<p>Climate change is driving more frequent and severe wildfires in northwestern North American boreal forests, initiating shifts from conifer to broadleaf deciduous forest dominance. The resulting forests sequester more carbon and are more resistant to burning. However, when deciduous forests do burn, patterns and drivers of carbon losses are important for predicting long-term carbon storage in boreal forest landscapes. Here we use a combination of field and statistical modelling approaches to quantify carbon combustion losses in burned deciduous boreal forests. On average, deciduous forests lose less than half as much carbon to wildfire combustion as conifer forests per unit burned area. Although deciduous stands are more sensitive to top–down fire weather drivers than conifer stands, carbon loss is always lower than the minimum for conifer stands. This, along with the fire-suppressive effects of deciduous stands, could slow the positive feedback between wildfire and climate in fire-prone boreal landscapes.</p>