124 RECOGNIZING AND CORRECTING DECLINING FORAGE 



plots of bed grounds that have been fenced against stock for 

 many years have revegetated very slowly indeed. For several 

 years after total protection against stock, only the vegetation of 

 the early successional stages is in evidence (Fig. 36). Such 

 species as Douglas knotweed, lamb's-quarters, tansy mustard, 

 and Mexican dock are often conspicuous. Furthermore, the 

 height growth of the different species, as well as the depth and 

 spread of their root systems, is appreciably less than on areas 

 whose soil has not been heavily packed. 



The slow reseeding is due largely to the heavy packing of the 

 soil, for whenever a bed ground is plowed the original cover is 

 soon replaced. So heavily packed is the surface soil on long- 

 used bed grounds that it takes the form of a series of laminated 

 " crusts."^ Therefore, either most of the seed that falls on such 

 areas fails to germinate, or the seedlings die soon after the food 

 stored in the seeds is exhausted. 



Revegetation of Lands Grazed Each Year before Seed Ma- 

 turity as Compared with that of Yearlong Protected Areas. — It 

 has been pointed out that in the somewhat advanced stages of 

 destructive grazing the highly palatable plants are the first to 

 weaken and fail to reproduce. This failure to reproduce is invari- 

 ably associated with a sharp decline in forage yield; neverthe- 

 less the buds at the plant's crown, though they remain dormant, 

 may survive for a considerable period. 



Where a considerable portion of the vegetation is alive, though 

 low in vigor, yearlong protection or, indeed, grazing after seed 

 maturity soon rejuvenates the cover and greatly stimulates 

 growth and reproduction. The following table and Figures 

 37A and 37B summarize the effect of yearlong protection and 

 of grazing each season before seed maturity. The unprotected 

 portion shown in Figure 37A was grazed moderately by sheep 

 and cattle each year prior to and while the study was in progress 

 and corresponds to the grazing practice to which the protected 

 portion of the area was subject before the initiation of the experi- 

 ment. When the protected area was fenced, the vegetation was 



1 Sampson, Arthur W., "Herding Hints from the Changing Range." Nat'l 

 Wool Grower, Vol. 10, No. 5, pp. 20, 21, May, 1920. 



