PLANT SUCCESSION AND RANGE MANAGEMENT. 61 
rying capacity is far below normal because of the use of established 
bed grounds. 
Contrary to the consensus of opinion among stockmen and others, 
the reduction in the forage crop on bed grounds can not be classed as 
temporary. The belief prevails that the large amount of fertilizer 
contained in the soil on the main part of a bed ground, and on the 
lands adjacent thereto, will favor the most rapid and thorough re- 
vegetation. Experimentation does not substantiate this opinion. 
In the plot shown in figure 25 1 after 5 years of protection against 
grazing, only a sparse stand of vegetation had gained a foothold, the 
cover being composed chiefty of species of the early-weed stage^ 
which are distinctly transitory, notably Douglas knot weed, goosefoot 
or lamb's-quarters, and tansy mustard, in addition to a few species 
which have been shown to be forerunners of the more permanent 
second-stage cover. In addition, the average height of the different 
species, as well as the depth of their root systems, was considerably 
less than over the range generally. This delayed colonization is 
accounted for by the physical rather than by the chemical condi- 
tion of the soil. To be sure, the abnormally large amount of avail- 
able nitrogen and other salts in the soil on bed grounds has a ten- 
dency to promote the height growth of the plant somewhat at the 
expense of seed production; but since a large amount of seed is de- 
posited annually on the bed ground, it is not probable that the organic 
deposits in the soil have any appreciable effect on the rate of the 
invasion or the extent of the establishment of the vegetation. It 
is well known, on the other hand, that the soil on bed grounds is 
packed exceedingly hard. So firmly packed is the surface on long- 
used bed grounds that nearly all the superficial seed either fails to 
germinate or the seedling dies as soon as the food stored in the seed 
is exhausted. As a rule, the radicle of the germinating seed fails 
to extend itself into the soil to a depth great enough to reach adequate 
available moisture. Containing, as the local soil does, a large per- 
centage of clay, the trampling, especially in wet weather, tends to 
produce the single-grain soil structure, which is most unfavorable 
to establishment and growth of vegetation. 
SUCCESSION ON MODERATELY DEPLETED RANGE GRAZED AN- 
NUALLY PRIOR TO SEED MATURITY COMPARED WITH SUC- 
CESSION ON SIMILAR RANGE PROTECTED YEARLONG. 
In certain stages of premature grazing or overstocking, the more 
hardy and persistent perennial plants may become so weakened that 
all reproduction is temporarily arrested. Long before this condi- 
1 The plot of which figure 25 is typical was fenced against grazing in 1912, prior to 
which it had been heavily used as a bed ground for several successive years. The bisect 
here shown traverses the plot and represents a strip 3 inches wide and 16 feet long. 
