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4
wae” Se@lected Yield Tables
Sette for Plantations and
Research Station
were Natural Stands in hg Inland Northwest Forests
Albert R. Stage David L. Renner Roger C. Chapman
B-/,xe*%dx
In(QH)=Fy(ADH0)
In{BAI}=f,(D.b.h., Habitat Crown)
SITE» INDEX
VOLUME
THE AUTHORS
ALBERT R. STAGE is principal mensurationist with the Forestry Sciences Laboratory, Intermountain Research Station, Moscow, ID.
DAVID L. RENNER is a forester with the Forestry Sciences Laboratory at Moscow, ID.
ROGER C. CHAPMAN is an associate professor of forest management, Department of Forestry and Range Manage- ment, Washington State University, Pullman.
ACKNOWLEDGMENTS
Tabulation of yields by site index and age was requested by members of the Inland Northwest Growth and Yield Cooperative, who also specified the species and manage- ment regimes to be represented.
RESEARCH SUMMARY
Yields arrayed by site index and age have been tabulated for plantations of 500 trees per acre, with five thinning regimes, for each of three planted species: Douglas-fir, grand fir, and western larch. In addition, yields have been tabulated for naturally regenerated stands of the grand fir- cedar-hemlock ecosystem of the Inland Empire. The yields were estimated with the Prognosis Model for Stand Develop- ment, version 5.2, including the Regeneration Establishment Model. Each planted species and the natural regeneration were simulated for the full range of site, geographic, and ecologic variables represented in a random inventory of the National Forests of the Inland Empire. Site index was obtained from the simulations by extracting heights of the 20 tallest trees per acre when they accumulated 50 rings at 4.5 feet.
Individual simulations were sorted into 10-foot site index classes and average yields were calculated. Weights in the averaging were proportional to the relative frequency with which the sites occur in the forests of the Inland Empire.
Simulations showed great variation in yields for stands of the same site index. Furthermore, comparisons between these yield tables for natural stands and 102 permanent sample plots show that these tables give less accurate estimates of growth than the Prognosis Model from which they were derived. Therefore, these yield tables should be used only when use of the Prognosis Model is precluded by lack of data on the site, geographic, and ecologic factors.
CONTENTS Page INtrOGUGCTION ....202.:cccesnseeeseces ven cunduence nsccetesoseotoas se eee 1 Applicability «....0:.:.025.ccssccsssccveoxersxcteneestesseacet teeta eee 1 Method ...i.icc.iccccesseceotedvastennscendactseeecsracr nese eee 2 Definition of Variables. «... .v..0..<csesscdnevscasozscnyesseer taste 2 Yield Tables for Natural Regeneration ............c:seseeseceseees 2 Yield Tables for Plantations. /.---<.s2-:s.-cs-c-cnc-eeseeeses eee 8 DOUQIAS-Fil «00: sic Soee'ceczctinteriavaarteseessgct eerste eee 8 Gra fii 5 i..cscesvensiesonsavodeatesctncenensatse Soseanentne a ae 25 Western larch)... ives. cschesetsescsvanceveves causetnen set eae 41 Comparison to Related Yield Estimates ..............::cceeee 55 RefGrences <. .2...1s.cccsesesscsuees ses csvevnccsesdots oper ee 56 Appendix Tables: Inventory Classes Used for Simulation DOUGIaS-Fil 5..2.50c.sccesessccdontssstexesouanssoetesnnerersesey see eeeeeeeeaa 57 Grain fit sic celocesesincsscaloapseantacccsenssetave stneteescot ee 57 Western larch s.cccccscivecsacecsisssccenes eavecaxeetrnein sees ieee 58 Naturally regenerated stands ..............csseeecceeeeenneeneenaee 58
Intermountain Research Station 324 25th Street Ogden, UT 84401
Selected Yield Tables for Plantations and Natural Stands in Inland Northwest Forests
Albert R. Stage David L. Renner Roger C. Chapman
INTRODUCTION
This report contains yield tables arrayed by site index and age for average ecological and topographic situations in the Inland Empire. Yields were estimated by the Prog- nosis Model for Stand Development, version 5.2. Esti- mates are provided for plantations of Douglas-fir (Pseu- dotsuga menziesii), western larch (Larix occidentalis), and grand fir (Abies grandis) and for natural stands in the grand fir-cedar-hemlock ecosystem. Five thinning regimes are presented for the plantations.
Yield tables that represent estimates of volumes con- tained in forest stands have traditionally been presented with site index and stand age as the table stubs, and vari- ous attributes of the expected stand—merchantable vo- lumes, total volumes, basal area, and mean diameter at breast height (d.b.h.)—in the body of the table.
Site index is only one factor influencing future yields. However, incorporating other productivity factors into the format of conventional yield tables, along with a multiplic- ity of alternative management regimes, would require extremely voluminous sets of tables. The obvious solution is to prepare the tables to specifications of the user with the Prognosis Model (Wykoff and others 1982).
Some information needs are not met by such yield- simulation procedures. In the most serious situation, the existing inventory may have been designed to provide only the traditional site index and age classification of the for- est, precluding the use of the more definitive techniques.
Another information need—comparing yields between forest types or regions—is hampered if the forests being compared are not described by the same variables. Al- though site index and age definitions often vary from re- gion to region and type to type, the problem is even more serious when the additional site variables are not used at all.
For these reasons, users or potential users of the Prog- nosis Model have asked to have yield information implicit in the Prognosis Model presented in the traditional format of site index and age. The tables in this publication are intended to meet that request.
APPLICABILITY
The tables presented here represent the forests of the Inland Empire, which includes northern Idaho, northeast- ern Washington, and western Montana.
Within the Inland Empire, the tables for natural stands represent the following habitat types:
Grand fir/pachistima Cedar/pachistima Hemlock/pachistima Subalpine fir/pachistima
Yield estimates for Douglas-fir plantations represent, in addition to those for the naturally established stands, the following habitats:
Douglas-fir/ninebark Douglas-fir/snowberry Douglas-fir/pinegrass Subalpine fir/menziesia Subalpine fir/woodrush Subalpine fir/twinflower Mountain hemlock/menziesia
Yield estimates for western larch plantations represent, in addition to those for the naturally established stands, the following habitats:
Douglas-fir/ninebark Spruce/pachistima
Grand fir/beargrass Subalpine fir/devil’s club Subalpine fir/beargrass Subalpine fir/twinflower Subalpine fir/whortleberry Mountain hemlock/beargrass Mountain hemlock/menziesia
Yield estimates for grand fir plantations represent, in addition to those for the naturally established stands, the following habitats:
Grand fir/beargrass Subalpine fir/menziesia Subalpine fir/beargrass Mountain hemlock/beargrass
Five management regimes are represented for planta- tions of each of the three species. Planting density and initial survival are assumed to provide 500 trees per acre 5 years after planting. In parentheses after each regime is a mnemonic code used to identify the regime on those figures that compare several regimes.
1. No thinning (000). 2. Precommercial thinning from below at 20 years to 250 trees per acre (P00).
3. Same as 2 with commercial thinning at 50 years to 100 trées per acre, such that the average d.b.h. before thinning is the same as after thinning (PC1).
4. Same as 3 but with commercial thinning from above at 50 years to 100 trees per acre (PCA).
5. Same as 3 but with commercial thinning from below at 50 years to 100 trees per acre (PCB).
Yields for natural stands are based on the clearcutting method of regeneration, with site preparation consisting of 64 percent of area burned and an additional 11 percent mechanically disturbed. No thinnings are scheduled.
METHODS
Growth and yield projections for 150 years were made using version 5.2 of the Stand Prognosis Model.
Geographic, topographic, and ecologic data to be used in the simulations were obtained from inventory plots that were a random sample of the forest. These plots represent the range and joint occurrence of site variables throughout the Inland Empire. The inventory plots were used to de- fine the distribution of five major site variables influencing tree growth: geographic location (defined by National For- est), habitat type (Daubenmire and Daubenmire 1968), slope percentage, aspect (degrees from north), and elevation (hundreds of feet).
Combinations of these five variables constituted a “cell,” each cell corresponding to a unique set of model coeffi- cients in the Prognosis Model. The values used for the slope and elevation variables were the mean +1 standard deviation within the geographic and habitat type classes. Aspect variation is represented by two classes correspond- ing to the maximum and minimum of the aspect effect on increment for that species. The appendix contains detailed information on the combinations of these variables and the nominal values used for the three planted species and naturally regenerated stands.
Initial stand conditions were defined by the Regenera- tion Establishment Model (Ferguson and others 1986) component of the Prognosis Model.
Site index was calculated for each projection by monitor- ing the simulated height growth for each tree record. Height at 50 years (rings at 4.5 feet) was calculated for each tree, then site index calculated as the average of the 20 trees per acre having the greater 50-year heights.
However, to prevent management treatment from influ- encing site calculations, each cell was assigned the site index value derived for the planting-no thinning manage- ment regime for that species.
Yields from the simulation were then sorted by 10-foot site index classes and management treatment and a weighted average yield value was calculated. Weights for each cell were proportional to the frequency with which inventory locations fell within the cell.
Although the site variables define a wide range of site productivity, there is still substantial variability within a cell. To represent this variability, multipliers of basal area increment for trees larger than 3 inches d.b.h., and height increment for smaller trees (<3 inches d.b.h.), were as- signed to each cell. The multipliers were entered with the BAIMULT and REGHMULT keywords (Wykoff and others 1982). Logarithm of BAIMULT was selected randomly
from a normal distribution having a mean of zero and standard deviation of 0.3. The choice of standard deviation was based on estimates of residual variation in growth histories of 102 permanent sample plots in northern Idaho
(Stage 1987).
DEFINITIONS OF VARIABLES
Site index. Average height in feet of the tallest 20 trees per acre when the trees have 50 rings at 4.5 feet above ground level.
Age. Number of years from planting or from date of har- vest or site preparation for natural-stand yields.
Top Height. Average height in feet of the 40 largest di- ameter (d.b.h.) trees per acre.
Volumes. Reported for three categories of size limits:
Total cubic feet includes all stems, from 1-foot stump to tip of main stem.
Merchantable cubic feet includes all stems greater than 7.0 inches d.b.h. from 1-foot stump to a top diameter in- side bark of 4.5 inches.
Board feet Scribner (Kemp 1956) includes all stems greater than 7.0 inches d.b.h. from 1-foot stump to a top diameter inside bark of 4.5 inches.
Accretion (ACC in yield table headings). Periodic mean annual change in total cubic foot volume of trees surviv- ing through the period,the length of which is indicated by column headed PRD yrs.
Mortality (MOR in yield table headings). Total cubic foot volume per year of trees dying in the period.
Total Yield. Standing volume plus volume removed by thinning, if any.
YIELD TABLES FOR NATURAL REGENERATION
Table 1 and figures 1, 2, and 3 represent the yields for the mix of species typically found in naturally regenerated stands of the grand fir-cedar-hemlock ecosystem. Grand fir is the most prevalent species followed by Douglas-fir and western white pine (Pinus monticola).
Entries for ages 5 and 10 represent only the established regeneration that would have been inventoried at age 5 years. From age 15 years on, the trees are those that would have been inventoried at age 15. Any subsequent regeneration is ignored.
Trends of tree d.b.h. with age and site index are dis- played in figure 4.
The distribution of site indices represented in these simulated yields (fig. 5) was determined by the distribution of site variables in the inventory and by the range of the random variation of the growth multipliers.
Individual simulations showed surprising range in yield for the same site index. These variations are attributed to factors influencing initial stocking and time to reach 4.5 feet height. Figure 6, for example, shows a range in yield of approximately 10,000 cubic feet for site index class 60 at 120 years. This variation is nearly as large as the range of variation of the mean yields over the full range of sites represented in the yield tables.
