Masticated Fuels and Fire Behavior in Forest of the Interior West
We propose research to address an urgent need to advance our understanding of the fire behavior resulting from the combustion of masticated fuels (mechanical mulching). First, we will characterize regional variation in masticated fuel beds from multiple machines, ages since treatment (1-4 yr) in lodgepole pine, dry forests dominated by ponderosa pine, and moist mixed conifer forests dominated by grand fir on the Umatilla and Deschutes National Forests and a young mixed conifer forest plantation on the University of Idaho Experimental Forest. For these in-situ fuels we will characterize particle size distribution and other fuelbed characteristics. Cluster analysis of results will be used to identify 3-8 typical fuelbeds. Second, we will conduct replicated laboratory experimental burns to characterize fire intensity, spread, duration, and combustion phase under treatments of moisture content, particle size, fuel bed depth, and wind. Third, we will repeat replicated experiments with prescribed fires in in-situ masticated fuels.
We will use two machines to conduct mastication in mixed conifer plantations being thinned on the University of Idaho Experimental Forest using a two machines: a rotary head mulcher and an excavator with a flail-head. Mastication will occur in project year 1 with prescribed fires in project years 2 and 3. Videography and ember traps in the lab and field will be used to evaluate ember production. We also plan to sample during prescribed burning operations in masticated fuels on the Umatilla National Forest to further evaluate scaling up from lab and field experiments to operational treatments. Our research results will be used to create custom fuel beds for use in fuel characteristics and fire behavior fuel models, along with pictures, fire behavior and emissions, all of which will be included in a web-based photo guide. Research results will be shared with managers and scientists, and will be incorporated into existing undergraduate and graduate courses.