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Paligi SS, Link RM, Isasa E, Bittencourt P, Cabral JS, Jansen S, Oliveira RS, Pereira L, Schuldt B. Assessing the agreement between the pneumatic and the flow-centrifuge method for estimating xylem safety in temperate diffuse-porous tree species. Plant Biol (Stuttg) 2023; 25:1171-1185. [PMID: 37703535 DOI: 10.1111/plb.13573] [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: 03/16/2023] [Accepted: 07/06/2023] [Indexed: 09/15/2023]
Abstract
The increasing frequency of global change-type droughts has created a need for fast, accurate and widely applicable techniques for estimating xylem embolism resistance to improve forecasts of future forest changes. We used data from 12 diffuse-porous temperate tree species covering a wide range of xylem safety to compare the pneumatic and flow-centrifuge method, two rapid methods used for constructing xylem vulnerability curves. We evaluated the agreement between parameters estimated with both methods and the sensitivity of pneumatic measurements to the duration of air discharge (AD) measurements. There was close agreement between xylem water potentials at 50% air discharged (PAD), estimated with the Pneumatron, and 50% loss of hydraulic conductivity (PLC), estimated with the flow-centrifuge method (mean signed deviation: 0.12 MPa, Pearson correlation: 0.96 after 15 s of gas extraction). However, the relationship between the estimated slopes was more variable, resulting in lower agreement in the xylem water potential at 12% and 88% PAD/PLC. The agreement between the two methods was not affected by species-specific vessel length distributions. All pneumatic parameters were sensitive to AD time. Overall agreement was highest at relatively short AD times, with an optimum at 16 s. Our results highlight the value of the Pneumatron as an easy and reliable tool to estimate 50% embolism thresholds for a wide range of diffuse-porous temperate angiosperms. Further, our study provides a set of useful metrics for methodological comparisons of vulnerability curves in terms of systematic and random deviations, as well as overall agreement.
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Affiliation(s)
- S S Paligi
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - R M Link
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| | - E Isasa
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - P Bittencourt
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - J S Cabral
- Ecosystem Modeling Group, Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - S Jansen
- Institute of Botany, Ulm University, Ulm, Germany
| | - R S Oliveira
- Department of Plant Biology, Instituto de Biologia, University of Campinas, Campinas, SP, Brazil
| | - L Pereira
- Institute of Botany, Ulm University, Ulm, Germany
| | - B Schuldt
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
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Zhang Y, Lamarque LJ, Torres-Ruiz JM, Schuldt B, Karimi Z, Li S, Qin DW, Bittencourt P, Burlett R, Cao KF, Delzon S, Oliveira R, Pereira L, Jansen S. Testing the plant pneumatic method to estimate xylem embolism resistance in stems of temperate trees. Tree Physiol 2018; 38:1016-1025. [PMID: 29474679 PMCID: PMC6025199 DOI: 10.1093/treephys/tpy015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 11/21/2017] [Revised: 01/19/2018] [Accepted: 01/31/2018] [Indexed: 05/23/2023]
Abstract
Methods to estimate xylem embolism resistance generally rely on hydraulic measurements, which can be far from straightforward. Recently, a pneumatic method based on air flow measurements of terminal branch ends was proposed to construct vulnerability curves by linking the amount of air extracted from a branch with the degree of embolism. We applied this novel technique for 10 temperate tree species, including six diffuse, two ring-porous and two gymnosperm species, and compared the pneumatic curves with hydraulic ones obtained from either the flow-centrifuge or the hydraulic-bench dehydration method. We found that the pneumatic method provides a good estimate of the degree of xylem embolism for all angiosperm species. The xylem pressure at 50% and 88% loss of hydraulic conductivity (i.e., Ψ50 and Ψ88) based on the methods applied showed a strongly significant correlation for all eight angiosperms. However, the pneumatic method showed significantly reduced Ψ50 values for the two conifers. Our findings suggest that the pneumatic method could provide a fast and accurate approach for angiosperms due to its convenience and feasibility, at least within the range of embolism resistances covered by our samples.
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Affiliation(s)
- Ya Zhang
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
| | - Laurent J Lamarque
- BIOGECO, INRA, University of Bordeaux, Pessac, France
- EGFV, INRA, University of Bordeaux, Villenave d’Ornon, France
| | | | - Bernhard Schuldt
- Albrecht-von-Haller-Institute for Plant Sciences, Göttingen University, Göttingen, Germany
| | - Zohreh Karimi
- Department of Biology, Faculty of Science, Golestan University, Gorgan, Iran
| | - Shan Li
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, PR China
| | - De-Wen Qin
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, PR China
| | - Paulo Bittencourt
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Régis Burlett
- BIOGECO, INRA, University of Bordeaux, Pessac, France
| | - Kun-Fang Cao
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, PR China
| | | | - Rafael Oliveira
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Luciano Pereira
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
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