southernmost distribution limits in the Mediterranean Basin. The projected climatic conditions, particularly an increase in dryness, might induce an altitudinal and latitudinal retreat at their southernmost distribution limit. Therefore, characterizing the morphological and physiological variability of temperate tree species under dry conditions is essential to understand species' responses to expected climate change. In this study, we compared branch-level hydraulic traits of four Scots pine and four sessile oak natural stands located at the western and central Mediterranean Basin to assess their adjustment to water limiting conditions. Hydraulic traits such as xylem- and leaf-specific maximum hydraulic conductivity (KS-MAX and KL-MAX), leaf-to-xylem area ratio (AL:AX) and functional xylem fraction (FX) were measured in July 2015 during a long and exceptionally dry summer. Additionally, xylem-specific native hydraulic conductivity (KS-N) and native percentage of loss of hydraulic conductivity (PLC) were measured for Scots pine. Interspecific differences in these hydraulic traits as well as intraspecific variability between sites were assessed. The influence of annual, summer and growing season site climatic aridity (P/PET) on intraspecific variability was investigated. Sessile oak displayed higher values of KS-MAX, KL-MAX, AL:AX but a smaller percentage of FX than Scots pines. Scots pine did not vary in any of the measured hydraulic traits across the sites, and PLC values were low for all sites, even during one of the warmest summers in the region. In contrast, sessile oak showed significant differences in KS-MAX, KL-MAX, and FX across sites, which were significantly related to site aridity. The striking similarity in the hydraulic traits across Scots pine sites suggests that no adjustment in hydraulic architecture was needed, likely as a consequence of a drought-avoidance strategy. In contrast, sessile oak displayed adjustments in the hydraulic architecture along an aridity gradient, pointing to a drought-tolerance strategy.
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Affiliation(s)
- Elisabet Martínez-Sancho
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
| | - Isabel Dorado-Liñán
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
- Departamento de Silvicultura y Gestión de los Sistemas Forestales, Centro de Investigación Forestal–Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
| | - Uwe G. Hacke
- Department of Renewable Resources, University of Alberta, EdmontonAB, Canada
| | - Hannes Seidel
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
| | - Annette Menzel
- Ecoclimatology, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
- Institute for Advanced Study, Technische Universität MünchenGarching, Germany
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46
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Torres-Ruiz JM, Cochard H, Mencuccini M, Delzon S, Badel E. Direct observation and modelling of embolism spread between xylem conduits: a case study in Scots pine. PLANT, CELL & ENVIRONMENT 2016; 39:2774-2785. [PMID: 27739597 DOI: 10.1111/pce.12840] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 09/29/2016] [Accepted: 10/04/2016] [Indexed: 06/06/2023]
Abstract
Xylem embolism is one of the main processes involved in drought-related plant mortality. Although its consequences for plant physiology are already well described, embolism formation and spread are poorly evaluated and modelled, especially for tracheid-based species. The aim of this study was to assess the embolism formation and spread in Pinus sylvestris as a case study using X-ray microtomography and hydraulics methods. We also evaluated the potential effects of cavitation fatigue on vulnerability to embolism and the micro-morphology of the bordered pits using scanning electron microscopy (SEM) to test for possible links between xylem anatomy and embolism spread. Finally, a novel model was developed to simulate the spread of embolism in a 2D anisotropic cellular structure. Results showed a large variability in the formation and spread of embolism within a ring despite no differences being observed in intertracheid pit membrane anatomical traits. Simulations from the model showed a highly anisotropic tracheid-to-tracheid embolism spreading pattern, which confirms the major role of tracheid-to-tracheid air seeding to explain how embolism spreads in Scots pine. The results also showed that prior embolism removal from the samples reduced the resistance to embolism of the xylem and could result in overestimates of vulnerability to embolism.
