From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought
IntroductionParameterizing 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 dete...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-03-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2023.1149760/full |
| _version_ | 1797869616896147456 |
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| author | Xia Wang Yanli Fan Congcong Zhang Yihong Zhao Guangyuan Du Min Li Bingcheng Si Bingcheng Si |
| author_facet | Xia Wang Yanli Fan Congcong Zhang Yihong Zhao Guangyuan Du Min Li Bingcheng Si Bingcheng Si |
| author_sort | Xia Wang |
| collection | DOAJ |
| description | IntroductionParameterizing 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.MethodsWe 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.ResultsThe 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.DiscussionTo 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. |
| first_indexed | 2024-04-10T00:14:21Z |
| format | Article |
| id | doaj.art-5acba283d1864c898fe0ff4862fedb7a |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-04-10T00:14:21Z |
| publishDate | 2023-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-5acba283d1864c898fe0ff4862fedb7a2023-03-16T06:02:08ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2023-03-011410.3389/fpls.2023.11497601149760From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive droughtXia Wang0Yanli Fan1Congcong Zhang2Yihong Zhao3Guangyuan Du4Min Li5Bingcheng Si6Bingcheng Si7College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, ChinaCollege of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, ChinaCollege of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, ChinaCollege of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, ChinaCollege of Science, Northwest A&F University, Yangling, ChinaCollege of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, ChinaCollege of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, ChinaDepartment of Soil Science, University of Saskatchewan, Saskatoon, SK, CanadaIntroductionParameterizing 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.MethodsWe 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.ResultsThe 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.DiscussionTo 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.https://www.frontiersin.org/articles/10.3389/fpls.2023.1149760/fulltrees response to droughtxylem water potentialsoil water availabilitydrought stress leveltranspirationstomatal conductance |
| spellingShingle | Xia Wang Yanli Fan Congcong Zhang Yihong Zhao Guangyuan Du Min Li Bingcheng Si Bingcheng Si From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought Frontiers in Plant Science trees response to drought xylem water potential soil water availability drought stress level transpiration stomatal conductance |
| title | From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought |
| title_full | From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought |
| title_fullStr | From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought |
| title_full_unstemmed | From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought |
| title_short | From comfort zone to mortality: Sequence of physiological stress thresholds in Robinia pseudoacacia seedlings during progressive drought |
| title_sort | from comfort zone to mortality sequence of physiological stress thresholds in robinia pseudoacacia seedlings during progressive drought |
| topic | trees response to drought xylem water potential soil water availability drought stress level transpiration stomatal conductance |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2023.1149760/full |
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