Meeting Abstract
P3-163 Sunday, Jan. 6 15:30 – 17:30 The Cost of Trait-Mediated Interactions and Indirect Effects within Predator-Prey Dynamics FLOCK, TM*; KRAMER, AM; LAJEUNESSE, MJ; University of South Florida; University of South Florida; University of South Florida tflock@mail.usf.edu
Predators shape food-web dynamics and ecosystem interactions in two ways. First by consuming prey, which removes individuals from populations and has positive effects on predator birth and survival. This is known as the density-mediated effect of predators on prey. Secondly, predators affect biotic interactions and food-web dynamics via nonconsumptive, trait-mediated effects. This occurs when predators and the risk they pose change the behavior, morphology, or physiology of prey. Trait-mediated interactions (TMIs) have been reported for a broad group of taxa, and early meta-analyses of these studies concluded that TMIs affect prey population dynamics as strongly as density-mediated interactions (DMIs). However, there has since been considerable growth in research on TMIs and DMIs, as well as new research synthesis standards and practices that can help provide new insight on the impact of direct and indirect effects of predators. Here we describe a phylogenetic meta-analysis that first tests whether DMIs are more or less influential at shaping prey populations than TMIs, and then examine the TMIs caused by invasive species. Invasive species are projected to increase over time and a better understanding of key trait-mediated interactions of invasive species is needed. Our synthesis contained mostly papers published after 2005 (532/664 papers that were relevant to the literature search were published after 2005), and we hypothesized that TMIs have similar effects as DMIs on shaping prey populations due to the cost of the tradeoffs imposed on prey species under nonlethal predator exposure. This meta-analysis updates and strengthens our understanding of biotic interactions and consumer-resource dynamics, and helps predict which invasive species traits are most detrimental to native species via TMIs and indirect effects.
