Prescribed fire mortality of Sierra Nevada mixed conifer tree species: effects of crown damage and forest floor combustion

Scott L. Stephens and Mark A. Finney

A total of 1025 trees were analyzed in a study of white fir, sugar pine, ponderosa pine, black oak, incense-cedar, and giant sequoia. These trees were analyzed to find out how they would be affected by a prescribed fire. Indicators that were measured included the diameter of the tree (DBH), the percent of the crown that was scorched, along with the height it was scorched at, and the amount of the forest floor that was consumed by the fire. It was found that these indicators were not significant for predicting the death of black oak. The indicators did conclude however that death rates were lower for giant sequoia, incense-cedar, and ponderosa pine than the other species measured. It was also found that consumption of life on the forest floor is a good indicator of morality in most species.

Data needed for this study was behavioral because the forest ecologists were determining how oaks and other species responded in levels of morality to a disturbance in surroundings. This is simply observing the tree’s behavior, but can be confusing because you are not testing human subjects. Data was collected by measuring four indicators of the tree’s overall health. Data was analyzed by running regression models for four different species, although there was no pre-burn data for the forest floor of the giant sequoias measured.

Stephens, Scott L., and Mark A. Finney. “Prescribed fire mortality of Sierra Nevada mixed conifer tree species: effects of crown damage and forest floor combustion.” Forest Ecology and Management 162.2 (2002): 261-271.