Figure 9. — Diameter trend ourves 

 of residual lodgepole pine trees 

 in the Moody Meadows area^ 

 Targhee National Forest. 

 The two periods of beetle 

 infestation are shown by 

 superimposed arosshatched bars. 



YEAR 



The substantial understory consists mainly of subalpine fir and some Douglas-fir 

 and comprises about 18.5 percent of the stand basal area shown in table 4. These trees 

 average about 3.75 inches d.b.h. including trees from 1 to 15 inches in diameter. The 

 distribution of these trees by diameter groups as illustrated in figure 4 resembles a 

 J-shaped curve which is typical of succeeding species. A large number of seedlings 

 (2,812 per acre) under 1 inch d.b.h. (mostly subalpine fir) provides a reservoir of 

 trees not shown in figure 6. When released by the death of beetle infested lodgepole 

 pines, these seedlings will grow to larger sizes a:id become more prominent in the 

 stand. 



One of the most obvious effects of tree killing by mountain pine beetles is the 

 depletion of the lodgepole pine stand. This effect is rather dramatic and can be 

 observed readily in the "red top" or faded trees that appear in the stand. The dead 

 trees gradually fade from the conspicuous "red top" condition to a gray appearance in 

 2 to 3 years and begin to fall and accumulate on the ground within about 5 years after 

 the infestation subsides (Flint 1924). 



Individual trees live and grow in harmony with their environment which in turn is 

 modified by the trees themselves. This modification results from processes such as 

 shading the forest floor, intercepting snow and rain, reducing wind movement over the 

 ground, utilizing soil moisture and nutrient materials, and adding organic matter to 

 the soil as well as cycling minerals, and many others. 



14 



