Publication Date: 2015.
Research in eco-evolutionary dynamics and community genetics has demon- strated that variation within a species can have strong impacts on associated communities and ecosystem processes. Yet, these studies have centred around individual focal species and at single trophic levels, ignoring the role of phenotypic variation in multiple taxa within an ecosystem. Given the ubi- quitous nature of local adaptation, and thus intraspecific variation, we sought to understand how combinations of intraspecific variation in multiple species within an ecosystem impacts its ecology. Using two species that co-occur and demonstrate adaptation to their natal environments, black cottonwood (Populus trichocarpa) and three-spined stickleback (Gasterosteus aculeatus), we investigated the effects of intraspecific phenotypic variation on both top-down and bottom-up forces using a large-scale aquatic mesocosm experiment. Black cottonwood genotypes exhibit genetic variation in their productivity and consequently their leaf litter subsidies to the aquatic system, which mediates the strength of top-down effects from stickleback on prey abundances. Abundances of four common invertebrate prey species and available phosphorous, the most critically limiting nutrient in freshwater systems, are dictated by the interaction between genetic variation in cotton- wood productivity and stickleback morphology. These interactive effects fit with ecological theory on the relationship between productivity and top- down control and are comparable in strength to the effects of predator addition. Our results illustrate that intraspecific variation, which can evolve rapidly, is an under-appreciated driver of community structure and eco- system function, demonstrating that a multi-trophic perspective is essential to understanding the role of evolution in structuring ecological patterns.
Author affiliation: Rudman, Seth M.. University Of British Columbia; Canadá
Author affiliation: Rodriguez Cabal, Mariano Alberto. University Of British Columbia; Canadá. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Author affiliation: Stier, Adrian. University Of British Columbia; Canadá. Nnational Center for Ecological Analysis and Synthesis; Estados Unidos
Author affiliation: Sato, Takuya . Kobe University. Graduate school of Science. Department of Biology; Japón
Author affiliation: Heavyside, Julian. University Of British Columbia; Canadá
Author affiliation: El Sabaawi, Rana W. . University Of Victoria; Canadá
Author affiliation: Crutsinger, Gregory M. . University Of British Columbia; Canadá
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas