SUGAR PINE. y 
Since slash from cuttings or natural damage, such as windfall or 
snowbreak, furnishes excellent breeding ground for destructive insects 
and materially increases the fire danger, such refuse should be dis- 
posed of by fire whenever possible before the spring following the 
cutting or other occurrence. 
These insects are normally kept i in check by wocdpeckers, certain 
predaceous and parasitic insects, and certain fungi. When, however, 
an infestation by the mountain-pine beetle commences to increase 
rapidly it can be controlled only by peeling the infested portions of 
the principal groups of affected trees during the fall or early spring 
before the beetles emerge. It is usuaily necessary as a precaution 
against fire to dispose of the resulting slash by burning at a safe time. 
These control measures, as conducted by the Forest Service, have cost 
from $2.50 to $5 per tree, according to conditions. For each tree cut 
in control work it seems-evident from statistics that one is saved. 
Since an average sugar pine tree is worth at least $15 on the stump, 
the saving is worth makin¢.' 
SILVICAL REQUIREMENTS. 
MOISTURE AND SOIL. 
The most essential requisite for the rapid development of sugar 
pine throughout all stages of its life history, but particularly during 
the seedling and sapling periods, is moisture in both soil and air. 
_ Lacking this, it becomes stunted, malformed, and useless as a tim- 
ber tree. It is generally found on cool northerly slopes and in 
ravines where the humidity is highest. 
Though sugar pine occurs on.a variety of soils, from glacial drift 
and volcanic ash to deep, loose sands and clays, its maximum devel- 
opment is reached only on comparatively moist, loose, deep sandy 
loam. Its presence is unusual on hot, dry slopes as well as on poorly 
drained wet soils. The chemical composition of the soil apparently 
has but little bearing on its distribution. 
The relative soil and moisture requirements of this species are 
indicated by the following list, in which the more exacting species 
precede the less exacting: . 
Soil. Moisture. 
Douelas fir, Red fir. 
Fate dips: 1) Sucar Prine. 
Red fir. Douglas fir. 
Sucar PINE. White fir. 
Incense cedar. Incense cedar. 
Yellow pine. Yeilow pine. 
Jeffrey pine. Jeffrey pine. 
1 For further details regarding control measures, see pages 87-89 of Bureau of Entomology Bulletin 83, 
Part I, 
