Wildfire is an important disturbance regime that can structure wildlife communities and their habitats for many years. Using a before-after-control-impact framework, we evaluated the effect of the Quartz Fire on a mixed broadleaf–conifer forest and associated bird community in southwestern Oregon, USA, over 10 yr. To assess whether fire severity explained changes better than simply whether an area was burned, we used a tiered sampling approach by comparing unburned control points with either all burned points combined (burned) or those same points partitioned by severity level (low, moderate, high). As expected, overall tree cover decreased while cover of shrubs increased in response to greater fire severity. This pattern was most pronounced in high-severity areas, where tree cover declined by 40% and remained depressed, but shrub cover recovered from 10% the year following fire to 75% by year 6. Ordinations of bird species density showed turnover in community composition in all burned areas combined, as well as in moderate-severity areas, shifting to a shrub-associated community 9 yr postfire. For individual species, annual density variations were best explained by fire for 14 of 37 species, with fire severity providing the best-fitting model for 7 species. Of those 7 species, 3 declined and 4 increased with greater severity. When grouped into guilds, flycatching foragers and shrub nesters increased with greater fire severity. Our results illustrate the importance of mixed-severity wildfire in creating diverse vegetation structure and composition that supports distinct bird communities for at least a decade following fire.
Vol. 117 • No. 3
Vol. 117 • No. 3