tively small and scattered, with white spruce on the 
better sites, black spruce on the wet, swampy flats, and 
Cottonwood, aspen, and willows on river bottoms and 
burns, as well as in mixture with the spruce. The forest 
becomes sparse and open away from the water courses, 
as is indicated on the range map following last page. 
The interior forests at present supply local needs for 
house logs, mining, agriculture, and to some extent 
for sawed lumber. The birch timber appears to be 
satisfactory for cabinet and general uses, and it is 
probable that a considerable commercial export of this 
product may be developed from the more accessible 
regions. Too little is known of the extent and amount 
of timber in the interior forests generally to venture 
any prediction regarding future commercial possi- 
bilities. Eastern Canada and some northern European 
countries, however, have built up industries on timber- 
lands which support very light and scattered stands of 
timber, and it is very possible that as the pinch of timber 
shortage is felt the interior forests of Alaska will be 
utilized, particularly where they are tributary to streams 
that will afford cheap and easy means of transportation 
to a central plant. 
NONFORESTEI) AREAS 
The nonforested parts of Alaska comprise treeless 
tundra and grassland. The grassland areas occur over 
the Alaska Peninsula, the Aleutian Islands, and the 
south slopes of the Alaska Range; the tundra, over the 
vast treeless section bordering the Bering Sea and 
Arctic Ocean and lying north of the Brooks Range. 
The grassland cover includes an abundant mixture 
of grasses and weeds, often waist high in summer, with 
a minor admixture of low, vinelike or trailing shrubs. 
The average composition of the tundra cover through- 
out is about 30 per cent lichens, 25 per cent sedges, 25 
per cent shrubs, and 20 per cent grasses, weeds, and 
mosses. Three main vegetative types are recognized; 
namely, wet tundra, dry tundra, and rocky or ridge 
areas. The wet and dry tundra areas are of heavier 
plant cover than the ridge areas, usually running 100 
per cent in rover and density, whereas the rocky or 
ridge type of the mountainous regions includes a larger 
proportion of lichens, grasses, and weeds. The wet- 
tundra type comprises chiefly cotton sedges, low or bog 
6* 
