REINDEER GRAZING INVESTIGATIONS IN ALASKA 27 
range observations. From results thus far obtained facts have been 
brought out regarding reproduction and recovery from injury that 
have an important bearing on the range management problem. The 
conclusions drawn are here stated, and, though not complete, are 
indicative of what may be expected in grazing a lichen range. 
GROWTH AXD REPRODUCTION 
The lichens are rapid in rate of reproduction or establishment 
of new plants. Reproduction and growth take place whenever 
favorable conditions of high moisture exist, usually in spring 
and fall. In a wet season growth may continue throughout the 
summer, but ordinarily the summers are dry and hot, and the 
lichens then lose their moisture, become brittle, and stop growing. 
Growth may continue into the winter also in sheltered, rocky situa- 
tions where the action of the sun on the frozen surface yields water 
easily. 
The average rate of growth of young plants of the species most 
important as reindeer forage is about an eighth to a quarter of an 
inch a year, and the initial growth is usually about a sixteenth to an 
eighth of an inch. In volume — that is, number — of new plants it 
is indicated that the lichens make rapid progress; in one measured 
area on overgrazed range they attained about half the normal vol- 
ume over a period of five years following denudation, or four years 
following the first appearance of new growth. Or from 1920 to 1923 
there is shown on this particular area a progressive annual increase 
in volume at the rate of approximately 50 per cent. At this rate 
the normal stand in volume or density of cover, which in this case 
is 40 per cent of lichen vegetation, should be reached in another 
two years — that is, seven years following denudation. The plants 
coming in on this area, in the order of their importance, were 
Cladonia sylvatica sylvestris, Cetraria cucullata, Cladonia bellidi- 
flora, C . coccifera, Sphaerophoru's corattoides, Alectoria nigricans, 
Cetraria islandica, Cladonia gracilis elongata, and C. alpestris. 
On the basis of the foregoing rates of growth and recovery, it 
would usually require 7 to 10 years of protection for a lichen range to 
come back to normal volume following initial growth ; and 15 to 20 
years to attain a normal height of 4 to 5 inches. These estimates, 
however, are not final, more years of observation being necessary, 
but the relative rate of recovery is apparently very slow and by 
reason of this fact, the proper management of winter range pre- 
sents an exceptionally important problem. 
QUADRAT STUDIES 
Further results obtained on several observation quadrats 1 meter 
square (pi. 18) tended to substantiate these estimates and pro- 
vided additional information on the action of lichen growth under 
partial cropping, represented artificially by cutting. These quadrats, 
established within inclosures, were on range containing a high per- 
centage of lichen vegetation (from 70 to 90 per cent). The height 
of the vegetation was from 3 to 4 to 6 inches, and occasionally 2^2 
inches at the lowest and 10 inches at the highest. The average 
height in all cases would be between 4 and 5 inches. 
