AGRICULTUKAL DEVELOPMENT IN ALASKA. 9 
currants, gooseberries, cranberries, blueberries, and other edible 
small fruits that are found in plentiful quantities over wide areas. 
The most widespread forms of plant life in Alaska are the mosses 
and lichens, and they claim attention both for their agricultural value 
and because they are also an obstacle to agricultural development. 
One of the lichens known as reindeer moss (Cladonia rangiferlna) 
grows widely in the western half of Alaska and in all that portion 
north of the Yukon. It is the principal winter food of the domesti- 
cated reindeer. 
Eeference has been made to the water and frost holding character- 
istics of the moss growth. It is this that makes the moss an impedi- 
ment to agricultural development in sections where tillage is feasible. 
It appears to decay very slowly, as is the case to a certain extent with 
all vegetable matter in localities where there are but brief periods of 
warm weather, so that a coat of moss varying in thickness from a few 
inches to a number of feet accumulates over much of the land surface. 
Even in those portions of Alaska where the winters are compara- 
tively mild, but the summers cool and moist, the frost will be so near 
the surface under a coat of moss that at any time during the summer 
a cane may be thrust through the moss to the frost line. Under these 
wet and cold conditions and the slow decay of the vegetation the soil 
is quite acid, as is evidenced by much of the plant growth, the species 
being those that grow on land that is too sour for most farm crops. 
When the timber and other plant growth, including the moss, is 
removed from the land, thus giving the heat of the sun and the air a 
chance to penetrate the soil and dry out the moisture, the frost line 
goes lower each season until it ceases to be an injurious factor, and 
in the meantime the acidity of the soil grows less. 
THE SOILS OF ALASKA. 
Alaskan soils have their origin largely in material formed by 
glacial action. They are not very rich in available plant food, as 
a rule. The vegetable matter that has accumulated on the surface 
is in such a partially decayed and acid condition that it is quite apt 
to be injurious to some cultivated plants. This is quite pronounced 
even in the regions of mild temperatures and abundant rainfall, as 
in southeastern Alaska, where vegetation is luxuriant and the soil 
is apt to be quite peaty and mucky. In fact, extensive beds of peat 
exist in various portions of Alaska. Wherever there has been suffi- 
cient drainage and the vegetable matter has fully decayed there is a 
rich black loam of varying depths; but these areas are limited to 
small valleys, some of which are the dried-up beds of former shallow 
lakes. The alluvial deposits along the larger streams contain good 
16470°— Bull. 50—13 2 
