Abstract
Community structure is the observable outcome of numerous processes. We conducted a laboratory experiment using a microbial model system to disentangle effects of nutrient enrichment, dispersal, and predation on prey species richness and predator abundance at local and metacommunity scales. Prey species included: Chilomonas sp., Colpidium striatum, Colpoda cucullus, Paramecium tetraurelia, P. caudatum, Philodina sp., Spirostomum sp., Tetrahymena thermophila, and Uronema sp., and Stentor coeruleus was the predator used. We hypothesized that: (1) increased basal resources should maintain greater species richness and higher predator abundance; (2) dispersal should maintain greater species richness; and (3) predation should reduce species richness, especially in the high resource treatments relative to no-predator treatments. Our results support all three hypotheses. Further, we show that dispersal affects richness at the local community scale but not at the metacommunity scale. However, predation seems to have major effects at both the local and metacommunity scale. Overall, our results show that effects of resource enrichment, dispersal, and predation were mostly additive rather than interactive, indicating that it may be sometimes easier to understand their effects than generally thought due to complex interactive effects.
Original language | English |
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Pages (from-to) | 150-157 |
Number of pages | 8 |
Journal | Oecologia |
Volume | 149 |
Issue number | 1 |
DOIs | |
State | Published - Aug 2006 |
Externally published | Yes |
Funding
Acknowledgments We are grateful to J. Drake and S. McMahon for serving as sounding boards. We wish to thank A. McDonald, J. Lowder, and M. Rana for greatly assisting in the carrying out of this experiment. We are grateful to W. Resetarits and two anonymous reviewers for helping to improve the quality of this manuscript. We wish to acknowledge the generous support from NSF (grant DEB 0206598) and a University of Tennessee EEB summer research grant to T.F. and M.W.C.
Keywords
- Dispersal
- Metacommunity
- Microcosm
- Predation
- Spatial scale