Bird community structure following multiple high severity fires and post-fire logging in the Klamath-Siskiyou region

Fire is the principal agent of natural disturbance in forested portions of western North America.  While an emerging literature is documenting wildlife response to a single stand-replacing fire, little is known about patterns of vertebrate community succession following disturbances that include recurrent fire (reburn) and post-fire salvage logging, particularly in forests with more frequent fire.  The mixed-severity fire regime of the mixed-conifer and broad-leaved evergreen forests of the Klamath-Siskiyou ecoregion represent a transitional system that has potential relevance to many forested regions, both wet and dry, across western North America.  From 2004-2006, we studied bird communities in southwestern Oregon in and around the area burned by the 2002 Biscuit fire.  We sampled areas with distinct disturbance histories varying in number of times severely burned (0, 1, or 2) and time since fire (2, 17, or 100+ years) and intensity of post-fire salvage logging.  Bird communities at different times since fire were distinct from one another as well as those following one versus two high severity fires.  Prevalence of fresh snags (once burned), re-sprouting shrubs (reburned), and live conifers (unburned) were the strongest environmental correlates associated with bird communities in each disturbance type.  Foragin and nesting guild and other natural history traits clearly separated areas with different disturbance histories as well.  Early seral habitats characterized by broad-leaved shrubs possessed higher abundance and species richness of birds relative to late seral, conifer-dominated sites.  These results underscore the role of fire-generated early seral stands in maintaining avian biodiversity on the landscape.