86 



THE OUTLOOK FOR TIMBER EN THE UNITED STATES 



Table 76. — Mortality of softwood growing stock and sawtimber per acre in the Pacific Coast Section, by owner 



class, 1952, 1962, and 1970, with projections to 2020 



Owner class 



Unit 



1952 



1962 



1970 



Projections 





1980 



1990 



2000 



2020 



National Forests: 

 Growing stock 



Cubic feet 



25. 1 

 141. 



23. 



121.7 



27. 5 



158. 3 



10.7 



49. 7 



21. 7 

 118. 8 



24. 8 

 136. 1 



24. 1 

 125. 6 



22. 3 

 120.3 



10. 5 

 44. 1 



20.9 

 110. 3 



24. 2 



129. 2 



23.9 

 113. 1 



19. 4 

 95.4 



11.4 

 44. 9 



20.4 

 101. 7 



23. 5 



120. 7 



25.8 

 123.6 



16. 5 

 73. 7 



13.4 

 49. 



20. 2 

 96. 6 



22. 9 

 112. 6 



27. 2 

 122. 9 



16. 

 63.7 



14.8 

 51. 1 



20.4 



91. 4 



22. 5 



104.9 



28. 7 

 122.8 



16.8 

 60. 1 



16. 4 

 54.4 



20.9 

 87.8 



22. 



Sawtimber _ _ 



Board feet 

 Cubic feet 



91. 4 



Other public: 

 Growing stock 



31. 4 



Sawtimber 



Board feet 



121. 7 



Forest industry: 

 Growing stock - 



Cubic feet 



20. 



Sawtimber 



Board feet 



62. 6 



Farm and miscellaneous private: 

 Growing stock _ 



Cubic feet _ 



19. 5 



Sawtimber 



Board feet 



62. 7 



All owners: 

 Growing stock 



Cubic feet 



22. 2 



Sawtimber 



Board feet 



83. 5 









Net growth and mortality of sawtimber in the 

 Pacific Coast 











softwoods 











_„ — - 



— -"■"" 



■ — ""* 





net growth — - — 











— ______^ mortality 











hardwoods 



____ 







-™ 



net growth 



iSSS 



ortality 











1952 1962 1970 



1980 1990 2000 2010 



Figure 40 



tions for National Forests and forest industry lands 

 decline substantially thereafter. Projections for 

 farm and miscellaneous lands show an increase 

 over the period as a result of projected increases 

 in inventories. Estimates for other public lands 

 indicate relatively constant mortality per acre. 



Trends in Inventory Volumes 



The excess of removals over growth that char- 

 acterizes the old-growth timber economy of the 

 Pacific Coast States has resulted in a downward 

 trend in inventories of standing timber (tables 

 68 and 69). Growing stock volumes dropped 

 about 5 percent in the 1952-70 period and saw- 

 timber volumes about 11 percent. 



On a per-acre basis, volumes for all owners 

 combined averaged 3,571 cubic feet and 18,347 

 board feet (tables 77 and 78). By the year 2020, 

 average volumes are projected to decline further 

 to 14.2 thousand board feet per acre, or 23 percent 

 less than in 1970. 



These projections indicate that the smallest 

 sawtimber inventories per acre in the year 2020 

 will be carried on industry lands, with the largest 

 inventories still on public lands. Only on farm and 

 miscellaneous private ownerships does the pro- 

 jected average sawtimber volume per acre increase. 



The prospective replacement of old-growth 

 forests bj 3-ounger age classes 'with smaller trees 

 is evident by comparing these trends in sawtimber 

 volumes with trends in growing stock volumes. For 

 all ownerships combined, projections of inventories 

 in cubic feet drop only moderatery in this base 

 projection, in contrast to a sizable drop in board 

 feet inventories. 



Although the Pacific Coast States will still 

 contain most of the Nation's large trees over the 

 next few decades, a shift toward smaller tree sizes 

 can be expected, as illustrated by the following 

 tabulation of percentage distributions of growing 

 stock inventories by tree sizes for selected areas : 



National Forests, Other public, 

 Western Oregon Western 



Washington 



Tree diameter class 

 (inches) 

 5 to 11 . . . - 



1970 



8 

 25 

 67 



2020 



18 

 32 

 50 



1970 



16 

 35 

 49 



2020 

 26 



11 to 20. ... 



61 



20 and larger 



13 



Total. 



100 



100 



100 



100 



