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Waite PA, Kumar M, Link RM, Schuldt B. Coordinated hydraulic traits influence the two phases of time to hydraulic failure in five temperate tree species differing in stomatal stringency. Tree Physiol 2024; 44:tpae038. [PMID: 38606678 DOI: 10.1093/treephys/tpae038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 03/08/2024] [Accepted: 03/28/2024] [Indexed: 04/13/2024]
Abstract
Worldwide, forests are increasingly exposed to extreme droughts causing tree mortality. Because of the complex nature of the mechanisms involved, various traits have been linked to tree drought responses with contrasting results. This may be due to species-specific strategies in regulating water potential, a process that unfolds in two distinct phases: a first phase until stomatal closure, and a second phase until reaching lethal xylem hydraulic thresholds. We conducted dry-down experiments with five broadleaved temperate tree species differing in their degree of isohydry to estimate the time to stomatal closure (tsc) and subsequent time to critical hydraulic failure (tcrit). We measured various traits linked to tree drought responses, such as the water potentials at turgor loss point (Ptlp), stomatal closure (Pgs90), and 12%, 50% and 88% loss of xylem hydraulic conductance (P12, P50, P88), hydraulic capacitance (C), minimum leaf conductance (gmin), hydroscape area (HSA) and hydraulic safety margins (HSM). We found that Pgs90 followed previously recorded patterns of isohydry and was associated with HSA. Species ranked from more to less isohydric in the sequence Acer pseudoplatanus < Betula pendula < Tilia cordata < Sorbus aucuparia < Fagus sylvatica. Their degree of isohydry was associated with leaf safety (Ptlp and gmin), drought avoidance (C) and tsc, but decoupled from xylem safety (HSM and P88) and tcrit. Regardless of their stomatal stringency, species with wider HSM and lower P88 reached critical hydraulic failure later. We conclude that the duration of the first phase is determined by stomatal regulation, while the duration of the second phase is associated with xylem safety. Isohydry is thus linked to water use rather than to drought survival strategies, confirming the proposed use of HSA as a complement to HSM for describing plant drought responses before and after stomatal closure.
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Affiliation(s)
- Pierre-André Waite
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- Forest Botany, TUD Dresden University of Technology, Pienner Straße 7, 01737, Tharandt, Germany
- CIRAD, UPR AIDA, 34398 Montpellier, France
| | - Manish Kumar
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- ICAR - Central Soil Salinity Research Institute (CSSRI), Karnal, 132001, India
| | - Roman M Link
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- Forest Botany, TUD Dresden University of Technology, Pienner Straße 7, 01737, Tharandt, Germany
| | - Bernhard Schuldt
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
- Forest Botany, TUD Dresden University of Technology, Pienner Straße 7, 01737, Tharandt, Germany
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2
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Wang S, Hoch G, Grun G, Kahmen A. Water loss after stomatal closure: quantifying leaf minimum conductance and minimal water use in nine temperate European tree species during a severe drought. Tree Physiol 2024; 44:tpae027. [PMID: 38412116 PMCID: PMC10993720 DOI: 10.1093/treephys/tpae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 02/18/2024] [Indexed: 02/29/2024]
Abstract
Residual canopy transpiration (Emin_canop) is a key physiological trait that determines trees' survival time under drought after stomatal closure and after trees have limited access to soil water. Emin_canop mainly depends on leaf minimum conductance (gmin) and vapor pressure deficit. Here we determined the seasonal variation of gmin and how gmin is related to interspecies variation in leaf cuticular and stomatal traits for nine European tree species in a mature forest. In addition, we determined the species-specific temperature responses of gmin. With this newly obtained insight, we calculated Emin_canop for the nine species for one day at our research site during the 2022 central European hot drought. Our results show that at ambient temperatures gmin ranged from 0.8 to 4.8 mmol m-2 s-1 across the nine species and was stable in most species throughout the growing season. The interspecies variation of gmin was associated with leaf cuticular and stomatal traits. Additionally, gmin exhibited strong temperature responses and increased, depending on species, by a factor of two to four in the range of 25-50 °C. For the studied species at the site, during a single hot drought day, Emin_canop standardized by tree size (stem basal area) ranged from 2.0 to 36.7 L m-2, and non-standardized Emin_canop for adult trees ranged from 0.3 to 5.3 L. Emin_canop also exhibited species-specific rapid increases under hotter temperatures. Our results suggest that trees, depending on species, need reasonable amounts of water during a drought, even when stomates are fully closed. Species differences in gmin and ultimately Emin_canop can, together with other traits, affect the ability of a tree to keep its tissue hydrated during a drought and is likely to contribute to species-specific differences in drought vulnerability.
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Affiliation(s)
- Songwei Wang
- Department of Environmental Sciences – Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
| | - Günter Hoch
- Department of Environmental Sciences – Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
| | - Georges Grun
- Department of Environmental Sciences – Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences – Botany, University of Basel, Schönbeinstrasse 6, 4056 Basel, Switzerland
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Andriantelomanana T, Améglio T, Delzon S, Cochard H, Herbette S. Unpacking the point of no return under drought in poplar: insight from stem diameter variation. New Phytol 2024; 242:466-478. [PMID: 38406847 DOI: 10.1111/nph.19615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/02/2024] [Indexed: 02/27/2024]
Abstract
A specific, robust threshold for drought-induced tree mortality is needed to improve the prediction of forest dieback. Here, we tested the relevance of continuous measurements of stem diameter variations for identifying such a threshold, their relationship with hydraulic and cellular damage mechanisms, and the influence of growth conditions on these relationships. Poplar saplings were grown under well-watered, water-limited, or light-limited conditions and then submitted to a drought followed by rewatering. Stem diameter was continuously measured to investigate two parameters: the percentage loss of diameter (PLD) and the percentage of diameter recovery (DR) following rewatering. Water potentials, stomatal conductance, embolism, and electrolyte leakage were also measured, and light microscopy allowed investigating cell collapse induced by drought. The water release observed through loss of diameter occurred throughout the drought, regardless of growth conditions. Poplars did not recover from drought when PLD reached a threshold and this differed according to growth conditions but remained linked to cell resistance to damage and collapse. Our findings shed new light on the mechanisms of drought-induced tree mortality and indicate that PLD could be a relevant indicator of drought-induced tree mortality, regardless of the growth conditions.
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Affiliation(s)
| | - Thierry Améglio
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, 63000, France
| | - Sylvain Delzon
- Université Bordeaux, INRAE, BIOGECO, Pessac, 33615, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, 63000, France
| | - Stephane Herbette
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, 63000, France
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4
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Jupa R, Pokorná K. Bark wounding triggers gradual embolism spreading in two diffuse-porous tree species. Tree Physiol 2024; 44:tpad132. [PMID: 37930242 PMCID: PMC10849750 DOI: 10.1093/treephys/tpad132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Xylem transport is essential for the growth, development and survival of vascular plants. Bark wounding may increase the risk of xylem transport failure by tension-driven embolism. However, the consequences of bark wounding for xylem transport are poorly understood. Here, we examined the impacts of the bark wounding on embolism formation, leaf water potential and gas exchange in the terminal branches of two diffuse-porous tree species (Acer platanoides L. and Prunus avium L.). The effects of bark removal were examined on field-grown mature trees exposed to increased evaporative demands on a short-term and longer-term basis (6 h vs 6 days after bark wounding). Bark removal of 30% of branch circumference had a limited effect on the xylem hydraulic conductivity when embolized vessels were typically restricted to the last annual ring near the bark wound. Over the 6-day exposure, the non-conductive xylem area had significantly increased in the xylem tissue underneath the bark wound (from 22-29% to 51-52% of the last annual ring area in the bark wound zone), pointing to gradual yet relatively limited embolism spreading to deeper xylem layers over time. In both species, the bark removal tended to result in a small but non-significant increase in the percent loss of hydraulic conductivity compared with control intact branches 6 days after bark wounding (from 6 to 8-10% in both species). The bark wounding had no significant effects on midday leaf water potential, CO2 assimilation rates, stomatal conductance and water-use efficiency of the leaves of the current-year shoot, possibly due to limited impacts on xylem transport. The results of this study demonstrate that bark wounding induces limited but gradual embolism spreading. However, the impacts of bark wounding may not significantly limit water delivery to distal organs and leaf gas exchange at the scale of several days.
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Affiliation(s)
- Radek Jupa
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Brno CZ-62500, Czech Republic
| | - Kamila Pokorná
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Brno CZ-62500, Czech Republic
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Liu J, Hochberg U, Ding R, Xiong D, Dai Z, Zhao Q, Chen J, Ji S, Kang S. Elevated CO2 concentration increases maize growth under water deficit or soil salinity but with a higher risk of hydraulic failure. J Exp Bot 2024; 75:422-437. [PMID: 37715996 DOI: 10.1093/jxb/erad365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/15/2023] [Indexed: 09/18/2023]
Abstract
Climate change presents a challenge for plants to acclimate their water relations under changing environmental conditions, and may increase the risks of hydraulic failure under stress. In this study, maize plants were acclimated to two different CO2 concentrations ([CO2]; 400 ppm and 700 ppm) while under either water stress (WS) or soil salinity (SS) treatments, and their growth and hydraulic traits were examined in detail. Both WS and SS inhibited growth and had significant impacts on hydraulic traits. In particular, the water potential at 50% loss of stem hydraulic conductance (P50) decreased by 1 MPa in both treatments at 400 ppm. When subjected to elevated [CO2], the plants under both WS and SS showed improved growth by 7-23%. Elevated [CO2] also significantly increased xylem vulnerability (measured as loss of conductivity with decreasing xylem pressure), resulting in smaller hydraulic safety margins. According to the plant desiccation model, the critical desiccation degree (time×vapor pressure deficit) that the plants could tolerate under drought was reduced by 43-64% under elevated [CO2]. In addition, sensitivity analysis showed that P50 was the most important trait in determining the critical desiccation degree. Thus, our results demonstrated that whilst elevated [CO2] benefited plant growth under WS or SS, it also interfered with hydraulic acclimation, thereby potentially placing the plants at a higher risk of hydraulic failure and increased mortality.
