34 CIRCULAR 884, U. S. DEPARTMENT OF AGRICULTURE 



The relatively heavy gopher population from 1931 to 1940 on meadow 

 B, which was in poor range condition at the beginning of the study, pre- 

 vented its improvement where grazed by sheep and caused its deteriora- 

 tion where ungrazed. During the same period, gopher-free meadow A 

 improved in range condition, progressing from a vegetation dominated 

 by perennial forbs to one dominated by perennial grasses and forbs or 

 weeds, both where sheep grazed and where they did not graze. 



As a result of removing the gophers from meadow B in 1940, annual 

 weeds and grasses decreased and desirable perennial forbs and grasses 

 increased greatly. Estimated grazing capacities for the grazed plot of the 

 meadow increased from 1.31 sheep months per acre in 1940 to 7.41 sheep 

 months in 1948; and for the ungrazed plot, from 0.59 sheep months in 

 1940 to 6.56 sheep months in 1948. 



Following the introduction of pocket gophers, in 1940, into meadow 

 A, the previously gopher-free meadow in fair condition, a reduction in 

 grazing capacity was noted in 1943. This was followed by an increase, 

 except in the dry year of 1947, until in 1948 the grazing capacity of 5.25 

 sheep months per acre on the grazed plot was about double the 1940 

 capacity. This increase, however, was materially less than that for the 

 grazed plot of gopher-free meadow B, which had increased its capacity 

 5.7 times between 1940 and 1948 from a poor-condition start. The un- 

 grazed plot of gopher-infested meadow A, starting with the highest 

 grazing capacity in 1940 of 3.5 sheep months per acre after being free of 

 gophers for 9 years, more than doubled its capacity. Except for a decline 

 in 1943, it showed a steady increase and had the highest capacity of any 

 plot in 1948. 



These results indicated that Dalles pocket gopher control is necessary 

 as a range-improvement practice to obtain satisfactory improvement of 

 infested mountain meadows that are in poor range condition. However, 

 where pocket gophers infest mountain meadows in fair range condition, 

 their control may not be necessary. In such a situation, the main value 

 of control is either to make available to livestock or game the forage the 

 gopher would use or destroy, or to permit more rapid restoration of 

 the range. 



LITERATURE CITED 



(1) Bailey, Vernon. 



1936. the mammals and life zones of. Oregon, U. S. Bureau Biol. Survey North 

 Amer. Fauna 55, 416 pp.. illus. 



(2) Crouch, W. E. 



1942. pocket gopher control. U. S. Dept. Interior Conserv. Bui. 23, 20 pp. r 

 illus. 



(3) Darwin, Charles R. 



1882. THE FORMATION OF VEGETABLE MOULD THROUGH THE ACTION OF WORMS WITH 



observations on their habits. V. 37. International Scientific Series. 



(4) Ellison, Lincoln. 



1946. the pocket gopher in relation to soil erosion on mountain range. 

 Ecology 27: 101-114, illus. 



(5) Reid, Elbert H., and Pickford, G. D. 



1946. JUDGING MOUNTAIN MEADOW RANGE CONDITION IN EASTERN OREGON AND- 



eastern Washington. U. S. Dept. Agr. Cir. 748, 31 pp., illus. 



(6) Scheffer, Theophilus H. 



1931. habits and economic status of the pocket gophers. U. S. Dept. Agr. 

 Tech. Bui. 224, 27 pp.. illus. 



