Meeting Abstract

P2.61  Saturday, Jan. 5  Wildfire’s Wild Survivors: How Bird Populations are Affected by a Changing Habitat SCHOENLE, L. A.*; CHRISTOPHERSON, G. L.; Virginia Tech; University of Arizona schoenle@vt.edu

Historically, wildfires in southern Arizona occurred frequently, were widespread, and of low intensity. After 100 years of fire suppression, we are observing high intensity wildfires that sterilize the soil and burn the forest crown. The change in wildfire regime appears to affect the montane bird species that evolved under historic conditions. These birds may be a useful indicator of ecosystem health due to their intermediate trophic level and ability to leave an undesirable area. We examined the relationship between burn severity (unburned, low, moderate, and high) and the density and diversity of bird species 9 years after the catastrophic Aspen Fire in the Santa Catalina Mountains north of Tucson, Arizona. We detected significantly greater numbers and species of birds in burned areas than in unburned areas. This suggests that wildfires may be necessary for maintaining populations of bird species, in addition to many plant species. When comparing species density and diversity among specific levels of burn severity, we found (1) significantly greater densities of birds in areas of low and high burn severity, than in unburned areas and (2) significantly greater species diversity in areas affected by low severity fires than in unburned areas. Low burn severity fires may most closely resemble historic fire conditions and as a result, areas of low burn severity may be preferred by a wider variety of bird species. Improving our understanding of the effects of burn severity on bird populations can have important implications for forest management.