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Affiliation(s)
- Junzhou Liu
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Uri Hochberg
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization Volcani Center, Bet Dagan, 7505101, Israel
| | - Risheng Ding
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Dongliang Xiong
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhanwu Dai
- Beijing Key Laboratory of Grape Science and Enology and Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Qing Zhao
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Jinliang Chen
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Shasha Ji
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Shaozhong Kang
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
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Petek-Petrik A, Petrík P, Lamarque LJ, Cochard H, Burlett R, Delzon S. Drought survival in conifer species is related to the time required to cross the stomatal safety margin. J Exp Bot 2023; 74:6847-6859. [PMID: 37681745 DOI: 10.1093/jxb/erad352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
The regulation of water loss and the spread of xylem embolism have mostly been considered separately. The development of an integrated approach taking into account the temporal dynamics and relative contributions of these mechanisms to plant drought responses is urgently needed. Do conifer species native to mesic and xeric environments display different hydraulic strategies and temporal sequences under drought? A dry-down experiment was performed on seedlings of four conifer species differing in embolism resistance, from drought-sensitive to extremely drought-resistant species. A set of traits related to drought survival was measured, including turgor loss point, stomatal closure, minimum leaf conductance, and xylem embolism resistance. All species reached full stomatal closure before the onset of embolism, with all but the most drought-sensitive species presenting large stomatal safety margins, demonstrating that highly drought-resistant species do not keep their stomata open under drought conditions. Plant dry-down time to death was significantly influenced by the xylem embolism threshold, stomatal safety margin, and minimum leaf conductance, and was best explained by the newly introduced stomatal margin retention index (SMRIΨ50) which reflects the time required to cross the stomatal safety margin. The SMRIΨ50 may become a key tool for the characterization of interspecific drought survival variability in trees.
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Affiliation(s)
- Anja Petek-Petrik
- Department of Vegetation Ecology, Institute of Botany, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Peter Petrík
- Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), 82467 Garmisch-Partenkirchen, Germany
| | - Laurent J Lamarque
- BIOGECO, University of Bordeaux, INRAE, F-33615 Pessac, France
- Département des Sciences de l'Environnement, UQTR, Trois-Rivières, Québec, Canada
| | - Hervé Cochard
- PIAF, University of Clermont Auvergne, INRAE, 63000 Clermont-Ferrand, France
| | - Régis Burlett
- BIOGECO, University of Bordeaux, INRAE, F-33615 Pessac, France
| | - Sylvain Delzon
- BIOGECO, University of Bordeaux, INRAE, F-33615 Pessac, France
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Haverroth EJ, Oliveira LA, Andrade MT, Taggart M, McAdam SAM, Zsögön A, Thompson AJ, Martins SCV, Cardoso AA. Abscisic acid acts essentially on stomata, not on the xylem, to improve drought resistance in tomato. Plant Cell Environ 2023; 46:3229-3241. [PMID: 37526514 DOI: 10.1111/pce.14676] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/15/2023] [Accepted: 07/22/2023] [Indexed: 08/02/2023]
Abstract
Drought resistance is essential for plant production under water-limiting environments. Abscisic acid (ABA) plays a critical role in stomata but its impact on hydraulic function beyond the stomata is far less studied. We selected genotypes differing in their ability to accumulate ABA to investigate its role in drought-induced dysfunction. All genotypes exhibited similar leaf and stem embolism resistance regardless of differences in ABA levels. Their leaf hydraulic resistance was also similar. Differences were only observed between the two extreme genotypes: sitiens (sit; a strong ABA-deficient mutant) and sp12 (a transgenic line that constitutively overaccumulates ABA), where the water potential inducing 50% embolism was 0.25 MPa lower in sp12 than in sit. Maximum stomatal and minimum leaf conductances were considerably lower in plants with higher ABA (wild type [WT] and sp12) than in ABA-deficient mutants. Variations in gas exchange across genotypes were associated with ABA levels and differences in stomatal density and size. The lower water loss in plants with higher ABA meant that lethal water potentials associated with embolism occurred later during drought in sp12 plants, followed by WT, and then by the ABA-deficient mutants. Therefore, the primary pathway by which ABA enhances drought resistance is via declines in water loss, which delays dehydration and hydraulic dysfunction.
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Affiliation(s)
- Eduardo J Haverroth
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Leonardo A Oliveira
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Moab T Andrade
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Matthew Taggart
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Scott A M McAdam
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA
| | - Agustin Zsögön
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Andrew J Thompson
- Centre for Soil, Agrifood and Biosciences, Cranfield University, Bedfordshire, UK
| | - Samuel C V Martins
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Amanda A Cardoso
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA
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Petruzzellis F, Di Bonaventura A, Tordoni E, Tomasella M, Natale S, Trifilò P, Tromba G, Di Lillo F, D'Amico L, Bacaro G, Nardini A. The optical method based on gas injection overestimates leaf vulnerability to xylem embolism in three woody species. Tree Physiol 2023; 43:1784-1795. [PMID: 37427987 DOI: 10.1093/treephys/tpad088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/26/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023]
Abstract
Plant hydraulic traits related to leaf drought tolerance, like the water potential at turgor loss point (TLP) and the water potential inducing 50% loss of hydraulic conductance (P50), are extremely useful to predict the potential impacts of drought on plants. While novel techniques have allowed the inclusion of TLP in studies targeting a large group of species, fast and reliable protocols to measure leaf P50 are still lacking. Recently, the optical method coupled with the gas injection (GI) technique has been proposed as a possibility to speed up the P50 estimation. Here, we present a comparison of leaf optical vulnerability curves (OVcs) measured in three woody species, namely Acer campestre (Ac), Ostrya carpinifolia (Oc) and Populus nigra (Pn), based on bench dehydration (BD) or GI of detached branches. For Pn, we also compared optical data with direct micro-computed tomography (micro-CT) imaging in both intact saplings and cut shoots subjected to BD. Based on the BD procedure, Ac, Oc and Pn had P50 values of -2.87, -2.47 and -2.11 MPa, respectively, while the GI procedure overestimated the leaf vulnerability (-2.68, -2.04 and -1.54 MPa for Ac, Oc and Pn, respectively). The overestimation was higher for Oc and Pn than for Ac, likely reflecting the species-specific vessel lengths. According to micro-CT observations performed on Pn, the leaf midrib showed none or very few embolized conduits at -1.2 MPa, consistent with the OVcs obtained with the BD procedure but at odds with that derived on the basis of GI. Overall, our data suggest that coupling the optical method with GI might not be a reliable technique to quantify leaf hydraulic vulnerability since it could be affected by the 'open-vessel' artifact. Accurate detection of xylem embolism in the leaf vein network should be based on BD, preferably of intact up-rooted plants.
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Affiliation(s)
- Francesco Petruzzellis
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Azzurra Di Bonaventura
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Viale delle Scienze 206, Udine 33100, Italy
| | - Enrico Tordoni
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, J. Liivi 2, Tartu 50409, Estonia
| | - Martina Tomasella
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Sara Natale
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Patrizia Trifilò
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, Messina 98166, Italy
| | - Giuliana Tromba
- Elettra Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
| | - Francesca Di Lillo
- Elettra Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
| | - Lorenzo D'Amico
- Elettra Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
- Department of Physics, University of Trieste, Via A. Valerio 2, Trieste 34127, Italy
| | - Giovanni Bacaro
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
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Blackman CJ, Billon LM, Cartailler J, Torres-Ruiz JM, Cochard H. Key hydraulic traits control the dynamics of plant dehydration in four contrasting tree species during drought. Tree Physiol 2023; 43:1772-1783. [PMID: 37318310 PMCID: PMC10652334 DOI: 10.1093/treephys/tpad075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/07/2023] [Accepted: 06/08/2023] [Indexed: 06/16/2023]
Abstract
Trees are at risk of mortality during extreme drought, yet our understanding of the traits that govern the timing of drought-induced hydraulic failure remains limited. To address this, we tested SurEau, a trait-based soil-plant-atmosphere model designed to predict the dynamics of plant dehydration as represented by the changes in water potential against those observed in potted trees of four contrasting species (Pinus halepensis Mill., Populus nigra L., Quercus ilex L. and Cedrus atlantica (Endl.) Manetti ex Carriére) exposed to drought. SurEau was parameterized with a range of plant hydraulic and allometric traits, soil and climatic variables. We found a close correspondence between the predicted and observed plant water potential (in MPa) dynamics during the early phase drought, leading to stomatal closure, as well as during the latter phase of drought, leading to hydraulic failure in all four species. A global model's sensitivity analysis revealed that, for a common plant size (leaf area) and soil volume, dehydration time from full hydration to stomatal closure (Tclose) was most strongly controlled by the leaf osmotic potential (Pi0) and its influence on stomatal closure, in all four species, while the maximum stomatal conductance (gsmax) also contributed to Tclose in Q. ilex and C. atlantica. Dehydration times from stomatal closure to hydraulic failure (Tcav) was most strongly controlled by Pi0, the branch residual conductance (gres) and Q10a sensitivity of gres in the three evergreen species, while xylem embolism resistance (P50) was most influential in the deciduous species P. nigra. Our findings point to SurEau as a highly useful model for predicting changes in plant water status during drought and suggest that adjustments made in key hydraulic traits are potentially beneficial to delaying the onset of drought-induced hydraulic failure in trees.
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Affiliation(s)
- Chris J Blackman
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, School of Natural Sciences, University of Tasmania, Hobart 7001, Australia
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - Lise-Marie Billon
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - Julien Cartailler
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - José M Torres-Ruiz
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63100, France
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Petrík P, Petek-Petrik A, Mukarram M, Schuldt B, Lamarque LJ. Leaf physiological and morphological constraints of water-use efficiency in C 3 plants. AoB Plants 2023; 15:plad047. [PMID: 37560762 PMCID: PMC10407996 DOI: 10.1093/aobpla/plad047] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 07/05/2023] [Indexed: 08/11/2023]
Abstract
The increasing evaporative demand due to climate change will significantly affect the balance of carbon assimilation and water losses of plants worldwide. The development of crop varieties with improved water-use efficiency (WUE) will be critical for adapting agricultural strategies under predicted future climates. This review aims to summarize the most important leaf morpho-physiological constraints of WUE in C3 plants and identify gaps in knowledge. From the carbon gain side of the WUE, the discussed parameters are mesophyll conductance, carboxylation efficiency and respiratory losses. The traits and parameters affecting the waterside of WUE balance discussed in this review are stomatal size and density, stomatal control and residual water losses (cuticular and bark conductance), nocturnal conductance and leaf hydraulic conductance. In addition, we discussed the impact of leaf anatomy and crown architecture on both the carbon gain and water loss components of WUE. There are multiple possible targets for future development in understanding sources of WUE variability in plants. We identified residual water losses and respiratory carbon losses as the greatest knowledge gaps of whole-plant WUE assessments. Moreover, the impact of trichomes, leaf hydraulic conductance and canopy structure on plants' WUE is still not well understood. The development of a multi-trait approach is urgently needed for a better understanding of WUE dynamics and optimization.
