older than 60-80 years, natural thinning processes such as fire, insects and disease, cause 

 mortality and fuel buildup to begin. Over time fuel loading becomes heavy enough that any fire 

 ignition will lead to a stand replacement fire that may cover large expanses of land. Increment 

 bore sampling and conversations with long-time local residents indicate that a large stand 

 replacement fire occurred in this drainage between 1920 and 1930. Mature lodgepole pine, 

 which are present on site show signs of fire scaring from frequent low intensity ground fires. 

 Most dominant trees have these scars on the up-hill side indicating that at some point they have 

 been exposed to light ground fires. When these fires occurred the trees were large enough and 

 fuels light enough to prevent the ground fire from killing them. 



The project area is dominated by two distinctly different habitat types: Douglas Fir/Dwarf 

 Huckleberry and Alpine Fir/Dwarf Huckleberry. Fisher and Bradley (1987) place both of these 

 in fire group seven. Group 7 are those habitat types which are cool and usually dominated by 

 lodgepole pine. In describing the role fire plays in this group they estimated that severe, stand 

 replacing, fire occurs on a 100 to 500 year basis below 7500 ft. in elevation. Above this 

 elevation the time period between stand replacing fires is longer. Low intensity fires occur on a 

 50 year cycle (Fischer and Bradley (1987). 



Work on the Beaverhead Forest by USFS personnel Diane Hutton and Brian Quinn, indicates 

 that on average, high elevation lodgepole pine timber types will receive 4-5 low intensity ground 

 fires during their life if there is no fire suppression (Diane Hutton pers. comm.). Lack of fire in 

 these stands, due to fire suppression, appears to be having significant effects on stocking levels, 

 fuel buildup, plant succession, historic age class distribution and nutrient cycling. This is 

 especially evident in Section 5 where a large portion of the section has a much higher downed 

 woody component than the remainder of the stands within the State's ownership. Within this 

 same stand an understory of subalpine fir has become well established indicating that climax tree 

 species will soon be a co-dominate. Present mature lodgepole pines are decadent and are dying 

 rapidly. These stands have a buildup of downed woody material and a substantial amount of 

 ladder fuels present. It appears to be at risk for a stand replacement type of fire. 



In Upper Willow Creek, forests appear to fall into two general types: Douglas fir generally 

 grows in stands that produce multiple aged classes. Small patches of trees are killed by insects or 

 diseases, which create openings and then, over time, regenerate creating a multistoried forest. 

 Fire has historically played an important role in the development of the Douglas fir type in this 

 area. Over a 150-3(X) year period, stands may end up consisting of 3 or 4 different age classes of 

 trees. 



Tree species such as lodgepole pine regenerate under conditions where there is abundant sunlight 

 and bare mineral soil. Natural disturbances in lodgepole pine tend to follow patterns, which 

 leave large areas of timber roughly the same age that became established after a major fire. 

 Between 30 and 100 years of age, trees will often be subjected to frequent, low intensity ground 

 fires, which act as a thinning agent. As stands become older, forest pathogens play a more active 

 role, killing larger portions of the forest and increasing fuel loading. Forest succession also 

 progresses creating an understory of more shade tolerant trees such as subalpine fir or Douglas 

 fir. Eventually a large stand replacement fire will occur and a new stand will again become 



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