SITKA spruce: uses, growth, management. 13 
common. Here the trees, though large and tall, are characterized 
by large buttressed bases, limbiness, and comparatively short clear 
length. On these moist sites the trees make a noticeably rapid 
and well-sustained diameter growth, especially from 100 to 200 
years of age. In this type Sitka spruce occurs also on tidelands 
and in swamps where there is considerable inundation ; but, although 
it can stand these conditions, it prefers an excess of soil moisture 
only with good drainage and in general avoids stagnant sites and 
acid soils. In contrast with the stands on the bottoms and benches, 
those in swamps are quite frequently pure, but the trees here are 
shorter and much more limby. Trees which occur on exposed situa- 
tions along the coast are small and scrubby and unfit for commercial 
uses. 
SLOPE TYPE. 
Spruce stands of the slope type are found on the moist but well- 
drained hills which border the lowlands and which afford all ad- 
vantages for excellent growth in their rounded ridges and gentle 
slopes of deep, rich soil. It is not only in the upland country that 
this type occurs; similar conditions exist on the rolling, sandy land 
along the coast. The trees on such sites are fine specimens, large and 
tall, with long, clear length; and, in contrast with those of the bot- 
tomland type they seldom develop buttressed bases. (PL XL) The 
wood is characteristically fine-grained, and this fact is frequently 
mentioned by lumbermen as a means of distinguishing between trees 
of the two types. Spruce in these stands is more often pure than in 
mixture, and this is especially true on the sandy lands which border 
the ocean. (PL XII.) 
COMPOSITION AND VOLUME OF STAND. 
Pure stands of Sitka spruce are usually not extensive but are apt 
to be limited to patches of a few acres in contrast with Douglas fir, 
which occurs pure over great areas. Larger pure forests of spruce 
are found occasionally, however, 40 or more acres in size in Oregon, 
Washington, and British Columbia, and even 100 acres in Alaska; 
but this is the exception rather than the rule. 
When Sitka spruce grows in mixture with other species, the most 
common associate is western hemlock, and large areas of these two 
species are found in Alaska and in the States as well. Sitka spruce 
is also associated with Douglas fir, western red cedar, lowland white 
fir, silver fir, and Pacific yew throughout the range, with Port Orford 
cedar and redwood only in southern Oregon and California, and 
with Alaska cedar and mountain hemlock on the upper slopes in 
British Columbia and Alaska. In the valley bottoms it occurs with 
such hardwoods as broadleaf maple, black cottonwood, and red alder. 
(PI. X.) 
