The limited importance of size-asymmetric light competition and growth of pioneer species in early secondary forest succession in Vietnam

Oecologia. 2008 Aug;157(1):1-12. doi: 10.1007/s00442-008-1048-4. Epub 2008 May 15.

Abstract

It is generally believed that asymmetric competition for light plays a predominant role in determining the course of succession by increasing size inequalities between plants. Size-related growth is the product of size-related light capture and light-use efficiency (LUE). We have used a canopy model to calculate light capture and photosynthetic rates of pioneer species in sequential vegetation stages of a young secondary forest stand. Growth of the same saplings was followed in time as succession proceeded. Photosynthetic rate per unit plant mass (P(mass): mol C g(-1) day(-1)), a proxy for plant growth, was calculated as the product of light capture efficiency [Phi(mass): mol photosynthetic photon flux density (PPFD) g(-1) day(-1)] and LUE (mol C mol PPFD(-1)). Species showed different morphologies and photosynthetic characteristics, but their light-capturing and light-use efficiencies, and thus P (mass), did not differ much. This was also observed in the field: plant growth was not size-asymmetric. The size hierarchy that was present from the very early beginning of succession remained for at least the first 5 years. We conclude, therefore, that in slow-growing regenerating vegetation stands, the importance of asymmetric competition for light and growth can be much less than is often assumed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomass
  • Euphorbiaceae / anatomy & histology
  • Euphorbiaceae / growth & development
  • Euphorbiaceae / metabolism
  • Ferns / anatomy & histology
  • Ferns / growth & development
  • Ferns / metabolism
  • Light*
  • Mallotus Plant / anatomy & histology
  • Mallotus Plant / growth & development
  • Mallotus Plant / metabolism
  • Melastomataceae / anatomy & histology
  • Melastomataceae / growth & development
  • Melastomataceae / metabolism
  • Photosynthesis*
  • Poaceae / anatomy & histology
  • Poaceae / growth & development
  • Poaceae / metabolism
  • Species Specificity
  • Trees / anatomy & histology
  • Trees / growth & development*
  • Trees / metabolism
  • Vietnam