4 BULLETIN 580, U. S. DEPARTMENT OF AGRICULTURE. 
period and also the total amount of damage during the entire graz- 
ing season. An examination was made also at the close of the 1914 
grazing season. Thus data on seasonal damage are available for two 
years, and data on total annual damage for three years. 
A supplemental study was undertaken in 1912 to determine the 
effects of protection from grazing upon the establishment, growth, 
and recovery of yellow-pine reproduction, and incidentally of forage 
plants. In each of five areas subject to close grazing and represen- 
tative of soil classes and forage types in the western yellow-pine 
belt, 2-acre plots were fenced so as to exclude all grazing. Check 
plots, established in the immediate vicinity of the fenced plots, were 
left to the usual amount of grazing. The height and spread of 
crown of the young trees within the plots were measured, and the 
location of each tree was recorded. In addition, the severity and 
probable date of past grazing injuries were noted. These data were 
secured in 1912, 1913, and 1914. It is planned to repeat the exami- 
nation every third year until a period of 10 years has elapsed, or 
until conclusive results are obtained. 
EXTENT OF DAMAGE TO WESTERN YELLOW-PINE REPRODUC- 
TION FROM GRAZING. 
AVERAGE ANNUAL DAMAGE. 
> 
The average annual damage to western yellow-pine reproduction 
due to grazing under existing practice is shown in Table I. The 
figures are those obtained during the final examinations at the 
close of the grazing seasons of 1912, 1918, and 1914. It will be seen 
that 42 per cent of the total number of trees observed are damaged 
to some extent annually. 
TaBLE I—Annual damage to western yellow-pine reproduction from grazing. 
Browsed. 
Number Injured. ; 
Year. of pices Severely. Moderately. Lightly. 
served. af 
Num- | Percent] Num- | Percent} Num- | Per cent} Num- | Per cent 
ber. | oftotal.| ber. |oftotal.| ber. | oftotal.| ber. | of total. 
GTQ ye Cees on 8, 945 853 9.5 1, 035 11.6 2,240 25 896 10 
19 EO 8,945 492 5.5 871 9.7| 1,301 14.5 915 10.2 
ORE ee sePe sede ssn Bee 8,945 448 5.0 589 6.6 698 7.8 382 4.3 
Average annual. -. 8, 945 598 6.7 832 9.3 1,413 15.8 731 8.2 