Table 1—Yields of naturally regenerated stands in the grand fir-cedar-hemlock ecosystem
Summary statistics Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _ Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D fae Ft? Bd ft Ft? Fits Bad ft Fi Ft Yr FL ade 40 5 681 0 0 0 0 0 0 0 1 2 1 5 0 0 0.5 10 666 2 0 0 0 0 0 0 1 2 4 5 1 0 0.5 20 1427 12 0 0 0 0 0 0 3 7, 8 10 3 0 0.6 30 1232 38 0 0 te) 0 0 0 6 13 14 10 9 0 0.9 40 1072 116 0 0 0 0 0 0 14 28 21 10 16 1 1.6 50 952 269 0 0 0 0 0 0 29 50 28 10 21 2 2.4 60 851 465 6 16 0 0 0 0 43 69 32 10 26 4 3.1 70 753 690 14 45 0 0 0 0 57 85 37 10 29 6 3.7 80 663 921 76 236 ) 0 0 0) 68 97 42 10 32 8 43 90 582 1163 327 1029 0 0 0 0 78 106 47 10 33 10 5.0 100 514 1403 544 1801 0 0 0 0 87 113 52 10 33 12 5.6 110 456 1613 748 2576 0 0 0 0 93 118 56 10 37 14 6.1 120 406 1847 1075 3778 0 0 0 0 99 122 60 10 37 15 6.7 130 366 2063 1413 5074 0 0 0 0 104 126 64 10 33 17 7.2 140 330 2217 1630 6006 0) 0 0 0 106 125 67 10 40 20 TE 150 297 2410 1917 7254 0 0 0 0 109 125 71 0 0 0 8.2 50 5 716 0 0 0 0 0 0 0 1 2 2 5 1 0 0.4 10 687 4 0) 0 0 ce) 0 0 1 3 6 5 1 0 05 20 1125 32 0 0 0 0 0 0 5 12 14 10 10 0 0.9 30 955 133 0 0 0 0 0 0 15 28 23 10 25 1 Vi 40 820 370 4 13 0 0 0 0 34 55 31 10 37 2 2.8 50 731 724 92 286 0 0 0 0 57 83 38 10 47 4 3.8 60 645 1147 413 1331 0 0 0 0 77 107 44 10 58 8 47 70 559 1649 926 3224 0 0 0 0 99 127 51 10 59 11 57. 80 486 2127 1460 5308 0 0 0 0 115 143 57 10 68 16 6.6 90 424 2650 2053 7829 0 0 0 0 131 156 63 10 71 20 75 100 372 3153 2645 10491 0 0 0 0 143 164 69 10 65 25 8.4 110 328 3562 =3119 12872 0 0) 0 0 150 168 75 10 76 30 9.2 120 289 4021 3629 15654 0 0 0 0 158 171 81 10 68 31 10.0 130 258 4394 4040 18039 0 0 0 0 163 172 86 10 68 35 10.8 140 230 4718 4397 20205 0 0 0 0 165 170 90 10 66 38 11.5 150 206 4998 4707 22183 0 0 0 0 167 167 95 0) 0 O 12.2 60 5 707 0 0 0 0 0 0 0 1 2 2 5 1 0 0.4 10 677 4 0 0 0 0 0 0 1 4 7 5 2 0 0.6 20 1262 43 0 0 0 0 0 0 7 16 15 10 14 0 1.0 30 1061 186 1 3 0 0 0 0 21 38 27 10 34 1 1.9 40 908 520 62 191 0 0 0 0 46 72 35 10 49 3 3.0 50 801 976 324 1084 0 0 0 0 71 103 44 10 61 7 4.0 60 682 1510 815 2900 0) ) 0) 0 94 127 52 10 70 12 5.0 70 578 2090 1437 5361 0 0 0 0 114 147 59 10 76 18 6.0 80 492 2673 2088 8152 0 0 0 0 131 161 66 10 81 24 7.0 90 420 3241 2727 11157 0 0 0 0 145 169 TA 10 87 30 7.9 100 360 3809 3353 14313 0 0 0 0 155 174 77 10 88 35 8.9 110 311 4340 3927 17462 0 0 0 0 164 176 82 10 91 40 9.8 120 271 4853 4483 20773 0 0 0 0 170 177 87 10 92 43 10.7 130 238 5339 5004 23906 0 0 0 0 176 177 91 10 95 48 11.6 140 210 5815 5504 27005 0 0 0 0 180 176 96 10 91 50.” 1255 150 186 6220 5928 29690 0 0 0 0 182 175 100 0) 0 0 13.4 70 5 684 0) 0) 0 0 0 0 0 1 2 2 5 1 0 0.4 10 656 6 0 0 0 0 0 0 2 4 8 5 5 0 0.7 20 1197 99 1 3 0 0 0 0 14 26 20 10 33 0 1.4 30 1028 423 63 206 0 0 0 0 38 61 33 10 67 2 2.6 40 887 1068 440 1506 0 0 0 0 76 108 44 10 93 vA 4.0 50 774 1933 1212 4485 0 0 0 0 116 152 53 10 112 15 5:2 60 656 2907 = 2225 8744 0 0 0 0 152 185 61 10 124 25 6.5 70 553 3896 3267 13626 0 0 0 0 180 207 69 10 137 37 Uae 80 467 4896 4340 19069 0 0 0 0 203 222 76 10 140 46 8.9 90 396 5834 5334 24513 0 0 0 0 220 230 82 10 144 56 10.1 100 338 6717 6269 29969 0 0 0 0 233 234 88 10 148 64 aly ler 110 291 7551 7141 35191 0 0 0 0 242 236 94 10 149 71 12.4 120 252 8324 7944 40077 0 0 0 0 250 236 99 10 153 77 13.5 130 221 9081 8724 44842 0 0 0 0 256 235 104 10 153 82 14.6 140 194 9798 9460 49326 0 0 0 0 260 234 109 10 150 86 15.7 150 172 10442 10118 53321 0 0 0 0 264 233 114 0 0 0 16.8 (con.)
Table 1 (Con.)
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _ Total able able Trees/ Total able able BA/ Top MOR/ _ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Ft? Fr? Bd ft Ft? Ft? Bd ft Ft? Ft Yr ts Fr?
80 5 758 0 0 0 0 0 0 0 1 2 2 5 1 0 0.4 10 724 7 0 0 0 0 0 0 2 5 8 5 6 0 0.7 20 1186 147 9 31 0 0 0 0 19 33 23 10 57 0 1:7 30 1024 714 257 900 0 0 0 0 58 85 37 10 119 4 3.2 40 877 1863 1210 4713 0 0 0 0 HAZ, 149 50 10 157 19 49 50 728 3245 2588 10922 0 0 0 0 168 196 61 10 186 38 6.5 60 585 4724 4117 18396 0 0 0 0 208 226 70 10 202 57 8.4 70 474 6172 5605 26255 0 0 0 0 238 244 79 10 213 75 9.6 80 387 7549 7043 34278 0 0 0 0 259 253 87 10 214 85:5 i 90 321 8833 8367 41931 0 0 0 0 275 259 95 10 223 99 12.5
100 268 10078 9641 49370 0 0 0 0 287 262 102 10 218 108 14.0 110 228 11180 10770 55888 0 0 0 0 295 263 108 10 221 117 15.4 120 196 12217 11834 61974 0 0 0 0 301 262 114 10 215 121 16.8 130 170 13153 12789 67494 0 0 0 0 305 261 120 10 219 128 18.2 140 148 14067 13718 72720 0 0 0 0 308 259 125 10 216 130 19.5 150 131 14922 14586 77586 0 0 0 0 311 257 130 0 0 0 20.9
90 5 671 0 i¢) 0 0 0 0 0 0 2 ie 5 2 0 0.4 10 641 8 0 0 0 0 0 0 2 5 9 5 8 0 0.8 20 1147 191 16 54 0 0 0 0 22 38 26 10 78 0 1.9 30 982 962 436 1576 0 0 0 0 69 96 42 10 160 4 3.6 40 841 2516 1858 7400 0 0 0 0 142 172 55 10 210 21 5.6 50 694 4403 3770 16259 0 0 0 0 206 229 68 10 239 50 7.4 60 553 6290 5705 26282 0 0 0 0 252 260 77 10 268 78 9.1 70 439 8186 7642 37038 0 0 0 0 287 278 86 10 284 105 11.0 80 350 9972 9476 47607 0 0 0 0 312 287 94 10 283 125 12.8 90 284 11553-11086 56899 0 0 0 0 328 291 103 10 294 145 14.5
100 233 13039 12600 65629 0 0 0 0 339 291 110 10 290 158 16.3 110 195 14362 13958 73343 0 0 0 0 347 290 116 10 277 162 = 18.1 120 166 15514 15129 80020 0 0 0 0 351 288 121 10 283 171 19.7 130 142 16643 16271 86341 0 0 0 0 354 286 127 10 284 180 21.4 140 123 17687 17324 92138 0 0 0 0 357 283 132 10 265 170 23.1 150 108 18635 18279 97315 0 0 0 0 359 281 137 (0) 0 0 24.7
100 5 759 0 0 0 0 0 0 0 1 2 2 5 2 0) 0.5 10 727 12 0 0 0 0 0 0 3 8 9 5 16 0 0.9 20 1099 352 36 117 0 0 0 0 35 54 30 10 132 1 2.4 30 936 1656 1054 3960 0 0 0 0 108 137 43 10 220 14 4.6 40 776 3711 3058 12437 0 0 0 0 193 21 58 10 318 44 6.7 50 624 6445 5776 26291 0 0 0 0 278 281 68 10 345 95 9.0 60 486 8934 8306 40218 0 0 0 0 329 308 81 10 326 139 11.1 70 380 10807 10258 51281 0 0 0 0 352 312 92 10 333 172 13.0 80 298 12427 =11937 61128 0 0 0 0 364 310 99 10 342 188 15.0 90 238 13964 13514 70172 0 0 0 0 371 305 108 10 337 200 16.9
100 195 15336 14913 78207 0 0 0 0 376 300 116 10 343 215 18.8 110 160 16615 16217 85752 0 0 0 0 380 295 124 10 315 199 20.8 120 137 17772 17386 92360 0 0 0 0 381 290 130 10 322 209 22.6 130 117 18906 18531 98686 0 0 0 0 382 287 136 10 330 222 24.4 140 101 19989 19623 104649 0 0 0 0 383 284 140 10 307 211 26.3 150 89 20952 20592 109801 0 0 0 0 383 282 144 0 0 O 28.4
24000 SITE INDEX | 100 w 20000 }+ 5 = 90 {=} > S 16000 i 80 oO | Lal ao =) © 12000 + z = | 70 {=} = 8000 + 60 50 4000 40 = — ——4 L kee See) Re 7 a ae a 4 10 20 30 40 50 60 70 80 90 100 110 120 130 140 4150 AGE Figure 1—Natural regeneration yield curves for Inland Northwest forests of the grand fir-cedar-hemlock ecosystem (total cubic feet, all stems). 24000 + SITE INDEX i 100 20000 WwW 3 { 90 =] oO > + 16000 + S) iP 80 i | = a 3 12000 + 5 70 jo lu = 8000 60 50 4000 40
Fi + 4 _ —" 4 + 4 " 4 4 4 2 4
10 20 30 40 50 660 70 80 g90 100 110 120 130 140 150
AGE
Figure 2—Natural regeneration yield curves for Inland Northwest forests of the grand fir-cedar-hemlock ecosystem (merchantable cubic feet, 4.5-inch top, stems greater than 7 inches d.b.h.).
SITE INDEX
100 100000 + 90 tw 80000 + BO = = =I a | > ome 8 60000 + re 70 jax} a - —t oO a 40000 + 60 50 20000 + 40 — —1 — —=—— ee | 4 4 eS | 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 AGE Figure 3—Natural regeneration yield curves for Inland Northwest forests of the grand fir-cedar-hemlock ecosystem (merchantable board feet [Scribner], 4.5-inch top, stems greater than 7 inches d.b.h.). SITE INDEX 30 100 90 ra) WwW x= oO te 80 ics 20 + jem WW be u 70 < H a z 60 Ww = 50 oO Hi 10 a a 40 =) Oo
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 4—Quadratic mean diameter vs. age for natural regeneration in Inland Northwest forests.
IN49d4d
SITE INDEX MIDPOINT
ation site index values for Inland
Northwest forests of the grand fir/cedar/hemlock eco
Figure 5—Distribution of natural regener
system.
age
rs of
. site index at 120 yea
ation yield vs
Figure 6—Natural regener.
(total cubic feet).
YIELD TABLES FOR PLANTATIONS
Yield estimates for plantations were produced assuming that there was no natural regeneration. On most sites in the Inland Empire, some natural regeneration can be ex- pected. Therefore, the yields in these tables will apply only to stands in which early and repeated thinnings remove the natural regeneration. Simulation of the combined yields from planted as well as naturally regenerated trees would also be possible with the Prognosis Model.
Douglas-fir
Expected yields for plantations with 500 Douglas-fir trees per acre at 5 years are listed in tables 2 through 6 and figures 7 through 9 for the five management regimes. In comparison to the yields estimated for natural stands, Douglas-fir plantations are estimated to produce higher volumes at the early and middle ages because the height
growth is faster at the early ages. This difference in height growth can be seen by comparing top heights at early ages for the same site index (table 2).
Variation of yields between simulations for the same site index is less than for the natural-stand yields because initial stocking is uniformly 500 trees per acre at 5 years (figs. 10, 11).
Treatment effects on mean d.b.h. are shown in figures 12 through 16. As expected, thinning from below produces the largest diameters, but response is slight on the lower site qualities.
Effects of thinning regimes on standing volume are com- pared in figures 17 through 22 for total cubic and mer- chantable board foot volumes. Effects of thinning regimes on total yield are compared in figures 23 through 28. To- tal yield was nearly constant for site index 90. For site indices 50 and 70, however, none of the thinning regimes matched the total yield of the unthinned plantations.
