EN eS 
EFFECT OF GRAZING ON WESTERN YELLOW PINE. 13 
grasses occur in much purer stand than over the remainder. In the 
rest of the Forest blue grama, Gambel’s oak, and succulent weeds 
form a considerable percentage of the vegetation comprising the 
bunchgrass type. Extensive observations in this portion, supple- 
mented by many others in the yellow-pine type in the Southwest, 
bear out the conclusion that where sheep are not forced to depend 
upon the rank growth of bunchgrasses for the main part of their 
feed, but have access to plenty of browse and palatable weeds, they 
will not cause such severe damage to yellow-pine reproduction in the 
bunchgrass type. If, however, the browse and weeds are not suf- 
ficient to supply the bulk of their feed, they are likely to cause very 
severe injury to young pines. 
The portion of the bunchgrass type on the Coconino Forest, over 
which the damage is excessive, includes about one-third of the total, 
or 130,000 acres. A circumstance which makes the injury to repro- 
duction here a serious matter is the fact that where the worst damage 
occurs reproduction is scattered, and for that reason is in special need 
of protection. 
CLASS OF STOCK AND METHODS OF HANDLING. 
CLASS OF STOCK. 
It is comparatively easy to determine the amount of damage for 
which cattle, horses, and burros are each responsible, because fre- 
quently these classes of stock are handled in pastures where each may 
be observed separately. In the case of sheep, however, which are not 
handled in pastures on the Coconino Forest, but share the open range 
with other classes of stock, it is difficult to determine the proportion 
_of the damage with which they can properly be charged. To arrive 
at a conclusion it was necessary to compare the amount of damage 
found on range occupied by both cattle and sheep with the amount 
of damage under similar grazing conditions on areas from which 
sheep are excluded and in pastures. This measure of sheep damage is 
believed to be fairly accurate, since there is no evidence that cattle 
do more damage to reproduction on a range which they share with 
sheep than on a range which they graze alone. Sheep injuries, 
furthermore, are characteristic and may be readily distinguished 
from those of cattle and horses. 
It is believed that horses and burros may be eliminated from the 
classes of stock responsible for severe injuries to reproduction. The 
many saddle horses, in all kinds of physical condition, ridden in the 
yellow-pine type, have shown no disposition to eat coniferous repro- 
duction. In a pasture 4 miles southwest of Flagstaff about 30 head 
