20 BULLETIN 791, U. S. DEPARTMENT OF AGRICULTURE. 



Of the bunch wheat grasses, slender wheat grass and blue bunch 

 wheat grass are about equal in the amount of dry matter produced 

 per unit of area, while violet wheat grass, occurring as it usually 

 does in rather scattered stands, seldom produces as much forage as 

 the other two species. Owing to the slightly higher palatability of 

 slender wheat grass as compared with blue bunch wheat grass, the 

 former supports slightly more stock per acre than the latter. 



The bunch wheat-grass areas, because of the class of plants which 

 they support, are better suited to the grazing of sheep than are the 

 turfed wheat-grass areas. The latter, on the other hand, are es- 

 pecially well adapted to the grazing of cattle and horses ; for to make 

 good gain these animals require less variety than sheep, and they 

 consume, proportionately, a smaller amount of weeds than sheep. 



In general the most efficient range for cattle and horses is one 

 upon which the palatable subclimax grass species have been pre- 

 served. In the case of sheep the range which will afford the largest 

 percentage of first-class feed and at the same time prove the most 

 efficient from the standpoint of pounds of gain for the season is one 

 upon which the grass stand has been sufficiently opened up to per- 

 mit of a good admixture of grass, weeds, and even browse. The fact 

 that sheep prefer a greater forage variety than is found on ranges 

 Avhere wheat grasses predominate does not imply that the climax 

 grass type should be grazed destructively with a view of fostering 

 the establishment of a large variety of more or less transitory weed 

 species. As a rule by far the biggest returns will be obtained from 

 the lands by grazing the class of stock upon them- which will most 

 fully utilize the forage crop. Sooner or later the original stand of 

 palatable plants may give way to other species, a condition which 

 may fully justify the grazing of both cattle and sheep. 



SUMMARY OF THE WHEAT-GRASS CONSOCIATION. 



Wheat grasses constitute the potential subclimax type in the high 

 mountain summer range of the Wasatch Mountains. That is to say, 

 lands occupied by a maximum cover of wheat grass support the high- 

 est and most stable type that the soil is capable of supporting. Ac- 

 cordingly, this type, when in a maximum state of productivity, affords 

 most reliable evidence of the fact that the range has not been over- 

 grazed, at least within a reasonable length of time. 



The wheat-grass type is composed of two general gi^owth forms; 

 namely, turf-forming and bunch-forming species. The turfed type 

 is characterized by roots which feed in the upper few inches of soil, 

 ^vhich tends to bind the soil firmly. The bunch type is characterized 

 by deeply penetrating roots, and since the space between the bunches 

 varies from a few inches to several feet, the stand is rather open. 