Table 2—Yields of Douglas-fir plantations having 500 trees per acre surviving 5 years, no thinning
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _ Total able able Trees/ Total able able BA/ Top MORL index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Fts Ft Bd ft Ft Fits Bd ft Ft2 Ft Yr rte ple 50 5 500 0 0 0 0 0) 0) 0 0 2 3 5 2 0.0 10 473 10 0 0 0 0 0 0) 1 5 8 10 4 0 0.7 20 432 47 0 0 0 0 0 0 5 14 16 10 14 0 1.5 30 391 186 0 0) 0 0 0 0 18 34 25 10 30 0 2.9 40 375 480 19 55 0 0 0 0 37 61 33 10 45 1 4.3 50 359 $13 251 767 0 0 0 0 61 88 41 10 54 4 5.6 60 340 1413 755 2464 0 0 0 0 83 112 48 10 60 6 6.7 70 321 1952 1370 4741 0 0 0 0 103 132 54 10 68 10 cA 80 300 2531 2051 7452 ) 0 0 0 123 151 60 10 66 14 8.7 90 281 3050 =. 2648 10018 0 0 0 0 138 164 65 10 66 19 9.5 100 262 3521 3172 12479 0 0 0 0 150 172 70 10 65 2310.3 110 242 3945 3650 14891 0 0 0 0 160 178 74 10 63 26 = 11.0 120 224 4317 4053 17162 0 0 0 0 167 180 78 10 64 29 ey 130 207 4664 4419 19352 0 0 0 0 174 182 81 10 63 31 12.4 140 192 4984 4751 21472 0 0) 0) 0 179 182 84 10 60 3313.1 150 177 5254 5032 23352 0 0 0 0 182 181 87 0 0 0 13.7 70 5 500 0 0 0 0 0 0 0 0 2 3 5 5 0 0.0 10 478 27 0 0 0 0 0 0) 4 10 12 10 20 0 1.2 20 447 226 3 9 0 0 0 0 20 37 27 10 68 1 2.8 30 416 898 218 705 0 0 0 0 61 90 40 10 107 3 5.2 40 401 1939 1174 4041 0 0 0 0 110 144 50 10 126 11 Tal 50 375 3090 2518 9263 0 0 0 0 153 186 60 10 134 24 8.7 60 341 4187 3726 14645 0 0 0 0 187 215 67 10 139 38 = 10.0 70 306 5192 4810 20115 0 0) 0 0 212 231 75 10 136 50 11.3 80 273 6052 5719 25276 0 0 0 0 229 238 81 10 130 60 12.4 90 242 6759 +6455 29831 0 0 0 0 240 240 86 10 130 68 13.5 100 214 7378 7091 34084 0 0 0 0 248 237 91 10 126 73° (14.6 110 190 7914 7640 37871 0 0 0 0 253 234 96 10 122 76 = (15.6 120 169 8374 8112 41226 0 0 0 0 255 228 101 10 116 79 =: 16.7 130 151 8748 8495 44068 0 0 0 0 256 222 105 10 110 80 17.7 140 135 9053 = 8807 46422 0 0 0 0 256 216 108 10 109 81 = 18.6 150 121 9340 9101 48605 0 0 0 0 255 210 112 0 0 0 19.6 90 5 500 0 0 0 ) 0 0 0 0 2 4 5 16 0 0.0 10 489 79 0 0 0 0 0) 0 9 21 18 10 72 ft) 1.8 20 472 801 253 771 0 0 0 0 54 83 40 10 171 3 4.6 30 450 2484 1760 6211 0) 0 0 0 131 169 56 10 200 18 7.3 40 417 4306 3703 14366 0 0 0 0 197 232 69 10 200 44, 9.3 50 371 5863 5365 22468 0 0 0 0 241 265 78 10 211 73 ~=—«:10.9 60 321 7239 = 6841 30564 0 0 0 0 271 281 85 10 209 94 §=12.5 70 276 8385 8029 38071 0 0 0 0 291 284 93 10 187 101 13.9 80 238 9246 8910 44064 0 0 0 0 301 281 98 10 188 112 8618.2 90 206 10005 9686 49320 0) 0 0) 0 307 275 102 10 182 115 = 16.5 100 179 10675 10367 54156 0) 0 0 0) 312 268 107 10 181 121 17.8 110 157 11275 10977 58378 0) 0 0 0 314 262 112 10 174 120. 19.2 120 138 11820 11530 62202 0 0 0 0 316 255 116 10 166 118 = 20.5 130 122 12299 12015 65560 0 0 0 0 317 249 119 10 158 118 21.8 140 109 12697 12419 68274 0 0 0 0 317 243 123 10 147 114 9 23.4 150 98 13028 12756 70585 0 0 0. 0 316 237 126 0 0 0 24.3
Table 3—Yields of Douglas-fir plantations having 500 trees per acre surviving 5 years, precommercial thinning from below to 250 trees per acre
at 20 years Summary statistics Volume per acre Removals per acre Merchant- Merchant- Merchant- Site Trees/ Total able able Treas/ Total able
index Age acre volume volume volume acre volume volume Fr? Ft? Bd ft Fr Fr? 50 5 500 0 0 0 0 0 0 10 473 10 0 0 0 0 0 20 432 47 0 0 182 8 0 30 232 155 0 0 0 0 0 40 225 396 37 108 0 0 0 50 217 744 260 829 0 0 0 60 209 1143 704 2362 0 0 0 70 200 1603 1254 4457 0 0 0 80 191 2076 1804 6714 0 0 0 30 181 2515 2286 8947 0 0 0 100 171 2918 2714 11051 0 0 0 110 161 3304 3113 13164 0 0 0 120 151 3670 3495 15336 0 0 0 130 141 4020 3850 17453 0 0 0 140 132 4340 4172 19518 0 0 0 150 124 4635 4469 21502 0 0 0 70 5 500 0 0 0 0 0 0 10 478 27 0 0 0 0 0 20 447 226 3 9 197 40 0 30 242 732 224 721 0 0 0 40 236 1589 1163 4042 0 0 0 50 226 2601 2332 8828 0 0 0 60 212 3622 3395 13877 0 0 0 70 196 4599 4378 19136 0 0 0 80 179 5462 5241 24234 0 0 0 90 163 6212 5990 28926 0 0 0 100 149 6878 6656 33273 0 0 0 110 135 7449 7228 37105 0 0 0 120 123 7943 7724 40470 0 0 0 130 111 8339 8122 43225 0 0 0 140 101 8695 8482 45688 0 0 0 150 92 8984 8774 47718 0 0 0 90 5 500 0 0 0 0 0 0 10 489 79 0 0 0 0 0 20 472 801 253 771 222 135 0 30 245 2026 1670 5960 0 0 0 40 234 3649 3400 13473 0 0 0 50 218 5229 4991 21796 0 0 0 60 198 6615 6365 29808 0 0 0 70 179 7756 7499 36916 0 0 0 80 161 8738 8477 43399 0 0 0 90 144 9598 9337 49138 0 0 0 100 130 10255 9994 53601 0 0 0 110 117 10865 10605 57717 0 0 0 120 106 11427 11169 61368 0 0 0 130 96 11939 11683 64679 0 0 0 140 87 12413 12159 67653 0 0 0 150 79 12765 12514 69883 0 0 0
Merchant- able volume
Bd ft
oooooocoo0co0co°cocoeo°c°o oo ooooooo0oo0ccocco0c°eo°0c9o
ooooooooco0cc°ce0co°ce°0c0c So
BA/ acre
Ft?
10
CCF
105
114 118 122 125 129
Growth MOR/ PRD ACC year D
Yr Ft? Fits
5 2 0 0.0 10 4 0 0.7 10 12 Cc 1.8 10 24 0 3.3 10 36 1 49 10 42 2 6.2 10 50 4 7.4 10 54 6 8.4 10 53 9 9.4 10 53 12 10.3 10 54 16 ata 10 55 18 11.9 10 56 21 12.7 10 55 23 13.4 10 54 25 14.2
0 0 0. 14:9
5 5 0 0.0 10 20 0 1.2 10 55 0 3.4 10 87 2 5.9 10 108 6 8.0
10 117 15 9.8 10 123 25 11.3 10 122 35 12.7 10 118 43 14.0 10 17. 50 15.2 10 114 57 16.3 10 vale 62 17.4 10 104 64 18.5 10 105 69 19.5 10 98 69 20.5
0 0 0: 21:5 5 16 0 0.0 10 72 0 1.8 10 137 1 5.6 10 171 9 8.6 10 183 25. 10:9
10 184 46 12.8 10 176 62 14.5 10 172 74 15.9 10 173 87 17.3 10 152 87 18.7 10 158 97 =. 20.0 10 153 97,- =221%2 10 155 104°". 2235 10 152 104 23.7 10 138 103 25.0
0 0 0 26.3
Table 4—Yields of Douglas-fir plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years,
and thinning from below to 100 trees per acre at 50 years
70
Trees/ Age acre 5 500 10 473 20 432 30 232 40 225 50 217 60 98 70 95 80 92 90 89 100 86 110 82 120 79 130 75 140 72 150 68 5 500 10 478 20 447 30 242 40 236 50 226 60 97 70 92 80 88 90 83 100 78 110 73 120 68 130 64 140 60 150 56 5 500 10 489 20 472 30 245 40 234 50 218 60 96 70 90 80 85 90 79 100 74 110 69 120 64 130 60 140 56 150 52
Volume per acre
Total volume
Fts
79 801 2026 3649 5229 4549 5734 6828 7684 8532 9192 9770 10269 10763 11153
Merchant- able volume
Fre
Summary statistics
Merchant- able volume
Bd ft
Removals per acre
Trees/ Total acre volume volume
ooooooocoocomn coonoo COOOCOOCOOOONOCOONOCO GO
oooooocoocoocom~oonco
Ft?
ooooooooo0oowooc@moo
oooooocoocoo
Merchant-
174
fo] =
oooooocoeceoonNoococo;o
able
Ft?
oooooooo°coeo+-o0coeo0o°0o
oooooococeocomoo°ece
Merchant- able volume
Bd ft
oooooococoonooco7°cn]e
279
oooocoocooocooconooocjo;9e
671
oooooooocooonoooco;o
BA/ acre
Ft?
Growth
Top MOR/
CCF height PRD ACC _ year Ft Yr Ft2 Ft 2 3 5 2 0 5 8 10 4 0 1 16 10 12 0 26 25 10 24 0 45 34 10 36 1 37 43 10 26 1 47 50 10 30 2 56 57 10 32 3 64 63 10 35 4 71 68 10 36 6 Th 73 10 36 7 82 77 10 36 9 85 81 10 37 11 88 84 10 37 12 90 88 10 37 13 92 91 0 0 0 2 3 5 5 0 10 12 10 20 0 28 27 10 55 0 66 40 10 87 2 105 52 10 103 6 79 62 10 77 5 96 70 10 82 10 108 78 10 84 14 117 84 10 90 20 125 90 10 90 25 131 96 10 87 30 135 101 10 88 35 138 105 10 83 36 140 109 10 78 41 141 113 10 80 45 141 116 0 0 0 2 4 5 16 ) 21 18 10 72 0 61 40 10 137 1 122 57 10 171 9 172 71 10 183 25 117 82 10 132 15 134 90 10 143 25 148 97 10 143 34 159 104 10 125 40 166 109 10 139 55 171 114 10 118 52 174 118 10 119 61 176 121 10 113 64 Wad 125 10 121 71 177 128 10 104 65 176 131 0 0 0
10.5 alae: 12.4 13.3 14.1 14.9 15:7 16.5
0.0 1.2 3.4 5.9 8.0 11.4 13.2 14.8 16.3 WE 19.1 20.3 21.5 22.6 23.7 24.7
0.0
1.8
5.6
8.6 10.9 14.8 16.8 18.8 20.6 22.0 23.6 24.9 26.2 27.3 28.7 29.8
11
Table 5—Yields of Douglas-fir plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning from above to 100 trees per acre at 50 years
Site
Trees/
index Age acre
50
70
90
478 447 242
226
Volume per acre
Summary statistics Removals per acre
Total volume
Fre
79 801 2026 3649 5229 2401 3630 4832 6069 7074 7874 8739 9411 9976 10457
Merchant- able volume
Fr?
Merchant- able volume
Bd ft
Trees/
acre volume volume
18
oO CCOOCOCOOOOONDONOC SO
197
oo
126
NO iw) ooooooocoom~oonoo oooooocooco;o
Total
a e
a
8
oooococo0cowoonoo oooococco0o0cowmv~oo0ocn0coo oooococoocooco0co0owocq@mao°9o
373
Merchant-
1
358
12
able
Ft?
Soo0000
NO
mooooooeoc9cjc#encooooooo
75
ooooo0oococoeomooo0oco cocoooooo°cdeo
Merchant- able volume
Bd ft
oooo0o°o
82
@
3
oooooooo°oco-co0c0c0coe0o ooooocoocoe0oce0cocotfOo O0C0CO ooooacoco0aoecc Oo
1644
BA/ acre
Fi?
