Wildland fuel mastication is rapidly becoming the preferred fuel treatment for many fire hazard reduction projects, especially in areas where reducing fuels with prescribed fire is challenging. Mastication is the process of mechanically modifying the live and dead surface and canopy biomass to lower fuelbeddepth and increase bulk density to reduce fire hazard. The problem is that little is known about the changes in masticated fuels as they age. In 2013, we initiated a comprehensive study called MASTIDON (MASTIcatedDecomposed fuel Operational Network) to measure the diverse characteristics of masticated fuelbedsat treatment sites of different ages to evaluate effects of different aged masticated fuelbedson fire behavior, fuel moisture dynamics, soil heating, and smoldering combustion. These investigations were then used to build fire behavior fuel models for masticated fuelbedsfor use in operational fire management. This presentation presents an overall summary of the research findings for the MASTIDON project emphasizing the influence of aging on the masticated fuel characteristics and properties. In summary, we found there were minor changes in masticated fuels as they aged for their (1) physical and chemical properties, (2) rate at which they dried, (3) amount of heat they pulsed into the soil, and (4) fire behavior when burned. We also found that the method of mastication had a more pronounced effect than aging on nearly all of our 15 sites.

This presentation is part of the Missoula Fire Sciences Lab 2018-2019 Seminar Series