EFFECT OF GRAZING ON WESTERN YELLOW PINE. 23 



Table 15. — Average mortality from all causes on grazed areas of seedlings of different ages. 





I>cadwood. 



South Fork. 



Year of age. 



Western 

 yellow pine. 



Douglas fir. 



Lodge pole 

 pine. 



Western 

 yellow pine. 



Douglas fir. 



1 



Per cent. 

 82 

 42 

 27 

 20 

 15 



11 

 8 

 6 

 5 



4 



3 



2.5 



2 



2 

 2 



1.5 

 1.5 

 1.5 

 1.5 



1.5 



1 

 1 

 .5 



Per cent. 

 80 

 47 

 28 

 20 

 16 



12 

 10 

 8 

 6 

 5 



4 



3 



2.5 



2 



1.5 



1.5 



.5 

 .5 

 .5 



Per cent. 

 50 

 35 

 24 

 16 

 11 



7 

 5 

 4 

 3 

 2.5 



2 



1.5 



1.5 



1.5 



.5 

 .5 

 . 5 



Per cent. 

 82 

 41 

 22 

 14 

 9 



7 

 5 

 4 

 3 

 2.5 



2.5 



2 



2 



2 



1.5 



1.5 



1.5 



1.5 



1 



1 



1 



.5 

 .5 



Per cent. 

 80 



2 



47 



3 



28 



4 



18 



5 



13 



6 ; 



10 



7 



8 



8 



6 



9 



4 



10 



3 



11 



2.5 



12 



2 



13 



1.5 



14 



1 



15 



1 



1G 



.5 



17 



.5 



18 



. 5 



19 



.5 



20 



.5 



21 to 25 



.5 



26 to 30 



.5 



Over 30 



.5 







Table 16. — Average number of seedlings per acre at different ages necessary to insure a 

 stand of 100 trees per acre of any of the three species at 150 years, if ordinary grazing 

 every year is permitted. 





Deadwood. 



South Fork. 



At beginning of year. 



Western 

 yellow 

 pine. 



Douglas 

 fir. 



Lodgepole 

 pine. 



Western 

 yellow 

 pine. 



Douglas 

 fir. 



1 



6,700 



1,200 



700 



510 



410 



345 

 310 

 285 

 265 

 255 



245 

 235 

 230 

 225 



220 



215 

 210 

 210 

 205 

 205 

 200 



6,850 



1,370 



725 



525 



420 



350 

 310 

 280 

 255 



240 



230 

 220 

 215 

 210 

 205 



205 

 200 

 200 

 195 

 195 

 190 



1,475 

 735 

 480 

 365 

 305 



270 

 255 

 240 

 230 

 225 



220 

 215 

 210 

 205 



205 



200 

 200 

 195 

 195 

 195 

 190 



4,350 

 790 

 470 

 365 

 315 



290 

 270 

 255 

 245 

 240 



230 

 225 

 220 

 215 

 210 



205 

 200 

 200 

 195 

 195 

 190 



5,170 



2 



1,085 



3 



575 



4 



415 



5 



340 



6 



295 



7 



265 



8 



245 



9 - 



230 



10 



220 



11 



215 



12 



210 



13 



205 



14 



200 



15 



195 



16 



195 



17 



195 



18 



190 



19 



190 



20 



190 



21 



190 







On the basis of the material in United States Department of Agri- 

 culture Bulletin 418, "Western Yellow Pine in Oregon/' a full stand 

 of western yellow pine of 16 inches diameter, approximately 150 years 