CCF
Growth
MOR/
PRD ACC _ year
Yr Ft? Fe’ 5 2 0 10 4 0 10 12 0 10 24 0 10 36 1 10 18 1 10 25 1 10 30 2 10 31 2 10 32 4 10 33 5 10 36 te 10 34 8 10 36 10 10 36 11 0) te) 0) 5 5 0 10 20 ) 10 55 0 10 87 2 10 108 6 10 54 4 10 69 4 10 78 7
0 0 0 5 16 0 10 72 0 10 137 1 10 171 9 10 183 25 10 99 8 10 131 8
D
0.0 0.7 1.8 3.3 4.9 5.1 6.4 TA. 8.9 10.0 10.9 11.8 12.8 13.6 14.5 15.3
0.0 1.2 3.4 5.9 8.0 8.0 9.9 11.8 13.6 15.2 16.7 18.0 19.3 20.5 21.7 22.8
0.0
1.8
5.6
8.6
10.9 10.6 12.9 15.3 17.4 19.5 21.1 22.6 24.2 25.5 26.8 28.0
Table 6—Yields of Douglas-fir plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning to 100 trees per acre at 50 years such that the mean d.b.h. before and after thinning is the same
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC_ year D Ft? Ft Bd ft Ft® Ft Bd ft Fiz Ft Yr Ft Ft 50 5 500 0 0 0 0 0 0 0 0 2 3 5 2 0 0.0 10 473 10 0 0 0 0 0 0 1 5 8 10 4 0 0.7 20 432 47 0 0 182 8 0 0 4 11 16 10 12 0 1.8 30 232 155 0 0 0 0 0 0 14 26 25 10 24 0 3.3 40 225 396 37 108 0 0 0 0 29 45 34 10 36 1 4.9 50 217 741 260 829 117 400 140 448 21 30 41 10 22 1 6.2 60 97 557 358 1203 0 0 0 0 30 38 49 10 28 1 75 70 94 821 665 2379 ) 0 0 0 38 47 56 10 31 2 8.7 80 91 1107 984 3724 0 0 0 0 47 56 63 10 31 3 9.8 90 88 1384 1277 5069 0 0 0 0 55 62 68 10 31 5 10.8 100 84 1645 1549 6391 0 0 0 0 62 68 72 10 33 6 11.6 110 80 1914 1822 7852 0 0 0 0 69 72 77 10 34 8 12.5 120 77 2181 2089 9366 0 0 0 0 75 76 81 10 34 9 13.4 130 73 2429 =. 2335 10838 0) 0 0 0 80 79 85 10 36 11 14.2 140 70 2680 2584 12379 0) 0 0 0 85 82 88 10 36 11 15.0 150 66 2924 2828 13919 0 0 0 0 90 84 91 0 0 0 15.8 70 5 500 0) 0 0 0 0 0 0) 0 2 3 5 5 0 0.0 10 478 27 0 0) 0 0 0 0 4 10 12 10 20 0 1:2 20 447 226 3 9 197 40 0 0 15 28 27 10 55 0 3.4 30 242 732 224 721 0 0) 0 0 47 66 40 10 87 2 5.9 40 236 1589 1163 4042 0 0 0 0 83 105 52 10 108 6 8.0 50 226 2601 2332 8828 126 1444 1294 4897 53 61 60 10 63 4 9.8 60 96 1747 1646 6784 0 0 0 0 70 77 69 10 75 7 11.6 70 92 2433 =. 2326 10388 0 0 0 0 89 91 77 10 79 10 13.4 80 87 3118 3003 14260 0 0 0 0) 106 102 84 10 79 14 14.9 90 83 3768 3645 18153 0 0) 0 0 120 110 90 10 82 19 16.3 100 78 4398 4267 21983 0 0) 0 0 133 117 95 10 80 230 «(17.7 110 74 4964 4828 25471 0 0 0 0 144 121 100 10 81 29 =—:18.9 120 69 5490 5350 28716 0 0 0 0 153 125 105 10 79 3220.1 130 65 5959 5815 31600 0 0 0 0 160 128 109 10 77 35 21.3 140 60 6380 6234 34183 0 0 0 0 166 129 113 10 77 38 22.4 150 56 6765 6617 36520 0 0 0 0 170 130 117 0 0 0 23.5 90 5 500 0 0 0 0 0 0 0 0 2 4 5 16 0 0.0 10 489 79 0 0) 0 0 0 0 9 21 18 10 72 0 1.8 20 472 801 253 771 222 135 0 0 42 61 40 10 137 1 5.6 30 245 2026 1670 5960 0 0 0 0 99 122 57 10 171 9 8.6 40 234 3649 3400 13473 0 0 0 0 152 172 71 10 183 25 10.9 50 218 5229 4991 21796 118 2816 2688 11723 90 94 77 10 113 10 12.8 60 95 3444 3318 15780 0 0 0 0 116 112 86 10 123 15 15.0 70 91 4530 4389 22187 0 0 0 0 142 127 93 10 123 22 = =16.9 80 86 5540 5386 28284 0 0 0 0 163 140 100 10 132 3218.6 90 81 6541 6375 34388 0 0 0 0 182 149 106 10 118 3720.3 100 76 7348 = =7173 39220 0 0 0 0 197 156 111 10 126 4721.8 110 71 8145 7964 43986 0 0 0 0 209 161 115 10 125 51 23.3 120 66 8887 8699 48393 0 0 0 0 220 165 120 10 125 58 24.7 130 62 9554 9362 52290 0 0 0 0 229 168 124 10 121 62 26.1 140 57 10150 9954 55795 0 0 0 0 236 170 127 10 111 64 927.5 150 53 10617 10419 58533 0 0 0 0 241 170 130 0 ) 0 28.7
13
20000
SITE INDEX 100 Ww 16000 5 a fo) > 5 30 ra 12000 Oo 80 Ht a 3 70 zl = 00 ° 80 60 50 4000 40
—a ————I a es a a a oe ot eae |
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 7—Douglas-fir yield curves for unthinned plantations in Inland Northwest forests (total cubic feet, all stems).
18000 SITE INDEX 100
¥ 15000
=
a |
[@)
>
i. 30
fo}
© 412000
ue 80
oO
H
a
5 70
= 9000
oO
th 60
>
6000 50 40 3000
10 20 30 40 50 60 70 80 g90 100 110 120 130 140 150
AGE
Figure 8—Douglas-fir yield curves for unthinned plantations in Inland Northwest forests (merchantable cubic feet, 4.5-inch top, stems greater than 7 inches d.b.h.).
14
in Inland Northwest
sts (merchantable board feet [Scribner], 4.5-inch top, stems greater than
Figure 9—Douglas-fir yield curves for unthinned plantations
SITE INDEX MIDPOINT
Figure 10—Distribution of Douglas-fir plantation site index values for Inland
sts.
st fore
Northwe
15000 -
142000 + i
9000
6000
TOTAL CUBIC FOOT VOLUME
3000
SITE INDEX
Figure 11—Douglas-fir yield vs. site index at 70 years of age (total
cubic feet). SITE INDEX 30 100 f 90 o Ww 80 oO a is 20 70 jem WwW Be 2 60 <= Lal Q z 50 = 40 oO Leal - 10 + a Q a9 = [e)
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 12—Quadratic mean diameter vs. age for Douglas-fir unthinned plantations in Inland Northwest forests.
16
SITE INDEX
30 100 90 me 80 wn WwW aS S 70 BI 20 oi w 60 WwW = <= Land 2 50 rs i a 40 oO H & 410 jem a <= =) fe) 40 20 30 40 50 60 70 80 90 4100 110 120 130 140 150 AGE Figure 13—Quadratic mean diameter vs. age for Douglas-fir precommercial thinning to 250 trees per acre at 20 years in Inland Northwest forests. 40 SITE INDEX 4100 if e 30 90 oO 4 B0 to 70 a WwW z= < 60 = 20 Zz <t = 50 = fe 40 xt a a = 10 o
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE Figure 14—Quadratic mean diameter vs. age for Douglas-fir precommercial
thinning to 250 trees per acre at 20 years and commercial thinning from below to 100 trees per acre at 50 years in Inland Northwest forests.
A,
40
SITE INDEX to 100 = 30
2 30 a 80 oh
ty 70 =
a
a 20 60 =
a
= 50 =
S 40 Cc
Qa
5 10
oO
10 20 30 40 50 60 70 80 90 100 110 420 130 140 150
AGE
Figure 15—Quadratic mean diameter vs. age for Douglas-fir precommercial thinning to 250 trees per acre at 20 years and commercial thinning to 100 trees per acre at 50 years such that the mean d.b.h. before and after thinning is the same.
40 SITE INDEX
a 100 5 30 zZ 90 S fe 80 u w 70 < tH a 20 60 rd < = S) 50 a 40 a A = 10 a
10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150
AGE
Figure 16—Quadratic mean diameter vs. age for Douglas-fir precommer- cial thinning to 250 trees per acre at 20 years and commercial thinning from above to 100 trees per acre at 50 years in Inland Northwest forests.
18
10000
8000 WwW = =) as {=} > MGMT 5 6000 rd 000 oO H a POO oO 2 4000 = fe PCB PC4 PCA 2000 40 20 30 40 50 60 70 80 90 1400 410 120 130 140 150 AGE Figure 17—Effect of thinning on standing volume of Douglas-fir plantations (total cubic feet), site index 50. 414000 12000 MGMT = 3 40000 a 9 POO S S 8000 - PCB ) PC4 a PCA O 6000 eal) << — oO F 4000 2000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 18—Effect of thinning on standing volume of Douglas-fir plantations (total cubic feet), site index 70.
19
18000
15000
TOTAL CUBIC FOOT VOLUME
3000 r
12000 -F
9000 r
6000 +
10
20
30
40
50
60
70
ee a a |
BO 90 100 4110 120 130 140 4150
AGE
Figure 19—Effect of thinning on standing volume of Douglas-fir plantations (total
cubic feet), site index 90.
25000
20000
15000
410000
TOTAL BOARD FOOT VOLUME
5000
MGMT
000
POO
PCB
PC1 PCA
80 90 100 110 120 130 140 4150
AGE
Figure 20—Effect of thinning on standing volume of Douglas-fir plantations
(merchantable board feet [Scribner]), site index 50.
20
45000
36000
27000
TOTAL BOARD FOOT VOLUME
18000
9000
— 41 _s__t. De SS
70
AGE
90
100
110
Figure 21—Effect of thinning on standing volume of Douglas-fir plantations
(merchantable board feet [Scribner]), site index 70.
65000
52000
39000
26000
TOTAL BOARD FOOT VOLUME
13000
AGE
Figure 22—Effect of thinning on standing volume of Douglas-fir plantations
(merchantable board feet [Scribner]), site index 90.
21
80
90
100
110
120
120
130
130
140
140
150
MGMT
000 POO
PCB
PC1 PCA
MGMT
000 POO
PCB
PC4 PCA
10000
8000 a — = MGMT > 6000 > Ww s) 000 2 = POO {=} 4000 PCB PCA PC4 2000 10 20 30 40 50 60 70 80 90 400 410 120 130 140 150 AGE Figure 23—Effect of thinning on total yield of Douglas-fir plantations (total cubic feet), site index 50. 14000 12000 + MGMT 10000 + ‘S 000 4 POO iw t PCA o PCB > 8000 ees Ww oO = a id e 6000 4000 2000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 24—Effect of thinning on total yield of Douglas-fir plantations (total cubic feet), site index 70.
22
18000
15000
12000
9000
TOTAL CFV YIELD
6000
3000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 25—Effect of thinning on total yield of Douglas-fir plantations (total cubic feet), site index 90.
25000 +
20000 +
TOTAL BFV YIELD
5000
—. 4 4 1 — a i Se or |
10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150
AGE
Figure 26—Effect of thinning on total yield of Douglas-fir plantations (merchantable board feet [Scribner]), site index 50.
23
MGMT
000
POO
PCB
PC1 PCA
MGMT
000 POO 45000 aia PCA PC4 Q 36000 WW H > > Le {ea} _, 27000 tt om {=} FE 18000 9000 1410 20 30 40 50 60 70 80 90 100 110 120 4130 140 4150 AGE Figure 27—Effect of thinning on total yield of Douglas-fir plantations (merchantable board feet [Scribner]), site index 70. MGMT 78000 } PCA 000 PC4 POO PCB 65000 4 7 52000 Lol > > Ww a 2 39000 fas oO Ee 26000 413000
ee |
10 20 30 40 50 60 70 80 90 100 110 4120 130 140 150
Figure 28—Effect of thinning on total yield of Douglas-fir plantations (merchantable board feet [Scribner]), site index 90.
24
Grand fir
Yields are summarized in tables 7 through 11 and fig-
ures 29 through 31.
In comparison to Douglas-fir plantations, early yields
are lower for grand fir, but by 100 years the grand fir
yields are higher for all site index classes. Site indices for the simulations (figs. 32, 33) of grand fir plantations are lower than for either the natural regen-
eration simulations or for the Douglas-fir plantations.
The differences are attributable to data for initial heights
at age 5 represented in the Regeneration Establishment
Model. Planting effect in the initial height estimation
equation gives little height advantage to planted grand fir compared to Douglas-fir.
Mean d.b.h. of the grand fir plantations starts slower than Douglas-fir but surpasses it in later years (figs. 34
through 38). Grand fir plantations always have trees of
larger diameter than the naturally regenerated stands,
which also contain a substantial proportion of grand fir. Effects of thinning regimes on standing volume are
compared in figures 39 through 44. Effects of thinnings
on total yield are compared in figures 45 through 50.
Table 7—Yields of grand fir plantations having 500 trees per acre surviving 5 years, no thinning
Site Trees/ Total index Age acre volume Fts
50 5 500 0 10 447 2 20 371 13 30 316 79 40 292 308 50 276 872 60 262 1758 70 246 2910 80 229 4166 90 210 5430 100 192 6700 110 174 7916 120 158 9072 130 143 10126 140 130 11108 150 118 12004 70 5 500 0 10 454 4 20 393 43 30 344 292 40 328 1216 50 312 2934 60 289 5203 70 259 7374 80 228 9329 90 198 11255 100 174 12935 110 151 14543 120 133 15989 130 118 17271 140 105 18408 150 93 19534 90 5 500 0 10 459 6 20 406 80 30 366 TAA 40 351 2789 50 323 6086 60 284 9408 70 245 11718 80 207 14256 90 178 16122 100 150 18068 110 129 19846 120 113 21302 130 101 22611 140 89 24022 150 79 25343
Summary statistics
Volume per acre
Merchant- able volume
Ft?
