Meeting Abstract

105.3  Tuesday, Jan. 7 08:30  Pervasive effects of size variation in tadpoles on pond communities CARLSON, BE*; LANGKILDE, T; Penn State University; Penn State University bec169@psu.edu

While ecologists historically focused on mean trait values in study populations, recent evidence has begun to demonstrate that intraspecific variation in traits may be similarly important for understanding ecological processes. Body size is a particularly variable trait within species and is known to be influenced by well-described factors such as competition. Size also has strong impacts on physiological processes and species interactions, making size variation a potentially very important characteristic of populations. We tested how tadpole size variation is affected by population densities in natural ponds, and used mesocosm experiments to compare the ecological impacts of populations of tadpoles that were either variable or homogeneous in size. We found that tadpole populations of higher density were also more variable in size. We also found that size-variable populations of tadpoles had different effects on periphyton, zooplankton, and newts than homogeneous populations of the same mean size. Size variation also interacted with the presence or absence of predatory newts, indicating that the effects are context-dependent. These findings highlight the importance of accounting for variation in size and other phenotypic traits in ecological studies.