A NATIONAL PLAN FOR AMERICAN FORESTRY 541 



years of Forest Service administration. To correct the overgrazing 

 prevalent in the local open valley areas and to speed up recovery 

 would have required such heavy reductions in the number of cattle 

 as to make further grazing by that class alone uneconomic. In 1922, 

 owners of part of the cattle grazing on the range were permitted to 

 replace them by sheep, and further changes were made later. As a 

 result, the sheep have made better use of forage on the slopes and 

 have been held off the open valley areas. The heavy grazing by 

 cattle on the spring range and in the previously overgrazed valleys 

 was practically eliminated. The spring ranges have improved from 

 100 to 200 percent and depleted parts of the summer range have im- 

 proved as much as 400 to 500 percent. A more profitable basis of 

 use of the range was developed and better watershed protection was 

 afforded as a result of the improvement of the protecting vegetation 

 on the depleted areas. 



On areas in Texas, Arizona, and Utah, supporting a considerable 

 quantity of browse there has been a tendency toward an increase in 

 use by goats. If goats are grazed in reasonable numbers they can 

 use many browse ranges to advantage where grazing capacity for 

 cattle is so low that it is difficult for that class to be grazed satis- 

 factorily. 



NUMBERS OF STOCK WHICH THE RANGE CAN SUPPORT 



One of the greatest and most widespread causes of range depletion 

 has been overstocking. Too often stockmen have been tempted to 

 obtain reasonably full use of an abundance of low-value species on 

 their ranges, with the inevitable result that high-value forage was 

 badly damaged or eliminated. An example of this is the efforts to 

 obtain rather heavy use of oak brush on ranges of southwestern Utah 

 grazed in summer by cattle. An experiment by the Forest Service 

 on this type of range showed that under more conservative grazing, 

 although fewer animals are grazed, these will yield a higher return 

 than would a larger number of animals crowded onto the range. 



The only safe basis of judging grazing capacity is the proper 

 utilization of the more important palatable forage plants of each 

 range area. In the West, as a whole, the main feed on forest ranges is 

 furnished by bunch grasses, some succulent weeds, and a few browse 

 plants that are of moderate to high palatability. Ordinarily average 

 utilization of approximately 60 percent of the foliage production each 

 year is as close use as these plants can withstand and maintain their 

 vigor, although a few plants will withstand utilization up to 80 or 

 90 percent of their foliage. Use of all the foliage of the main forage 

 plants robs them of their food-making parts and upsets their ability 

 to compete with the lightly grazed vegetation. Such use leads to 

 reduced grazing capacity and may result in rapid deterioration of 

 range values. 



There is a considerable difference in the quantity of forage produced 

 in good years and in years unfavorable to plant growth. If stocking 

 is based upon average forage production rather than upon the 

 occasional very high forage yield, the intermittent years of poor plant 

 growth can often be tided over without unwarranted injury to the 

 range. 



Precipitation is extremely important in forage production on forest 

 ranges. Studies by the Forest Service of precipitation in relation to 



