Burning experiments in the laboratory on samples of forest floor (L + F + H organic layers) from an old-growth Tsuga heterophylla/Pseudotsuga taxifolia forest, indicated a 25-64% loss of N from the forest floor at temperatures of 300-700 C. Burning increased the N concentration of the residual material, but the total amount of N decreased. This may explain the frequent reports of an increase in N after burning.