542 A NATIONAL PLAN FOR AMERICAN FORESTRY 



growth of vegetation in different parts of the West indicate that 

 below-normal conditions have prevailed on the average over much 

 of the range during the last 8 to 15 years. Thus in the foothills of 

 the San Joaquin Valley of California precipitation for the period 

 from 1923 to 1931 was about 14 percent below normal; precipitation 

 at Boise, Idaho from 1919 to 1931, inclusive, was below average in 9 

 years out of 13; while at Roosevelt, on the Salt River watershed in 

 Arizona from 1922 to 1930, inclusive, 6 years were well below average 

 and 3 years were only slightly above average. Such continued sub- 

 normal precipitation, in a naturally semiarid region, makes it ex- 

 tremely difficult for the vegetation to maintain itself. If stocking is 

 not adjusted currently to reduced forage production, rather serious 

 depletion results. For example, on woodland ranges of southern 

 Idaho, largely in private ownership and in the public domain, results 

 from measured plots have shown that the forage cover has been re- 

 duced from 40 to 80 percent of the original cover over large areas. 

 On national forests, where an effort is made to adjust numbers of 

 livestock to average feed production over the years and thus prevent 

 overgrazing, the large increases in numbers of livestock during the 

 war, as an emergency measure, resulted in overstocking on many 

 national-forest ranges. It has been difficult, in view of the sub- 

 normal precipitation, to reduce stocking rapidly enough to check 

 range depletion. Where voluntary reductions were not sufficient 

 it has been necessary to require reductions in the number of livestock. 

 Fortunately, such required reductions have not been great or wide- 

 spread. 



PROPER SEASONAL USE 



Grazing forage plants before they have made enough growth to 

 withstand cropping has also been one of the principal causes of the 

 deterioration of western forest ranges. If grazing promptly removes 

 the first growth it deprives the plants of their food-making parts. 

 As a result, the vitality of the forage plants is lowered, forage produc- 

 tion is reduced, and the weakened plants are unable to produce fertile 

 seed, or may be killed out entirely. Therefore, the date when grazing 

 can satisfactorily begin should be based upon the development of the 

 more important palatable plants on the particular range. With 

 sufficient growth, utilization of part of it will not injure the vigor of 

 the plants. 



The close of a summer-grazing period should be governed usually 

 by weather conditions and by the supply of feed. It is not advisable, 

 as a rule, to graze the range in the fall up to the point that livestock can 

 get only enough forage for sustenance. 



PROPER DISTRIBUTION OF LIVESTOCK ON THE RANGE 



Adequate distribution of watering places and salt offer the most 

 practicable and economical means of procuring satisfactory distribu- 

 tion of cattle and full and uniform use of available feed. 



Examples of beneficial results from more effective distribution of 

 cattle on national-forest ranges are numerous. While in most in- 

 stances the main result has been to overcome local overgrazing without 

 reducing the number of cattle, one national forest supervisor, for 

 example, reports an increase from 1,574 cattle to 2,200 on one range 

 in 7 years as a result of some 66 new, well placed salt troughs. Another 



