22 



BULLETIX 738, U. S. DEPARTMENT OF AGEICULTUEE. 



Table 13. — Comparative damage from sheep grazing and from other causes. 



I All years and species. 





Nature of injury. 



Allotment and cause of injury. 



Needles. 



Side 



branch. 



Leader. 



Bark. 



Tram- 

 pled. 



All not 

 killed. 



Killed. 



Deadwood: 



Sheep 



Other 



Silver Creek: 



Sheep 



Other 



34 

 5 



18 



1 



2 



2 



4 

 32 



71 



9 

 20 



65 



577 



68 

 715 



12 

 261 



13 



1 

 5 



1 

 5 



84 



4 



11 



194 

 631 



105 

 792 



2S 

 290 



753 

 3,022 



970 

 2 797 



South Fork: 



Sheep 



Other 



4 



2 



59 

 204 



Table 14. — Gauses of d eat I 



hs of seedlings between the end of the summer of 191* 

 end of the summer of 191 A- 



] and the 







Less than 1 year old. 



More than 1 year old. 



Cause of death. 



Western 



yellow 

 pine. 



Douglas 

 fir. 



Lodge- 

 pole 

 pine. 



Western 

 yellow 

 pine. 



Douglas 

 fir. 



Lodge- 

 pole 

 pine. 



Sheep: 



520 

 838 

 917 

 523 



72 

 119 

 264 

 215 



US 

 118 

 523 

 2S2 



201 

 201 

 615 



216 



91 



99 



298 



161 



2 



1 



is' 



114 



Probable 



116 



Drought 



267 



Winter-killed 





Frost I 





4 



1 



Erosion '.. 













m 



2-iO 



7 5> 



iio 





Fungus 



Bitten off bv rodents or birds . . . 



;;;;; 



2 



5 





2 



Dug up bv rodent 



" 



1 











3 

 2 

 4 

 3 







Mole 







Babbits 



• 









Deer 







Bear 











Cattle 



2 

 2 



12 





3 

 1 



20 

 5 

 4 

 4 





1 







1 



Men 



2 3 





Insects 











Shade 



3 







i 



Crowded." 





1 











Total 





2,719 



614 935 



1, 191 



579 



514 











VALUATION OF DAMAGE. 



Using the table of height growth and the average proportions of 

 seedlings of different sizes killed by all agencies on the grazed plots 

 on all areas, curves were constructed to show the per cent of mor- 

 tality at different ages. Table 15 was read off from these curves, 

 and from it was computed Table 16, which shows the number of 

 seedlings of any age up to 20 years necessary to insure a stand of 

 100 trees per acre of any of the three species at an assumed maturity 

 of- 150 years. These figures allow for deaths from all ordinary 

 causes, including grazing every year, but, of course, do not allow for 

 extraordinary deaths due to such causes as fires or epidemics of 

 insects or of fungous diseases. 



