Bird communities following high-severity fire: Response to single and repeat fires in a mixed-evergreen forest, Oregon, USA.
Authors:
Fontaine, Joseph B. Donato, Daniel C. Robinson, W. Douglas Law, Beverly E. Kauffman, J. Boone USDA, FS
Source:
Forest ecology and management. 2009 Mar. 10, v. 257, no. 6 [Amsterdam]: Elsevier Science, p. 1496-1504.
NALT Subjects:
wild birds population density coniferous forests fires forest-wildlife relations community ecology species diversity wildlife habitats fire severity forest ecosystems vegetation structure environmental factors animal communities indicator species Mediterranean climate Oregon
Other Subjects:
Biscuit Fire avian communities
Issue Date:
10-Mar-2009
Abstract:
Fire is a widespread natural disturbance agent in most conifer-dominated forests. In light of climate change and the effects of fire exclusion, single and repeated high-severity (stand-replacement) fires have become prominent land management issues. We studied bird communities using point counting in the Klamath-Siskiyou ecoregion of Oregon, USA at various points in time after one or two high-severity fires. Time points included 2 and 3 years after a single fire, 17 and 18 years after a single fire, 2 and 3 years after a repeat fire (15 year interval between fires), and >100 years since stand-replacement fire (mature/old-growth forest). Avian species richness did not differ significantly among habitats. Bird density was highest 17 and 18 years after fire, lowest 2 years after fire, and intermediate in repeat burns and unburned forest. Bird community composition varied significantly with habitat type (A =0.24, P <0.0001) with two distinct gradients in species composition relating to tree structure (live to dead) and shrub stature. Using indicator species analysis, repeat burns were characterized by shrub-nesting and ground-foraging bird species while unburned mature forests were characterized by conifer-nesting and foliage-gleaning species. Bird density was not related to snag basal area but was positively related to shrub height. Contrary to expectations, repeated high-severity fire did not reduce species richness, and bird densities were greater in repeat burns than in once-burned habitats. Broad-leaved hardwoods and shrubs appear to play a major role in structuring avian communities in the Klamath-Siskiyou region. In light of these results, extended periods of early seral broadleaf dominance and short-interval high-severity fires may be important to the conservation of avian biodiversity.
