Thursday, August 5, 2010: 8:00 AM-11:30 AM
303-304, David L Lawrence Convention Center
Latitudinal variation in the strength of species interactions is thought to maintain patterns of biodiversity. Many hypotheses have been proposed to explain why the intensity of interactions such as competition, herbivory, and predation might increase at low latitudes; however, rigorous experiments that directly test hypotheses across broad geographic ranges are empirically difficult. Global threats to biodiversity and current rates of species loss make it critical to understand how diverse communities are maintained across broad spatial gradients. This organized oral session highlights the research of eight leading researchers using novel approaches to examine the causes and consequences of broad scale patterns in species interactions. We will synthesize current knowledge, and foster collaboration among scientists presenting the most recent theoretical, empirical and technological advances, an approach that is critical to understanding the long and short term consequences of global biodiversity loss. Specifically, the first half of the session will focus on patterns of trophic interactions across latitude. We will first begin by presenting a synthetic overview of some of the major ecological hypotheses proposed by scientists to explain latitudinal patterns of species interactions and gaps in the literature. Next, we will focus on latitudinal gradients in top-down versus bottom-up pressure, describing examples from four different habitat types, and consequences for food-web structure. The final part of the session will focus on the consequences of latitudinal variability on entire communities and ecosystems in the face of global climate change. Together, these talks will synthesize population, food web, and ecosystem perspectives in effort to explain the causes and consequences of latitudinal gradients in biodiversity.