Spatial interpolation and simulation of post-burn duff thickness after prescribed fire

Prescribed fire is used as a site treatment after timber harvesting. These fires result in spatial patterns with some portions consuming all of the fo rest floor material (duff) and others consuming little. Prior to the burn, spatial sampling of duff thickness and duff water content can be used to ge nerate geostatistical spatial simulations of these characteristics. Results from field studies indicated that spatial patterns of duff characteristics occurred, and they were then modeled by kriging, simulation and a trend-su rface modeling techniques. The higher elevations of the study unit burned m ore severely than the lower portion. This is believed to be due to the heat generated by the fire drying out the upper portions of the units, thus con suming more duff material and thinner preburn duff thickness due to ground- based harvesting techniques. Attempts to predict duff consumption and subse quent post-burn duff thickness were successful using a trend-surface model developed for this site and a general duff consumption model. Knowledge of spatial patterns of duff remaining may help land managers adjust prescripti ons and alter ignition patterns to reduce areas where total consumption of duff might occur.