31 735 2543 4852 7038 8997 10921 12603 14211 15658 16942 18083 19210
Merchant- able volume
Bd ft
102513
0
0
0 1175 9459 26543 44885 58472 73051 83469 94258 103758 111471 118360 125692 132570
Trees/
acre volume volume
oooooococo0coc0ceococcceco oooocoocceococc0co0co0oc0coo cooooooooocooco0c0c0ccc0d
Removals per acre
Total
au] o
ooooococoeoccococ0coe0coo cocooooooocococeococo0c0c0 oe oooooococe0o0aoaoccocaccodc fo
Merchant-
able
Fi?
oooooococececococooceceoco oooooooococococo oooooooococo0ccecoc0csd
Merchant- able volume
=>
SSCOCDCOO OOOO OOOO OO ODO OOOO OOOO OOO OO COCO OCC OOO OC CCO Cod &
BA/ acre
Ft?
CCF
110 ual 124 130 136 142 148
Growth
MOR/
PRD ACC year Yr Fits rts 5 ) 0 10 1 0 10 7 0 10 23 0 10 58 1 10 92 4 10 125 10 10 145 19 10 157 31 10 172 45 10 177 55 10 182 67 10 182 77 10 185 86 10 182 92 0 0 0 5 1 0 10 4 0 10 25 0 10 93 1 10 176 4 10 247 21 10 268 51 10 277 82 10 307 114 10 298 130 10 316 155 10 307 163 10 296 168 10 289 175 10 294 182 0 0 0 5 1 0 10 8 0 10 64 0 10 208 1 10 347 AW? 10 400 67 10 352 120 10 428 174 10 374 187 10 431 237 10 417 239 10 376 231 10 367 236 10 386 246 10 388 256 0) 0 0
10.2 1157 13.1 14.4 15.7 16.9 18.1 19.3 20.4
0.0 0.8 1.8 3.8 6.7 9.4 1157 13.6 15.3 17.0 18.6 20.2 21.8 23.3 24.8 26.3
0.0 1.0 2.2 5:2 8.8 12.0 14.4 16.3 18.3 20.1 22.1 24.0 25.7 27.4 29.2 31.0
25
Table 8—Yields of grand fir plantations having 500 trees per acre surviving 5 years, precommercial thinning from below to 250 trees per acre at
20 years Summary statistics Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _——‘ Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC year OD Fts Ft? Bd ft lage Fr? Bd ft Ete Ft Yr Ft Ft?
50 5 500 0 0 0 0 0 0 0 0 2 1 5 0 G 0.0 10 447 2 0 0 0 0 0 0 1 3 6 10 1 0 0.6 20 371 13 0 0 121 it 0 0 3 7 12 10 6 0 1.4 30 216 70 0 0 0 0 0 0 9 19 21 10 21 0 2.8 40 204 278 57 189 0 0 0 0 24 44 29 10 51 1 47 50 194 776 458 1617 0 0 0 0 52 82 37 10 84 2 7.0 60 186 1593 1344 5146 0 0 0 0 86 121 47 10 112 Tf 9.2 70 178 2644 2444 10267 0 0 0 0 119 152 56 10 134 15 11.4 80 167 3839 3645 16635 0 0 0 0 149 176 65 10 148 24 12.8 90 156 5074 4871 23646 0 0 0 0 174 195 73 10 158 35 14.3
100 145 6303 6090 30847 0 0 0 0 195 210 81 10 166 46 3915.7 110 133 7509 7287 37917 0 0 0 0 212 222 88 10 169 56 17:4 120 123 8642 8413 44488 ) 0 0 0 225 231 95 10 172 66 18.3 130 113 9707 9474 50532 0 0 0 0 235 237 101 10 174 74 19.6 140 103 10713 10476 56107 0 0 0 0 243 241 107 10 173 80 20.8 150 95 11643 11404 61157 0 0 0 0 249 244 1413; 0 0 0 21.9
70 5 500 0 0 0 0 0 0 0 0 2 2 5 1 0 0.0 10 454 4 0 0 0 0 0 0 2 5 a, 10 4 0 0.8 20 393 43 0 0 143 4 0 0 6 13 17 10 21 0 24 30 227 252 23 75 0 0 0 0 22 42 30 10 81 0 43 40 220 1051 678 2415 0 0 0 0 66 104 41 10 152 3 7.4 50 213 2541 2298 9110 0 0 0 0 123 163 53 10 206 12. 10.3 60 202 4472 4244 19060 0 0 0 0 177 210 64 10 248 33: “1237. 70 186 6623 6373 31436 0 0 0 0 223 247 vas 10 280 60 14.8 80 169 8819 8547 44298 0 0 0 0 260 274 85 10 273 81 16.8 90 153 10735 10449 55334 0 0 0 0 284 291 94 10 294 12> 18:5
100 136 12566 12270 65600 0 0 0 0 303 302 103 10 281 124 20.2 110 121 14136 13836 74108 0 0 0) 0 315 308 110 10 289 140 21.8 120 109 15632 15327 82140 0 0 0 0 324 312 117 10 284 149 23.4 130 98 16985 16679 89283 0 0 0 0 331 314 124 10 278 158 24.9 140 88 18190 17884 95577 0 0 0 0 335 314 1314 10 280 164 26.4 150 80 19349 19042 101548 0 0 0 0 339 314 137 0 0 0 28.0
90 5 500 0 0 0 0 0 0 0 0 2 3 5 1 0 0.0 10 459 6 0 0 0 0 0 0 2 6 8 10 8 0 1.0 20 406 80 0 0 156 8 0 0 10 20 21 10 57 0 2.6 30 235 635 281 1027 0 0 0 0 46 74 36 10 207 1 6.0 40 229 2696 2438 10450 0 0 0 0 133 176 55 10 371 13 10.3 50 216 6268 5998 29285 0 0 0 0 233 263 74 10 283 47 = 14.0 60 199 8634 8333 42318 0 0 0 0 280 299 84 10 460 110: = 1641 70 172 12127 11797 61876 0 0 0 0 333 339 96 10 401 146 18.8 80 151 14685 14340 75913 0 0 0 0 362 356 107 10 359 169 921.0 90 133 16585 16233 86302 a) 0 0 0 376 363 113 10 397 203 22.8
100 116 18522 §=18166 96700 0 0 0 0 387 366 122 10 374 207. 24.8 110 101 20182 19826 105655 0 0 0 0 393 366 128 10 407 234 26.7 120 90 21914 21556 114805 0 0 0 0 400 367 135 10 340 208 28.6 130 81 23229 22870 121656 0 0 0 0 404 368 141 10 385 240 830.3 140 72 24677 24317 129187 0 0 0 0 408 367 146 10 387 245 = 32.1 150 64 26094 25734 136479 0 0 0 0 411 365 153 0 0 0 34.2
26
Table 9—Yields of grand fir plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning from below to 100 trees per acre at 50 years
Site
Trees/
index Age acre
70
Total volume
Volume per acre
Merchant- able volume
Ft?
Merchant- able volume
Ft?
1027 10450 29285 37270 50117 65093 80242 95001
108111 117243 124896 129748 135201
Summary statistics
Removals per acre Merchant- Merchant-
Trees/ Total able able acre volume volume volume Bd ft Ft? Fr 0 0 0 0 0 0 0 0 121 1 0 0 0 0 0 0 0 0 0 0 94 207 40 133 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 143 4 0 0 0 0 0 0 0 0 0 0 113 819 674 2405 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 156 8 0 0 0 0 0 0 0 0 0 0 116 1367 1262 4808 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
BA/ acre
Bd ft 0
CCF
Ft?
Top height
Growth
MOR/
PRD ACC _ year Ft Yr Ft° 5 0 0 10 1 0 10 6 0 10 21 0 10 51 1 10 60 1 10 82 3 10 100 7 10 118 13 10 124 19 10 135 27 10 145 34 10 140 39 10 150 48 10 150 53 0 0 0 5 1 0 10 4 0 10 21 0 10 81 0 10 152 3 10 144 4 10 190 12 10 209 24 10 239 43 10 235 54 10 252 75 10 265 91 10 251 98 10 249 110 10 239 118 0 0 0 5 1 0) 10 8 0 10 57 0 10 207 1 10 371 13 10 249 18 10 278 42 10 355 73 10 400 109 10 431 148 10 436 183 10 349 172 10 320 172 10 248 155 10 304 199 0 0 0
D Ft?
0.0 0.6 1.4 2.8 4.7 8.1 10.5 12.6 14.5 16.3 17.9 19.4 20.9 22.3 23.6 24.9
0.0 0.8 2.1 43 7.4 12.1 14.8 17.4 19.6 21.8 23.7 25.6 27:5 29.2 30.8 32.3
0.0
1.0
2.6
6.0 10.3 17.5 20.1 22.4 25.1 27.8 30.3 33.0 34.9 36.7 38.0 39.9
27
Table 10—Yields of grand fir plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning from above to 100 trees per acre at 50 years
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _ Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC year D Fe? Fre Bd ft Fr Ft® Bd ft Ft Ft Yr ts Fite 50 5 500 0 ) 0 0) 0 ) 0 0 2 1 5 ) 0) 0.0 10 447 2 0) 0) 0 0 0 0 1 3 6 10 1 0) 0.6 20 371 13 0 0 121 1 0 0 3 7 12 10 6 0 1.4 30 216 70 0 0 0 0 0 0 9 19 21 10 21 0 2.8 40 204 278 57 189 0 0 0 0 24 44 29 10 51 1 4.7 50 194 776 458 1617 94 557 422 1499 17 29 31 10 36 1 5.6 60 96 573 422 1489 0) 0 0 0 34 52 40 10 59 1 8.0 70 93 1147 1045 4108 0 0 0 0 55 73 50 10 79 3 10.4 80 90 1905 1804 7966 0 0 0 0 76 92 60 10 99 U 12.5 90 87 2823 2710 13092 0 0 0 0 98 110 69 10 114 12 14.4 100 83 3845 3718 19000 0 0 0 0 119 127 | 78 10 129 18 16.2 110 79 4950 4809 25310 0 0 0 0 138 143 86 10 139 24 PAS) 120 75 6097 5944 31716 0 0 0 0 155 157 94 10 137 31 19.5 130 71 7155 6992 37516 0 0 0 0 169 168 101 10 143 40 21.0 140 66 8178 8006 43020 0 0 0 0 181 176 107° 10 148 46 922.4 150 62 9202 9023 48447 0 0 0 0 192 184 113 0 0 0 23:7, 70 5 500 0 0 0 0 0 0 0 0 2 2 5 1 0 0.0 10 454 4 0 0 0 0 0 0 2 5 tf 10 4 0 0.8 20 393 43 0 0 143 4 0 0 6 13 AZ; 10 21 0 2st 30 227 252 23 75 0 0 0 0 22 42 30 10 81 0 43 40 220 1051 678 2415 0 0 0 0 66 104 41 10 152 3 7.4 50 213 2541 2298 9110 113 1862 1752 7185 37 57 45 10 91 2 8.2 60 96 1571 1470 5978 0 0 0 0 66 84 - 58 10 145 4 11.2 70 94 2979 2860 13740 0 0 0 0 103 115 69 10 190 10 14.1 80 90 4785 4638 24083 0 0 0 0 141 148 82 10 228 23 16.9 90 86 6838 6663 35595 0 0 0 0 A: 179 93 10 251 39 19.4 100 81 8961 8762 47095 0 0 0 0 208 205 102 10 245 54 21.7 110 76 10868 10652 57206 0 0 0 0 233 224 111 10 242 71 23.7 120 71 12583 12353 66225 0 0 0 0 251 237 119 10 238 82 25.5 130 66 14146 13905 74315 0 0 0 0 266 247 126 10 265 108 27.1 140 61 15720 15470 82470 0 0 0 0 279 256 133 10 251 111 28.9 150 57 17126 16870 89740 0 0 0 0 289 262 138 0 0 0 30.6 90 5 500 0 0) 0 0) 0 ) 0 0 2 3 5 1 0 0.0 10 459 6 0 0 0 0 0 0 2 6 8 10 8 0 1.0 20 406 80 0 0 156 8 ) 0 10 20 21 10 57 0) 2.6 30 235 635 281 1027 0 0 0 0 46 74 36 10 207 1 6.0 40 229 2696 2438 10450 0 0 0 0 133 176 55 10 371 13 10.3 50 216 6268 5998 29285 116 5190 5009 25605 52 73 52 10 123 3 9.8 60 97 2278 2171 9531 0 0 0 0 87 103 65 10 181 5 12.9 70 95 4038 3903 19850 0 0 0 0 127 138 80 10 306 17 15.7 80 90 6932 6754 36266 0 0 0 0 182 185 94 10 379 38 19.3 90 85 10345 10125 54574 0 0 0 0 236 229 109 10 374 69 226 100 79 13391 13141 70416 0 0 0 0 274 261 119 10 320 94 25.2 110 73 15645 15377 82187 0 0 0 0 297 277 128 10 341 125. 27:3 120 67 17801 17518 93313 0 0 0 0 318 291 135 10 275 Ti? 43295 130 62 19386 19095 101522 0 0 0 0 329 299 141 10 293 145 331.1 140 57 20864 20567 109179 0 0 0 0 338 303 147 10 361 171 32.8 150 53 22768. 22463 119047 0 0 0 0 350 311 154 0 0 0 349
28
Table 11—Yields of grand fir plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning to 100 trees per acre at 50 years such that the mean d.b.h. before and after thinning is the same
