The post-fire distribution of bird species in relation to fire severity

Background/Question/Methods -- It is becoming more and more apparent that severe fire is a detectable component of every fire regime, even the low-severity fire regimes.  In essence, ALL fires have every severity; it is the proportion of those severities within and among fires in any place that varies.  Unfortunately, severe fire in these systems is still routinely labeled “unnatural” or “unprecedented.”  If rare components of a distribution (even rare disturbance events themselves) are ecologically important then we ecologists need to demonstrate that fact.  So how important is the high-severity component, especially in dry forests thought to be dominated by low-severity fire, or in mid-elevation forests dominated by mixed-severity fire?  Unfortunately, the ecological importance of severe fire to conifer forest plants and animals tends to be rather anecdotal.  I offer here an analysis of a large point-count database built from bird surveys conducted at more than 3500 points distributed across more than 50 different fires in the Intermountain West. 

Results/Conclusions -- The data reveal that some bird species (e.g., Black-backed Woodpecker, Three-toed Woodpecker, Lewis’ Woodpecker, Mountain Bluebird) are not only present in, but nearly restricted to, the severe component of these fires.  Because most of these species occur rarely outside the severe fire context, the results expose an unambiguous ecological importance of the severely burned patches that occur in mixed-conifer forests falling within the low- mixed- and high-severity fire regimes.  These data serve to reinforce the view that severe fire is an integral part of the vast majority of most western North American conifer forest systems, and the empirical data help highlight the challenge confronting fire managers who try to maintain a severe fire component in the face of human presence in forested landscapes throughout the West.