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Affiliation(s)
- Peter Petrík
- Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
| | - Anja Petek-Petrik
- Institute of Botany, Czech Academy of Sciences, Lidická 971, 602 00 Brno, Czech Republic
| | - Mohammad Mukarram
- Department of Phytology, Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, 960 01 Zvolen, Slovakia
| | - Bernhard Schuldt
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technical University of Dresden (TUD), Pienner Str. 7, 01737 Tharandt, Germany
| | - Laurent J Lamarque
- Département des Sciences de l’environnement, Université du Québec à Trois-Rivières, Trois-Rivières, QC G8Z 4M3, Canada
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11
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Keppel G, Sarnow U, Biffin E, Peters S, Fitzgerald D, Boutsalis E, Waycott M, Guerin GR. Population decline in a Pleistocene refugium: Stepwise, drought-related dieback of a South Australian eucalypt. Sci Total Environ 2023; 876:162697. [PMID: 36898535 DOI: 10.1016/j.scitotenv.2023.162697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/03/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Refugia can facilitate the persistence of species under long-term environmental change, but it is not clear if Pleistocene refugia will remain functional as anthropogenic climate change progresses. Dieback in populations restricted to refugia therefore raises concerns about their long-term persistence. Using repeat field surveys, we investigate dieback in an isolated population of Eucalyptus macrorhyncha during two droughts and discuss prospects for its continued persistence in a Pleistocene refugium. We first confirm that the Clare Valley in South Australia has constituted a long-term refugium for the species, with the population being genetically highly distinct from other conspecific populations. However, the population lost >40 % of individuals and biomass through the droughts, with mortality being just below 20 % after the Millennium Drought (2000-2009) and almost 25 % after the Big Dry (2017-2019). The best predictors of mortality differed after each drought. While north-facing aspect of a sampling location was significant positive predictor after both droughts, biomass density and slope were significant negative predictors only after the Millennium Drought, and distance to the north-west corner of the population, which intercepts hot, dry winds, was a significant positive predictor after the Big Dry only. This suggests that more marginal sites with low biomass and sites located on flat plateaus were more vulnerable initially, but that heat-stress was an important driver of dieback during the Big Dry. Therefore, the causative drivers of dieback may change during population decline. Regeneration occurred predominantly on southern and eastern aspects, which would receive the least solar radiation. While this refugial population is experiencing severe decline, some gullies with lower solar radiation appear to support relatively healthy, regenerating stands of red stringybark, providing hope for persistence in small pockets. Monitoring and managing these pockets during future droughts will be essential to ensure the persistence of this isolated and genetically unique population.
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Affiliation(s)
- Gunnar Keppel
- UniSA STEM and Future Industries Institute, University of South Australia, GPO Box 2471, SA 5001 Adelaide, Australia; AMAP, Université de Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, France.
| | - Udo Sarnow
- UniSA STEM and Future Industries Institute, University of South Australia, GPO Box 2471, SA 5001 Adelaide, Australia
| | - Ed Biffin
- State Herbarium of South Australia, Botanic Gardens and State Herbarium, Department for Environment and Water, Adelaide, Australia.
| | - Stefan Peters
- UniSA STEM and Future Industries Institute, University of South Australia, GPO Box 2471, SA 5001 Adelaide, Australia.
| | - Donna Fitzgerald
- UniSA STEM and Future Industries Institute, University of South Australia, GPO Box 2471, SA 5001 Adelaide, Australia.
| | - Evan Boutsalis
- UniSA STEM and Future Industries Institute, University of South Australia, GPO Box 2471, SA 5001 Adelaide, Australia.
| | - Michelle Waycott
- State Herbarium of South Australia, Botanic Gardens and State Herbarium, Department for Environment and Water, Adelaide, Australia.
| | - Greg R Guerin
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.
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12
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Barkaoui K, Volaire F. Drought survival and recovery in grasses: Stress intensity and plant-plant interactions impact plant dehydration tolerance. Plant Cell Environ 2023; 46:1489-1503. [PMID: 36655754 DOI: 10.1111/pce.14543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 01/07/2023] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Plant dehydration tolerance confers drought survival in grasses, but the mortality thresholds according to soil water content (SWC), vapour pressure deficit (VPD) and plant-plant interactions are little explored. We compared the dehydration dynamics of leaf meristems, which are the key surviving organs, plant mortality, and recovery of Mediterranean and temperate populations of two perennial grass species, Dactylis glomerata and Festuca arundinacea, grown in monocultures and mixtures under a low-VPD (1.5 kPa) versus a high-VPD drought (2.2 kPa). The lethal drought index (LD50 ), that is, SWC associated with 50% plant mortality, ranged from 2.87% (ψs = -1.68 MPa) to 2.19% (ψs = -4.47 MPa) and reached the lowest values under the low-VPD drought. Populations of D. glomerata were more dehydration-tolerant (lower LD50 ), survived and recovered better than F. arundinacea populations. Plant-plant interactions modified dehydration tolerance and improved post-drought recovery in mixtures compared with monocultures. Water content as low as 20.7%-36.1% in leaf meristems allowed 50% of plants to survive. We conclude that meristem dehydration causes plant mortality and that drought acclimation can increase dehydration tolerance. Genetic diversity, acclimation and plant-plant interactions are essential sources of dehydration tolerance variability to consider when predicting drought-induced mortality.
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Affiliation(s)
- Karim Barkaoui
- CIRAD, UMR ABSys, F-34398 Montpellier, France
- ABSys, Univ Montpellier, CIHEAM-IAMM, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Florence Volaire
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, INRAE, Montpellier, France
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13
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Tonet V, Carins-Murphy M, Deans R, Brodribb TJ. Deadly acceleration in dehydration of Eucalyptus viminalis leaves coincides with high-order vein cavitation. Plant Physiol 2023; 191:1648-1661. [PMID: 36690460 PMCID: PMC10022613 DOI: 10.1093/plphys/kiad016] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/08/2022] [Accepted: 12/17/2022] [Indexed: 05/17/2023]
Abstract
Xylem cavitation during drought is proposed as a major driver of canopy collapse, but the mechanistic link between hydraulic failure and leaf damage in trees is still uncertain. Here, we used the tree species manna gum (Eucalyptus viminalis) to explore the connection between xylem dysfunction and lethal desiccation in leaves. Cavitation damage to leaf xylem could theoretically trigger lethal desiccation of tissues by severing water supply under scenarios such as runaway xylem cavitation, or the local failure of terminal parts of the leaf vein network. To investigate the role of xylem failure in leaf death, we compared the timing of damage to the photosynthetic machinery (Fv/Fm decline) with changes in plant hydration and xylem cavitation during imposed water stress. The water potential at which Fv/Fm was observed to decline corresponded to the water potential marking a transition from slow to very rapid tissue dehydration. Both events also occurred simultaneously with the initiation of cavitation in leaf high-order veins (HOV, veins from the third order above) and the analytically derived point of leaf runaway hydraulic failure. The close synchrony between xylem dysfunction and the photosynthetic damage strongly points to water supply disruption as the trigger for desiccation of leaves in this hardy evergreen tree. These results indicate that runaway cavitation, possibly triggered by HOV network failure, is the tipping agent determining the vulnerability of E. viminalis leaves to damage during drought and suggest that HOV cavitation and runaway hydraulic failure may play a general role in determining canopy damage in plants.
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Affiliation(s)
- Vanessa Tonet
- School of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania 7001, Australia
| | - Madeline Carins-Murphy
- School of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania 7001, Australia
| | - Ross Deans
- ARC Centre of Excellence in Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
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14
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Wang X, Fan Y, Zhang C, Zhao Y, Du G, Li M, Si B. From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought. Front Plant Sci 2023; 14:1149760. [PMID: 37008484 PMCID: PMC10060868 DOI: 10.3389/fpls.2023.1149760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 02/27/2023] [Indexed: 06/19/2023]
Abstract
INTRODUCTION Parameterizing the process of trees from the comfort zone to mortality during progressive drought is important for, but is not well represented in, vegetation models, given the lack of appropriate indices to gauge the response of trees to droughts. The objective of this study was to determine reliable and readily available tree drought stressindices and the thresholds at which droughts activate important physiological responses. METHODS We analyzed the changes in the transpiration (T), stomatal conductance, xylem conductance, and leaf health status due to a decrease in soil water availability (SWA), predawn xylem water potential (ψpd), and midday xylem water potential (ψmd) in Robinia pseudoacacia seedlings during progressive drought. RESULTS The results showed that ψmd was a better indicator of drought stress than SWA and ψpd, because ψmd was more closely related to the physiological response (defoliation and xylem embolization) during severe drought and could be measured more conveniently. We derived the following five stress levels from the observed responses to decreasing ψmd: comfort zone (ψmd > -0.9 MPa), wherein transpiration and stomatal conductance are not limited by SWA; moderate drought stress (-0.9 to -1.75 MPa), wherein transpiration and stomatal conductance are limited by drought; high drought stress (-1.75 to -2.59 MPa), wherein transpiration decreases significantly (T< 10%) and stomata closes completely; severe drought stress (-2.59 to -4.02 MPa), wherein transpiration ceases (T< 0.1%) and leaf shedding orwilting is > 50%; and extreme drought stress (< -4.02 MPa), leading to tree mortality due to xylem hydraulic failure. DISCUSSION To our knowledge, our scheme is the first to outline the quantitative thresholds for the downregulation of physiological processes in R. pseudoacacia during drought, therefore, can be used to synthesize valuable information for process-based vegetation models.
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Affiliation(s)
- Xia Wang
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Yanli Fan
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Congcong Zhang
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Yihong Zhao
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Guangyuan Du
- College of Science, Northwest A&F University, Yangling, China
| | - Min Li
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Bingcheng Si
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
- Department of Soil Science, University of Saskatchewan, Saskatoon, SK, Canada
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15
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Losso A, Challis A, Gauthey A, Nolan RH, Hislop S, Roff A, Boer MM, Jiang M, Medlyn BE, Choat B. Canopy dieback and recovery in Australian native forests following extreme drought. Sci Rep 2022; 12:21608. [PMID: 36517498 PMCID: PMC9751299 DOI: 10.1038/s41598-022-24833-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
In 2019, south-eastern Australia experienced its driest and hottest year on record, resulting in massive canopy dieback events in eucalypt dominated forests. A subsequent period of high precipitation in 2020 provided a rare opportunity to quantify the impacts of extreme drought and consequent recovery. We quantified canopy health and hydraulic impairment (native percent loss of hydraulic conductivity, PLC) of 18 native tree species growing at 15 sites that were heavily impacted by the drought both during and 8-10 months after the drought. Most species exhibited high PLC during drought (PLC:65.1 ± 3.3%), with no clear patterns across sites or species. Heavily impaired trees (PLC > 70%) showed extensive canopy browning. In the post-drought period, most surviving trees exhibited hydraulic recovery (PLC:26.1 ± 5.1%), although PLC remained high in some trees (50-70%). Regained hydraulic function (PLC < 50%) corresponded to decreased canopy browning indicating improved tree health. Similar drought (37.1 ± 4.2%) and post-drought (35.1 ± 4.4%) percentages of basal area with dead canopy suggested that trees with severely compromised canopies immediately after drought were not able to recover. This dataset provides insights into the impacts of severe natural drought on the health of mature trees, where hydraulic failure is a major contributor in canopy dieback and tree mortality during extreme drought events.
