RANGE IMPROVEMENT BY DEFERRED GRAZING. 7 
ESTABLISHMENT OF SEEDLING PLANTS. 
Even if a crop of fertile seed has germinated there is no definite 
assurance of material increase in the forage stand. The establish- 
ment of forage seedlings, especially early in the season, depends 
largely upon climate and soil conditions. 
During the germinating period the soil is invariably well supplied 
with moisture. In the higher mountains rather severe freezes are 
common, and as a result of alternating extremes in temperature the 
soil heaves. When this takes place the seedling roots, then poorly 
developed, are partly lifted out of the soil and the growth of the 
plant is arrested. As the season advances the temperature rises 
and the moisture in the surface soil is largely lost, so that only the 
deeply rooted and more vigorous plants survive. The loss varies 
from 20 to TO per cent, depending chiefly upon the extent to which 
the soil heaves and the development of the seedling roots at the time 
the disturbance occurs. (PI. II.) 
On the lower elevations freezing does not usually occur after the 
seed has germinated, but because of the relatively high temperature 
the soil dries out seriously, so that even there those seedlings which 
are poorly planted, and therefore poorly rooted, are likely to be lost. 
The thoroughness with which the seed is covered before germina- 
tion and the character of the soil, therefore, are everywhere important 
factors in establishing seedling stands. In hard-packed soils, . like 
those of much-used bed grounds, sheep trails, and the like, the seed- 
lings have difficulty in extending their roots, and the loss is natu- 
rally great. Heavy loss also occurs on warm, exposed situations, 
but since these usually have a dense seedling stand in the spring, the 
final stand compares well with that of more favorable localities. 
Once they have passed through the first six weeks of their existence, 
seedlings are not likely to be affected by drought or adverse tempera- 
ture. The root system develops rapidly in the autumn of the first 
year, which not only protects the plant from winter killing, but in- 
sures it against moderate gullying and drought the following season. 
During the second year of growth the young plants develop a 
splendid root system. (PL III.) This has penetrated deep enough 
into the soil before the usual spring drought period to enable it to 
continue its rapid development, and at the close of the season the 
deepest roots often extend 6 inches below the surface. In the case of 
some of the bunch grasses from 20 to 40 basal leaf blades (root leaves) 
from 3 to 5 inches long are produced. By autumn of the third year 
the perennial plants attain full development and produce fertile 
seeds. From 3 to 5 flower stalks are usually sent up, and leaf blades 
and root growth are very prominent. (PI. IV.) 
So far the discussion has dealt with the loss of seedlings under 
purely natural conditions. It is plain, however, that grazing, especi- 
