Climate Dipoles as Continental Drivers of Plant and Animal Populations

Ecological processes, such as migration and phenology, are strongly influenced by climate variability. Studying these processes often relies on associating observations of animals and plants with climate indices, such as the El Niño–Southern Oscillation (ENSO). A common characteristic of climate indices is the simultaneous emergence of opposite extremes of temperature and precipitation across continental scales, known as climate dipoles. The role of climate dipoles in shaping ecological and evolutionary processes has been largely overlooked. We review emerging evidence that climate dipoles can entrain species dynamics and offer a framework for identifying ecological dipoles using broad-scale biological data. Given future changes in climatic and atmospheric processes, climate and ecological dipoles are likely to shift in their intensity, distribution, and timing. Climate variability is cataloged using climate indices that ecologists rely on to study phenology, migration, and population dynamics.Climate dipoles are a common characteristic of climate variability that emerge in terrestrial and marine systems as contrasting patterns in anomalies of temperature or precipitation appearing at two different geographic locations at the same time.Climate dipoles have the potential to entrain continent-wide processes ranging from bird migration to plant reproduction and produce ecological dipoles.Ecological dipoles can be identified by applying approaches of space–time analysis to biological and climatological observations collected at continental scales.Given the altered patterns of atmospheric processes, increasing synchrony of weather, and land-use-driven changes in climate, it is likely that climate and ecological dipoles will shift dramatically in the future.