Observations show vulnerability segmentation between stems and leaves is highly variable within and between environments. While a number of species exhibit conventional vulnerability segmentation (stem (Figure presented.) leaf (Figure presented.)), others exhibit no vulnerability segmentation and others reverse vulnerability segmentation (stem (Figure presented.) leaf (Figure presented.)). We developed a hydraulic model to test hypotheses about vulnerability segmentation and how it interacts with other traits to impact plant conductance. We do this using a series of experiments across a broad parameter space and with a case study of two species with contrasting vulnerability segmentation patterns: Quercus douglasii and Populus trichocarpa. We found that while conventional vulnerability segmentation helps to preserve conductance in stem tissues, reverse vulnerability segmentation can better maintain conductance across the combined stem-leaf hydraulic pathway, particularly when plants have more vulnerable (Figure presented.) s and have hydraulic segmentation with greater resistance in the leaves. These findings show that the impacts of vulnerability segmentation are dependent upon other plant traits, notably hydraulic segmentation, a finding that could assist in the interpretation of variable observations of vulnerability segmentation. Further study is needed to examine how vulnerability segmentation impacts transpiration rates and recovery from water stress.
Bibliographical noteFunding Information:
We would like to thank Jessica Diaz for assistance with the vulnerability measurements for . This work was supported by a National Science Foundation Graduate Research Fellowship (Grant No. DGE 1752814 to Jean V. Wilkening); a National Science Foundation CAREER Award (Grant No. DEB‐2045610 to Xue Feng); and a FLAIR Fellowship from the British Royal Society and the African Academy of Sciences (Award No. FLR\R1\191609 to Robert P. Skelton). The FLAIR Fellowship Programme is a partnership between the African Academy of Sciences and the Royal Society funded by the UK Government's Global Challenges Research Fund. Populus trichocarpa
© 2023 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.
- hydraulic model
- hydraulic segmentation
- plant hydraulics
- vulnerability segmentation
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't