Habitat complexity does not promote coexistence in a size-structured intraguild predation system
Article first published online: 24 SEP 2012
© 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society
Journal of Animal Ecology
Volume 82, Issue 1, pages 55–63, January 2013
How to Cite
Reichstein, B., Schröder, A., Persson, L., De Roos, A. M. (2013), Habitat complexity does not promote coexistence in a size-structured intraguild predation system. Journal of Animal Ecology, 82: 55–63. doi: 10.1111/j.1365-2656.2012.02032.x
- Issue published online: 17 JAN 2013
- Article first published online: 24 SEP 2012
- Manuscript Accepted: 25 JUL 2012
- Manuscript Received: 19 DEC 2011
- ontogenetic niche shift;
- size-dependent interactions;
- trophic interactions
- Size-dependent interactions and habitat complexity have been identified as important factors affecting the persistence of intraguild predation (IGP) systems. Habitat complexity has been suggested to promote intraguild (IG) prey and intraguild predator coexistence through weakening trophic interactions particularly the predation link.
- Here, we experimentally investigate the effects of habitat complexity on coexistence and invasion success of differently sized IG-predators in a size-structured IGP system consisting of the IG-predator Poecilia reticulata and a resident Heterandria formosa IG-prey population. The experiments included medium-long and long-term invasion experiments, predator–prey experiments and competition experiments to elucidate the mechanisms underlying the effect of prey refuges.
- Habitat complexity did not promote the coexistence of IG-predator and IG-prey, although the predation link was substantially weakened. However, the presence of habitat structure affected the invasion success of large IG-predators negatively and the invasion success of small IG-predators positively. The effect of refuges on size-dependent invasion success could be related to a major decrease in the IG-predator's capture rate and a shift in the size distribution of IG-predator juveniles.
- In summary, habitat complexity had two main effects: (i) the predation link was diminished, resulting in a more competition driven system and (ii) the overall competitive abilities of the two species were equalized, but coexistence was not promoted. Our results suggest that in a size-structured IGP system, individual level mechanisms may gain in importance over species level mechanisms in the presence of habitat complexity.