Dear Editor:

In late October, the Forest Service conducted the Devil Creek Prescribed Burn in the Turkey Springs area. The burn was carried out in an area previously thinned as part of the Turkey Springs Biofuels Demo Contract, the precursor to the Pagosa Area Long-Term Stewardship Contract (PALTSC). (The PALTSC was awarded to Forest Health Company/JR Ford on June 4, 2012. The 10-year contract was authorized to meet objectives for fuels reduction, forest restoration, and forest health improvement on San Juan National Forest lands surrounding the Pagosa Springs community, while utilizing forest biomass derived from thinning operations.) This was the first prescribed burn conducted within a biomass-treatment unit on the Pagosa Ranger District. Post burn, we reflect on observations that were made regarding outcomes and conditions on the ground, as well as lessons learned.

While the burn was not completely successful in achieving our objectives, it was a valuable learning experience for future prescribed burns in biomass units. When a prescribed burn plan is developed by fire managers, several factors come into play; some key factors are timing, weather and available fuels. Our conclusions regarding our relative success tied to these factors are as follows. First, seasonal timing is important. The burn was conducted on October 24, which is late in the season for conducting burns on north/northeast aspects, such as those found in the unit. Seasonal timing required us to start our ignition late in the morning to allow for appropriate weather conditions (i.e, temperature, relative humidity and wind) conducive to proper burning. Previous weather strongly influenced conditions, as the unusually wet September and early October resulted in atypical amounts of green grass which hindered fire from carrying effectively throughout the unit.

The most interesting observation was made involving the last factor, available fuels. The Turkey Springs Biofuel Demo Contract required cutting, and removal from the unit, of whole trees (and some shrubs) designated for thinning. In contrast with typical thinning operations that leave behind substantial amounts of “slash” (which often have to be treated at some later time), this contract required the removal of stems, plus branches, tops, and foliage. With this limited amount of fuel, in addition to the other factors discussed above, the prescribed burn exhibited low-intensity fire behavior, which equated to less smoke, shorter flame lengths and reduction in overall impacts from prescribed burning. We expect similar less intense fire behavior when fire does occur — whether management-ignited or lightning caused — in biomass treatment areas. The take home message on future fire in biomass units is that impacts, such as smoke, on the land and to publics are reduced as a result of thinning in biomass treatment areas. This effort will help in restoring our forests to conditions more resilient to future disturbance, reduce wildfire risk to people and property, and better sustain our forests for future generations.

Kevin Khung

This story was posted on December 5, 2013.