Wildfire Effects on Stream Temperature and Flow in Humid Mountain Forest

Wildfires can alter hydrology and stream temperature (Ts) in headwater catchments, yet effects in humid forests remain poorly understood. In the western U.S., warming climates and declining snowpacks are increasing fire activity, threatening small but critical streams. We examined how catchment storage mediates post‑fire changes in summer low flows and Ts in the H.J. Andrews Experimental Forest, Oregon. Long‑term hydrologic records show increasing low flows after fire, likely due to reduced evapotranspiration, while high flows showed little change. Using 75 temperature sensors across six streams, we observed post‑fire warming of 0.5–3 °C, greatest in low‑storage, high‑severity catchments, underscoring subsurface storage as a key buffer to fire impacts.