INCREASING FORAGE YIELDS ON INTERMOUNTAIN WINTER RANGES 37 
TaBLE 9.—Herbage production per acre within a depleted black 
sagebrush-winterfat subtype in 1934 and after 4 and 13 years of 
grazing under moderate and heavy intensities * 
Tidal Moderate grazing Heavy grazing 
Species Wieldsc |ascerae Fea all ERR rE 
1934 1938 1947 1938 1947 
Shrubs: Pounds | Pounds | Pounds | Pounds | Pounds 
Black sagebrush —_ =< =_7 = 20.6 44.7 295.8 13.8 | 27.9 
Small rabbitbrush__-__-___-_ 66.3 100.2 23).9 161.9 243.7 
NWA Gertie = 32 ee ee 181.1 369.6 279.4 205.2 153.4 
Others ies eo ee soe 3.0 (2) @) (2) (7) 
‘Allishrubs-222 22.2% 271.0 514.5 603 .7 380.9 424 .6 
Grasses: = 
Galletak eGo ee ee tS a4 6.0 2.8 5.0 Beal 
Indian ricegrass___-______- 9.9 14.8 40.9 11.1 18.6 
NoUuEReltall ss ee ee on 4.1 28.3 13 4.5 
Others se ees (2) (2) (2) (?) (2) 
All grasses____-__- 16.4 24.9 7220 17.4 26.2 
Forbs: 
Globemallow___--______-_ (2) 4.8 Zeal: (2) 4.8 
Russian-thistle._-.-_____- (2) (2) 6.0 3.0 96.7 
Otherstaaass Ge ee (2) 9 9 (2) 9 
Mletonrbss. 3 = (2) De 9.0 3.0 102.4 
Totals ses ee ees 287 .4 545.1 684.7 401.3 55302 
Usable forage *_____ 2 V4 9 283 .9 433.1 160.8 168.0 
1 Calculated from plant density data. 
? Less than 0.1 pound per acre. 
’ Calculated from utilization records. 
Grasses increased more than fourfold under moderate grazing. The 
greatest increases occurred in the palatable squirreltail and Indian rice- 
grass. Yield of squirreltail in 1947 was more than nine times and that 
of Indian ricegrass four times as great as in 1934. Although these 
species made pronounced gains, they produced only about 10 percent of 
the total herbage and 12 percent of the forage in 1947. These species 
made little gain under heavy grazing. 
Production of Russian-thistle on the moderately grazed range was 
very low in all years. In contrast, yield of this species on the heavily 
grazed range in 1947 was about 97 pounds per acre, one-sixth of the 
total yield. 
Additional observations on vegetal changes were made on a deteri- 
orated black sagebrush-shadscale range in Snake Valley, 3 miles north 
of the Desert Experimental Range. A 4-acre enclosure was con- 
structed on the range in 1937 and herbage production of all plant species 
was recorded on plots inside and outside in 1937, 1939, and 1947 
(table 10). | 
