PARENT SESSION
Contributed Oral Session 46: Predator - Prey Ecology: Communities and Environmental Impacts
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 519 B, Level 5, Palais des congrès de Montréal
Evaluating predator impact on old growth and logged stream macroinvertebrate diversity.
Zaradic, Patricia1, 1 Stroud Water Research Center, Avondale, PA, USA
ABSTRACT- The role of abiotic variables in intensifying or reducing competitive interactions and thereby determining community composition has been suggested. Similarly, abiotic variables may intensify or reduce the role of predator-prey interactions in determining community composition. Taking advantage of changes in abiotic variables due to logging, this study evaluates the impact of a top predator on prey diversity and invertebrate community composition across two habitat types with differing abiotic limitations. An artificial neural net model based on long term study data is used to evaluate the results of a field experiment comparing benthic macroinvertebrate assemblages subjected to predation by Pacific giant salamander larvae (Dicamptodon tenebrosus). Results suggest that at high density, old growth sites, selective predation by Pacific giant salamander larvae increases the diversity of the benthic macroinvertebrate assemblage. In contrast, at logged, open canopy sites and low density, Pacific giant salamander larvae prey more selectively but have less of a role in structuring the benthic macroinvertebrate community.
Key words: (Dicamptodon tenebrosus), ANN, old growth, stream macroinvertebrate