38 CIRCULAR 925, U. S. DEPARTMENT OF AGRICULTURE 
TABLE 10.—Herbage production per acre in an ungrazed enclosure and 
on adjacent heavily grazed range within a black sagebrush-shadscale- 
grass subtype at two intervals after establishment of the enclosure in 1937 
Ungrazed Heavily grazed 
Species eS SSS SS 
1937 1939 1947 1937 1939 1947 
Shrubs: Pounds | Pounds | Pounds | Pounds | Pounds | Pounds 
Shadscales-==— ==. = 118.1 104.7 238 .9 120.3 168.3 319.3 
Bud sagebrush__—____ 4.7 6.2 24.1 a) 3.4 6.6 
Wantertat = = 11020 je 66.0 99.8 57 .4 32.6 
Black sagebrush __- ___ 13.5 22.8 | 196.4 Tork 12.3 22.1 
Other= 22 ee 522 5.9 16.0 3 1.5 16.4 
All shrabs == =-== 2515 5\> 256. 7-- 54s 4a 2397-84242 9 397 .0 
Grasses: 
Indian ricegrass__ ___- 42.9 90.0 26.8 43.7 56.0 39.1 
Galletaze=— = ee 16.6 FD 2.4 26.7 5.4 5.0 
equirreltail = = s— = s DD 4.3 74.7 320 3.8 20.2 
Other See ee a2, 4 6.3 =¢ 1.0 18.5 
All grasses_______ 61.9 98 .2 110.2 14-0 4 66-2 $2.8 
Rorbse Sse ee 1355 1.5 Biles: 10.8 13.8 26.3 
otales 2. Se 326.9 | 366.4 | 683.4 | 325.2 | 322.9 506.1 
Usable forage See lode 192.2} 339.2 152 2% 13727 180.7 
1 Calculated from utilization records. 
Yield of black sagebrush within the ungrazed enclosure rose from 13 
pounds per acre in 1937 to 196 pounds in 1947, about a fifteenfold 
increase. This species produced only 4 percent of the herbage in 1937 
and 29 percent in 1947. On the heavily grazed adjacent range it still 
comprised only 4 percent even though its total yield was about 50 
percent greater in 1947 than in 1937. Approximately the same relative 
increase in black sagebrush was obtained on the moderately grazed 
range in Antelope Valley as in this ungrazed enclosure. 
Bud sagebrush and squirreltail also made significant increases within 
the enclosure, in contrast to smaller gains obtained under heavy grazing. 
Shadseale also increased on both areas, but the increase was more 
pronounced on the heavily grazed range. Shadscale frequently in- 
creases on overgrazed ranges, especially where winterfat and black 
sagebrush are injured by excessive grazing. 
Grasses were quite variable in their response. Indian ricegrass in- 
creased between 1937 and 1939 and then declined. Galleta declined 
throughout the entire period. Squirreltail increased remarkably on the 
protected area, from 2 pounds per acre in 1937 to 75 pounds in 1947. 
The increase under heavy grazing was not so pronounced. 
The estimated usable forage more than doubled between 1937 and 
1947 in the protected enclosure, whereas on the heavily grazed range 
forage production declined in 1939 and then increased in 1947, largely 
as a result of fluctuation in precipitation. Yield of forage within the 
enclosure in 1947 was almost twice as great as on the heavily grazed 
range, yet total herbage was only 35 percent greater. 
