The role of fire as a mineralizing agent in a Sierran coniferous forest.

The role of fire as an agent for mineralizing forest floor organic matter was investigated in a Sierra Nevada sequoia-mixed conifer forest. Soil chemical properties were determined in a series of small paired plots on and adjacent to burns done by the National Park Service in their control burn program. Total nitrogen, carbon, and cation exchange capacity were found to be significantly lower on burned plots, and phosphorus, calcium, magnesium, potassium, and pH were significantly higher on burned plots. The seasonal course of certain soil chemical properties was determined in a single set of larger plots. Total nitrogen, nitrate, ammonium, phophorus, and pH were shown to increase in the spring. It is concluded that fire is an effective but not a conservative mineralizing agent.