Abstract

The ecology of many tropical rain forest organisms, not the least in Africa, remains poorly understood. Here, we present a detailed ecological study of epiphytic lichens in the equatorial montane rain forest of Bwindi National Park (331km(2)), Uganda. We evaluated all major lichen growth forms, including selected groups of crustose lichens. In 14 transects at elevations of 1290m to 2500m, we sampled 276 trees belonging to 60 species. We recorded all lichen species on each tree trunk between ground level and 2m above the ground, yielding 191 lichen species in 67 genera, with a mean of 4.7 species per tree. We used non-metric multi-dimensional scaling to separate epiphytic lichen assemblages according to tree species composition and elevation. Structural equation modeling indicated that elevation influenced tree species composition and that tree species composition largely determined lichen species composition. Thus, elevation acted indirectly on the lichen assemblages. Further studies examining factors such as bark properties and lichen colonization ecology may clarify what determines the association between tree species and lichen assemblages. The link between lichen assemblages and large-scale elevation patterns, as well as disturbance and regrowth histories, warrants further study. An analysis of lichen species composition on individual tree species that occur over large elevation ranges would distinguish the effect of tree species on lichen assemblages from the effect of elevation and thus climate. Our study highlights the limited extent of our knowledge of tropical epiphytic lichens.

Keywords

Bwindi; crustose; equatorial; non-metric multi-dimensional scaling; structural equation modeling; transects; Uganda

Published in

Biotropica
2015, Volume: 47, number: 5, pages: 542-549
Publisher: WILEY-BLACKWELL

SLU Authors

• Frisch, Andreas

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Sjögren, Jörgen

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

• Caruso, Alexandro

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Thor, Göran

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Gustafsson, Lena

  • Department of Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology
Forest Science


Publication identifier

DOI: https://doi.org/10.1111/btp.12237

Permanent link to this page (URI)

https://res.slu.se/id/publ/68521