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Lis Ft? Bd ft Ft Et Bd ft Ft2 Ft Yr Ft? Fts 50 5 500 0 0 0 0 0 0 0 0 2 1 5 0 0 0.0 10 447 2 0) 0 0 0 0 0 1 3 6 10 1 0 0.6 20 371 13 0 0 121 1 0 0 3 7 +2 10 6 0 1.4 30 216 70 0 0 0 0 0 0 9 19 21 10 21 0 2.8 40 204 278 57 189 0 0 0 0 24 44 29 10 51 1 4.7 50 194 776 458 1617 94 380 227 800 27 42 36 10 48 1 7.0 60 97 870 743 2856 0 0 0 0 46 64 45 10 70 2 9.4 70 94 1544 1442 6152 0 0 0 0 68 85 55 10 90 SS 80 91 2398 2288 10710 0 ) 0 0 90 104 64 10 106 9 13.5 90 87 3364 3241 16161 0 0 0 0 112 122 72 10 119 15 15.4 100 83 4398 4262 22099 0 0 0 0 131 138 81 10 129 22— 17.0 110 78 5468 5320 28159 0 ) 0 0 148 151 88 10 134 28 = 18.6 120 74 6525 6366 34033 0 0 0 0 163 163 96 10 140 3620.1 130 70 7567 7399 39700 0 0 0 0 176 173 102 10 143 42 21.5 140 65 8574 8398 45086 0 0 0 0 187 181 109 10 144 49 22.9 150 61 9526 9344 50130 0 0 0 0 196 187 114 0 0 O 24.2 70 5 500 0 0 0 0 0 0 0 0 2 2 5 1 0 0.0 10 454 4 0 0 0 0 0 0 2 5 u 10 4 0 0.8 20 393 43 0 0 143 4 0 0 6 13 17 10 21 0 2.1 30 227 252 23 75 0 0 0 0 22 42 30 10 81 0 4.3 40 220 1051 678 2415 0 0 0 0 66 104 41 10 152 3 7.4 50 213 2541 2298 9110 113 1348 1219 4834 58 77 50 10 115 3 10.3 60 97 2316 2203 10037 0 0 0 0 91 106 62 10 163 7 13.1 70 94 3871 3735 18846 0 0) 0 0 127 137 74 10 209 17. 15.7 80 90 5792 5628 29699 0 0 0 0 164 169 85 10 210 28 = 18.3 90 85 7611 7425 39757 0 0 0 0 193 192 95 10 242 48 20.4 100 79 9549 9343 50145 0 0 0 0 220 214 104 10 243 63 22.5 110 74 11346 11124 59627 0 0 0 0 241 229 112 10 250 79 24.5 120 68 13059 12824 68619 0 0 0 0 258 242 120 10 236 87 =. 26.3 130 64 14543 14299 76333 0 0 0) 0 271 251 126 10 226 98 28.0 140 59 15829 15579 82985 0 0 0 0 281 257 133 10 234 111. 29.5 150 54 17057 16801 89358 0 0 0 0 289 261 139 0 0 0 31.2 90 5 500 0 0 0 0 0 0 0 0 2 3 5 1 0 0.0 10 459 6 0 0 0 0 0 0 2 6 8 10 8 0 1.0 20 406 80 0 0 156 8 0 0 10 20 21 10 57 0 2.6 30 235 635 281 1027 0 0 0 0 46 74 36 10 207 1 6.0 40 229 2696 2438 10450 0 0 0 0 133 176 55 10 371 13 10.3 50 216 6268 5998 29285 116 3373 3227 15757 107 121 66 10 171 7 14.0 60 97 4537 4386 22400 0 0 0 0 145 153 78 10 340 22 «16.6 70 91 7709-7512 39671 0 0 0 0 204 203 94 10 329 42 20.2 80 87 10585 10355 55221 0 0 0 0 247 239 105 10 309 70 =. 22.9 90 81 12978 12725 68003 0 0 0 0 278 262 114 10 338 100 25.1 100 74 15354 15082 80565 0 0 0 0 303 281 123 10 325 116 9.27.4 110 68 17441 17155 91438 0 0 0 0 322 295 130 10 355 142 29.5 120 62 19569 19271 102467 0 0 0 0 339 306 137 10 306 141. 31.5 130 58 21215 20907 110978 0 0 0 0 351 314 143 10 344 171 33.4 140 53 22944 22629 119944 0 0 0 0 361 320 149 10 341 177. 35.4 150 48 24586 24265 128454 0 0 0 0 370 325 155 0 0) 0 37.5
29
30000
SITE INDEX 25000 20 Bs B80 =I S 20000 0 5 oO WwW = 60 o S 15000 2 = 50 o 10000 40 30 5000
10 20 30 40 50 60 70 80 g0 100 110 120 130 140 150
AGE
Figure 29—Grand fir yield curves for unthinned plantations in Inland Northwest forests (total cubic feet all stems).
SITE INDEX 25000 90 Ww 80 = = 8 20000 > 70 — oO oO Ue 60 q 45000 =) oO rs) 50 jem WwW = 140000 40 30 5000
10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150
AGE
Figure 30—Grand fir yield curves for unthinned plantations in Inland Northwest forests (merchantable cubic feet, 4.5-inch top, stems greater than 7 inches d.b.h.).
30
SWN10A 1004 GkvOEs
in Inland Northwest
sts (merchantable board feet [Scribner] 4.5-inch top, stems greater than
Figure 31—Grand fir yield curves for unthinned plantations 7 inches d.b.h.).
fore
IN40u3d
50 60 FO 80 SITE INDEX MIDPOINT
O
alues for Inland
Figure 32—Distribution of grand fir plantation site index v
Northwest forests.
24000
20000
16000
12000
TOTAL CUBIC FOOT VOLUME
8000
4000
10 20 30 40 50 60° .«° “70 80 90
SITE INDEX
Figure 33—Grand fir yield vs. site index at 110 years (total cubic feet).
40 SITE INDEX
8 30 = 30 a 80 ry | 70 Hf 60 2 o [ 50
20 ra a 7 40 o L > 30 jam Qa 5 10 (es)
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 34—Quadratic mean diameter vs. age for grand fir unthinned plantations in Inland Northwest forests.
32
40
SITE INDEX 30
no Hi 80 ee 30 oO 4 70 or 60 ty = 50 H S 20 + es ig 40 = o + 30 i < a ey <= =) 10 + [es}
i
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 35—Quadratic mean diameter vs. age for grand fir precommercial thinning to 250 trees per acre at 20 years in Inland Northwest forests.
SITE INDEX 40 30 80 o 70 + 30 3G 60 P-4 H ry 50 Ww z tt H a 20 + 40 q WwW = 30 oO b H bE <x a a 5 10 + Oo
AGE
Figure 36—Quadratic mean diameter vs. age for grand fir precommercial thinning to 250 trees per acre at 20 years and commercial thinning from below to 100 trees per acre at 50 years in Inland Northwest forests.
33
SITE INDEX
40 - 30 80
to 70
x 30 +
oO
a 60
jem
he 50
WwW
=
<t
H
= 20 + 40
Zz
4
WwW
= 30
oO t
o
m
xt
a
a
5 10
Tac) r
SS — L 4 = a 10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150 AGE
Figure 37—Quadratic mean diameter vs. age for grand fir precommercial
thinning to 250 trees per acre at 20 years and commercial thinning to 100 trees
per acre at 50 years such that the mean d.b.h. before and after thinning is the
same.
a0 SITE INDEX
90 80
i
r 30 70
oO
Zz
4 60
acs
50
WwW
=
—t
a
20 +
40
—t
WwW
=
S | 30
H
kb
<<
a
2
3 40 +
10 20 30 40 50 60 70 80 90 100 4110 4120 130 140 150
AGE
Figure 38—Quadratic mean diameter vs. age for grand fir precommercial thinning to 250 trees per acre at 20 years and commercial thinning from above to 100 trees per acre at 50 years in Inland Northwest forests.
34
15000
MGMT WwW = 000 3 12000 ae {=} > e PCB 9 PCt * — goo0 PCA oO Lal fea) =) 2 | =I = ie 3000 + —t 4 —— 1 7 — | + 1 EEE eet 4 a — eS Se | 10 20 30 40 50 60 70 80 90 100 410 120 130 140 150 AGE Figure 39—Effect of thinning on standing volume of grand fir plantations (total cubic feet), site index 50. 24000 MGMT 20000 000 POO PCB Ww PCA = PC1 3 16000 > Kk oO oO ti 2 412000 ao =) oO ll t = 2 8000 4000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 40—Effect of thinning on standing volume of grand fir plantations (total cubic feet), site index 70.
35
30000
20000
15000
TOTAL CUBIC FOOT VOLUME
10000
5000
cubic feet), site index 90.
66000
55000
44000
33000
TOTAL BOARD FOOT VOLUME
22000
11000
+
140 20 30 40 50 60 70 80 90 100 110 120 130 140 150 AGE Figure 41—Effect of thinning on standing volume of grand fir plantations (total pe eaten ee a Se 40 20 30 40 50 60 70 80 90 100 110 120 4130 140 150 AGE
Figure 42—Effect of thinning on standing volume of grand fir plantations (merchant-
able board feet [Scribner]), site index 50.
36
MGMT
000 POO
PCB
PC41 PCA
90000
72000
‘
54000
TOTAL BOARD FOOT VOLUME
36000
18000
Figure 43—Effect of thinning on standing volume of grand fir plantations (merchant- able board feet [Scribner]), site index 70.
4120000
72000
TOTAL BOARD FOOT VOLUME
48000
24000
AGE
Figure 44—Effect of thinning on standing volume of grand fir plantations (merchantable
board feet [Scribner]), site index 90.
37
MGMT
000 POO
PCB
PCA PC1
MGMT
15000
MGMT 000 4 12000 poe a3 m PCB s PC4 rf PCA S 9000 sa | tt — [=) co 6000 3000 + 140 20 30 40 50 60 70 80 90 400 110 120 130 140 150 AGE Figure 45—Effect of thinning on total yield of grand fir plantations (total cubic feet), site index 50. 24000 MGMT 288 20000 PEA PCB PC4 5 16000 WwW Lal > > i oO 1 12000 at — oO i 8000 4000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
Figure 46—Effect of thinning on total yield of grand fir plantations (total cubic feet), site index 70.
38
30000
25000
20000
15000
TOTAL CFV YIELD
10000
5000
10 20 30 40
50
60
70
80
AGE
90
100
110
120
130
Figure 47—Effect of thinning on total yield of grand fir plantations (total cubic feet),
site index 90.
66000
55000
44000
33000
TOTAL BFV YIELD
22000
11000
10 20 30 40
50
60
70
AGE
80
90
100
110
120
130
Figure 48—Effect of thinning on total yield of grand fir plantations (merchantable
board feet [Scribner]), site index 50.
39
140
140
150
150
MGMT
000 POO
PCB
PC4 PCA
90000
72000
54000
TOTAL BFV YIELD
36000
18000
10 20 30 40
50
60
70
80
AGE
90
100
110
120
Figure 49—Effect of thinning on total yield of grand fir plantations (merchant-
able board feet [Scribner]), site index 70.
125000
400000
75000
TOTAL BFV YIELD
50000
25000
10 20 30 40
Figure 50—Effect of thinning on total yield of grand fir plantations (merchantable
board feet [Scribner]), site index 90.
50
60
70
AGE
40
80
90
100
110
120
130
130
140
140
150
150
Western Larch
Yields predicted for western larch plantations in tables 12-16 are the lowest of all the species included in this col- lection. The lower yields must be attributed to lower lev- els of stocking because the distribution of site indices (figure 51) is comparable to the distribution for naturally regenerated stands (figure 5) and for Douglas-fir planta- tions (figure 10). The general shape of the yield curves (figures 52-54) is similar to the corresponding curves for the plantations of the other species. The reduced stocking
is attributable to both slower diameter growth (figs. 56 through 60) and higher mortality rates than for Douglas- fir or grand fir. Larch casebearer (Coleophora laricella) was a common pest of western larch throughout most of the Inland Empire during the period upon which the Prognosis Model was calibrated. Whether future stands of western larch will continue to be afflicted as much as these data indicate remains to be seen. Effects of thin- ning regimes on standing volume and total yield are com- pared in figures 61 through 64 and figures 65 through 68, respectively.
