20 



BULLETIN 741, U. S. DEPARTMENT OF AGRICULTURE. 



10 



8 so 



^ so 



Table S shows that while the plot was grazed much more closely 

 than would be warranted on the basis of sustained forage yield, only 

 8 of the 69 sprouts on the transect (11.6 *per cent) were seriously 

 grazed and thus likely subsequently either to die or become very 

 deformed. All the other sprouts were in vigorous condition; and 

 though they were browsed slightly, the damage was not such as to 

 manifest itself in the future development of the stand. In most in- 

 stances the browsing was confined to the lateral branches, only 20 

 of the 69 sprouts (29 per cent) having both the terminals and the 

 laterals removed. Only 3,483 of the 30,056 sprouts to the acre were 



seriously weakened 

 by browsing, leaving 

 26,571 vigorous speci- 

 mens for the estab- 

 lishment of the stand, 

 a number exceeding 

 by more than 24,000 

 the quantity neces- 

 sary to restock the 

 land fully. 



The most signifi- 

 cant fact brought out 

 by the experiment is 

 that the maximum 

 height of sheep brows- 

 ing was 47 inches, 

 and this occurred only 

 in the case of a single 

 To show 

 more clearly than in 

 Table 8 the average 

 height at which the 



4-0 



30 



4? 

 O 





* 





















































J-^J" 4 



-. 



^^^^^^ 





rf*' 









> 



-^ < 



— ""* < 



-^ 



















































4 S 6 7 

 C/ass Of Sprouts 



S 



Average Height Of Sprouts 

 ^Heyht Of Sprouts Exempt From specimen. 

 [Serious Drowsing 

 — .__ Average Height drowsed 



Fig. 6.— Heights at which sprouts are browsed. browsing occurred the 



sprouts were grouped into 6-inch height classes and the average height 



of the browsing in the case of each height class recorded. The figures 



are given in Table 9 and the results are shown graphically in figure 6. 



Table 9. — Summary of heights at which aspen sprouts are browsed by sheep. 





Number of 



Height class. 





Height 

 class No. 



specimens 

 in each 







height 







grazed. 





height class. 



Average. 



Mean. 







Inches. 



Inches. 



Inches. 



1 



1 



18 to 23 



21 



21.0 



2 



2 



24 to 29 



27 



29.0 



3 



6 



30 to 35 



33 



30.7 



4 



13 



36 to 41 



39 



36.8 



5 



10 



42 to 47 



45 



41.1 



6 



10 



48 to 53 



51 



39.0 



7 



12 



54 to 59 



57 



40.1 



8 



5 



60 t o 65 



63 



38.2 



9 



10 



66 to 71 



69 



41.8 



