Plant Ecology

, Volume 166, Issue 2, pp 295–306

Light environment and tree strategies in a Bolivian tropical moist forest: an evaluation of the light partitioning hypothesis


DOI: 10.1023/A:1023295806147

Cite this article as:
Poorter, L. & Arets, E.J. Plant Ecology (2003) 166: 295. doi:10.1023/A:1023295806147


Light partitioning is thought to contribute to the coexistence of rain forest tree species. This study evaluates the three premises underlying the light partitioning hypothesis; 1) there is a gradient in light availability at the forest floor, 2) tree species show a differential distribution with respect to light, and 3) there is a trade-off in species performance that explains their different positions along the light gradient. To address these premises, we studied the light environment, growth, and survival of saplings of ten non-pioneer tree species in a Bolivian moist forest. Light availability in the understorey was relatively high, with a mean canopy openness of 3.5% and a mean direct site factor of 6.8%. Saplings of two light demanding species occurred at significantly higher light levels than the shade tolerant species. The proportion of saplings in low-light conditions was negatively correlated with the successional position of the species. Light-demanding species were characterised by a low share of their saplings in low-light conditions, a high sapling mortality, a fast height growth and a strong growth response to light. These data show that all three premises for light partitioning are met. There is a clear gradient in shade-tolerance within the group of non-pioneer species leading to a tight packing of species along the small range of light environments found in the understorey.

Bolivia Hemispherical photographs Irradiance Niche differentiation Sapling growth Shade tolerance 

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  1. 1.Programa Manejo de Bosques de la Amazonía Boliviana (PROMAB)CasillaBolivia
  2. 2.Forest Ecology and Forest Management Group, Department of Environmental SciencesWageningen UniversityWageningenThe Netherlands
  3. 3.Department of Plant EcologyUtrecht UniversityUtrechtThe Netherlands

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