Quadrat Analysis of Wildland Fuel Spatial Variability

Abstract

Quadrat analysis of two fuel properties (loading and depth) was used to assess the relation between variation and sample plot size. By this method, an optimum range of spatial resolutions was established for sampling Artemisia tridentata subsp. wyomingensis (Wyoming big sagebrush) and Pinus contorta (lodgepole pine) fuel types in Colorado. Results of the analysis demonstrated that quadrats provide homogeneous strata and precise measures of central tendency on both fuelbeds studied. Findings indicated that field inventories in which A. tridentata is viewed as a fire fuel could use sample spacings up to 60 m (i.e., reasonably small sample sizes). The optimum range of resolution for the P. contorta fuel type was down to 20-30 m so that larger sample sizes are required. Quadrat analysis shed light on more precise fuel sampling schemes by accounting for the microsite variation of fuel characteristics. Thus, analogous studies can reveal further the semi-stochastic phenomena that govern wildland fire behaviour and effects.