Description

From the text ... '[A]ttempts to suppress all natural and man caused fires in the sequoia-mixed conifer forest during the past half century or more have resulted in the accumulation of extreme quantitites of dead and living fuels. This buildup has resulted in what has been termed the highest degree of fire hazard ever observed in sequoia communities (Hartesveldt 1964). In part to meet this challenge, the National Park Service at Sequoia and Kings Canyon National Parks has initiated several programs aimed at restoring fire, as nearly as possible, to its natural role in the forest (Schuft 1972; McLaughlin 1972).The current management program for the giant sequoia-mixed conifer forestsof Sequoia and Kings Canyon National Parks is based on the hypothesis that the giant sequoia exists today because of the role fire has played in its life cycle. Fire at intervals of probably 8 to 20 years reduced litter accumulations, limited the succession of tolerant understory species, and provided suitable conditions for sequoia reproduction....The present investigation attempts to record the impact of prescribed fire on certain biotic and abiotic elements of the sequoia-mixed conifer forest ecosystem by measuring these elements before and after burning.'From the Summary ... 'A 5-acre experimental plot was burned in November 1970....This prescribed burn killed more than 87 percent of white fir and sugar pine saplings and 38 percent of trees between 6 and 12 inches diameter. Only one tree greater than 12 inches diameter was killed. This apparently adjusted the successional pattern by reducing the numbers of surviving white fir to more nearly approach the proportion found in the mature age class, a class which germinated under prefire suppression conditions. While understory cover diminished significantly, the amount of sunlight reaching the forest floor increased only slightly because of the almost continuous crown canopy provided by the mature overstory. No tree seedlings were found after this late fall burn because rain and snow immediately after the fire prevented seeds from reaching the mineral soil.Coverage and frequency of shrubs, grasses, and herbaceous plants were extremely low, both before and after burning....Litter and duff fuels were reduced from a preburn 50 tons/acre to 7.7 tons/acre following burning. Combined with a major decrease in understory trees, this presumably caused a significant decline in the potential for crown fires in this giant sequoia-mixed conifer fores.'