Sprouting by plants: the effects of modular organization

Authors

  • P. A. VESK,

    Corresponding author
    1. Australian Centre for Biodiversity: Analysis, Policy and Management. School of Biological Sciences, Monash University, Clayton, VIC 3800, and
      †Author to whom correspondence should be addressed. E-mail: peter.vesk@sci.monash.edu.au
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  • M. WESTOBY

    1. School of Biological Sciences, Macquarie University, Sydney, NSW 2089, Australia
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†Author to whom correspondence should be addressed. E-mail: peter.vesk@sci.monash.edu.au

Summary

  • 1Plant survival following disturbance was modelled simply as the probability that at least one of n stems sprouts, each stem having an independent probability of sprouting, s. This first-order model with any stem on any plant in any species having probability s = 0·18 of sprouting after clipping (s = 0·09 after burning) explained nearly half of the deviance associated with species’ mortality in a field experiment on 43 species from a range of growth forms.
  • 2Allowing species to take either a low or high per-stem sprouting probability (SSP) improved statistical explanation substantially. Fitting growth form SSP was less effective, showing that much of the apparent among-species variation in SSP was within growth forms.
  • 3Allowing each species to have a different SSP essentially provided a saturated model. The estimated species-specific probabilities were positively related to the depth from which sprouts could emerge after disturbance. Predicting species’ bud depth from some simply measured morphological trait would be a considerable advance. Limited evidence suggested that sprout depth was associated with thick or dense leaves (low specific leaf area and leaf water content).
  • 4Depicting plants as a collection of independent stems with equal probability of sprouting appears a reasonable first-order model for whole-plant sprouting, despite being morphologically simplified.

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