PATTERNS OF WOODBORING BEETLE ACTIVITY FOLLOWING RECENT FIRES AND BARK-BEETLE OUTBREAKS IN MONTANE FORESTS OF CALIFORNIA.
Chris Ray; Institute for Bird Populations; PO Box 1346, Point Reyes Station, CA, 94956; (415) 233-0684; cray@birdpop.org; Daniel R. Cluck, Rodney B. Siegel, Angela M. White, Gina L. Tarbill, Christine A. Howell, Sarah C. Sawyer, Robert (Bob) L. Wilkerson
Increasing frequency and severity of drought in the western United States has contributed to increased forest fire frequency, fire season length, and frequency of bark-beetle outbreaks that kill large numbers of trees. Predicted changes in climate are expected to perpetuate these trends, especially in montane habitats, prompting interest in best practices for managing western forests and conserving the wildlife they support. Woodboring beetles colonize dead trees and speed succession of habitats altered by fire or bark beetles, while serving as forage for early-successional habitat specialists, including several woodpecker species. To understand how tree mortality affects this prey base, we sampled larval and adult woodboring beetle activity, tree and stand characteristics, and woodpecker foraging sign within montane forests of California at 16 sites burned or attacked by bark beetles in the previous 1-8 years. Woodborer activity was generally higher at sites burned mid-season. In burned sites, some adult woodborer taxa were more common in severely burned stands, while larval woodborer activity was inversely related to bark-beetle presence and was more common on pines, smaller trees and southern bole aspects. Similarly, in bark-beetle outbreak sites, larval woodborers were most common at the site richest in pine and lowest in bark-beetle activity.
Wildfire and Wildlife