Northwest Gateway Forest Restoration

Manzanita Lake area forest comparison (1925 vs. 1993)
Human suppression of wildfire has led to overly dense conditions in the Manzanita Lake and Lost Creek areas, known as Northwest Gateway. This photo series highlights the change in forest conditions in the absence of fire.

Alan Taylor

 
Human suppression of wildfire has resulted in overly dense conditions; loss of old-growth trees and wildlife habitat; and increased risk of severe wildfire in the Manzanita Lake and Lost Creek areas. These combined areas are known as the Northwest Gateway, which contains numerous facilities and other infrastructure along the park highway. The Northwest Gateway project uses a two-step process to reduce forest density through one-time use of mechanized equipment and then apply prescribed fire to restored forests 3 to 5 years after mechanical treatment.
 

Restoration Goals

The overall goal of this treatment strategy is to re-establish a fire adapted forest landscape by restoring a more resilient, diverse forest structure. Specifically, the treatment will maintain a multi-aged forest with significant old-growth elements, promote a more varied stand structure and stand species diversity, and restore and protect wildlife habitat.

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.

 
A graphic with three photos of a forest before and after different fire management treatments.
Before and after photos from Northwest Gateway Project Unit 4. The treatment area is one of 22 units within developed sections of Manzanita and Lost Creek areas.
 

Project Accomplishments and Next Steps

Mechanical treatment in 2014 successfully restored natural fuel loads to areas closest to the Manzanita Lake Area (units 1-7).

Prescribed fire application in October 2018 reintroduced fire to unit 4 (shown as burn area C below). Firefighters applied low-intensity fire to help maintain the conditions restored through mechanical treatment in 2014. The reintroduction of fire to manually treated areas has been delayed largely due to dry conditions and resulting longer fire seasons, which limit the window for prescribed burn application.

Mechanical treatment planned for fall 2022. A contractor will complete mechanical treatment on 124 acres near Lost Creek Group Campground and Volcano Adventure Camp (units 12, 13, 18). This work includes removing live understory and ladder fuels identified by a prescription for each unit. The contractor will rehabilitate all work areas once fuel removal is complete.

Prescribed fire application planned for fall 2022. Firefighters will apply prescribed (Rx) fire to 225 acres near Manzanita Lake as conditions permit. The burn units include mechanical treatment units 5-7 (completed in 2014). Burn units are identified by letters, vary slightly from the mechanical treatment units, and have their own Rx prescription. Burn units within Northwest Gateway that are planned for this fall are unit G (92 acres) and F (133 acres).

Completion of prescribed fire application fall 2022. Fire Management personnel burned Unit G (92 acres/37 hectares) on October 31 and Nov 1, 2022.

Prescribed fire application planned for spring 2023. Planning to burn Unit F in May or June of 2023.

Mechanical treatment planned for 2023. Mechanical thinning operations began in Unit 12 in October, 2022. By June of 2023, thinning operations will be complete in Units 12, 13, 14, 16, 17, and 18. Fire Management staff plan to initiate prescribed fire in these units in the fall of 2025. Mechanical thinning of Units 8, 9, 10, and 11 is planned to begin in the fall of 2023.

 
A map of colored shapes indicating areas for mechanical treatment.
The NWG Project includes mechanical treatment in 22 units. Mechanical treatment is planned in units 12, 13, 18 in fall 2022. Firefighters apply prescribed fire 3-5 years after mechanical fuel removal; see prescribed treatment map below.
 
A map of areas outlined in red indicating prescribed burn treatment units.
Prescribed burn units in Phase 1 of the NWG Project (identified in red) mostly overlap mechanical treatment shown on the map above. Prescribed burning is planned for fall 2022 in unit G and F.
 

NWG Project Q&As

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.

 

Northwest Gateway Project News

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    Last updated: March 6, 2023

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