Northwest Gateway Forest Restoration

One hundred years of fire exclusion has resulted in overly dense and unhealthy forest areas. In the absence of surface fires, young white fir have formed dense thickets crowding out old growth pines, aspen stands, and understory shrub and grass vegetation. Restoring forests to pre-suppression conditions will reduce old growth mortality rates, promote a more varied stand structure, and restore and protect wildlife habitat.

The first step in this forest restoration process involves one-time entry with mechanized equipment to reduce live understory and ladder fuels. Prescriptions for each unit identify which fuels will be removed and focus on areas near old-growth pine, aspen groves, and healthy pine stands. Successful fuel removal reduces the possibility of high-intensity wildfire and prepares the forest for a return to historic and natural fire activity.

Once natural fuel load levels are restored through mechanical treatment, fire is reintroduced through application of prescribed fire. This second step is completed approximately 3 to 5 years after mechanical treatment. Historically, fire burned regularly in this area every 5 to 20 years, naturally maintaining density and forest health. Prescribed fire applications in similar conditions without prior mechanical treatment have resulted in high-intensity fire behavior. The combination of both treatments restores healthy forest structure and supports the use of prescribed fire to maintain areas without further use of mechanical equipment.

Reducing fuels and restoring forest health in the treatment areas will:

• Increase wildfire resilience in developed areas (containing or adjacent to infrastructure)
  Treatment removes dense thickets of white fir, which can thrive without regular fire. Restoring pre-suppression density helps to reduce the risk of severe wildfire.
   
• Reduce old-growth mortality rates and promote a more varied stand structure
  Treatment reduces crowding around old-growth pines and helps to restore pre-suppression forest structure (proportions of different-aged trees).
   
• Restore and protect wildlife habitat
  Treatment reduces forest density to reduce crowding and foster growth of old-growth pines, aspen stands, and understory shrub and grass vegetation.

One hundred years of human suppression of wildfire has resulted in overly dense conditions and loss of old-growth trees and wildlife habitat. In the absence of wildfire, white fir is crowding out other vegetation, gradually replacing jeffrey pine, and creating hazarous fire conditions. 

White fir is a shade-tolerant species that can thrive in forests without regular fires. Jeffrey pine needs the sunny gaps in forest canopies that periodic fires create, where there is enough light for pines to establish and grow. Mechanical treatment, followed by the reintroduction of fire, restores forests to pre-suppression conditions.

Mechanical treatment is an effective and efficient tool for reducing fuels in developed areas. NWG treatment units are adjacent to numerous facilities and infrastructure including campgrounds, historic buildings, and trails. Mechanical treatment prescriptions for the units identify which fuels will be removed and focus on areas near old-growth pine, aspen groves, and healthy pine stands.

Once fuel reduction is complete, prescribed fire and lightning-ignited fire will be used to maintain forest health. Prescribed fire applications in forests with similar pre-restoration conditions have resulted in high-intensity fire behavior.

Prescribed fire mimics nature's way of maintaining forest health. Once fuels are stored to pre-suppression levels through mechanical treatment, manual treatment, or lightning-ignited fire, prescribed fire can be applied to reintroduce natural fire regimes. In the NWG project, prescribed fire is applied 3 to 5 years after mechanical treatment. Prescribed fire applications in forests with similar pre-restoration conditions have resulted in high-intensity fire behavior.

The relatively moderate effects of the 2021 Dixie Fire within Lassen Volcanic are one example of the positive impacts of fire management. Past fuel reduction activities, weather, and firefighting efforts helped to slow the fire's progression through the park and resulted in more varied levels of burn severity. Effects of the nearly one-millon-acre fire were much more severe in untreated forests that remained overly dense following 100 years of fire exclusion.