Loss of riparian forests from wildfire led to increased stream temperatures in summer, yet salmonid fish persisted

Native salmonid fishes—cutthroat trout (Oncorhynchus clarkii) and steelhead/rainbow mykiss)—are ecologically, culturally, economically important species distributed across western North America. These fish are generally considered “cold-water” adapted species. As such, recent studies have speculated about the potential effects of climate change on these native salmonids if stream temperature thresholds exceed 16–20°C during summer. However, magnitude thermal responses to slow but steady increases in regional temperatures associated with remains uncertain hard predict. Comparatively, abrupt disturbances, such as wildfire, may produce almost instantaneous substantial that persist for multiple years until near-stream vegetation becomes re-established. In first summer following a severe wildfire Oregon, we observed initial persistence populations O. clarkii (coastal cutthroat trout) mykiss (rainbow/steelhead trout). The fire burned entire catchment, including riparian area (~76% watershed at moderate or high severity), resulting regularly exceeded 20°C represented 6–7°C relative prefire conditions. mechanisms enabling cold-water fishes despite dramatic remain unclear require further investigation. Nevertheless, wildfires represent acute natural disturbances can substantially alter regimes provide unique insights allow us better understand how systems cope projected temperatures.