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Affiliation(s)
| | - Hervé Cochard
- PIAF, INRA, Univ. Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Maurizio Mencuccini
- School of Geosciences, University of Edinburgh, Crew Building, The Kings Buildings, West Main Road, EH93JF, Edinburgh, UK
- ICREA at CREAF, 08193, Cerdanyola del Vallès, Barcelona, Spain
| | | | - Eric Badel
- PIAF, INRA, Univ. Clermont Auvergne, 63000, Clermont-Ferrand, France
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47
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Lüpke M, Leuchner M, Steinbrecher R, Menzel A. Impact of summer drought on isoprenoid emissions and carbon sink of three Scots pine provenances. TREE PHYSIOLOGY 2016; 36:1382-1399. [PMID: 27591438 PMCID: PMC5225987 DOI: 10.1093/treephys/tpw066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 06/24/2016] [Indexed: 05/13/2023]
Abstract
Scots pine (Pinus sylvestris L.) provenances cover broad ecological amplitudes. In a greenhouse study, we investigated the impact of drought stress and rewetting on gas exchange for three provenances (Italy: Emilia Romagna; Spain: Alto Ebro; Germany: East-German lowlands) of 2-year old Scots pine seedlings. CO2, water vapour and isoprenoid exchange of stressed and control trees were quantified with a four-chamber dynamic-enclosure system in the controlled environment of a climate chamber. The three provenances showed distinct isoprenoid emission patterns and were classified into a non-Δ3-carene, with either high α-/β-pinene or β-myrcene fraction, and a Δ3-carene dominated type. Isoprenoid emission rates, net-photosynthesis and transpiration were reduced during summer drought stress and significantly recovered after rewetting. A seasonal increase of isoprenoid emission rates towards autumn was observed for all control groups. Compared with the German provenance, the Spanish and Italian provenances revealed higher isoprenoid emission rates and more plastic responses to drought stress and seasonal development, which points to a local adaptation to climate. As a result of drought, net carbon uptake and transpiration of trees was reduced, but recovered after rewetting. We conclude from our study that Scots pine isoprenoid emission is more variable than expected and sensitive to drought periods, likely impacting regional air chemistry. Thus, a provenance-specific emission assessment accounting for reduced emission during prolonged (summer) drought is recommend for setting up biogenic volatile organic compound emission inventories used in air quality models.
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Affiliation(s)
- M Lüpke
- Ecoclimatology, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - M Leuchner
- Ecoclimatology, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
- Institute for Advanced Study, Technische Universität München, Lichtenbergstraße 2a, 85748 Garching, Germany
- Springer Science+Business Media B.V. , Van Godewijckstraat 30, 3311 GX Dordrecht, The Netherlands
| | - R Steinbrecher
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research Atmospheric Environmental Research (IMK-IFU) , Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
| | - A Menzel
- Ecoclimatology, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
- Institute for Advanced Study, Technische Universität München, Lichtenbergstraße 2a, 85748 Garching, Germany
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Sass-Klaassen U, Fonti P, Cherubini P, Gričar J, Robert EMR, Steppe K, Bräuning A. A Tree-Centered Approach to Assess Impacts of Extreme Climatic Events on Forests. FRONTIERS IN PLANT SCIENCE 2016; 7:1069. [PMID: 27493654 PMCID: PMC4954821 DOI: 10.3389/fpls.2016.01069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/06/2016] [Indexed: 05/09/2023]
Affiliation(s)
- Ute Sass-Klaassen
- Forest Ecology and Forest Management Group, Wageningen UniversityWageningen, Netherlands
| | - Patrick Fonti
- Landscape Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
| | - Paolo Cherubini
- Landscape Dynamics Unit, Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
| | - Jožica Gričar
- Department of Forest Yield and Silviculture, Slovenian Forestry InstituteLjubljana, Slovenia
| | - Elisabeth M. R. Robert
- CREAFCerdanyola del Vallès, Spain
- Laboratory of Plant Biology and Nature Management, Vrije Universiteit BrusselBrussels, Belgium
- Laboratory of Wood Biology and Xylarium, Royal Museum for Central AfricaTervuren, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent UniversityGhent, Belgium
| | - Achim Bräuning
- Department of Geography and Geosciences, Friedrich-Alexander-University Erlangen-NurembergErlangen, Germany
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Venturas MD, MacKinnon ED, Dario HL, Jacobsen AL, Pratt RB, Davis SD. Chaparral Shrub Hydraulic Traits, Size, and Life History Types Relate to Species Mortality during California's Historic Drought of 2014. PLoS One 2016; 11:e0159145. [PMID: 27391489 PMCID: PMC4938587 DOI: 10.1371/journal.pone.0159145] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 06/28/2016] [Indexed: 11/21/2022] Open
Abstract
