14 BULLETIN 580, U. S. DEPARTMENT OF AGRICULTURE. 
of horses were grazed from May until November, 1910. The only 
other stock using the pasture were from three to five head of cattle 
and two or three head of sheep. The number of stock was greater 
than the carrying capacity warranted, and in the fall all forage was 
cropped very closely and the horses were poor and rough. Counts 
made in October showed that of 365 trees only 8 trees, or 2 per cent 
of the total, were seriously browsed. In a grama-grass weed pastur 
at Fort Valley, containing approximately 360 acres, about 12 horses 
were kept during the grazing season of 1910. Observations on 15 
plots showed practically no damage. 
Burros form a very small proportion of the total number of stock 
on the Forest. However, the fact that they often show little dis- 
crimination in the selection of their feed raises the question of the 
amount of damage which they do to forest reproduction. At the 
Rees’s sheep-headquarters camp, located in the bunchgrass type on 
the north slope of the San Francisco Peaks, five burros were run 
during the seasons of 1913 and 1914 in a pasture containing about 
160 acres. Observations made in October, 1914, upon 200 trees less 
than 4 feet in height showed no damage whatever by grazing. 
The amount of damage under different range conditions on sheep- 
grazed areas and on areas from which sheep are excluded has already 
been discussed. In order, however, to estimate the relative damage 
chargeable to sheep and to cattle under average conditions in the 
yellow-pine type, range conditions has been given a weight in per 
cent representing the importance of each to the whole. The per- 
centage of severe damage attributable to cattle and to sheep has 
been multiplied by the number representing the importance of each 
range condition and an average arrived at which represents the 
relative amount of damage for which these two classes of stock are 
responsible and the total per cent of damage which each class is 
believed to be causing over the entire Forest. The results are given 
in Table VI. 
TaBLE VI.—Comparison of cattle and sheep damage. 
Amount of Amount of 
Com- | serious damage Com- | serious damage 
ioe in (pe cent ot Pel seated (per cent of 
gs = otal stand). sys ve im- 
Condition of range. | portance. stand) Condition of range. | portance. total stand). 
iPercentilsaa- ase ae Per cent | >= oases 
of total. | Cattle. | Sheep. of total. | Cattle. | Sheep. 
Normally grazed ......-- 38 0. 008 ANS) MMi Hatsse. eee oe = eases 0.92) 0.20 | 0. 20 
Overgrazed.......-..---- 6 - 78 2.10 |} Around water and salt ! 
Poorly stocked with for- licks ree Sirs a eee 05 - 03 03 
AGC.eE ecb oseeb eee 12 04 -31 |} Corrals, ranches, and 
Wellstocked with forage.| 28 . 08 - 62 bed grounds.....-..--- - 03 02 02 
Bunchgrass.....-....---- 15 001 1.50 
Totalee secu sce wesc 100.00 | 1.159 8.96 
