Ecosystem Processes and Human Influences Regulate Streamflow Response to Climate Change at Long-Term Ecological Research Sites
Analyses of long-term records at headwater research sites in the US and Canada indicate that
climate change effects on hydrology are not as clear as might be expected from trends in
climate, potentially reflecting a buffered response via ecosystem processes, including
evaporation, transpiration, and water storage in soil, snow, ice, and groundwater. Although
streamflow at these headwater basins was correlated with climate variability, intrinsic ecosystem
processes muted the expression of long-term climate trends on streamflow. Long-term
succession in response to past disturbances (both natural and anthropogenic), vegetation
adaptations to conserve water, snow/ice accumulation and melt, and groundwater influence
streamflow responses to climate variability and change. Timing of spring runoff shifted in
snowmelt-influenced basins, but otherwise streamflow changed little from 1950 to 2010.