Wildfires have increased in western North America, creating extensive areas of regenerating forests. There is concern that recent large, stand-replacing fires will synchronize forest development and commit landscapes to a future of increased disturbance, such as bark beetle outbreaks that require extensive, well-connected forests of large host trees. We analyzed forest development after large high-severity 1988 fires in Yellowstone National Park to assess future susceptibility to bark beetle outbreak. Although stands originated from the same event, persistent variation in postfire tree density and size protracted the onset of susceptibility to bark beetle attack among stands. Furthermore, postfire variability delayed emergence of the habitat connectivity required for broad-scale outbreaks, suggesting spatial variability is an important dampening mechanism for disturbance interactions.
Seidl, R.; Donato, D.C.; Raffa, K.F.; Turner, M.G. 2016. Spatial variability in tree regeneration after wildfire delays and dampens future bark beetle outbreaks. PNAS. 113(46): 13075-13080.