GEAZING EAIs^GES IK^ SOUTHEEN ARIZOlSrA. 37 



Recovery. — It is the unanimous opinion of all who know the region 

 that the carrying capacity of the completely protected area has im- 

 proved very much over its condition at the beginning of the experi- 

 ments. There is likewise no doubt that the carrying capacity of the 

 inclosed areas under stock is now greater than that of the adjacent 

 unfenced land of similar character. 



Bate of recovery. — ^Previous publications relative to this project 

 have stated that recovery of that part of the reserve inside the large 

 field and lying above the 3,500-foot contour occurred in marked 

 degree in about three years after inclosure. The improvement in that 

 area since that time has continued, but the increase in productivity 

 has been growing less and less each year, indicating that that part of 

 the reserve has now about completely recovered. The area of in- 

 creased productivity has been gradually spreading until all parts of 

 the inclosure are now more or less improved. In the opinion of the 

 present writer, that part of the reserve below the 3,200-foot contour 

 may be expected to continue to improve for a number of j^ears more, 

 under protection, and the recovery experiment should be continued 

 at least until such time as complete recovery of this area is obtained. 



Some definite answers are now available as to the time necessary 

 for recovery under different conditions. Three years of complete 

 protection gave about three-fourths of complete recovery for the area 

 where crowfoot grama is the dominant grass, at levels of about 3,500 

 to 4,000 feet, where an annual rainfall of 15 to 18 inches occurs. One 

 inclosed pasture of this type having an area of 794 acres, which has 

 been stocked with horses and burros at the average rate of about 11 

 head per section, recovered somewhat more slowly than the com- 

 pletely protected area beside it and at the same level, but after 11 

 years protection is now not appreciably clifferent in carrying capacity 

 from the completely protected area, a condition which has obtained 

 on this pasture for the last two or three years. This would indicate 

 that this pasture recovered under light stocking in about double the 

 time required for the completely protected area. Areas at higher 

 levels might be expected to do at least as well if not better imder 

 similar treatment. 



Three other areas, 1,065, 1,695, and 1,889 acres in extent, respec- 

 tively, which have been judiciously pastured with approximately 

 all the cattle they could carry, are known to show better productivity 

 than adjacent unprotected grazing land of the same character; 

 and by their users these areas are believed to have materially 

 increased in carrying capacity under this kind of treatment within 

 a period of 11 years. Table VII and the curves in figure 5 show a 

 gradual increase in numbers carried on the two larger areas. Hence, 

 if these pastures have been stocked to their proper limit all the time 

 and the condition of the pastures has not declined, the curves indi- 



