Fire has long been a major factor in the ecology of forests in North America (Ahlgren and Ahlgren, 1960). Its role in the red fir forest of the Sierra Nevada, however, has received little study. Investigations in mixed conifer forests in Sequoia, Kings Canyon, and Yosemite National Parks by Biswell (1961), Hartesveldt (1964), and Reynolds (1959) lead to the conclusion that fires have been less numerous during the past 50 years than they were in primitive forests. Estimates of frequency in such primitive forests range from a fire every year or two to one every 21 years (1961), with a generally agreed upon average of something like 8 to 10 years between fires for individual trees. A conservative estimate would be that each tree was burned every 10 to 20 years. This is confirmed by the fire scars which some of the trees bear. As such, fires were an integral and important environmental factor in the evolution and maintenance of many plant communities in the Sierra Nevada before effective and widespread fire suppression activities came into being