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Affiliation(s)
- Adriano Losso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020, Innsbruck, Austria.
| | - Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Plant Ecology Research Laboratory PERL, Ecole Polytechnique Fédérale de Lausanne EPFL, 1015, Lausanne, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Samuel Hislop
- Forest Science, NSW Department of Primary Industries, Parramatta, NSW, 2150, Australia
| | - Adam Roff
- Department of Planning, Industry and Environment, Remote Sensing and Landscape Science, 26 Honeysuckle Drive, Newcastle, NSW, 2302, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- College of Life Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou, Zhejiang, China
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
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16
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Chen Z, Li S, Wan X, Liu S. Strategies of tree species to adapt to drought from leaf stomatal regulation and stem embolism resistance to root properties. Front Plant Sci 2022; 13:926535. [PMID: 36237513 PMCID: PMC9552884 DOI: 10.3389/fpls.2022.926535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Considerable evidences highlight the occurrence of increasing widespread tree mortality as a result of global climate change-associated droughts. However, knowledge about the mechanisms underlying divergent strategies of various tree species to adapt to drought has remained remarkably insufficient. Leaf stomatal regulation and embolism resistance of stem xylem serves as two important strategies for tree species to prevent hydraulic failure and carbon starvation, as comprising interconnected physiological mechanisms underlying drought-induced tree mortality. Hence, the physiological and anatomical determinants of leaf stomatal regulation and stems xylem embolism resistance are evaluated and discussed. In addition, root properties related to drought tolerance are also reviewed. Species with greater investment in leaves and stems tend to maintain stomatal opening and resist stem embolism under drought conditions. The coordination between stomatal regulation and stem embolism resistance are summarized and discussed. Previous studies showed that hydraulic safety margin (HSM, the difference between minimum water potential and that causing xylem dysfunction) is a significant predictor of tree species mortality under drought conditions. Compared with HSM, stomatal safety margin (the difference between water potential at stomatal closure and that causing xylem dysfunction) more directly merge stomatal regulation strategies with xylem hydraulic strategies, illustrating a comprehensive framework to characterize plant response to drought. A combination of plant traits reflecting species' response and adaptation to drought should be established in the future, and we propose four specific urgent issues as future research priorities.
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Affiliation(s)
- Zhicheng Chen
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
| | - Shan Li
- Department of Environmental Science and Ecology, School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi’an, China
| | - Xianchong Wan
- Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing, China
| | - Shirong Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
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17
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Pritzkow C, Brown MJM, Carins-Murphy MR, Bourbia I, Mitchell PJ, Brodersen C, Choat B, Brodribb TJ. Conduit position and connectivity affect the likelihood of xylem embolism during natural drought in evergreen woodland species. Ann Bot 2022; 130:431-444. [PMID: 35420657 PMCID: PMC9486930 DOI: 10.1093/aob/mcac053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND AIMS Hydraulic failure is considered a main cause of drought-induced forest mortality. Yet, we have a limited understanding of how the varying intensities and long time scales of natural droughts induce and propagate embolism within the xylem. METHODS X-ray computed tomography (microCT) images were obtained from different aged branch xylem to study the number, size and spatial distribution of in situ embolized conduits among three dominant tree species growing in a woodland community. KEY RESULTS Among the three studied tree species, those with a higher xylem vulnerability to embolism (higher water potential at 50 % loss of hydraulic conductance; P50) were more embolized than species with lower P50. Within individual stems, the probability of embolism was independent of conduit diameter but associated with conduit position. Rather than the occurrence of random or radial embolism, we observed circumferential clustering of high and low embolism density, suggesting that embolism spreads preferentially among conduits of the same age. Older xylem also appeared more likely to accumulate embolisms than young xylem, but there was no pattern suggesting that branch tips were more vulnerable to cavitation than basal regions. CONCLUSIONS The spatial analysis of embolism occurrence in field-grown trees suggests that embolism under natural drought probably propagates by air spreading from embolized into neighbouring conduits in a circumferential pattern. This pattern offers the possibility to understand the temporal aspects of embolism occurrence by examining stem cross-sections.
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Affiliation(s)
- Carola Pritzkow
- School of Biology, University of Tasmania, Hobart, TAS, 7005, Australia
| | - Matilda J M Brown
- School of Biology, University of Tasmania, Hobart, TAS, 7005, Australia
| | | | - Ibrahim Bourbia
- School of Biology, University of Tasmania, Hobart, TAS, 7005, Australia
| | | | - Craig Brodersen
- School of the Environment, Yale University, New Haven, CT 06511, USA
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2750, Australia
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18
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Gleason SM, Barnard DM, Green TR, Mackay S, Wang DR, Ainsworth EA, Altenhofen J, Brodribb TJ, Cochard H, Comas LH, Cooper M, Creek D, DeJonge KC, Delzon S, Fritschi FB, Hammer G, Hunter C, Lombardozzi D, Messina CD, Ocheltree T, Stevens BM, Stewart JJ, Vadez V, Wenz J, Wright IJ, Yemoto K, Zhang H. Physiological trait networks enhance understanding of crop growth and water use in contrasting environments. Plant Cell Environ 2022; 45:2554-2572. [PMID: 35735161 DOI: 10.1111/pce.14382] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Plant function arises from a complex network of structural and physiological traits. Explicit representation of these traits, as well as their connections with other biophysical processes, is required to advance our understanding of plant-soil-climate interactions. We used the Terrestrial Regional Ecosystem Exchange Simulator (TREES) to evaluate physiological trait networks in maize. Net primary productivity (NPP) and grain yield were simulated across five contrasting climate scenarios. Simulations achieving high NPP and grain yield in high precipitation environments featured trait networks conferring high water use strategies: deep roots, high stomatal conductance at low water potential ("risky" stomatal regulation), high xylem hydraulic conductivity and high maximal leaf area index. In contrast, high NPP and grain yield was achieved in dry environments with low late-season precipitation via water conserving trait networks: deep roots, high embolism resistance and low stomatal conductance at low leaf water potential ("conservative" stomatal regulation). We suggest that our approach, which allows for the simultaneous evaluation of physiological traits, soil characteristics and their interactions (i.e., networks), has potential to improve our understanding of crop performance in different environments. In contrast, evaluating single traits in isolation of other coordinated traits does not appear to be an effective strategy for predicting plant performance.
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Affiliation(s)
- Sean M Gleason
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Dave M Barnard
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Timothy R Green
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Scott Mackay
- Department of Geography & Department of Environment and Sustainability, University at Buffalo, Buffalo, New York, USA
| | - Diane R Wang
- Department of Agronomy, Purdue University, West Lafayette, Indiana, USA
| | - Elizabeth A Ainsworth
- United States Department of Agriculture, Global Change and Photosynthesis Research Unit, Agricultural Research Service, Urbana, Illinois, USA
| | - Jon Altenhofen
- Northern Colorado Water Conservancy District, Berthoud, Colorado, USA
| | - Timothy J Brodribb
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
- Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, The University of Tasmania Node, Hobart, Tasmania, Australia
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, France
| | - Louise H Comas
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Mark Cooper
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland, Australia
- Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland Node, St. Lucia, Queensland, Australia
| | - Danielle Creek
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, France
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Kendall C DeJonge
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Sylvain Delzon
- Université Bordeaux, INRAE, BIOGECO, Pessac, cedex, France
| | - Felix B Fritschi
- Division of Plant Science and Technology, University of Missouri, Columbia, Missouri, USA
| | - Graeme Hammer
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland, Australia
- Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland Node, St. Lucia, Queensland, Australia
| | - Cameron Hunter
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Danica Lombardozzi
- National Center for Atmospheric Research (NCAR), Climate & Global Dynamics Lab, Boulder, Colorado, USA
| | - Carlos D Messina
- Department of Horticultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Troy Ocheltree
- Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, Colorado, USA
| | - Bo Maxwell Stevens
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Jared J Stewart
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
- Department of Ecology & Evolutionary Biology, University of Colorado, Boulder, Colorado, USA
| | | | - Joshua Wenz
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Ian J Wright
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
- Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, Western Sydney University Node, Penrith, New South Wales, Australia
| | - Kevin Yemoto
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
| | - Huihui Zhang
- United States Department of Agriculture, Water Management and Systems Research Unit, Agricultural Research Service, Fort Collins, Colorado, USA
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19
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Levionnois S, Kaack L, Heuret P, Abel N, Ziegler C, Coste S, Stahl C, Jansen S. Pit characters determine drought-induced embolism resistance of leaf xylem across 18 Neotropical tree species. Plant Physiol 2022; 190:371-386. [PMID: 35567500 PMCID: PMC9434246 DOI: 10.1093/plphys/kiac223] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/19/2022] [Indexed: 05/16/2023]
Abstract
Embolism spreading in xylem is an important component of plant drought resistance. Since embolism resistance has been shown to be mechanistically linked to pit membrane characters in stem xylem, we speculate that similar mechanisms account for leaf xylem. We conducted transmission electron microscopy to investigate pit membrane characters in leaf xylem across 18 Neotropical tree species. We also conducted gold perfusion and polar lipid detection experiments on three species covering the full range of leaf embolism resistance. We then related these observations to previously published data on embolism resistance of leaf xylem. We also incorporated previously published data on stem embolism resistance and stem xylem pit membranes to investigate the link between vulnerability segmentation (i.e. difference in embolism resistance) and leaf-stem anatomical variation. Maximum pit membrane thickness (Tpm,max) and the pit membrane thickness-to-diameter ratio (Tpm,max/Dpm) were predictive of leaf embolism resistance, especially when vestured pits were taken into account. Variation in Tpm,max/Dpm was the only trait predictive of vulnerability segmentation between leaves and stems. Gold particles of 5- and 10-nm infiltrated pit membranes in three species, while the entry of 50-nm particles was blocked. Moreover, polar lipids were associated with inner conduit walls and pits. Our results suggest that mechanisms related to embolism spreading are determined by Tpm, pore constrictions (i.e. the narrowest bottlenecks along pore pathways), and lipid surfactants, which are largely similar between leaf and stem xylem and between temperate and tropical trees. However, our mechanistic understanding of embolism propagation and the functional relevance of Tpm,max/Dpm remains elusive.
