expected conversion from nongrowing to growing 
types increases the estimated annual growth for the 
decade 1953-62 to 1,060 million cubic feet or 4.1 
billion board feet. Detail for the various units is 
given in table 24. Improved forest management 
could further increase realizable mean annual 
growth considerably. 
Realizable growth in board feet for the decade 
1933-42 is greater than current growth for every 
unit except the Umpqua River unit, and for the 
region as a whole is 43 percent greater. In the 
Umpqua River unit current board-foot growth is 
greater than realizable growth for the first decade 
because in 1933 many of the growing stands were 
at an age at which current annual growth in board 
feet was greater than the average annual increment 
for the assumed life of the stands. In following 
decades, as more nongrowing old-growth timber 
stands are assumed to be converted to growing 
stands, realizable growth increases and exceeds 
current growth in this unit as well as in the others. 
The same explanation applies to the fact that cur- 
Tasie 24.—Realizable mean annual growth | of conifers of indicated diameter range in the various survey units of the Douglas-fir 
region, by decades 
5.1+ inches d. b. h. 11.1+ inches d. b. h. 15.1+ inches d. b. h 
Unit s 
1933-42 1943-52 1953-62 1933-42 1943-52 1953-62 1933-42 1943-52 1953-62 
Million Million Million Million Million Million Million Million Million 
Puget Sound units: cubic feet | -cubic feet | cubic feet | board feet | board feet | board feet | board feet | board feet | board feet 
Northebuget Sound = 22 22 a4 fore 56 72 79 336 413 442 213 254 266 
‘CentralePuget|/Sound-=) 22s 8 100 140 154 515 705 | 780 309 401 435 
SouthtPuget;Sound S2ss2se eee es ee 66 88 102 418 527 | 594 314 378 409 
| | 
Oval eg ste we teen en eas ee ee 222 300 | 335 1, 269 1, 645 | 1, 816 836 1, 033 1,110 
| 
Gray stl arbor sess ete rian meee! 59 84 98 | 354 485 | 550 | 261 344 377 
Columbia River units: 
Columbia River, Wash___._---_-_--------- 74 94 103 462 562 599 328 380 394 
ColumpbiajRiverOreg-22224- coe ease eee = 90 119 128 541 675 711 344 418 433 
Motels ame tsas 2 Ae aise Susie eae Te ee 164 213 | 231 1, 003 1, 237 | 1, 310 672 798 827 
Willamette River__-:---2--22------c-eceneee 2 118 142 162 797 906 | 980 559 613 642 
Oregon coast units: 
North Oregon coast 3_________________---___- 53 71 79 402 491 511 316 370 378 
South’ Oregon coastis!22=.S 28 2. eee 58 73 82 427 489 | 530 343 377 396 
i} 
MIN FN a Se 111 144 161 829 980 1, 041 659 747 774 
South Oregon units: 
Wim PQ UarR iy eres ete ee ee 37 42 45 288 307 316 240 248 250 
IROgUC IR ver rant see ee ae Se ose 22 28 28 135 153 153 | 79 86 86 
TG tal eens tare Besos ENN 59 70 | 73 423 460 469 | 319 334 336 
Regionalitotal Sov ssek Sass ee 733 953 1, 060 4, 675 5, 713 6, 166 3, 306 3, 869 4, 066 
Summarv by districts: Percent Percent Percent Percent Percent Percent Percent Percent Percent 
Puget SOundse-ce sewers ee 30. 3 31.5 31.6 22 28. 8 29. 5 25.3 26.7 27.3 
GrayssHarporses eee 8.0 8.8 9.2 7.6 8.5 8.9 7.9 8.9 9.3 
Columbia: Rivers 25 =e sere 22.4 22. 4 21.8 21.5 21.6 21.2 20.3 20.6 20. 3 
Wiillamettcunivers swsse= ce Sr lie lees 16.1 14.9 15.3 17.0 15.9 15.9 16.9 15.9 15.8 
Oregon coast_______ 15.1 15.1 15.2 a Gare 17.2 16.9 19.9 19.3 19.0 
South Oregon____ 8.1 ree: 6.9 9.0 8.0 7.6 eae SY f 8.6 8.3 
Regionalitotal ess ess 3 Se 100.0 100.0 100.0 100.0 100. 0 100.0 100. 0 100.0 100.0 
! Growth that, according to the calculations described in the text, may be expected if growth and depletion trends revealed by the survey continue 
through the designated period. Growth shown for trees 15.1 inches d. b. h. or more was calculated by estimating volumes in 32-foot logs to 12-inch top, 
by Scribner rule. 
? Data exclude growth on 182,060 acres of potential conifer forest land temporarily occupied by hardwoods (type 31). 
3 Data exclude growth on 14,520 acres of potential conifer forest land temporarily occupied by hardwoods (type 31). 
59 
That shown for trees 11.1 inches d. b. h. or more was calculated by estimating volumes in 16-foot logs to 8-inch top, by Scribner rule. 
