Oecologia

, Volume 176, Issue 3, pp 837–848

Functional importance of avian seed dispersers changes in response to human-induced forest edges in tropical seed-dispersal networks

  • Francisco Saavedra
  • Isabell Hensen
  • Stephan G. Beck
  • Katrin Böhning-Gaese
  • Denis Lippok
  • Till Töpfer
  • Matthias Schleuning
Community ecology - Original research

DOI: 10.1007/s00442-014-3056-x

Cite this article as:
Saavedra, F., Hensen, I., Beck, S.G. et al. Oecologia (2014) 176: 837. doi:10.1007/s00442-014-3056-x

Abstract

Although seed-dispersal networks are increasingly used to infer the functioning of ecosystems, few studies have investigated the link between the properties of these networks and the ecosystem function of seed dispersal by animals. We investigate how frugivore communities and seed dispersal change with habitat disturbance and test whether relationships between morphological traits and functional roles of seed dispersers change in response to human-induced forest edges. We recorded interaction frequencies between fleshy fruited plants and frugivorous bird species in tropical montane forests in the Bolivian Andes and recorded functional bird traits (body mass, gape width and wing tip length) associated with quantitative (seed-removal rate) and qualitative (seed-deposition pattern) components of seed-dispersal effectiveness. We found that the abundance and richness of frugivorous birds were higher at forest edges. More fruits were removed and dispersed seeds were less clustered at edges than in the interior. Additionally, functional and interaction diversity were higher at edges than in the interior, but functional and interaction evenness did not differ. Interaction strength of bird species increased with body mass, gape width and wing tip length in the forest interior, but was not related to bird morphologies at forest edges. Our study suggests that increases in functional and interaction diversity and an even distribution of interaction strength across bird morphologies lead to enhanced quantity and tentatively enhanced quality of seed dispersal. It also suggests that the effects of species traits on ecosystem functions can vary along small-scale gradients of human disturbance.

Keywords

Ecosystem functioning Functional diversity Morphological traits Montane forest Plant–frugivore interactions 

Supplementary material

442_2014_3056_MOESM1_ESM.docx (129 kb)
Supplementary material 1 (DOCX 128 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Francisco Saavedra
    • 1
    • 2
    • 3
  • Isabell Hensen
    • 1
  • Stephan G. Beck
    • 3
  • Katrin Böhning-Gaese
    • 2
    • 4
  • Denis Lippok
    • 1
  • Till Töpfer
    • 2
    • 5
    • 6
  • Matthias Schleuning
    • 2
  1. 1.Institute of Biology/Geobotany and Botanical GardenMartin Luther University Halle-WittenbergHalle (Saale)Germany
  2. 2.Biodiversity and Climate Research Centre (BiK-F) and Senckenberg Gesellschaft für NaturforschungFrankfurt (Main)Germany
  3. 3.Herbario Nacional de Bolivia, Instituto de EcologíaUniversidad Mayor de San AndresCorreo Central La PazBolivia
  4. 4.Institute for Ecology, Evolution and DiversityGoethe University FrankfurtFrankfurt (Main)Germany
  5. 5.Zoological Research Museum Alexander KoenigBonnGermany
  6. 6.Senckenberg Naturhistorische SammlungenMuseum für TierkundeDresdenGermany