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Affiliation(s)
| | - Lucian Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Ulm D-89081, Germany
| | | | - Nina Abel
- Institute of Systematic Botany and Ecology, Ulm University, Ulm D-89081, Germany
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, Nancy 54000, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
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20
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Hajek P, Link RM, Nock CA, Bauhus J, Gebauer T, Gessler A, Kovach K, Messier C, Paquette A, Saurer M, Scherer-Lorenzen M, Rose L, Schuldt B. Mutually inclusive mechanisms of drought-induced tree mortality. Glob Chang Biol 2022; 28:3365-3378. [PMID: 35246895 DOI: 10.1111/gcb.16146] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Unprecedented tree dieback across Central Europe caused by recent global change-type drought events highlights the need for a better mechanistic understanding of drought-induced tree mortality. Although numerous physiological risk factors have been identified, the importance of two principal mechanisms, hydraulic failure and carbon starvation, is still debated. It further remains largely unresolved how the local neighborhood composition affects individual mortality risk. We studied 9435 young trees of 12 temperate species planted in a diversity experiment in 2013 to assess how hydraulic traits, carbon dynamics, pest infestation, tree height and neighborhood competition influence individual mortality risk. Following the most extreme global change-type drought since record in 2018, one third of these trees died. Across species, hydraulic safety margins (HSMs) were negatively and a shift towards a higher sugar fraction in the non-structural carbohydrate (NSC) pool positively associated with mortality risk. Moreover, trees infested by bark beetles had a higher mortality risk, and taller trees a lower mortality risk. Most neighborhood interactions were beneficial, although neighborhood effects were highly species-specific. Species that suffered more from drought, especially Larix spp. and Betula spp., tended to increase the survival probability of their neighbors and vice versa. While severe tissue dehydration marks the final stage of drought-induced tree mortality, we show that hydraulic failure is interrelated with a series of other, mutually inclusive processes. These include shifts in NSC pools driven by osmotic adjustment and/or starch depletion as well as pest infestation and are modulated by the size and species identity of a tree and its neighbors. A more holistic view that accounts for multiple causes of drought-induced tree mortality is required to improve predictions of trends in global forest dynamics and to identify mutually beneficial species combinations.
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Affiliation(s)
- Peter Hajek
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Roman M Link
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
| | - Charles A Nock
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Freiburg, Germany
| | - Tobias Gebauer
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
- ETH Zurich, Institute of Terrestrial Ecosystems, Zurich, Switzerland
| | - Kyle Kovach
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Christian Messier
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
- University of Quebec in Outaouais (UQO), Institut des Sciences de la Forêt Tempérée (ISFORT), Gatineau, Quebec, Canada
| | - Alain Paquette
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | | | - Laura Rose
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Bernhard Schuldt
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
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21
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Hajek P, Link RM, Nock CA, Bauhus J, Gebauer T, Gessler A, Kovach K, Messier C, Paquette A, Saurer M, Scherer-Lorenzen M, Rose L, Schuldt B. Mutually inclusive mechanisms of drought-induced tree mortality. Glob Chang Biol 2022; 28:3365-3378. [PMID: 35246895 DOI: 10.1101/2020.12.17.423038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/16/2021] [Indexed: 05/22/2023]
Abstract
Unprecedented tree dieback across Central Europe caused by recent global change-type drought events highlights the need for a better mechanistic understanding of drought-induced tree mortality. Although numerous physiological risk factors have been identified, the importance of two principal mechanisms, hydraulic failure and carbon starvation, is still debated. It further remains largely unresolved how the local neighborhood composition affects individual mortality risk. We studied 9435 young trees of 12 temperate species planted in a diversity experiment in 2013 to assess how hydraulic traits, carbon dynamics, pest infestation, tree height and neighborhood competition influence individual mortality risk. Following the most extreme global change-type drought since record in 2018, one third of these trees died. Across species, hydraulic safety margins (HSMs) were negatively and a shift towards a higher sugar fraction in the non-structural carbohydrate (NSC) pool positively associated with mortality risk. Moreover, trees infested by bark beetles had a higher mortality risk, and taller trees a lower mortality risk. Most neighborhood interactions were beneficial, although neighborhood effects were highly species-specific. Species that suffered more from drought, especially Larix spp. and Betula spp., tended to increase the survival probability of their neighbors and vice versa. While severe tissue dehydration marks the final stage of drought-induced tree mortality, we show that hydraulic failure is interrelated with a series of other, mutually inclusive processes. These include shifts in NSC pools driven by osmotic adjustment and/or starch depletion as well as pest infestation and are modulated by the size and species identity of a tree and its neighbors. A more holistic view that accounts for multiple causes of drought-induced tree mortality is required to improve predictions of trends in global forest dynamics and to identify mutually beneficial species combinations.
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Affiliation(s)
- Peter Hajek
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Roman M Link
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
| | - Charles A Nock
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Freiburg, Germany
| | - Tobias Gebauer
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
- ETH Zurich, Institute of Terrestrial Ecosystems, Zurich, Switzerland
| | - Kyle Kovach
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Christian Messier
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
- University of Quebec in Outaouais (UQO), Institut des Sciences de la Forêt Tempérée (ISFORT), Gatineau, Quebec, Canada
| | - Alain Paquette
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | | | - Laura Rose
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Bernhard Schuldt
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
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22
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Challis A, Blackman C, Ahrens C, Medlyn B, Rymer P, Tissue D. Adaptive plasticity in plant traits increases time to hydraulic failure under drought in a foundation tree. Tree Physiol 2022; 42:708-721. [PMID: 34312674 DOI: 10.1093/treephys/tpab096] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The viability of forest trees, in response to climate change-associated drought, will depend on their capacity to survive through genetic adaptation and phenotypic plasticity in drought tolerance traits. Genotypes with enhanced plasticity for drought tolerance (adaptive plasticity) will have a greater ability to persist and delay the onset of hydraulic failure. By examining populations from different climate-origins grown under contrasting soil water availability, we tested for genotype (G), environment (E) and genotype-by-environment (G × E) effects on traits that determine the time it takes for saplings to desiccate from stomatal closure to 88% loss of stem hydraulic conductance (time to hydraulic failure, THF). Specifically, we hypothesized that: (i) THF is dependent on a G × E interaction, with longer THF for warm, dry climate populations in response to chronic water deficit treatment compared with cool, wet populations, and (ii) hydraulic and allometric traits explain the observed patterns in THF. Corymbia calophylla saplings from two populations originating from contrasting climates (warm-dry or cool-wet) were grown under well-watered and chronic soil water deficit treatments in large containers. Hydraulic and allometric traits were measured and then saplings were dried-down to critical levels of drought stress to estimate THF. Significant plasticity was detected in the warm-dry population in response to water-deficit, with enhanced drought tolerance compared with the cool-wet population. Projected leaf area and total plant water storage showed treatment variation, and minimum conductance showed significant population differences driving longer THF in trees from warm-dry origins grown in water-limited conditions. Our findings contribute information on intraspecific variation in key drought traits, including hydraulic and allometric determinants of THF. It highlights the need to quantify adaptive capacity in populations of forest trees in climate change-type drought to improve predictions of forest die-back.
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Affiliation(s)
- Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Chris Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- School of Biological Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Collin Ahrens
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Belinda Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Paul Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
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23
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Lira-Martins D, Quesada CA, Strekopytov S, Humphreys-Williams E, Herault B, Lloyd J. Wood Nutrient-Water-Density Linkages Are Influenced by Both Species and Environment. Front Plant Sci 2022; 13:778403. [PMID: 35444675 PMCID: PMC9014131 DOI: 10.3389/fpls.2022.778403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Tropical trees store a large amount of nutrients in their woody tissues, thus triggering the question of what the functional association of these elements with other wood traits is. Given the osmotic activity of mineral elements such as potassium, sodium, and calcium, these elements should be strong candidates in mediating the water storing capacity in tropical trees. We investigated the role of wood nutrients in facilitating wood water storage in trees by using branch samples from 48 tropical tree species in South America and examined their associations with wood density (ρ). Wood density varied from 316 kg/m3 in Peru plots, where the soil nutrient status is relatively higher, to 908 kg/m3 in Brazil plots, where the nutrient availability is lower. Phosphorus content in wood varied significantly between plots with lowest values found in French Guiana (1.2 mol/m3) and plots with highest values found in Peru (43.6 mol/m3). Conversely, potassium in woody tissues showed a significant cross-species variation with Minquartia guianensis in Brazil showing the lowest values (8.8 mol/m3) and with Neea divaricata in Peru having the highest values (114 mol/m3). We found that lower wood density trees store more water in their woody tissues with cations, especially potassium, having a positive association with water storage. Specific relationships between wood cation concentrations and stem water storage potential nevertheless depend on both species' identity and growing location. Tropical trees with increased water storage capacity show lower wood density and have an increased reliance on cations to regulate this reservoir. Our study highlights that cations play a more important role in tropical tree water relations than has previously been thought, with potassium being particularly important.
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Affiliation(s)
- Demetrius Lira-Martins
- Department of Life Sciences, Imperial College London, London, United Kingdom
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Carlos Alberto Quesada
- Coordination of Environmental Dynamics, National Institute for Amazonian Research (INPA), Manaus, Brazil
| | - Stanislav Strekopytov
- Imaging and Analysis Centre, Natural History Museum, London, United Kingdom
- National Measurement Laboratory, LGC, Teddington, United Kingdom
| | | | - Bruno Herault
- UR Forests and Societies, Centre de Coopération Internationale en Recherche Agronomique Pour le Développement (Cirad), Montpellier, France
- Université de Montpellier, Montpellier, France
- Institut National Polytechnique Félix Houphouët-Boigny, Yamoussoukro, Ivory Coast
| | - Jon Lloyd
- Department of Life Sciences, Imperial College London, London, United Kingdom
- Centre for Tropical, Environmental and Sustainability Sciences, College of Science and Engineering, James Cook University, Smithfield, QLD, Australia
- Faculdade de Filosofia, Ciencias e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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24
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Li X, Xi B, Wu X, Choat B, Feng J, Jiang M, Tissue D. Unlocking Drought-Induced Tree Mortality: Physiological Mechanisms to Modeling. Front Plant Sci 2022; 13:835921. [PMID: 35444681 PMCID: PMC9015645 DOI: 10.3389/fpls.2022.835921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
Drought-related tree mortality has become a major concern worldwide due to its pronounced negative impacts on the functioning and sustainability of forest ecosystems. However, our ability to identify the species that are most vulnerable to drought, and to pinpoint the spatial and temporal patterns of mortality events, is still limited. Model is useful tools to capture the dynamics of vegetation at spatiotemporal scales, yet contemporary land surface models (LSMs) are often incapable of predicting the response of vegetation to environmental perturbations with sufficient accuracy, especially under stressful conditions such as drought. Significant progress has been made regarding the physiological mechanisms underpinning plant drought response in the past decade, and plant hydraulic dysfunction has emerged as a key determinant for tree death due to water shortage. The identification of pivotal physiological events and relevant plant traits may facilitate forecasting tree mortality through a mechanistic approach, with improved precision. In this review, we (1) summarize current understanding of physiological mechanisms leading to tree death, (2) describe the functionality of key hydraulic traits that are involved in the process of hydraulic dysfunction, and (3) outline their roles in improving the representation of hydraulic function in LSMs. We urge potential future research on detailed hydraulic processes under drought, pinpointing corresponding functional traits, as well as understanding traits variation across and within species, for a better representation of drought-induced tree mortality in models.
