Quantifying streamflow change following bark beetle outbreak in multiple central Colorado catchments

Abstract

Over the last decade, millions of acres of western North American forest have been reduced to areas of standing dead trees following eruptions in bark beetle populations. This thesis provides up-to-date information on streamflow response to the recent bark beetle outbreak in subalpine forests of the Colorado Rockies. Streamflow and climate measures are evaluated in eight central Colorado catchments with long-term data records and varying levels of beetle outbreak. No detectable streamflow change is observed in 7 of 8 highly impacted catchments. A significant reduction in streamflow is observed in 1 highly impacted catchment and is likely driven by tree mortality and record warm temperatures. These findings deviate from expected results and have important implications for vegetation and streamflow change under a warmer climate.