Evaluating Charcoal Resulting from Conservation Burn Piles: An Analysis of Hand Crew Practices in Remote Locations

This study investigates the effects of an alternative method of conservation burn pile design on burn temperature and charcoal conversion efficiency during forestry restoration work on San Juan Island, Washington. Forest thinning treatments at both sites generated wood debris that was processed using conservation burn pile techniques. This study explores the following two research questions: Does the addition of a single-layer sheet metal heat shield during a conservation burn pile have a significant effect on the average burn temperature? Does the addition of a single-layer sheet metal heat shield during a conservation burn pile have a significant effect on the charcoal conversion rate? Forty piles were constructed and assigned either of two treatments: (1) standard open-air pile burns and (2) heat shield piles designed with a single layer of sheet metal around the pile perimeter. Statistical analysis using the Shapiro-Wilk and Bartlett tests confirmed the assumptions of normality and equal variance for the data variables in question. Two-sample t-tests (p=0.05) were used to assess differences between pile types in mean burn temperatures and charcoal conversion rates. Results indicated no significant differences in average burn temperatures between standard and heat shield piles. Similarly, results indicate no significant difference in charcoal conversion efficiency between pile types. These findings suggest that the addition of the designed heat shield did not substantially influence burn temperatures or charcoal conversion rate under the conditions tested.