Masticating Fuels: Effects on Prescribed Fire Behavior and Subsequent Vegetation Effects

In fire management, there is an ongoing quest to find cost-effective, ecologically sound, and risk-reducing approaches to restoring dry conifer forests. So far little is known about the effectiveness of using mastication equipment in conjunction with prescribed burning to help meet management and restoration goals. Richy Harrod is the Deputy Fire Management Officer at the Okanogan-Wenatchee National Forest in Wenatchee, Washington. He and his colleagues began to address this knowledge gap and found that mastication may be a cost-effective and important tool for managers looking for additional support for prescribed burns. Mastication in this study appears to help meet restoration goals, and is comparable in cost to other methods. Furthermore, mastication and burning took place in the same year. According to their findings, any mastication effort helped support prescribed burning goals.Key Findings All mastication treatments added fuel load to the forest floor, but the amounts varied by fuel size class and treatment. The mastication equipment used in this study was successful at thinning non-merchantable trees and there was minimal damage to residual overstory trees. Burning after mastication reduced fuel across treatments. Burning after mastication also significantly decreased fuel bed, litter, and duff depth. Soil heating was relatively low within all mastication treatment units that were burned. Fire following mastication generally supported forest management goals. Average cost was comparable to other fuel treatment methods, and may be more efficient.