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Affiliation(s)
- Ximeng Li
- College of Life and Environmental Science, Minzu University of China, Beijing, China
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Benye Xi
- Ministry of Education Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing, China
| | - Xiuchen Wu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Jinchao Feng
- College of Life and Environmental Science, Minzu University of China, Beijing, China
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
- Global Centre for Land-based Innovation, Western Sydney University, Richmond, NSW, Australia
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25
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Griebel A, Peters JMR, Metzen D, Maier C, Barton CVM, Speckman HN, Boer MM, Nolan RH, Choat B, Pendall E. Tapping into the physiological responses to mistletoe infection during heat and drought stress. Tree Physiol 2022; 42:523-536. [PMID: 34612494 DOI: 10.1093/treephys/tpab113] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Mistletoes are important co-contributors to tree mortality globally, particularly during droughts. In Australia, mistletoe distributions are expanding in temperate woodlands, while their hosts have experienced unprecedented heat and drought stress in recent years. We investigated whether the excessive water use of mistletoes increased the probability of xylem emboli in a mature woodland during the recent record drought that was compounded by multiple heatwaves. We continuously recorded transpiration ($T_{SLA}$) of infected and uninfected branches from two eucalypt species over two summers, monitored stem and leaf water potentials ($\Psi $) and used hydraulic vulnerability curves to estimate percent loss in conductivity (PLC) for each species. Variations in weather (vapor pressure deficit, photosynthetically active radiation, soil water content), host species and % mistletoe foliage explained 78% of hourly $T_{SLA}$. While mistletoe acted as an uncontrollable sink for water in the host even during typical summer days, daily $T_{SLA}$ increased up to 4-fold in infected branches on hot days, highlighting the previously overlooked importance of temperature stress in amplifying water loss in mistletoes. The increased water use of mistletoes resulted in significantly decreased host $\Psi _{\rm{leaf}}$ and $\Psi _{\rm{trunk}}$. It further translated to an estimated increase of up to 11% PLC for infected hosts, confirming greater hydraulic dysfunction of infected trees that place them at higher risk of hydraulic failure. However, uninfected branches of Eucalyptus fibrosa F.Muell. had much tighter controls on water loss than uninfected branches of Eucalyptus moluccana Roxb., which shifted the risk of hydraulic failure towards an increased risk of carbon starvation for E. fibrosa. The contrasting mechanistic responses to heat and drought stress between both co-occurring species demonstrates the complexity of host-parasite interactions and highlights the challenge in predicting species-specific responses to biotic agents in a warmer and drier climate.
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Affiliation(s)
- Anne Griebel
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Jennifer M R Peters
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
- Climate Change Science Institute & Environmental Science Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA
| | - Daniel Metzen
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Chelsea Maier
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Craig V M Barton
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Heather N Speckman
- Department of Botany, University of Wyoming, 1000 E. Univ. Ave, Laramie, WY 82071, USA
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
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26
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Britton TG, Brodribb TJ, Richards SA, Ridley C, Hovenden MJ. Canopy damage during a natural drought depends on species identity, physiology and stand composition. New Phytol 2022; 233:2058-2070. [PMID: 34850394 DOI: 10.1111/nph.17888] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Vulnerability to xylem cavitation is a strong predictor of drought-induced damage in forest communities. However, biotic features of the community itself can influence water availability at the individual tree-level, thereby modifying patterns of drought damage. Using an experimental forest in Tasmania, Australia, we determined the vulnerability to cavitation (leaf P50 ) of four tree species and assessed the drought-induced canopy damage of 2944 6-yr-old trees after an extreme natural drought episode. We examined how individual damage was related to their size and the density and species identity of neighbouring trees. The two co-occurring dominant tree species, Eucalyptus delegatensis and Eucalyptus regnans, were the most vulnerable to drought-induced xylem cavitation and both species suffered significantly greater damage than neighbouring, subdominant species Pomaderris apetala and Acacia dealbata. While the two eucalypts had similar leaf P50 values, E. delegatensis suffered significantly greater damage, which was strongly related to the density of neighbouring P. apetala. Damage in E. regnans was less impacted by neighbouring plants and smaller trees of both eucalypts sustained significantly more damage than larger trees. Our findings demonstrate that natural drought damage is influenced by individual plant physiology as well as the composition, physiology and density of the surrounding stand.
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Affiliation(s)
- Travis G Britton
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Timothy J Brodribb
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Shane A Richards
- School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Chantelle Ridley
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
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27
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Harrison PA, Camarretta N, Krisanski S, Bailey TG, Davidson NJ, Bain G, Hamer R, Gardiner R, Proft K, Taskhiri MS, Turner P, Turner D, Lucieer A. From communities to individuals: Using remote sensing to inform and monitor woodland restoration. Eco Management Restoration 2021. [DOI: 10.1111/emr.12505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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28
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Lemaire C, Blackman CJ, Cochard H, Menezes-Silva PE, Torres-Ruiz JM, Herbette S. Acclimation of hydraulic and morphological traits to water deficit delays hydraulic failure during simulated drought in poplar. Tree Physiol 2021; 41:2008-2021. [PMID: 34259313 DOI: 10.1093/treephys/tpab086] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 07/07/2021] [Indexed: 05/27/2023]
Abstract
The capacity of trees to tolerate and survive increasing drought conditions in situ will depend in part on their ability to acclimate (via phenotypic plasticity) key hydraulic and morphological traits that increase drought tolerance and delay the onset of drought-induced hydraulic failure. However, the effect of water-deficit acclimation in key traits that determine time to hydraulic failure (THF) during extreme drought remains largely untested. We measured key hydraulic and morphological traits in saplings of a hybrid poplar grown under well-watered and water-limited conditions. The time for plants to dry-down to critical levels of water stress (90% loss of stem hydraulic conductance), as well as the relative contribution of drought acclimation in each trait to THF, was simulated using a soil-plant hydraulic model (SurEau). Compared with controls, water-limited plants exhibited significantly lower stem hydraulic vulnerability (P50stem), stomatal conductance and total canopy leaf area (LA). Taken together, adjustments in these and other traits resulted in longer modelled THF in water-limited (~160 h) compared with well-watered plants (~50 h), representing an increase of more than 200%. Sensitivity analysis revealed that adjustment in P50stem and LA contributed the most to longer THF in water-limited plants. We observed a high degree of trait plasticity in poplar saplings in response to water-deficit growth conditions, with decreases in stem hydraulic vulnerability and leaf area playing a key role in delaying the onset of hydraulic failure during a simulated drought event. These findings suggest that understanding the capacity of plants to acclimate to antecedent growth conditions will enable better predictions of plant survivorship during future drought.
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Affiliation(s)
- Cédric Lemaire
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand F-63000, France
| | - Chris J Blackman
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand F-63000, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand F-63000, France
| | - Paulo Eduardo Menezes-Silva
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand F-63000, France
- Department of Biology, Goiano Federal Institute of Education, Science and Technology-IF Goiano, Rio Verde, Goiás, Brazil
| | - José M Torres-Ruiz
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand F-63000, France
| | - Stéphane Herbette
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand F-63000, France
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Abstract
We examine the evidence linking species’ traits to contemporary range shifts and find they are poor predictors of range shifts that have occurred over decades to a century. We then discuss reasons for the poor performance of traits for describing interspecific variation in range shifts from two perspectives: ( a) factors associated with species’ traits that degrade range-shift signals stemming from the measures used for species’ traits, traits that are typically not analyzed, and the influence of phylogeny on range-shift potential and ( b) issues in quantifying range shifts and relating them to species’ traits due to imperfect detection of species, differences in the responses of altitudinal and latitudinal ranges, and emphasis on testing linear relationships between traits and range shifts instead of nonlinear responses. Improving trait-based approaches requires a recognition that traits within individuals interact in unexpected ways and that different combinations of traits may be functionally equivalent.
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Affiliation(s)
- Steven R. Beissinger
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, California 94720, USA
| | - Eric A. Riddell
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50050, USA
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30
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Nadal-Sala D, Grote R, Birami B, Knüver T, Rehschuh R, Schwarz S, Ruehr NK. Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress. Front Plant Sci 2021; 12:715127. [PMID: 34539705 PMCID: PMC8448192 DOI: 10.3389/fpls.2021.715127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/08/2021] [Indexed: 06/01/2023]
Abstract
During drought, trees reduce water loss and hydraulic failure by closing their stomata, which also limits photosynthesis. Under severe drought stress, other acclimation mechanisms are trigged to further reduce transpiration to prevent irreversible conductance loss. Here, we investigate two of them: the reversible impacts on the photosynthetic apparatus, lumped as non-stomatal limitations (NSL) of photosynthesis, and the irreversible effect of premature leaf shedding. We integrate NSL and leaf shedding with a state-of-the-art tree hydraulic simulation model (SOX+) and parameterize them with example field measurements to demonstrate the stress-mitigating impact of these processes. We measured xylem vulnerability, transpiration, and leaf litter fall dynamics in Pinus sylvestris (L.) saplings grown for 54 days under severe dry-down. The observations showed that, once transpiration stopped, the rate of leaf shedding strongly increased until about 30% of leaf area was lost on average. We trained the SOX+ model with the observations and simulated changes in root-to-canopy conductance with and without including NSL and leaf shedding. Accounting for NSL improved model representation of transpiration, while model projections about root-to-canopy conductance loss were reduced by an overall 6%. Together, NSL and observed leaf shedding reduced projected losses in conductance by about 13%. In summary, the results highlight the importance of other than purely stomatal conductance-driven adjustments of drought resistance in Scots pine. Accounting for acclimation responses to drought, such as morphological (leaf shedding) and physiological (NSL) adjustments, has the potential to improve tree hydraulic simulation models, particularly when applied in predicting drought-induced tree mortality.
