132 Journal of Agricultural Research voi. in. No. 2 



In Table VIII it will be seen that the seedling stand before grazing 

 was rather dense, the average for all quadrats being 100.8 per square 

 meter. Fortunately the less valuable species, such as sickle sedge, were 

 the ones most weakened by drought, their condition, as will be noted, 

 corresponding closely with the character of the soil, the more porous 

 types supporting the less vigorous plants. 



After grazing (Table IX) the average stand was reduced to 48.5 per 

 square meter, a loss of 50.9 per cent. The heaviest loss was at the 

 upper limit of the area, where the short growing season caused the seed- 

 lings to be less deeply rooted. At the lower elevations the heaviest loss 

 was where the young plants were cropped. Many of the lateral roots 

 were pulled out or broken, and death followed. 



On account of the rather severe and uneven grazing, it was practically 

 impossible to determine definitely what species were best able to with- 

 stand trampUng. An examination of the root systems showed that 

 smooth wild rye had almost invariably pushed its roots more deeply 

 into the soil than any other species. Short-awned brome-grass also 

 develops an unusually strong, deep, and spreading root, and showed 

 ability to withstand trampling and to recover its vigor when portions 

 of the root were pruned off below the surface, or even when segments of 

 the rootlets were exposed to the air. Seedlings of mountain bunch- 

 grass also withstood trampling comparatively well, notwithstanding 

 the fact that at the time the range was cropped it was not so far advanced 

 as the other species. 



At High Elevation. — Owing to a great variety of conditions at the 

 high elevations, 62 quadrats were established late in August before 

 grazing. The range, which has a minimum altitude of approximately 

 7,500 feet, is distinctly herbaceous, the growth consisting primarily of 

 grasses, with mountain bunch-grass and western porcupine grass pre- 

 dominating in the order named. (See text fig. 5.) In addition, there are 

 several species of sedges and rushes, with a sprinkling of weeds and non- 

 grasslike plants, especially in the moister situations. 



At the time of the first observations nearly all the seedlings were in 

 good condition, though dead individuals were often found in the drier 

 situations. In other cases the terminal portions of some of the leaf 

 blades were dead, but this did not necessarily indicate a weakened con- 

 dition of the plant. The seedling stand, before and after grazing, is 

 shown in Tables X and XI. 



