Restoration of northern rocky mountain moist forests: Integrating fuel treatments from the site to the landscape

Restoration and fuel treatments in the moist forests of the northern Rocky Mountains are complex and far different from those applicable to the dry ponderosa pine forests. In the moist forests, clearcuts are the favored method to use for growing early-seral western white pine and western larch. Nevertheless, clearcuts and their associated roads often affect wildlife habitat, water and soil resources, and scenic values. To address this issue, we are applying and quantifying integrative silvicultural methods and systems that are applicable for regenerating and growing these, and other early seral species, while maintaining forest characteristics that are relevant to many contemporary forest management objectives. The silvicultural options we developed maintain multiple tree densities, a variety of canopy cover, and enhance old-forest attributes and most importantly, the harvesting, mastication, grapple piling, and prescribed fire treatments we applied will modify both wildfire intensity and burn severity. We found that the heterogeneous forest structures we created, even with small openings (average size 2.6 ha) and the minor proportion of the landscape (3 percent) treated, would alter a wildfire's progression, flame length, and fire type, according to FlamMap and FARSITE wildfire simulations. This analysis showed the placement, juxtaposition, and location of treatments within the landscape would disrupt a hypothetical wildfire's progression under weather conditions that occurred during one of the worst fire seasons (1967) in the northern Rocky Mountains. We found that masticating fuels after harvest in these multi-species and highly variable forest conditions was as cost effective as grapple piling the fuels and offered additional benefits.