Effect of Prescribed Burning of Forest Litter on Total Soil Nitrogen

Abstract The effect of prescribed burning of ponderosa pine forest floor on soil nitrogen was investigated. Standardized soil columns were placed under the forest floor and subjected to three burning treatments: no burn, light burn, and intense burn. One‐third of the columns were removed immediately after burning, one‐third 4 months later, and the remainder 16 months later. All burning and post‐burning treatments showed net gains of nitrogen, those of no‐burn and light‐burn being greater than that for intense burning. The gain of nitrogen in the first inch of soil for the no‐burn and light‐burn treatments was 11.1 pounds per acre per year. This gain is attributed to leaching of the decomposing forest floor remaining after treatment and indicates a decomposition rate of 3.0%. The combined effects of light and intense burning reduced the nitrogen in the forest floor by 124 pounds per acre.