Get access

Niche assembly of epiphytic bryophyte communities in the Guianas: a regional approach

Authors

  • Sylvia Mota de Oliveira,

    Corresponding author
    1. Institute of Environmental Biology, Section Plant Ecology and Biodiversity, Utrecht University, Utrecht
      *Sylvia Mota de Oliveira, Plant Ecology and Biodiversity, Sorbonnelaan 14, Room No. 405, 3584 CA Utrecht, The Netherlands. E-mail: s.motadeoliveira@uu.nl
    Search for more papers by this author
  • Hans Ter Steege,

    1. Institute of Environmental Biology, Section Plant Ecology and Biodiversity, Utrecht University, Utrecht
    Search for more papers by this author
  • Johannes H. C. Cornelissen,

    1. Department of Systems Ecology, Institute of Ecological Science, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands
    Search for more papers by this author
  • S. Robbert Gradstein

    1. Institute of Plant Sciences, University of Göttingen, Göttingen, Germany
    Search for more papers by this author

*Sylvia Mota de Oliveira, Plant Ecology and Biodiversity, Sorbonnelaan 14, Room No. 405, 3584 CA Utrecht, The Netherlands. E-mail: s.motadeoliveira@uu.nl

Abstract

Aim  Epiphytic bryophyte communities of tropical forests show a gradient in species composition from the base to the top of the host trees, indicating a strong role of niche assembly. This pattern, however, has never been tested at a regional scale. The aim of this study was to test whether niche assembly, rather than dispersal limitation, predominantly drives species composition of bryophyte communities across large spatial scales.

Location  Three lowland forests in the Guianas: one near Saul, French Guiana; and two near Mabura Hill, Guyana.

Methods  Communities of epiphytic bryophytes were sampled from six different height zones of several trees in three lowland forests. We analysed the composition of these communities using detrended correspondence analysis in order to find the best explanatory variable for the variation in community composition. A multi-response permutation procedure was used to test the significance of grouping communities by height zone. We conducted an indicator species analysis to classify species as specialists or generalists and then tested, through weighted averaging, if specialists would indeed maintain their preferred height zone across the Guianas.

Results  Community composition was explained mainly by height zone. The similarity among communities inhabiting the same height zone of trees, across a distance of up to 640 km, was higher than the similarity among communities established along the vertical gradient of a single standing tree (30–50 m). More than half (57%) of the species had a preferred height zone, and the preference was consistent: species occupied roughly the same height zone on host trees in the different localities. The three local communities investigated were found to belong to the same regional species pool.

Main conclusions  Throughout the Guianas, epiphytic bryophyte communities are drawn from the same regional species pool, and their composition is shaped by micro-environmental conditions. The predominance of niche assembly over dispersal assembly rules is consistently found at both local and regional scales.

Get access to the full text of this article

Ancillary