Chaparral is the most abundant vegetation type in California and current climate change models predict more frequent and severe droughts that could impact plant community structure. Understanding the factors related to species-specific drought mortality is essential to predict such changes. We predicted that life history type, hydraulic traits, and plant size would be related to the ability of species to survive drought. We evaluated the impact of these factors in a mature chaparral stand during the drought of 2014, which has been reported as the most severe in California in the last 1,200 years. We measured tissue water potential, native xylem specific conductivity, leaf specific conductivity, percentage loss in conductivity, and chlorophyll fluorescence for 11 species in February 2014, which was exceptionally dry following protracted drought. Mortality among the 11 dominant species ranged from 0 to 93%. Total stand density was reduced 63.4% and relative dominance of species shifted after the drought. Mortality was negatively correlated with water potential, native xylem specific conductivity, and chlorophyll fluorescence, but not with percent loss in hydraulic conductivity and leaf specific conductivity. The model that best explained mortality included species and plant size as main factors and indicated that larger plants had greater survival for 2 of the species. In general, species with greater resistance to water-stress induced cavitation showed greater mortality levels. Despite adult resprouters typically being more vulnerable to cavitation, results suggest that their more extensive root systems enable them to better access soil moisture and avoid harmful levels of dehydration. These results are consistent with the hypothesis that short-term high intensity droughts have the strongest effect on mature plants of shallow-rooted dehydration tolerant species, whereas deep-rooted dehydration avoiding species fare better in the short-term. Severe droughts can drive changes in chaparral structure as a result of the differential mortality among species.
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Affiliation(s)
- Martin D. Venturas
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
- Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid, Avda. de las Moreras s/n, 28040, Madrid, Spain
- * E-mail:
| | - Evan D. MacKinnon
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
| | - Hannah L. Dario
- Natural Science Division, Pepperdine University, 24255 Pacific Coast Highway, Malibu, CA 90263, United States of America
| | - Anna L. Jacobsen
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
| | - R. Brandon Pratt
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
| | - Stephen D. Davis
- Natural Science Division, Pepperdine University, 24255 Pacific Coast Highway, Malibu, CA 90263, United States of America
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Seidel H, Menzel A. Above-Ground Dimensions and Acclimation Explain Variation in Drought Mortality of Scots Pine Seedlings from Various Provenances. FRONTIERS IN PLANT SCIENCE 2016; 7:1014. [PMID: 27458477 PMCID: PMC4935725 DOI: 10.3389/fpls.2016.01014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/27/2016] [Indexed: 05/04/2023]
Abstract
Seedling establishment is a critical part of the life cycle, thus seedling survival might be even more important for forest persistence under recent and future climate change. Scots pine forests have been disproportionally more affected by climate change triggered forest-dieback. Nevertheless, some Scots pine provenances might prove resilient to future drought events because of the species' large distributional range, genetic diversity, and adaptation potential. However, there is a lack of knowledge on provenance-specific survival under severe drought events and on how acclimation alters survival rates in Scots pine seedlings. We therefore conducted two drought-induced mortality experiments with potted Scots pine seedlings in a greenhouse. In the first experiment, 760 three-year-old seedlings from 12 different provenances of the south-western distribution range were subjected to the same treatment followed by the mortality experiment in 2014. In the second experiment, we addressed the question of whether acclimation to re-occurring drought stress events and to elevated temperature might decrease mortality rates. Thus, 139 four-year-old seedlings from France, Germany, and Poland were subjected to different temperature regimes (2012-2014) and drought treatments (2013-2014) before the mortality experiment in 2015. Provenances clearly differed in their hazard of drought-induced mortality, which was only partly related to the climate of their origin. Drought acclimation decreased the hazard of drought-induced mortality. Above-ground dry weight and height were the main determinants for the hazard of mortality, i.e., heavier and taller seedlings were more prone to mortality. Consequently, Scots pine seedlings exhibit a considerable provenance-specific acclimation potential against drought mortality and the selection of suitable provenances might thus facilitate seedling establishment and the persistence of Scots pine forest.
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Affiliation(s)
- Hannes Seidel
- Professorship of Ecoclimatology, Department of Ecology and Ecosystem Management, TUM School of Life Sciences Weihenstephan, Technische Universität MünchenFreising, Germany
| | - Annette Menzel
- Professorship of Ecoclimatology, Department of Ecology and Ecosystem Management, TUM School of Life Sciences Weihenstephan, Technische Universität MünchenFreising, Germany
- Institute for Advanced Study, Technische Universität MünchenGarching, Germany
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