Table 12—Yields of western larch plantations having 500 trees per acre surviving 5 years, no thinning
Volume per acre
Summary statistics
Removals per acre
Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _ Total able able Trees/ Total able able BA/ Top index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Ft? Ets Bd ft Ft? Ft? Bd ft Ft Ft Yr Ete Fte
50 5 500 0 0 0 0 0 0 0 0 1 3 5 0 0 0.0 10 462 3 0 0 0 0 0 0 1 2 8 10 2 0 0.7 20 405 19 0 0 0 0 0 0 5 6 16 10 TE 0 1.4 30 349 90 0 0 0 0 0 0 13 15 24 10 18 0 27 40 327 262 4 14 0) 0 0 0) 28 29 33 10 30 1 3.9 50 306 553 95 363 0 0 0 0 46 45 41 10 39 3 5:2 60 287 918 369 1465 0 0 0 ) 64 60 48 10 47 4 6.4 70 268 1343 868 3545 0 0 0 0 81 75 55 10 53 Ti Ts) 80 250 1795 1406 5902 0 0 0 0 97 88 61 10 56 11 8.4 90 233 2248 1945 8334 0 ) 0 0 110 98 66 10 56 15 9.3 100 216 2660 2409 10522 0 0 0 0 120 106 72 10 58 19 10.1 110 198 3050 2830 12595 0 0 0 0 128 111 77 10 57 22 =10.9 120 182 3395 3194 14491 0 0 0 0 134 115 81 10 57 25 11.6 130 167 3712 3522 16329 0 0 0 0 138 117 85 10 54 28 12.3 140 152 3969 3788 17965 0 0 0 0 141 118 89 10 53 31 13.0 150 139 4189 4015 19451 0 0 0 0 142 118 93 0 0 0 13.7 70 5 500 0 0 0 0 0 0 0 0 1 3 5 0 0.0 10 465 8 0 0 0 0 0 0 3 4 12 10 8 0 1.0 20 420 83 0 0 0 0 0 0 12 14 25 10 33 0 2.3 30 372 405 30 116 0 0 0 0 38 38 38 10 66 1 43 40 354 1047 407 1621 0 0 0 0 73 69 49 10 87 6 6.2 50 329 1855 1300 5387 0 0 0 0 107 98 58 10 97 15 7.7 60 299 2677 = 2265 9701 0) 0 0 0 134 119 67 10 104 26 9.1 70 266 3464 3139 13885 0 0 ) 0 153 135 75 10 100 35 = 10.3 80 235 4111 3842 17486 0 0 0 0 166 142 82 10 99 45 11.4 90 206 4645 4402 20645 0 0 0 0 173 146 88 10 94 51 12.4 100 180 5071 4848 23490 0 0 0 0 176 146 93 10 91 56 13.4 110 158 5421 5214 25957 0 0 0 0 177 145 99 10 89 59 14.4 120 138 5717 §522 28175 0 0 0 0 177 142 103 10 85 61 15.3 130 122 5959 5775 30072 0 0 0 0 175 139 108 10 79 62 16.3 140 108 6129 5955 31427 0 0 0 0 173 136 112 10 77 63 17.2 150 95 6265 6100 32516 0 0 0 0 169 132 116 0 0 0 18.1 80 5 500 0 0 0 0 0 0 0 0 1 3 5 3 0 0.0 10 473 14 0 0 0 0 0 0 4 5 14 10 16 0 1.3 20 437 177 0 0 0 0 0 0 21 22 31 10 66 1 3.0 30 396 833 205 809 0 0 0 0 63 61 45 10 108 3 5.4 40 376 1880 1208 4999 0 0 0 0 110 101 58 10 126 14 7.3 50 341 3000 2502 10719 0 0 0 0 147 132 68 10 133 30 8.9 60 301 4030 3650 16135 0 0 0 0 172 151 77 10 137 47 10.3 70 259 4928 4615 21211 0 0 0 0 188 161 85 10 137 61 11.5 80 221 5685 5410 25918 0 0 0 0 197 165 93 10 130 71 12.8 90 188 6283 6035 29976 0 0 0 0 200 165 100 10 126 81 14.0 100 160 6734 6506 33319 0 0 0 0 200 161 106 10 117 84 15.1 110 137 7066 6855 35826 0 0 0 0 197 157 112 10 108 88 16.3 120 117 7261 7065 37422 0 0 0 0 192 150 117 10 107 91 17.3 130 101 7423 7240 38595 0 0 0 0 187 145 122 10 97 85 18.4 140 88 7544 7372 39451 0 0 0 0 182 139 127 10 92 87 19.5 150 77 7586 7425 39736 0 0 0 0 176 133 131 0 0 0 20.5
41
Table 13—Yields of western larch plantations having 500 trees per acre surviving 5 years, precommercial thinning from below to 250 trees per acre at 20 years
Site index
50
70
80
Trees/ Age acre
5 500 10 462 20 405 30 221 40 208 50 197 60 187 70 178 80 169 90 159 100 149 110 138
120 129 130 119 140 110 150 102
5 500 10 465 20 420 30 233 40 224 50 211 60 196 70 179 80 161 90 145
100 129 110 116 120 104 130 93 140 83 150 75
5 500 10 473 20 437 30 238 40 229 50 213 60 194 70 173 80 152 90 134
100 117 110 103 120 90 130 79 140 69 150 61
Total volume
Ft®
Summary statistics
Volume per acre
Merchant- able volume
Ft?
Merchant- able volume
Bd ft
Removals per acre Merchant- Merchant-
Trees/ Total able able acre volume volume volume Ft? Ft? Bd ft
ak es) ooooooocoococ0coe0oonoo oooooococoeocococococe0c0cccceoe oooooccecececoecececnoncond
ooooooocooco0co0coo0o0co~mw~o0oo oooocooocooco0co0co0c0c0onoo ooooocodcoec0c0cdc0c0 owdcao
42
oooooocoococeceooco0cccoo oooooocococcoco0c00cce0o0c0coe ooocoooocoececedc0dcdc90dCeco co
ooooooocooocoocoocoecocoe0co0c0o oooaocoocoeoco0ce0o0c0c00coc0coo ooooooocodceccce0c00c0dc cof
BA/ acre
Ft?
102 108 114 120 125 129 133
Growth MOR/ PRD ACC _ year D
Yr Ft Ft?
5 0 0 0.0 10 2 0 0.7 10 6 0 1.6 10 14 0 2.9 10 24 1 4.3 10 32 2 5.7 10 37 3 6.9 10 40 5 8.0 10 45 8 8.9 10 45 10 9.9 10 47 13° 10:7
10 48 16 11.5 10 46 l?é 12.3 10 45 21 13.1 10 48 23 13.8
0 0 0 14.5 5 2 0 0.0 10 8 0 1.0 10 27 0 yay 10 53 1 4.8 10 73 4 6.7
10 84 10 8.4 10 87 17 9.9 10 89 26 11.2 10 87 33 12.4 10 84 39 13.5 10 84 44 14.6 10 19 47 15.6 10 78 51 16.6 10 76 52 17.6 10 70 54 18.5
0 0 0 19.5 5 3 0 0.0 10 16 0 1.3 10 52 0 3.4 10 87 2 6.0 10 108 9 8.1
10 113 20 9.8 10 117 34 11.3 10 117 44 12.7 10 110 54 14.0 10 114 63 15.2 10 104 66 16.4 10 99 72 17.5 10 90 76 18.6 10 89 77 19.7 10 80 74 20.7
0 0 0. 21.8
Table 14—Yields of western larch plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning from below to 100 trees per acre at 50 years
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Fis Fle Bd ft Fte Fts Bd ft Ft? Ft Yr Fts Ft?
50 5 500 0) 0 0 0 0) 0 0 0 1 3 5 0 0 0.0 10 462 3 0 0 0 0 0 0 1 2 8 10 2 0 0.7 20 405 19 0 0 155 3 0 0 4 4 16 10 6 0 1.6 30 221 75 0 0 0 0 0 0 10 11 25 10 14 0 2.9 40 208 212 7 27 0 0) 0 ft) 21 21 33 10 24 1 43 50 197 444 102 394 97 144 1 2 22 21 41 10 21 1 6.4 60 97 500 316 1279 0 0 0 0 31 28 48 10 25 2 7.6 70 94 735 619 2592 0 0 0 0 39 35 56 10 28 3 8.8 80 89 987 892 3839 0 0 ) 0) 47 42 63 10 28 4 9.8 90 85 1225 1140 4999 0 ) 0 0 47 68 10 32 6 10.8
100 81 1485 1399 6257 0 ) 0 0 60 52 73 10 32 7 #7 110 76 1732 1646 7547 0 0 0 0 66 56 78 10 9 12.6 120 72 1969 1883 8880 0 0 0 0 71 59 83 10 34 10 13.4 130 68 2208 2122 10282 0 0 0 0 75 62 87 10 33 12 14.2 140 63 2422 2335 11616 0 0 0 0) 79 64 91 10 32 13- 15:4 150 60 2613 2527 12925 0 0) 0 0 81 65 95 0 0 oO 15.8
70 5 500 0 0 0 0 0 0 0 0 1 3 5 2 0 0.0 10 465 8 0 0 0 0 0 0 3 4 12 10 8 0 1.0 20 420 83 0 0 170 12 0 0 10 11 25 10 27 0 21 30 233 336 29 113 0 0 0 0 29 29 38 10 53 1 4.8 40 224 851 391 1566 0 0 0 0 55 52 49 10 73 4 6.7 50 211 1540 1202 5050 111 556 324 1301 50 45 60 10 53 “ 9.6 60 96 1480 1384 6121 0 0 0 0 65 57 69 10 60 8 11.2 70 89 1997 1897 8715 0 0 0 0 78 66 78 10 64 12 12.7 80 83 2509 2405 11556 ) 0 0 0 90 74 85 10 64 17 14.1 90 77 2980 2874 14484 0 0 0 ft) 99 80 92 10 63 21 = 15.3
100 71 3403 3296 17102 0 0) 0) 0 106 84 98 10 63 26 «=: 16.6 110 65 3777 3669 19479 0 0 0 0 111 87 103 10 62 28 RICATA 120 4119 4011 21622 0 0 0 0 115 89 108 10 58 30 18.8 130 55 4400 4292 23317 0 0 0) 0) 118 90 112 10 58 3319.9 140 4652 4545 24741 0 0 0 0 120 91 nlale4 10 57 35 20.9 150 46 4869 4764 25851 0 0 0 0 121 91 121 0 0 0 21.9
80 5 500 0 0) 0 0 ) 0) 0) 0) 1 3 5 3 0 0.0 10 473 14 0 ) 0 0 0 0 4 5 14 10 16 0 1.3 20 437 177 0 0 187 29 0 0 16 17 31 10 52 0 3.4
238 664 184 730 0 0 0 0 47 44 46 10 87 2 6.0
40 229 1514 mili 4642 0 0 0 0 82 74 58 10 108 9 8.1 50 213 2504 2233 9711 113 912 743 3118 69 60 70 10 70 8 ain fe 60 95 2218 2110 9693 0 ft) 0) 0 84 71 79 10 79 17 12.8 70 87 2842 = 2731 13176 ) 0) ) 0) 98 80 87 10 82 21 14.4 80 80 3449 3335 16987 0 0 0 0 108 87 96 10 85 27s 15.8 90 73 4030 3913 20658 0 0 0 0 118 93 103 10 81 33 1752 100 66 4507 4390 23645 0 0 0 0 124 96 109 10 80 40 18.5 110 60 4912 4795 26092 0 0 0 0 127 97 115 10 77 44 19.7 120 5240 5124 27913 0 0 0 0 129 98 121 10 70 47 =20.9 130 49 5466 5353 29046 0 0 0) 0 129 97 125 10 71 51 22.0 140 44 5662 5552 29865 0 0 0 0 129 96 130 10 65 50 23.1 150 40 5816 5708 30426 0 ) 0 ) 128 94 135 0 0 0 24.2
43
Table 15—Yields of western larch plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning from above to 100 trees per acre at 50 years
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ _— Total able able Trees/ Total able able BA/ Top MOR/ index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Ft? Fits Bd ft Ft? Ft? Bd ft Ft? Ft Yr Ft Ft?
