Post-fire management of snag forest habitat in the Sierra Nevada

"Snag forest" is a highly biodiverse habitat type created by patches of high severity fire in conifer forests. Such habitat generally exists within a mosaic of low and moderate severity fire effects. Little effort has been spent studying the particular habitat requirements of species associated with snag forest patches, or the potential conservation concerns raised by fire suppression and post-fire logging. Nor has the historic spatiotemporal extent of high severity fire been adequately investigated.; This dissertation is comprised of three chapters relevant to the management of snag forest habitat. Chapter One investigates the relative foraging density of the Black-backed Woodpecker (Picoides arcticus), Hairy Woodpecker (Picoides villosus), and White-headed Woodpecker (Picoides albolarvatus) among four post-fire forest strata: unburned; moderate severity/unlogged; high severity/unlogged; and high severity/logged. Chapter Two explores the extent to which three common conifer species may "flush" (produce new foliage in the year following the fire from scorched portions of the crown) and survive, the failure to account for which could lead to overestimations of snag forest extent. Chapter Three studies the historic extent of high severity fire in the central and northern Sierra Nevada, overlaying a digitized map of 19th century high severity fire patches with modern GIS vegetation layers.; The results of Chapter One indicate that Black-backed Woodpeckers are restricted to unlogged snag forest habitat for their foraging needs, Hairy Woodpeckers forage most in unlogged moderate and high severity patches, and all three woodpecker species forage on large fire-killed trees more than expected based upon their availability. Chapter Two results reveal that, among ponderosa pines (Pinus ponderosa) and Jeffrey pines (Pinus jeffreyi) with 100% initial crown scorch (no green foliage), approximately half of the larger trees flush and survive. Most large red fir (Abies magnifica) with high levels of crown scorch were also found to flush and survive. Chapter Three results indicate high severity fire was not rare historically in the montane forests of the central and northern Sierra Nevada, particularly at middle and upper elevations and on steeper slopes, and the current extent of high severity fire may be low compared to historic extent.