The Science

This paper provides insights into how embolism repair may have evolved and describes the anatomical and physiological features that are thought to facilitate this process.  A modeling framework was developed to test alternative hypotheses about if, when, and in what ecosystems rapid embolism repair occurs during droughts and emerges as ecologically important.

The Impact

This project proposes a new framework that incorporates embolism repair into the “hydraulic efficiency-safety” spectrum.  The researchers propose a second framework for advancing functional diversity and mortality functions in dynamic vegetation models by describing how vulnerability curves operate in plants that recover from embolism.

Summary

The team reviews and synthesizes current research regarding embolism repair of plant xylem during droughts. Two new frameworks are proposed for developing hypotheses about the physiology and ecology of embolism repair.

A hypothesized conceptual framework proposing how embolism refilling may be an additional strategy to the continuum of hydraulic safety and hydraulic efficiency. For example, plants may have low safety, and a high ability to recover from embolism. Note that capacitance, which acts as a buffer against embolism, may be regarded as one aspect of avoidance, representing an additional strategy. The research team hypothesizes that species may be able to refill embolism, particularly if they are high water users. Species may also be high water users and unable to refill embolism, using other drought avoidance or tolerance strategies. Alternatively, species may be able to refill embolism and have conservative hydraulic strategies.

Principal Investigator

Thomas Powell
Lawrence Berkeley National Laboratory
tlpowell@lbl.gov

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

Funding support was provided in full or in part as follows: MZ by Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) DE120100518. TK by the Benoziyo Fund for the Advancement of Science; Mr. and Mrs. Norman Reiser, together with the Weizmann Center for New Scientists; and the Edith and Nathan Goldberg Career Development Chair. WRLA by a National Oceanic and Atmospheric Administration (NOAA) Climate and Global Change Postdoctoral fellowship, administered by the University Corporation of Atmospheric Research. JB by the Austrian Science Fund (FWF): M1757-B22 through the Lise Meitner Program. PJH by the University of New Mexico. NKR by the German Federal Ministry of Education and Research (BMBF), through the Helmholtz Association and its research programme ATMO and by the German Research Foundation through its Emmy Noether Programme (RU 1657/2-1). TLP by student research funding from the Department of Organismic and Evolutionary Biology (OEB) and by the Next-Generation Ecosystem Experiments (NGEE)–Tropics project of the Office of Biological and Environmental Research, within the U.S. Department of Energy Office of Science. GvA by the Swiss State Secretariat for Education, Research and Innovation SERI (SBFI C14.0104 and C12.0100).  W.R.L.A. acknowledges funding from National Science Foundation 1714972 and from the Agricultural and Food Research Initiative Competitive Program’s Ecosystem Services and Agroecosystem Management of the U.S. Department of Agriculture’s National Institute of Food and Agriculture (grant no. 2017-05521).

References