Resource Management

Elements of a Prescribed Burn

Brookshire Hazardous Fuels Reduction Project - Colson Burn Unit was initiated on December 12 and continued on through December 14, 2005. This prescribed burn project will be used as an example to explain prescribed fire.

The project area is within the Sisquoc watershed. which has had 9 large wildfires over 10,000 acres each since 1911. Wildfire was the primary natural disturbance process in this landscape at the time the project was done and about 80% of the watershed was at a critical level for hazardous fuels. Older chaparral burns intensely, and a high intensity wildfire can result in major effects upon ecosystem processes such as:

  • severe vegetation loss,
  • soil erosion,
  • reduced land stability, and
  • degradation of stream habitat

The project goal was to burn some of the older and dead fuel in order protect private property (Tepusquet residents) and public resources such as watersheds, wilderness and species habitat from wildfire damage.

Project

This project was designed to allow fire to occur safely under manageable conditions.

[Photograph]: Dozer used to clear fuel break.

This project began a year before the burn, by preparing a fuelbreak along Buckhorn Ridge. Dozers were used to open up the overgrown jeep trail along the ridgeline on the project boundary area to make it accessible for fire engines.

[Photograph]: showing jeepway cleared of brush.

Brush next to the jeep trail was pushed into piles located within the project area and left to dry. (Photo taken after piles had been burned.)

[Photograph]: Burned area on the right side of the jeepway.

When some piles were burned, the fire was allowed to spread slightly into the adjacent brush to form a blackened strip along the fuelbreak. Why did the fire stop midslope? Expertise on the part of the ignition specialist! When fire is applied in the right conditions, it will back downslope until it hits a cooler, moist, or shady area; the fire then looses heat, and dies out.

[Photograph]: Oak tree with low branches and overgrown brush.

Dead lower branches of oak trees can carry fire into the crowns (known as ladder fuels). As part of site preparation, the lower branches were cut off and scattered away from trees along the fuelbreak.

[Photograph]: Shows brush treated with prescribed fire on the right side and untreated brush on the left side of the photo

Treated vs untreated chaparral on the edge of the fuelbreak.

After one year, some chaparral re-sprouted to approximately 2-3 feet tall, with tender green growth, and less dense spacing compared to adjacent older brush. Compare the right side and left side of the photo.

Helitorch Operations

[Photograph]: Helicopter transporting a helitorch.

A fuel canister and lighting mechanism (helitorch) is suspended below the helicopter. The helicopter used the helitorch to drip flaming fuel into the chaparral just below the fuelbreak.

[Photograph]: Helicopter igniting brush with the helitorch mounted below it.

 

Prescribed Fire Operation

[Photograph]: Burning brush during the prescribed burn.

The chaparral caught fire quickly and burned the short distance to the fuelbreak before gathering too much intensity. The low fire intensity allowed the fire to die out when it reached the fuelbreak and ran out of fuels to burn.

[Photograph]: Fire engines and crews were place along the road. Fire can be seen below where they are located.

Fire crews were strategically placed along the road , while the line of fire moved toward fuelbreak.

[Photograph]: Firefighters and fire engines observe the prescribed burn; ready in case they are needed.

Crews were on standby to be available in case of fire spotting across the fuelbreak.

[Photograph]: Large column of smoke travels straight up into the atmosphere, just what is desired.

Plume rising straight up demonstrates a favorable condition for dissipating smoke from the area.

[Photograph]: Smoke seen from the prescribed burn.

High altitude winds moved smoke away from adjacent populated areas.

[Photograph]: Mosaic of vegetation seen in the area treated by the prescribed burn.

The treated area resulted in a fine mosaic of burned and unburned areas which provides favorable habitat for wildlife and retards the spread of future wildfires.

[Photograph]: Large flames are seen during the prescribed burn.

The burn flared up in pockets of fuel accumulations, especially on drier south-facing slopes which have lighter, flashier fuels.

[Photograph]: Fire slowly creeping down slope.

Fire slowly backed down the slope, at low intensity which is favorable for maintaining healthy soil conditions. The fire died as it reached more moist conditions or shady cool spots.

[Photograph]: Plant skeletons left where the chaparral burned.

Light intensity fire traveled through chaparral and left charred brush skeletons.

[Photograph]: Organic material left after the fire went through the area.

Organic material was lightly burned in some areas and still provided soil cover.

[Photograph]: Green grass is left in the burned area

The burn was light enough in some places to leave some twigs unburned; note the green grass shoots.

[Photograph]: A sage plant, only partially charred, within the burn area.

Partially burned sage.

[Photograph]: Areas of unburned vegetation within the burned area.

Pockets of unburned vegetation created favorable habitat mosaics of cover for wildlife and help control erosion.

[Photograph]: Areas of unburned vegetation within the burn area.

A light underburn in an oak stand located in the valley below the fuelbreak.

[Photograph]: Green grass not burned in the prescribed fire area, only the dead grasses burned.

Fire of light intensity only burned the dead grasses below the oaks along the fuelbreak.

Water Guzzler in Burned Area

[Photograph]: A water guzzler provides water for wildlife.

Brush removal revealed a water guzzler. A water guzzler collects water on the roof and it drains into tank. A ramp from the edge of the tank to inside water level allows wildlife to reach water.

[Photograph]: Lower outlet of guzzler; before the fire it was not seen due to the dense brush covering it.

The burn exposed a lower outlet of the guzzler located under dense brush.

[Photograph]: Wildlife were using the guzzler shortly after the burn had traveled through the area.

Several birds were using this water within 3-4 hours after the burn. A bobcat exited the blackened area from a patch of unburned chaparral. Local wildlife species are adapted to the many fire events that are typical in chaparral habitat. Birds fly away, large mammals flee to safety and small mammals, reptiles and amphibians find refuge underground. Soil is a great insulator from heat!

[Photograph]: Column of smoke during the prescribed burn.

Burn prescription weather was only available for a few days allowing treatment of about 2600 acres of the 7300 acre Colson unit.

[Photograph]: Large column of smoke billowing within the mountains in the prescribed burn.

When prescription conditions are met again, the remainder of the unit will be treated.