The role of gap phase processes in the biomass dynamics of tropical forests

Kenneth J. Feeley, Stuart J. Davies, Peter S. Ashton, Sarayudh Bunyavejchewin, M. N. Nur Supardi, Abd Rahman Kassim, Sylvester Tan, Jérôme Chave

Research output: Contribution to journalArticle

40 Scopus citations

Abstract

The responses of tropical forests to global anthropogenic disturbances remain poorly understood. Above-ground woody biomass in some tropical forest plots has increased over the past several decades, potentially reflecting a widespread response to increased resource availability, for example, due to elevated atmospheric CO2 and/or nutrient deposition. However, previous studies of biomass dynamics have not accounted for natural patterns of disturbance and gap phase regeneration, making it difficult to quantify the importance of environmental changes. Using spatially explicit census data from large (50 ha) inventory plots, we investigated the influence of gap phase processes on the biomass dynamics of four 'old-growth' tropical forests (Barro Colorado Island (BCI), Panama; Pasoh and Lambir, Malaysia; and Huai Kha Khaeng (HKK), Thailand). We show that biomass increases were gradual and concentrated in earlier-phase forest patches, while biomass losses were generally of greater magnitude but concentrated in rarer later-phase patches. We then estimate the rate of biomass change at each site independent of gap phase dynamics using reduced major axis regressions and ANCOVA tests. Above-ground woody biomass increased significantly at Pasoh (+ 0.72% yr-1) and decreased at HKK (-0.56% yr-1) independent of changes in gap phase but remained stable at both BCI and Lambir. We conclude that gap phase processes play an important role in the biomass dynamics of tropical forests, and that quantifying the role of gap phase processes will help improve our understanding of the factors driving changes in forest biomass as well as their place in the global carbon budget.

Original languageEnglish (US)
Pages (from-to)2857-2864
Number of pages8
JournalProceedings of the Royal Society B: Biological Sciences
Volume274
Issue number1627
DOIs
StatePublished - Nov 22 2007
Externally publishedYes

    Fingerprint

Keywords

  • Carbon cycling
  • Carbon dioxide
  • Disturbance
  • Global change
  • Succession
  • Tree-fall gaps

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Environmental Science(all)
  • Agricultural and Biological Sciences(all)

Cite this

Feeley, K. J., Davies, S. J., Ashton, P. S., Bunyavejchewin, S., Nur Supardi, M. N., Kassim, A. R., Tan, S., & Chave, J. (2007). The role of gap phase processes in the biomass dynamics of tropical forests. Proceedings of the Royal Society B: Biological Sciences, 274(1627), 2857-2864. https://doi.org/10.1098/rspb.2007.0954