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Affiliation(s)
- Daniel Nadal-Sala
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Rüdiger Grote
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Benjamin Birami
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
- University of Bayreuth, Chair of Plant Ecology, Bayreuth, Germany
| | - Timo Knüver
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Romy Rehschuh
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Selina Schwarz
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Nadine K. Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
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31
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Guillemot J, Asensio V, Bordron B, Nouvellon Y, le Maire G, Bouillet JP, Domec JC, Delgado Rojas JS, Abreu-Junior CH, Battie-Laclau P, Cornut I, Germon A, De Moraes Gonçalves JL, Robin A, Laclau JP. Increased hydraulic constraints in Eucalyptus plantations fertilized with potassium. Plant Cell Environ 2021; 44:2938-2950. [PMID: 34033133 DOI: 10.1111/pce.14102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
Fertilization is commonly used to increase growth in forest plantations, but it may also affect tree water relations and responses to drought. Here, we measured changes in biomass, transpiration, sapwood-to-leaf area ratio (As :Al ) and sap flow driving force (ΔΨ) during the 6-year rotation of tropical plantations of Eucalyptus grandis under controlled conditions for throughfall and potassium (K) fertilization. K fertilization increased final tree height by 8 m. Throughfall exclusion scarcely affected tree functioning because of deep soil water uptake. Tree growth increased in K-supplied plots and remained stable in K-depleted plots as tree height increased, while growth per unit leaf area increased in all plots. Stand transpiration and hydraulic conductance standardized per leaf area increased with height in K-depleted plots, but remained stable or decreased in K-supplied plots. Greater Al in K-supplied plots increased the hydraulic constraints on water use. This involved a direct mechanism through halved As :Al in K-supplied plots relative to K-depleted plots, and an indirect mechanism through deteriorated water status in K-supplied plots, which prevented the increase in ΔΨ with tree height. K fertilization in tropical plantations reduces the hydraulic compensation to growth, which could increase the risk of drought-induced dieback under climate change.
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Affiliation(s)
- Joannès Guillemot
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
| | - Verónica Asensio
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
- Center of Nuclear Energy in Agriculture, Universidade de São Paulo (USP-CENA), Piracicaba, Brazil
- Edafotec SL, Vigo, Spain
| | - Bruno Bordron
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
| | - Yann Nouvellon
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
| | - Guerric le Maire
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- NIPE, UNICAMP, Campinas, Brazil
| | - Jean-Pierre Bouillet
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
| | - Jean-Christophe Domec
- Bordeaux Sciences Agro, UMR INRAe-ISPA 1391, Gradignan, France
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Juan Sinforiano Delgado Rojas
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
| | | | - Patricia Battie-Laclau
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
- Center of Nuclear Energy in Agriculture, Universidade de São Paulo (USP-CENA), Piracicaba, Brazil
| | - Ivan Cornut
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Amandine Germon
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- School of Agricultural Sciences, UNESP-São Paulo State University, Botucatu, Brazil
| | | | - Agnès Robin
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
- Department of Forest Sciences, Universidade de São Paulo, "Luiz de Queiroz" College of Agriculture (USP-ESALQ), Piracicaba, Brazil
- School of Agricultural Sciences, UNESP-São Paulo State University, Botucatu, Brazil
| | - Jean-Paul Laclau
- CIRAD, UMR Eco&Sols, Montpellier, France
- Eco&Sols, Univ Montpellier, CIRAD, INRAe, IRD, Montpellier SupAgro, Montpellier, France
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32
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Chen YJ, Choat B, Sterck F, Maenpuen P, Katabuchi M, Zhang SB, Tomlinson KW, Oliveira RS, Zhang YJ, Shen JX, Cao KF, Jansen S. Hydraulic prediction of drought-induced plant dieback and top-kill depends on leaf habit and growth form. Ecol Lett 2021; 24:2350-2363. [PMID: 34409716 DOI: 10.1111/ele.13856] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 04/19/2021] [Accepted: 07/11/2021] [Indexed: 01/05/2023]
Abstract
Hydraulic failure caused by severe drought contributes to aboveground dieback and whole-plant death. The extent to which dieback or whole-plant death can be predicted by plant hydraulic traits has rarely been tested among species with different leaf habits and/or growth forms. We investigated 19 hydraulic traits in 40 woody species in a tropical savanna and their potential correlations with drought response during an extreme drought event during the El Niño-Southern Oscillation in 2015. Plant hydraulic trait variation was partitioned substantially by leaf habit but not growth form along a trade-off axis between traits that support drought tolerance versus avoidance. Semi-deciduous species and shrubs had the highest branch dieback and top-kill (complete aboveground death) among the leaf habits or growth forms. Dieback and top-kill were well explained by combining hydraulic traits with leaf habit and growth form, suggesting integrating life history traits with hydraulic traits will yield better predictions.
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Affiliation(s)
- Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Yunnan, China.,Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan, China.,Forest Ecology and Forest Management Group, Wageningen University and Research, Wageningen, the Netherlands
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Frank Sterck
- Forest Ecology and Forest Management Group, Wageningen University and Research, Wageningen, the Netherlands
| | - Phisamai Maenpuen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Masatoshi Katabuchi
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan, China
| | - Kyle W Tomlinson
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, CP6109, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, Maine, USA
| | - Jing-Xian Shen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.,Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan, China
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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33
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Arend M, Link RM, Patthey R, Hoch G, Schuldt B, Kahmen A. Rapid hydraulic collapse as cause of drought-induced mortality in conifers. Proc Natl Acad Sci U S A 2021; 118:e2025251118. [PMID: 33846261 DOI: 10.1073/pnas.2025251118] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the vulnerability of trees to drought-induced mortality is key to predicting the fate of forests in a future climate with more frequent and intense droughts, although the underlying mechanisms are difficult to study in adult trees. Here, we explored the dynamic changes of water relations and limits of hydraulic function in dying adults of Norway spruce (Picea abies L.) during the progression of the record-breaking 2018 Central European drought. In trees on the trajectory to drought-induced mortality, we observed rapid, nonlinear declines of xylem pressure that commenced at the early onset of xylem cavitation and caused a complete loss of xylem hydraulic conductance within a very short time. We also observed severe depletions of nonstructural carbohydrates, though carbon starvation could be ruled out as the cause of the observed tree death, as both dying and surviving trees showed these metabolic limitations. Our observations provide striking field-based evidence for fast dehydration and hydraulic collapse as the cause of drought-induced mortality in adult Norway spruce. The nonlinear decline of tree water relations suggests that considering the temporal dynamics of dehydration is critical for predicting tree death. The collapse of the hydraulic system within a short time demonstrates that trees can rapidly be pushed out of the zone of hydraulic safety during the progression of a severe drought. In summary, our findings point toward a higher mortality risk for Norway spruce than previously assumed, which is in line with current reports of unprecedented levels of drought-induced mortality in this major European tree species.
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34
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López R, Cano FJ, Martin-StPaul NK, Cochard H, Choat B. Coordination of stem and leaf traits define different strategies to regulate water loss and tolerance ranges to aridity. New Phytol 2021; 230:497-509. [PMID: 33452823 DOI: 10.1111/nph.17185] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/31/2020] [Indexed: 06/12/2023]
Abstract
Adaptation to drought involves complex interactions of traits that vary within and among species. To date, few data are available to quantify within-species variation in functional traits and they are rarely integrated into mechanistic models to improve predictions of species response to climate change. We quantified intraspecific variation in functional traits of two Hakea species growing along an aridity gradient in southeastern Australia. Measured traits were later used to parameterise the model SurEau to simulate a transplantation experiment to identify the limits of drought tolerance. Embolism resistance varied between species but not across populations. Instead, populations adjusted to drier conditions via contrasting sets of trait trade-offs that facilitated homeostasis of plant water status. The species from relatively mesic climate, Hakea dactyloides, relied on tight stomatal control whereas the species from xeric climate, Hakea leucoptera dramatically increased Huber value and leaf mass per area, while leaf area index (LAI) and epidermal conductance (gmin ) decreased. With trait variability, SurEau predicts the plasticity of LAI and gmin buffers the impact of increasing aridity on population persistence. Knowledge of within-species variability in multiple drought tolerance traits will be crucial to accurately predict species distributional limits.
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Affiliation(s)
- Rosana López
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Madrid, 28040, Spain
| | - Francisco Javier Cano
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | | | - Hervé Cochard
- Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, 63000, France
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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35
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Liang X, Ye Q, Liu H, Brodribb TJ. Wood density predicts mortality threshold for diverse trees. New Phytol 2021; 229:3053-3057. [PMID: 33251581 DOI: 10.1111/nph.17117] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/20/2020] [Indexed: 05/16/2023]
Affiliation(s)
- Xingyun Liang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Guangzhou, 510650, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Guangzhou, 510650, China
- College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Rd., Nansha District, Guangzhou, 511458, China
| | - Hui Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Guangzhou, 510650, China
| | - Timothy J Brodribb
- School of Biological Sciences, University of Tasmania, TAS, Private Bag 55, Hobart, 7001, Australia
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36
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Corrigendum. New Phytol 2020; 229:1822-3. [PMID: 33616934 DOI: 10.1111/nph.16991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 06/12/2023]
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37
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Liu X, Zhang Q, Song M, Wang N, Fan P, Wu P, Cui K, Zheng P, Du N, Wang H, Wang R. Physiological Responses of Robinia pseudoacacia and Quercus acutissima Seedlings to Repeated Drought-Rewatering Under Different Planting Methods. Front Plant Sci 2021; 12:760510. [PMID: 34938307 PMCID: PMC8685255 DOI: 10.3389/fpls.2021.760510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/08/2021] [Indexed: 05/03/2023]
Abstract
Changing precipitation patterns have aggravated the existing uneven water distribution, leading to the alternation of drought and rewatering. Based on this variation, we studied species, namely, Robinia pseudoacacia and Quercus acutissima, with different root forms and water regulation strategy to determine physiological responses to repeated drought-rewatering under different planting methods. Growth, physiological, and hydraulic traits were measured using pure and mixed planting seedlings that were subjected to drought, repeated drought-rewatering (i.e., treatments), and well-irrigated seedlings (i.e., control). Drought had negative effects on plant functional traits, such as significantly decreased xylem water potential (Ψmd), net photosynthetic rate (AP), and then height and basal diameter growth were slowed down, while plant species could form stress imprint and adopt compensatory mechanism after repeated drought-rewatering. Mixed planting of the two tree species prolonged the desiccation time during drought, slowed down Ψmd and AP decreasing, and after rewatering, plant functional traits could recover faster than pure planting. Our results demonstrate that repeated drought-rewatering could make plant species form stress imprint and adopt compensatory mechanism, while mixed planting could weaken the inhibition of drought and finally improve the overall drought resistance; this mechanism may provide a theoretical basis for afforestation and vegetation restoration in the warm temperate zone under rising uneven spatiotemporal water distribution.
