HcigJit and diameter C'f'oicth of Douglas fir. 



Height growth. 



Diameter growth. 



Age. 



Coast 

 form. 



Mountain form. 



Coast 

 form. 



:Monntain form. 





















Western 



Washing- 



ton.o 



Tar- 

 ghee. & 



Uinta, c 



San 

 Juan.c 



Western 

 Washing- 

 ton. o 



Tar- 

 ghee, b 



Uiuta.c 



San 

 Juan.c 



; 



Years. 



Feet. 



Feet. 



FecL 



Feet. 



Inches. 



Inches. 



Inches. 



Inches. 



10 

 20 

 30 

 40 

 50 



8 

 25 

 48 

 64 



80 





1 



3 



5 



9 



14 



0.8 

 1.8 

 3.5 

 5.5 

 9 













4.0 

 7,5 

 10.6 

 13.7 







1.6 

 3.5 

 5.9 



0.2 

 1.6 

 3.3 



1 





'"o.r 



1.4 





60 



93 





20 



13 



16.2 



8.3 



5.2 



2.4 1 



70 



106 



54 



28 



17 



18.4 



10.5 



6.9 - 



3 5 , 



80 



118 



59 



36 



21 



20.5 



12.3 



8.6 



4.4 



90 



128 



65 



43 



27 



22.5 



14.0 



10.0 



5.3 



100 



138 



70 



51 



32 



24.3 



15.6 



11.3 



6.2 



110 



148 



75 



58 



37 



26.0 



17.0 



12.4 



7.2 



120 



157 



79 



64 



41 



27.4 



18.2 



13.4 



8.1 



130 



165 



83 



69 



45 



28.7 



19.3 



14.4 



9.0 



140 



173 



86 



73 



48 



30.0 



20.3 



15.2 



9.9 



150 



180 



89 



75 



50 



31.3 



21.1 



16.1 



10.7 



160 



186 



91 



77 



52 



32.6 



21.9 



16.9 



11.4 



170 



192 



95 



78 



53 



33.8 



22.7 



17.8 



12.1 



180 



198 



95 



79 



54 



35.0 



23.5 



18.7 



12.8 



190 



204 



96 



80 



55 



36.2 



24.2 



19.6 



13.4 



200 



209 



97 





56 



37.4 



24.9 



20.6 



14.0 



210 

 220 

 230 

 240 

 250 

 260 

 270 

 280 

 290 

 300 



213 

 217 

 221 

 225 

 228 

 231 

 234 

 236 

 238 

 240 



97 

 98 

 98 

 98 

 98 

 99 

 99 

 99 

 99 

 99 





56 



57 

 57 



38.4 

 39.5 

 40.6 

 41.6 

 42. 6 

 43.6 

 44.6 

 45.6 

 46.5 

 47.4 







14.6 

 15.3 

 15.9 

























■ 







"i 



■ 



■ 





. 1 



■ 1 







1 



1 

















1 









1 







j 



'^ Washington figures from Forest Service Bulletin No. 33, " The Western Hemlock," 

 1899. by E. T. Allen. 



^ Targhee figures from Henry's Lake Working Plan, 1906, by J. G. Peters and A. T. 

 Boisen. 



•^ Uinta and San .Juan figures from analyses by E. H. Frothingham on the Uinta and 

 San Juan National Forests, 1907. 



It is important to note that these figures are entirely too few to be 

 representative for large areas. They are of value, however, to illus- 

 trate in a general way the immense differences in rate of growth 

 and size w4iich exist between the coast and mountain forms of Doug- 

 las fir. Thus, at the age of TO years the mountain form in the 

 Targhee Xational Forest is only half as high and has only five- 

 ninths as great a diameter as the coast form in western ^Tashington, 

 while at 300 years it remains less than half as high and has prac- 

 tically ceased its height gTowi:h, though the coast form is still gTOW- 

 ing at the rate of 2 feet in ten years. The figures for the San Juan 

 Xational Forest show that at high altitudes in the Roclry Mountains 

 Douglas fir requires 230 years to reach a size which the coast form in 

 western Washington attains in less than 60 years. 



TTlien the coast form of Douglas fir comes up in crowded, even- 

 aged stands, as it often does on buras, the trees make a rapid growth 



[Cir. 150] 



