The periostracum is an organic layer, secreted as the outermost layer of most mollusk shells that protects the underlying shell from erosion.
Behavioural interactions between ecosystem engineers control community species richness
Article first published online: 21 AUG 2009
© 2009 Blackwell Publishing Ltd/CNRS
Volume 12, Issue 11, pages 1127–1136, November 2009
How to Cite
Gribben, P. E., Byers, J. E., Clements, M., McKenzie, L. A., Steinberg, P. D. and Wright, J. T. (2009), Behavioural interactions between ecosystem engineers control community species richness. Ecology Letters, 12: 1127–1136. doi: 10.1111/j.1461-0248.2009.01366.x
- Issue published online: 13 OCT 2009
- Article first published online: 21 AUG 2009
- Editor, Marcel Holyoak Manuscript received 10 June 2009 First decision made 10 July 2009 Manuscript accepted 21 July 2009
- ecosystem engineer;
- facilitation cascades;
- habitat-forming species;
- invasive species;
- trait-mediated indirect effects
Behavioural interactions between ecosystem engineers may strongly influence community structure. We tested whether an invasive ecosystem engineer, the alga Caulerpa taxifolia, indirectly facilitated community diversity by modifying the behaviour of a native ecosystem engineer, the clam Anadara trapezia, in southeastern Australia. In this study, clams in Caulerpa-invaded sediments partially unburied themselves, extending >30% of their shell surface above the sediment, providing rare, hard substrata for colonization. Consequently, clams in Caulerpa had significantly higher diversity and abundance of epibiota compared with clams in unvegetated sediments. To isolate the role of clam burial depth from direct habitat influences or differential predation by habitat, we manipulated clam burial depth, predator exposure and habitat (Caulerpa or unvegetated) in an orthogonal experiment. Burial depth overwhelmingly influenced epibiont species richness and abundance, resulting in a behaviourally mediated facilitation cascade. That Caulerpa controls epibiont communities by altering Anadara burial depths illustrates that even subtle behavioural responses of one ecosystem engineer to another can drive extensive community-wide facilitation.