116 BULLETIN 1105, U. S. DEPARTMENT OF AGRICULTURE. 



occurring during the summer rainy season, when forage is at its 

 best, is considerable. During the fall months the damage falls off 

 appreciably, but is still important. 



On overgrazed range open to all classes of stock 35 per cent of 

 the seedlings were severely injured annually, as against 11 per cent 

 on range which was grazed normally. 



Palatability of forage is an important factor. The coarse bunch 

 grass, Festuca arizonica, which predominates on what is known as 

 the bunch-grass type, is little relished by any stock and is par- 

 ticularly ill adapted for sheep feed. In 1912 and 1913, 32 per cent 

 of the seedlings were injured on this type of range when grazed 

 by both sheep and cattle, and considerable numbers were found to 

 have been actually killed. Much less damage occurs when the 

 forage is made up largely of more palatable plants, such as grama 

 grass and succulent weeds. About one-third of the bunch-grass 

 tyP^i aggregating 130,000 acres on the Coconino, is classed by Hill 

 as suffering from excessive damage by grazing. 



Sheep are responsible, on the average, for about eight times as 

 much damage as cattle. On the bunch-grass range the ratio shows 

 a still wider disparity. Cattle do considerable damage in places 

 where they congregate, especially if confined and underfed. On 

 the whole, however, the damage by cattle and horses is not sufficient 

 to cause serious concern. 



The following is quoted from Hill's recommendations : 



1. Since overgi-azing is the cause of the most severe grazing damage it should 

 be avoided by all means. An overgrazed condition may exist even though the 

 general appearance of the range does not indicate it, as, for instance, on a 

 bunch-grass range allotted to sheep. The principal grasses may be largely 

 uneaten, while sheep feed, consisting of palatable weeds and grasses, and, too 

 often, of yellow-pine reproduction, may be largely destroyed. Overgrazing 

 may result from allotting too many stock to a range, or from poor distribution 

 of a proper number of stock due to lack of sufficient well-located watering 

 places, poor salting arrangements, or, in the case of sheep, to poor herding. 

 In any case the cause should be determined and removed. 



2. Sheep should not be depended upon primarily to utilize the bunch-grass 

 range. This type should be utilized chiefly by cattle and horses, held in pas- 

 tures if possible. On this type, wherever the bunch-grass species occur in 

 nearly pure stand during early spring, sheep should be run in May and the 

 fore part of June while the grasses are tender and most palatable. Where 

 the succulent weeds and browse species occur In mixture with the bunch 

 grasses, sheep may be grazed season-long together with cattle and horses. 



3. Sheep should be excluded from cutting areas on which they are causing 

 severe damage until reproduction is well established, usually for a period of 

 from 15 to 20 years. They should be excluded also for a period of from two 

 to five years from cutting areas where the stand of reproduction is deficient 

 but has been suppl^emented by an abundant crop of seedlings which, having 

 survived the first winter and spring, promise to become established, even though 

 injury to the reproduction already established is not severe. 



