AVIAN COMMUNITY DYNAMICS ARE DISCORDANT IN-SPACE AND TIME

The threat of global climate change challenges community ecologists to predict long-term and continental-scale changes in the structure of e cological communities. However, the vast majority of studies have been done at small temporal and spatial scales. Can conclusions about comm unity dynamics based on small-scale studies be extrapolated to larger spatial and temporal scales? We compared the dynamics of regionally co existing bird species over different spatial and temporal scales using data from the North American Breeding Bird Survey. We found that such extrapolation is suspect. Bird species that had similar local year-to -year population fluctuations did not have similar long-term populatio n trends. Additionally, species that had similar population dynamics i n one region rarely exhibited similar dynamics in the different region s where they occurred together.