eCite Digital Repository

Drought response strategies define the relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality

Citation

Mitchell, PJ and O'Grady, AP and Tissue, DT and White, DA and Ottenschlaeger, ML and Pinkard, EA, Drought response strategies define the relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality, New Phytologist, 197, (3) pp. 862-872. ISSN 0028-646X (2013) [Refereed Article]

Copyright Statement

Copyright 2012 CSIRO

DOI: doi:10.1111/nph.12064

Abstract

  • Plant survival during drought requires adequate hydration in living tissues and carbohydrate reserves for maintenance and recovery. We hypothesized that tree growth and hydraulic strategy determines the intensity and duration of the ‘physiological drought’, thereby affecting the relative contributions of loss of hydraulic function and carbohydrate depletion during mortality.
  • We compared patterns in growth rate, water relations, gas exchange and carbohydrate dynamics in three tree species subjected to prolonged drought.
  • Two Eucalyptus species (E. globulus, E. smithii) exhibited high growth rates and water-use resulting in rapid declines in water status and hydraulic conductance. In contrast, conservative growth and water relations in Pinus radiata resulted in longer periods of negative carbon balance and significant depletion of stored carbohydrates in all organs. The ongoing demand for carbohydrates from sustained respiration highlighted the role that duration of drought plays in facilitating carbohydrate consumption.
  • Two drought strategies were revealed, differentiated by plant regulation of water status: plants maximized gas exchange, but were exposed to low water potentials and rapid hydraulic dysfunction; and tight regulation of gas exchange at the cost of carbohydrate depletion. These findings provide evidence for a relationship between hydraulic regulation of water status and carbohydrate depletion during terminal drought.
  • Item Details

    Item Type:Refereed Article
    Keywords:carbon limitation, drought mortality, hydraulic conductance, hydraulic failure, nonstructural carbohydrates, plant strategy
    Research Division:Biological Sciences
    Research Group:Evolutionary Biology
    Research Field:Plant Systematics and Taxonomy
    Objective Division:Expanding Knowledge
    Objective Group:Expanding Knowledge
    Objective Field:Expanding Knowledge in the Biological Sciences
    Author:Mitchell, PJ (Dr Patrick Mitchell)
    Author:O'Grady, AP (Dr Anthony O'Grady)
    Author:Ottenschlaeger, ML (Ms Maria Ottenschlaeger)
    ID Code:119531
    Year Published:2013
    Web of Science® Times Cited:128
    Deposited By:Centre for Ecology and Biodiversity
    Deposited On:2017-08-02
    Last Modified:2017-09-29
    Downloads:0

    Repository Staff Only: item control page