120 BULLETIN 1105, U. S. DEPARTMENT OE AGRICULTURE. 



Since both of the above pastures have been closely grazed by 

 cattle and horses, the only conclusion which can be drawn is that 

 the excellent reproduction is due to the exclusion of sheep. It should 

 also be borne in mind that these areas, outside as well as inside 

 the pastures, represent optimum conditions for yellow pine reproduc- 

 tion. The counts still show a fairly good number of seedlings out- 

 side the fences, although they are as a rule injured. It is possible 

 that on such sites as this the pine may eventually restock in spite 

 of sheep grazing, as it has evidently done on certain areas in the 

 j)ast. This is by no means certain, however, as indicated by the 

 following examples on the Apache and Sitgreaves National For- 

 ests, where conditions in general are more favorable for reproduc- 

 tion than on the Coconino and Tusayan. 



A most striking example of the effects of sheep grazing is found 

 on the White Mountain Indian Reservation near Cooley, Ariz. 

 About 8 miles east of Cooley is a drift fence. On the east side sheep 

 have grazed for years. The forest is a heavy virgin stand of yellow 

 pine. Reproduction is scanty, and almost every seedling is badly 

 damaged by sheep. On the west side of the fence sheep have been 

 excluded. The timber, topography, and soil are in no way different 

 from the east side; but immediately on passing through the fence 

 one finds seedlings in considerable numbers, which increase until 

 one-half mile west of the fence the openings between groups of trees 

 are completely stocked with saplings ranging from 3 to 6 feet in 

 height. Evidence shows that sheep have gone through the fence 

 to some extent, thus accounting for the lighter stocking of seedlings 

 near the fence than farther to the west. The fact that the forage 

 here is mainly bunch grass is probably an important factor. 



In May, 1919, Chapman noted, regarding the Chevalon district 

 on the Sitgreaves National Forest : 



The conclusion is that the presence of all the reproduction in those portions 

 of the Chevalon District which are reproduced is due to the fact that sheep 

 have not been present to any extent on these areas during the years when the 

 seedlings originated and were growing to a height of three feet — and that 

 reproduction is practically absent on all areas continually grazed by sheep for 

 30 years, while on areas grazed for a lesser period the age classes are absent 

 which would correspond to the period within which sheep have grazed. 



Chapman makes similar observations regarding the Heber dis- 

 trict on the Sitgreaves and various parts of the Coconino. 



Dozens of examples can be cited which are no less impressive 

 than the ones just described. A partial list of areas in the vicinity 

 of Flagstaff is given in Table 28. In every instance the evidence 

 of destruction by sheep is overwhelming. In some instances, no 

 doubt, the excessive damage outside the fence is due partly to over- 

 grazing by all classes of stock, especially sheep; but grazing has 



