Current food web theory incorporates both top-down and bottom-up processes. For example, the exploitation ecosystem hypothesis (EEH) predicts that the number of trophic levels tends to increase with increasing productivity and that the relative influence of top-down or bottom-up forces will change along productivity gradients with top-down forces being more important in more productive systems. In terrestrial systems, the EEH model has been used to explain the dynamics of carnivore-herbivore interactions and their implications for plants, but has mainly been tested in linear food chains with simple trophic structure, often ignoring the litter and detritivore (mostly invertebrate) trophic levels. We are studying invertebrate detritivore populations and the extent to which carnivores may be generalized enough to prey on detritivores and herbivores.
Research supported by: Natural Sciences and Engineering Research Council of Canada, BC Grasslands Conservation Council, Forest Investment Account Forest Science Program of BC.
Partners: Dr. Roy Turkington (UBC)
Current students: William Harrower (PhD)
Past students: Dr. Brian Patrick (PhD); Eleanor Bassett (MSc); Amanda Schmidt