UNITED STATES DEPARTMENT OF AGRICULTURE 
J BULLETIN No. 741 { 
Contribution from the Forest Service 
HENRY S. GRAVES, Forester 
JEr^SL 
Washington, D. C. 
PROFESSIONAL PAPER 
February 7, 1919 
EFFECT OF GRAZING UPON ASPEN REPRODUCTION. 
By Arthur W. Sampson, Plant Ecologist. 
CONTENTS. 
Purpose 1 
Method 2 
Injury to aspen reproduction by live stock in 
standing timber 3 
Effect of sheep browsing 3 
Relation between intensity of grazing 
and injury to sprouts 5 
Relation between intensity of grazing 
and injury to sprouts of different 
height classes 7 
Summary 8 
Effect of cattle browsing 9 
Injury to aspen reproduction by grazing on 
clear-cut lands.. 10 
Effect of sheep browsing 10 
Injury to aspen reproduction— Continued. 
Effect of cattle browsing 15 
Comparative injury to aspen sprouts by sheep 
and cattle 16 
Height at which reproduction is exempt from 
grazing injuries 18 
Height to which sheep browse 18 
Height to which cattle browse 21 
Rate of growth of aspen reproduction 21 
Sil vicultural management of aspen 23 
Methods of cutting 23 
Methods of brush disposal 24 
S umm ary 25 
Recommendations 27 
PURPOSE. 
It is desirable that on lands bearing a stand of aspen (Populus 
tremuloides) x a proper balance be maintained between timber 
production and grazing. In many of the National Forests, particu- 
larly those in northern New Mexico and Arizona, in Colorado and 
Utah, and in portions of Idaho and Nevada, aspen is a tree of con- 
siderable commercial value. It is used chiefly for fuel, posts, corral 
poles, lumber, boxwood, excelsior, and mine props, and the demand 
for it is steadily increasing. As a protective cover for watersheds, 
aspen, by reason of its extensive lateral root system, is probably more 
valuable than any other tree species with which it commonly is found. 
i Some taxonomists claim that the proper title of the western aspen is Populus aurea Tidestrom 
being distinguished from the more eastern Populus tremuloides Michaux by certain technical differences 
in the flowers and fruit, as well as by the fact that after frost the leaves of the former take on a golden- 
orange rather than a light-yellow hue. Without entering into the merits of the question, the present 
usage of the Forest Service is here adhered to. 
76783°— 19— Bull. 741 1 
