Measurement repeatability of a large-scale inventory of forest fuels

An efficient and accurate inventory of forest fuels at large scales is critical for assessment of forest fire hazards across landscapes. The Forest Inventory and Analysis (FIA) program of the USDA Forest Service conducts a national inventory of fuels along with blind remeasurement of a portion of inventory plots to monitor and improve data quality. The goal of this study was to evaluate the measurement repeatability/biases of FIA's national inventory of fuels and suggest opportunities for improving data quality and application of sampling protocols. Results indicated that more than half of the attributes did not attain the desired levels of repeatability and about one-third exhibited a non-zero measurement bias. However, the bias generally had little affect on plot-level estimates. A number of factors that contributed to these results were examined and a holistic approach that considers all aspects of inventory was suggested to improve measurement repeatability.