GEAZING RANGES IIST SOUTHEKISr ARIZONA. 



31 



To understand these possibilities it is only necessary to call atten- 

 tion to two or three factors which w^ould affect the result. If for 

 any reason a pasture were understocked there would be excess feed 

 on it, but the figures for average monthly and yearly numbers car- 

 ried, as well as the average carrying capacity, would be lowered. 

 Such a condition might arise if the stock-w^ater supply should 

 diminish or fail, a condition that did obtain for some time on the 

 Ruelas place during 1913 and part of 1914. 



If, because of exceptionally high prices, a man should sell a large 

 part of his stock and not restock at once, or if, for any reason, he 

 should be forced to sell or was unable to buy whenever his pasture 

 warranted it, the number of animals on the pasture would be less 



Fig. 5. — Curves showing variations in the rate of stocking on those parts of the reserve 

 that have carried stoclv for the past six years. The curves numbered 1 show the 

 average number of mature animals (cattle, horses, or burros) carried on each pasture, 

 by months, for the full period. Curves numbered 2 show the same data by years. 

 Curves numbered 3 show the average carrying capacity in acres per head per year for 

 each pasture during the period of observation. Curves numbered 3 rest upon the 

 assumption that the pastures have been stocked to their legitimate limit each year. 



than it could carry, and all the figures relating to numbers carried 

 and carrying capacity would again be below what the feed in the 

 pasture might warrant. 



Again, if the user should overestimate the capacity of his range 

 and put on more stock than it could properly carry, the result w^ould 

 be an increase in all the figures, at least for a time, and a noticeable 

 drop at a later period. Seasonal climatic variations of marked degree 

 also would tend to decrease all values if unfavorable and to increase 

 them if favorable to the growth of forage, though such variations 

 would tend. to counteract each other during a series of years. 