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Affiliation(s)
- Xiao Liu
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Qinyuan Zhang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Meixia Song
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | | | - Pan Wu
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Kening Cui
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Peiming Zheng
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Du
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Hui Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- *Correspondence: Hui Wang,
| | - Renqing Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
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38
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Levionnois S, Ziegler C, Jansen S, Calvet E, Coste S, Stahl C, Salmon C, Delzon S, Guichard C, Heuret P. Vulnerability and hydraulic segmentations at the stem-leaf transition: coordination across Neotropical trees. New Phytol 2020; 228:512-524. [PMID: 32496575 DOI: 10.1111/nph.16723] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/18/2020] [Indexed: 05/23/2023]
Abstract
Hydraulic segmentation at the stem-leaf transition predicts higher hydraulic resistance in leaves than in stems. Vulnerability segmentation, however, predicts lower embolism resistance in leaves. Both mechanisms should theoretically favour runaway embolism in leaves to preserve expensive organs such as stems, and should be tested for any potential coordination. We investigated the theoretical leaf-specific conductivity based on an anatomical approach to quantify the degree of hydraulic segmentation across 21 tropical rainforest tree species. Xylem resistance to embolism in stems (flow-centrifugation technique) and leaves (optical visualization method) was quantified to assess vulnerability segmentation. We found a pervasive hydraulic segmentation across species, but with a strong variability in the degree of segmentation. Despite a clear continuum in the degree of vulnerability segmentation, eight species showed a positive vulnerability segmentation (leaves less resistant to embolism than stems), whereas the remaining species studied exhibited a negative or no vulnerability segmentation. The degree of vulnerability segmentation was positively related to the degree of hydraulic segmentation, such that segmented species promote both mechanisms to hydraulically decouple leaf xylem from stem xylem. To what extent hydraulic and vulnerability segmentation determine drought resistance requires further integration of the leaf-stem transition at the whole-plant level, including both xylem and outer xylem tissue.
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Affiliation(s)
- Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- UMR SILVA, INRAE , Université de Lorraine, Nancy, 54000, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, D-89081, Germany
| | - Emma Calvet
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Camille Salmon
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Sylvain Delzon
- Univ. Bordeaux , INRAE, BIOGECO, Pessac, F-33615, France
| | - Charlotte Guichard
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
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De Kauwe MG, Medlyn BE, Ukkola AM, Mu M, Sabot MEB, Pitman AJ, Meir P, Cernusak LA, Rifai SW, Choat B, Tissue DT, Blackman CJ, Li X, Roderick M, Briggs PR. Identifying areas at risk of drought-induced tree mortality across South-Eastern Australia. Glob Chang Biol 2020; 26:5716-5733. [PMID: 32512628 DOI: 10.1111/gcb.15215] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
South-East Australia has recently been subjected to two of the worst droughts in the historical record (Millennium Drought, 2000-2009 and Big Dry, 2017-2019). Unfortunately, a lack of forest monitoring has made it difficult to determine whether widespread tree mortality has resulted from these droughts. Anecdotal observations suggest the Big Dry may have led to more significant tree mortality than the Millennium drought. Critically, to be able to robustly project future expected climate change effects on Australian vegetation, we need to assess the vulnerability of Australian trees to drought. Here we implemented a model of plant hydraulics into the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model. We parameterized the drought response behaviour of five broad vegetation types, based on a common garden dry-down experiment with species originating across a rainfall gradient (188-1,125 mm/year) across South-East Australia. The new hydraulics model significantly improved (~35%-45% reduction in root mean square error) CABLE's previous predictions of latent heat fluxes during periods of water stress at two eddy covariance sites in Australia. Landscape-scale predictions of the greatest percentage loss of hydraulic conductivity (PLC) of about 40%-60%, were broadly consistent with satellite estimates of regions of the greatest change in both droughts. In neither drought did CABLE predict that trees would have reached critical PLC in widespread areas (i.e. it projected a low mortality risk), although the model highlighted critical levels near the desert regions of South-East Australia where few trees live. Overall, our experimentally constrained model results imply significant resilience to drought conferred by hydraulic function, but also highlight critical data and scientific gaps. Our approach presents a promising avenue to integrate experimental data and make regional-scale predictions of potential drought-induced hydraulic failure.
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Affiliation(s)
- Martin G De Kauwe
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Evolution & Ecology Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Anna M Ukkola
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | - Mengyuan Mu
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Manon E B Sabot
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Evolution & Ecology Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Andrew J Pitman
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Patrick Meir
- Research School of Biology, The Australian National University, Acton, ACT, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Qld, Australia
| | - Sami W Rifai
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Michael Roderick
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
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40
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Cardoso AA, Billon LM, Fanton Borges A, Fernández-de-Uña L, Gersony JT, Güney A, Johnson KM, Lemaire C, Mrad A, Wagner Y, Petit G. New developments in understanding plant water transport under drought stress. New Phytol 2020; 227:1025-1027. [PMID: 32662102 DOI: 10.1111/nph.16663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- Amanda A Cardoso
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Lise-Marie Billon
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Ana Fanton Borges
- Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT, 06511, USA
| | | | - Jess T Gersony
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Aylin Güney
- Institute of Botany, University of Hohenheim, Garbenstr 30, D-70599, Stuttgart, Germany
- Department of Biology, Faculty of Science, Akdeniz University, 07058, Antalya, Turkey
| | - Kate M Johnson
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Cédric Lemaire
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Assaad Mrad
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Yael Wagner
- Department of Plant & Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Giai Petit
- Department TeSAF, Università degli Studi di Padova, Viale dell'Università 16, 35020, Legnaro, Italy
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41
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Nolan RH, Blackman CJ, de Dios VR, Choat B, Medlyn BE, Li X, Bradstock RA, Boer MM. Linking Forest Flammability and Plant Vulnerability to Drought. Forests 2020; 11:779. [DOI: 10.3390/f11070779] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Globally, fire regimes are being altered by changing climatic conditions. New fire regimes have the potential to drive species extinctions and cause ecosystem state changes, with a range of consequences for ecosystem services. Despite the co-occurrence of forest fires with drought, current approaches to modelling flammability largely overlook the large body of research into plant vulnerability to drought. Here, we outline the mechanisms through which plant responses to drought may affect forest flammability, specifically fuel moisture and the ratio of dead to live fuels. We present a framework for modelling live fuel moisture content (moisture content of foliage and twigs) from soil water content and plant traits, including rooting patterns and leaf traits such as the turgor loss point, osmotic potential, elasticity and leaf mass per area. We also present evidence that physiological drought stress may contribute to previously observed fuel moisture thresholds in south-eastern Australia. Of particular relevance is leaf cavitation and subsequent shedding, which transforms live fuels into dead fuels, which are drier, and thus easier to ignite. We suggest that capitalising on drought research to inform wildfire research presents a major opportunity to develop new insights into wildfires, and new predictive models of seasonal fuel dynamics.
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Pritzkow C, Williamson V, Szota C, Trouvé R, Arndt SK. Phenotypic plasticity and genetic adaptation of functional traits influences intra-specific variation in hydraulic efficiency and safety. Tree Physiol 2020; 40:215-229. [PMID: 31860729 DOI: 10.1093/treephys/tpz121] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 09/24/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
Understanding which hydraulic traits are under genetic control and/or are phenotypically plastic is essential in understanding how tree species will respond to rapid shifts in climate. We quantified hydraulic traits in Eucalyptus obliqua L'Her. across a precipitation gradient in the field to describe (i) trait variation in relation to long-term climate and (ii) the short-term (seasonal) ability of traits to adjust (i.e., phenotypic plasticity). Seedlings from each field population were raised under controlled conditions to assess (iii) which traits are under strong genetic control. In the field, drier populations had smaller leaves with anatomically thicker xylem vessel walls, a lower leaf hydraulic vulnerability and a lower water potential at turgor loss point, which likely confers higher hydraulic safety. Traits such as the water potential at turgor loss point and ratio of sapwood to leaf area (Huber value) showed significant adjustment from wet to dry conditions in the field, indicating phenotypic plasticity and importantly, the ability to increase hydraulic safety in the short term. In the nursery, seedlings from drier populations had smaller leaves and a lower leaf hydraulic vulnerability, suggesting that key traits associated with hydraulic safety are under strong genetic control. Overall, our study suggests a strong genetic control over traits associated with hydraulic safety, which may compromise the survival of wet-origin populations in drier future climates. However, phenotypic plasticity in physiological and morphological traits may confer sufficient hydraulic safety to facilitate genetic adaptation.
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Affiliation(s)
- Carola Pritzkow
- School of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Blvd Burnley, VIC 3121, Australia
| | - Virginia Williamson
- School of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Blvd Burnley, VIC 3121, Australia
| | - Christopher Szota
- School of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Blvd Burnley, VIC 3121, Australia
| | - Raphael Trouvé
- School of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Blvd Burnley, VIC 3121, Australia
| | - Stefan K Arndt
- School of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Blvd Burnley, VIC 3121, Australia
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43
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Liu X, Li Q, Wang F, Sun X, Wang N, Song H, Cui R, Wu P, Du N, Wang H, Wang R. Weak Tradeoff and Strong Segmentation Among Plant Hydraulic Traits During Seasonal Variation in Four Woody Species. Front Plant Sci 2020; 11:585674. [PMID: 33329647 PMCID: PMC7732674 DOI: 10.3389/fpls.2020.585674] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/03/2020] [Indexed: 05/08/2023]
Abstract
Plants may maintain long-term xylem function via efficiency-safety tradeoff and segmentation. Most studies focus on the growing season and community level. We studied species with different efficiency-safety tradeoff strategies, Quercus acutissima, Robinia pseudoacacia, Vitex negundo var. heterophylla, and Rhus typhina, to determine the seasonality of this mechanism. We separated their branches into perennial shoots and terminal twigs and monitored their midday water potential (Ψmd), relative water content (RWC), stem-specific hydraulic conductivity (Ks), loss of 12, 50, and 88% of maximum efficiency (i.e., P12, P50, P88) for 2 years. There were no correlations between water relations (Ψmd, RWC, Ks) and embolism resistance traits (P12, P50, P88) but they significantly differed between the perennial shoots and terminal twigs. All species had weak annual hydraulic efficiency-safety tradeoff but strong segmentation between the perennial shoots and the terminal twigs. R. pseudoacacia used a high-efficiency, low-safety strategy, whereas R. typhina used a high-safety, low-efficiency strategy. Q. acutissima and V. negundo var. heterophylla alternated these strategies. This mechanism provides a potential basis for habitat partitioning and niche divergence in the changing warm temperate zone environment.
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Affiliation(s)
- Xiao Liu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Qiang Li
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Feng Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Xiaohan Sun
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Huijia Song
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Rong Cui
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Pan Wu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Du
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Hui Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- *Correspondence: Hui Wang,
| | - Renqing Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
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