Article thumbnail

Diversity of larger consumers enhances interference competition effects on smaller competitors

By Francisco J. A. Nascimento, Agnes M. L. Karlson, Johan Näslund and Ragnar Elmgren


Competition between large and small species for the same food is common in a number of ecosystems including aquatic ones. How diversity of larger consumers affects the access of smaller competitors to a limiting resource is not well understood. We tested experimentally how species richness (0–3 spp.) of benthic deposit-feeding macrofauna changes meiofaunal ostracods’ incorporation of fresh organic matter from a stable-isotope-labeled cyanobacterial bloom, using fauna from the species-poor Baltic Sea. Presence of macrofauna mostly decreased meiofaunal incorporation of bloom material, depending on the macrofauna species present. As expected, the species identity of macrofauna influenced the incorporation of organic matter by meiofauna. Interestingly, our results show that, in addition, species richness of the macrofauna significantly reduced meiofauna incorporation of freshly settled nitrogen and carbon. With more than one macrofauna species, the reduction was always greater than expected from the single-species treatments. Field data from the Baltic Sea showed a negative correlation between macrofauna diversity and meiofaunal ostracod abundance, as expected from the experimental results. We argue that this is caused by interference competition, due to spatial niche differentiation between macrofauna species reducing the sediment volume in which ostracods can feed undisturbed by larger competitors. Interference from macrofauna significantly reduces organic matter incorporation by meiofauna, indicating that diversity of larger consumers is an important factor controlling the access of smaller competitors to a limiting food resource

Topics: Population ecology - Original Paper
Publisher: Springer-Verlag
OAI identifier:
Provided by: PubMed Central

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.

Suggested articles


  1. (1983). Field experiments on interspecific competition.
  2. (2000). Is space necessary? Interference competition and limits to biodiversity. Ecology 81:3226–3232 Aljetlawi AA, Leonardsson K
  3. (2009). Settling cyanobacterial blooms do not improve growth conditions for soft bottom meiofauna. J Exp Mar Biol Ecol 368: 138–146 O ´lafsson E, Modig H, van de Bund WJ
  4. (1975). The size structure of the deep-sea benthos. Int Rev Ges Hydrobiol 60:575–606 Tita