Avian community responses to post-fire habitat conditions: Implications for fire management

Background/Question/Methods

Fire is a natural process and the dominant disturbance shaping plant and animal communities in mixed conifer forests of the western United States. Given that fire size and severity are predicted to increase in the future, it has become increasingly important to understand how wildlife responds to post-fire landscapes. Several studies have addressed avian response to post fire conditions, but have relied on fire as a binomial or categorical variable leading to uncertainty in best fire management practices for biodiversity. The Angora wildfire burned 1,243 hectares of mixed conifer forest in South Lake Tahoe, California. Using a systematic grid, we conducted avian point count and vegetation surveys at 75 locations to investigate which habitat characteristics are most important for re-establishing or maintaining the native avian community in post-fire landscapes. Specifically, we used a multi-species occurrence model to estimate how the avian community is influenced by the density of live and dead trees and shrub cover. While accounting for variations in the detectability of species, our approach can be used to estimate the occurrence probabilities of all avian species including those that are rarer or observed infrequently.

Results/Conclusions

Although all species were detected in burned areas, species-specific modeling results predicted that some species were strongly associated with specific post-fire conditions. These results have important implications for fire management. Prescribed fire or managed wildfire that burns at low to moderate severity without at least some high severity effects is both unlikely to alter the composition of avian species or to provide habitat for burn specialists. Additionally, the probability of occurrence for many species was associated with higher levels of standing dead trees indicating that intensive post-fire harvest of these structures could negatively impact habitat of a considerable proportion of the avian community.