Final Environmental Impact Statement Rio de los Pinos Vegetation ...

Final Environmental Impact Statement Rio de los Pinos Vegetation Management Project
3.20 Fire and Fuels Management
Scope of Analysis
The focus of this analysis for fire and fuels management will be on the 1,379 acre analysis area
and will be directed to the spruce-fir timber type where harvesting is proposed. Fire and fuels
concerns outside the analysis area will be analyzed through the district fuels program. No
assumptions will be made as to whether or not a fire will occur on these lands, since increased
risk of a wildfire after a spruce beetle outbreak only lasts for two to three years. However,
intensity and severity, should a fire happen, can be measured by modeling prior to and sampling
of the area after a fire occurs. Intensity, as predicted by such programs as BEHAVE, BehavePlus
and First Order Fire Effects Model (FOFEM) can be described in terms of rate of spread, flame
length and scorch height, and are all described as above the surface. Burn severity relates to the
subsurface heat regime. It is generally described as residence time of the fire on the landscape,
and directly relates to consumption of litter, duff, and large diameter fuels. The higher the
percentage of large diameter fuels on the surface, the longer the residence time, the higher the
severity and therefore the greater the influence on soils and plants.
Past Actions that have affected the Existing Condition
Past fire and fuels management activities in the Rio de los Pinos Analysis Area have been
limited. See the Silviculture/Timber section for more detailed information on past activities
related to timber harvest. Fire activity and suppression in this analysis area as well as most other
spruce-fir forests is very limited due to the moist forest floor and dense canopy closure. The
combination of past timber harvest practices, fire suppression, and to some degree grazing, has
jointly contributed to the development of current stand conditions. Almost all of the analysis area
has been treated by a first entry of a 3 step shelterwood. Throughout the analysis area there has
been some fire-wood cutting activities that have helped to reduce some of the surface fuel
accumulation. In the northern portion of the analysis area, timber harvesting of the larger size
class of Engelmann spruce and sub-alpine fir in the 1950’s and 1970’s created a more open stand
of timber that has remained less prone to spruce beetle infestation. The lack of timber
management activities or natural and prescribed fire in the remaining portion of the analysis area
has allowed the stand to approach a late seral stage and has set the stage for a greater possibility
of beetle infestation and increased surface litter and debris accumulations.
Existing Condition
The Rio de los Pinos Analysis Area has been logged on at least one occasion in the past 40 years,
and has been accessible to firewood gathering after that time. There have been sporadic
outbreaks of spruce beetle over the years but none that have killed large numbers of trees. Due
to the openness of the stand left behind after the timber harvest the public has been able to
harvest most trees dying from spruce beetle up until the early 2000’s when the drought has made
conditions better suited for beetles. The public hasn’t been able to keep the spruce beetles in
check through firewood collecting in the Rio de los Pinos Analysis Area. Several factors
contribute to an area’s susceptibility to tree mortality from wildfire and the amount of change
Chapter 3 – Affected Environment & Environmental Consequences Page 3-95