Abstract:
Delayed tree mortality is an unpredictable occurrence when prescribed burning is implemented. Fire scorched trees may die as the result of crown scorching, stem charring, root injury, bark beetle attack, or through a
combination of these factors. This study examined ponderosa pine mortality and the incidence of two bark beetle species (Dendroctonus brevicomis LeConte and Ips pini Say Coleoptera: Scolytidae) following spring and fall prescribed burning on four replicated ponderosa pine stands. There was a positive linear relationship for total tree mortality and Scolytidae incidence with stem char height. No relationship in total tree mortality or Scolytidae incidence was observed between seasons of burn when accounting for stem char height. The presence
of established bark beetle galleries was negatively correlated with external stem charring within destructively sampled ponderosa pines that died following burn application. In a related study, woodpecker use and decay dynamics of ponderosa pines dying post-fire were assessed. Woodpecker bark foraging was closely associated with the presence of bark beetles and woodborers (Coleoptera: Buprestidae and Cerambycidae). There was a positive linear relationship
between woodpecker cavity excavation and snag DBH. The probability of a snag possessing a woodpecker cavity was significantly greater if the snag had sustained a broken top. Wood deterioration within destructively sampled
ponderosa pine snags was negatively influenced by charring sustained to the bark in comparison to uncharred portions of the tree.
