Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass

PLoS One. 2012;7(3):e32162. doi: 10.1371/journal.pone.0032162. Epub 2012 Mar 13.

Abstract

The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analysis of Variance
  • Biomass
  • Carbon / analysis*
  • Models, Biological*
  • Nitrogen / analysis*
  • Phosphorus / analysis*
  • Plant Development*
  • Plants / chemistry
  • Species Specificity

Substances

  • Phosphorus
  • Carbon
  • Nitrogen