50 5 500 0 0 0 0 0 0 0 0 1 3 5 0 0 0.0 10 462 3 0 0 0 0 0 0 1 2 8 10 2 0 0.7 20 405 19 0 0 155 3 0 0 4 4 16 10 6 0 1.6 30 221 75 0 0 0 0 0 0 10 11 25 10 14 0 2.9 40 208 212 7 27 0 0 0) 0 21 21 33 10 24 1 43 50 197 444 102 394 97 298 101 394 13 13 35 10 14 1 48 60 93 277 76 295 0 0 0 0 19 18 43 10 20 1 6.2 70 89 470 286 1162 0 0 0 0 27 25 51 10 25 1 75 80 86 701 581 2441 0 0 0 0 35 32 59 10 26 3 8.7 30 82 938 847 3651 0 0 0 0 43 38 66 10 30 4 9.7
100 78 1196 1114 4909 0 0 0 0 49 43 he 10 30 5 10.8 110 74 1446 1364 6148 0) 0) 0 0 56 48 77 10 33 Te Vee 120 70 1707 1625 7531 0 0 0 0 61 52 82 10 31 8 12.6 130 67 1938 1856 8836 0 0 0 0 66 55 87 10 34 10 13.5 140 63 2174 2092 10275 0 0 0 0 7A 58 91 10 31 11 14.3 150 59 2378 2296 11543 0 0 ) 0 74 60 95 0 0 Of 1541 70 5 500 0 0 0 0 0 0 0 0 1 3 5 2 0 0.0 10 465 8 0 0 0) ) 0 0) 3 4 12 10 8 0 1.0 20 420 83 0 0 170 12 0 0 10 11 25 10 27 0 2.7 30 233 336 29 113 0) 0 0 0) 29 29 38 10 53 1 4.8 40 224 851 391 1566 0 0 0 0 55 52 49 10 73 4 6.7 50 211 1540 1202 5050 111 1066 952 4051 28 26 53 10 38 4 ws 60 92 819 696 2946 0 0 0 0 39 35 64 10 48 4 8.8 70 87 1255 1160 5089 0 0 0 0 52 46 74 10 54 7 10:5 80 82 1733 1641 7468 0 0 0 0 64 55 82 10 55 10 12.0 90 76 2184 2090 9891 0 0 0 0 74 62 89 10 57 14 13.3 100 71 2621 2525 12458 0 0 0 0 83 68 96 10 62 18 14.6 110 66 3067 2969 15299 0 0 0 0 91 73 102 10 60 20 15.9 120 61 3466 3367 17773 0 0 0 0 97 77 108 10 59 24 17.1 130 56 3812 3713 19922 0 0 0 0 102 79 113 10 59 27 —s 18.3 140 52 4134 4035 21789 0 0 0 0 106 82 117 10 57 30 819.4 150 48 4411 4312 23334 0 0) 0 0 109 83 122 0 0 Om 20:5 90 5 500 0 0 0 0 0 0 0 0 1 3 5 3 0 0.0 10 473 14 0 0 0 0 0 0 4 5 14 10 16 0 1.3 20 437 177 0) 0 187 29 0 0 16 17 31 10 52 0 3.4 30 238 664 184 730 0 0 0 0 47 44 46 10 87 2 6.0 40 229 1514 1111 4642 0 0 0 0 82 74 58 10 108 9 8.1 50 213 2504 2233 9711 113. 1735 1621 7155 37 34 62 10 53 7 8.3 60 91 1224 1126 4904 0 0 0 0 50 44 74 10 68 8 10.0 70 84 1826 1729 7836 0 0 0 0 65 56 85 10 73 10 11.9 80 79 2458 2358 11301 0 0 0 0 79 66 93 10 75 17. 13.6 90 73 3043 2940 14789 0 0 0 0 90 73 102 10 80 23 «15.0 100 67 3609 3504 18314 0 0 0 0 99 79 109 10 76 27 ~—s- 16.5 110 61 4095 3989 21327 0 0 0 0 106 83 115 10 76 34 =—s:«17.8 120 56 4519 4413 23856 0 0 0 0 111 86 121 10 72 36 «19.1 130 51 4878 4773 25844 0 0 0 0 115 87 127 10 71 41 20.3 140 46 5173 5069 27336 0) 0 0 0 117 88 132 10 68 45 21.5 150 42 5401 5298 28373 0 0 0 0 118 88 136 0 0 OS... 22*7,
44
Table 16—Yields of western larch plantations having 500 trees per acre surviving 5 years, thinning from below to 250 trees per acre at 20 years, and thinning to 100 trees per acre at 50 years such that the mean d.b.h. before and after thinning is the same
Summary statistics
Volume per acre Removals per acre Merchant- Merchant- Merchant- Merchant- Growth Site Trees/ Total able able Trees/ Total able able BA/ Top MOR/ = index Age acre volume volume volume acre volume volume volume acre CCF height PRD ACC _ year D Fis Ft Bd ft Fits Fits Bd ft Ft, Ft Yr Fits Firs 50 5 500 0 0 0 0 0 0 0 0 1 3 5 0 0 0.0 10 462 3 0 0 0 0 0 0 1 2 8 10 2 0 0.7 20 405 19 0 0 155 3 0 0 4 4 16 10 6 0 1.6 30 221 75 0 0 0 0 0 0 10 dit 25 10 14 0 2.9 40 208 212 7 27 0 0 0 0 21 21 33 10 24 1 43 50 197 444 102 394 97 221 52 202 18 17 39 10 18 1 5.7 60 95 390 198 797 0 0 0 0 25 24 47 10 22 1 7.0 70 91 597 448 1855 0 0 0 0 33 30 54 10 24 2 8.2 80 88 819 712 3027 0 0 0 0 40 36 61 10 28 3 9.2 90 83 1063 975 4248 0 0 0 0 48 42 67 10 29 5 10.2 100 79 1305 1220 5424 0 0 0 0 54 47 72 10 31 6 11.1 110 75 1549 1466 6669 0 0 0 0 59 51 78 10 31 ie: 12.1 120 71 1783 1700 7939 0 0 0 0 65 54 82 10 32 9 12.9 130 67 2012 1929 9267 0 0 0 0 69 57 87 10 32 10 13.8 140 63 2229 2146 10607 0 0 0 0 73 60 91 10 32 12 14.6 150 59 2434 2351 11912 0 0 0 0 76 62 94 0 0 O 15.4 70 5 500 0 0 0 0 0 0 0 0 1 3 5 2 0) 0.0 10 465 8 0 0 0 0 0 0 3 12 10 8 0 1.0 20 420 83 0) 0 170 12 0 0 10 11 25 10 27 0 OF, 30 233 336 29 113 0 0 0 0 29 29 38 10 53 1 4.8 40 224 851 391 1566 0 0 0 0 55 52 49 10 73 4 6.7 50 211 1540 1202 5050 111 815 639 2686 39 35 58 10 46 4 8.4 60 94 1150 1039 4539 0 0 0 0 52 46 67 10 52 6 10.1 70 88 1607 1510 6825 0 0 0 0 64 55 76 10 55 9 11.6 80 82 2063 1966 9274 0 0 0 0 75 63 84 10 56 13 12.9 90 76 2495 2396 11731 0 0 0 0 84 69 90 10 58 17. 14.2 100 70 2911 2812 14236 0 0 0 0 92 74 96 10 58 20 = =—15.5 110 65 3294 3193 16690 0 0 0 0 98 78 102 10 58 23 «16.6 120 60 3636 3536 18833 ) 0 0 0 103 80 107 10 57 26 «17.8 130 55 3940 3839 20698 0 0 0 0 107 82 111 10 54 2918.8 140 51 4196 4096 22219 0 0 0 0 109 83 116 10 55 31 19.9 150 47 4438 4339 23539 0 0 0 0 111 84 120 0 0 0 209 80 5 500 0 0 0 0 0 0 ) 0 1 3 5 3 0 0.0 10 473 14 0 0 0 0 0 0 4 5 14 10 16 0 1.3 20 437 177 0 0 187 29 0 0 16 17 31 10 52 0 3.4 30 238 664 184 730 0 0 0 0 47 44 46 10 87 2 6.0 40 229 1514 1111 4642 0 0 0 0 82 74 58 10 108 9 8.1 50 213 2504 2233 9711 113 1331 1188 5164 53 47 68 10 63 7 9.8 60 93 1729 1626 7350 0 0 0 0 67 58 78 10 71 11 11S 70 86 2329 2225 10549 0 0 0 0 81 68 87 10 76 16 13.2 80 79 2929 2822 14040 0 0 0 0 93 76 95 10 77 2214.7 90 ae 3481 3372 17451 0 0 0 0 102 82 102 10 78 28 (16.1 100 66 3984 3875 20551 0 0 0 0 110 86 109 10 76 3317.5 110 60 4415 4305 23153 0 0 0 0 115 89 115 10 73 38 = «118.8 120 54 4769 4660 25208 0 0 0 0 118 90 120 10 69 42 20.0 130 49 5036 4929 26646 0 0 0 0) 119 90 125 10 65 46 21.1 140 44 5233 5128 27559 0 0 0 0 119 89 130 10 62 48 223 150 40 5376 5275 28153 0 0 0 0 118 88 135 0 0 0 23.3
45
50 60 ‘70 SITE INDEX MIDPOINT
n larch plantation site index values for
fo) A INS0u4d
SWN10A LOOS SIGNI WLOL
12000
40000 = =} rs) SITE INDEX > g000 = S 80 Le = Be 6000 70 oO 5 a 60 = 4000 50 40 2000 a
10 20 30 40 50 60 70 80 90 100 110 4120 130 140 150
AGE
Figure 53—Western larch yield curves for unthinned plantations in Inland Northwest forests (merchantable cubic feet, 4.5-inch top, stems greater than 7 inches d.b.h.).
SITE INDEX 42000 80 35000 70 ¥ 3 28000 S 60 ia oO oO i 21000 ed 50 4 oO fea) 44000 40 7000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 AGE
Figure 54—Western larch yield curves for unthinned plantations in Inland Northwest forests (merchantable board feet, 4.5-inch top, stems greater than 7 inches d.b.h.).
47
12000
410000
8000
6000
TOTAL CUBIC FOOT VOLUME
4000
2000
10 20 30 40 50 60 70 80 390 100
SITE INDEX
Figure 55—Western larch yield vs. site index at 80 years of age (total cubic feet).
30 r
a SITE INDEX WwW aa oO ae A B80
20 + ry 70 = Ww = a 60 Ht e) z 50 WwW 7 40 ci H i 10 + oe pe <a = {es}
ea ! 4 4 4 4 4 A ee a |
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
Figure 56—Quadratic mean diameter vs. age for western larch unthinned plantations in Inland Northwest forests.
48
30
SITE INDEX wo r a 80 PA S 20 70 fac WwW tw 60 = t Lye! a 50 z WwW 40 = Oo Ht Ei 10 (ar a << =) fe) L 4 + 4 EE EE EE EE EE EE ES ee) 10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150 AGE Figure 57—Quadratic mean diameter vs. age for western larch precommercial thinning to 250 trees per acre at 20 years in Inland Northwest forests. 30 SITE INDEX = 80 wn WwW 5 70 7S a 20 a 60 WwW bE Ww = ASS 50 a Ze 40 WW >, oO Leal E 10 a a =C =) {es} 4 4 SS SS LS aS ee ee ee ee 4 1 4 4 4 —L 4 1 — 4 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE Figure 58—Quadratic mean diameter vs. age for western larch precommercial
thinning to 250 trees per acre at 20 years and commercial thinning from below to 100 trees per acre at 50 years in Inland Northwest forests.
49
30 -
SITE INDEX oO uw 80 S a 70 20 + ion hs 60 WwW = pa a 50 Zz < 40 = oO H 3 10 + jem a << =| Go 4 SEE EEE eeEEeeEEEE EEE —E—EE— EEE SS Sa! " 4 4 et SS Se
10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150
AGE
Figure 59—Quadratic mean diameter vs. age for western larch precommercial thinning to 250 trees per acre at 20 years and commercial thinning from above to 100 trees per acre at 50 years in Inland Northwest forests.
30 SITE INDEX L a 80 a S 70 a 20 + ry 60 Wi Ww = a = 50 z 40 W = oO | aoe | mi 10 + iam a tt =’ (ee) — a = 4 re 4 eS |
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 AGE
Figure 60—Quadratic mean diameter vs. age for western larch precommercial thinning to 250 trees per acre at 20 years and commercial thinning to 100 trees per acre at 50 years such that the mean d.b.h. before and after thinning is the same.
50
8000
Wi = =) 3 6000 > i oO oO Ww oO H jee} 3B 4000 eal | <t bE oO a 2000
10 20 30 40 50 60 70
80
AGE
90
100
110
120
130
Figure 61—Effect of thinning on standing volume of western larch for Inland North-
west forests (total cubic feet), site index 50.
10000 uw -B000 =) aI oO > be (=)
oO uw 6000 oO H a =} oO z 5 4000 E 2000
AGE
80
90
100
110
120
Figure 62—Effect of thinning on standing volume of western larch for Inland
Northwest forests (total cubic feet), site index 70.
51
130
140
140
150
150
24000
MGMT 20000 000 Ww = POO 3 16000 > bk {=} (=) a PCB & 12000 pct 3 ZO | <t | ol 2 8000 4000
a ee
10 20 30 40 50 60 70 80 90 100 110 120 4130 140 150
AGE
Figure 63—Effect of thinning on standing volume of western larch for Inland Northwest forests (merchantable board feet [Scribner]), site index 50.
36000 MGMT 000 POO 30000 WwW 3 PCB 3 PC1 2 24000 oe ‘a Oo oO WwW ca © 18000 [m} ea} | tt md [ao - 412000 6000 -
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 64—Effect of thinning on standing volume of western larch for Inland Northwest forests (merchantable board feet [Scribner]), site index 70.
52
8000
5 6000 WJ H > = MGMT Ww oO z 000 (2) 4000 a POO PCB PCA PC4 2000 a | 4 A 4 L 40 20 30 40 50 60 70 80 90 100 110 120 130 140 150 AGE Figure 65—Effect of thinning on total yield of western larch plantations (total cubic feet), site index 50. 10000 + i 8000 [ a MGMT as w = = 000 us 6000 | ood PCB 2 PC1 = oO BE 4000 2000
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 66—Effect of thinning on total yield of western larch plantations (total cubic feet), site index 70.
53
24000
20000
16000
12000
TOTAL BFV YIELD
8000
4000
| OO Se a |
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
AGE
Figure 67—Effect of thinning on total yield of western larch plantations (merchantable board feet [Scribner]), site index 50.
36000
30000
24000
18000
TOTAL BFV YIELD
6000
-
10 20 30 40 50 60 70 80 90 100 4110 120 130 140 150
AGE
Figure 68—E ffect of thinning on total yield of western larch plantations (merchantable board feet [Scribner]), site index 70.
54
MGMT
000
POO
COMPARISON TO RELATED YIELD ESTIMATES
Cochran (1979) has published estimates of net volume yields for natural stands of white (grand) fir and Douglas- fir east of the Cascades in Oregon and Washington. Although his samples were from natural stands, his rigor- ous screening for uniform spacing, minimal past mortal- ity, and even-aged character of the stand would suggest that the yields he presents might also represent planta- tions. Furthermore, because his tables are arrayed by breast-high age, effects of the wide variation in early height growth found in natural stands would be reduced. Cochran’s site index was defined as the height of the tall- est tree on the /s-acre plot at 50 years age at breast height. Although his rate of selection of five trees per acre was less than the 20 trees per acre we used, the dif-
24000
20000
16000
12000
TOTAL CUBIC FOOT VOLUME
8000
4000
ference in site index definitions is estimated to be about 3 feet for site indices of about 70 feet. To shift our tables to a breast-high age basis, we estimated years to reach a height of 4.5 feet for plantations from the coefficients in table 13 of Ferguson and others (1986). For combinations of habitat types, elevations, slopes, and aspects that pro- duce site index 70, time from regeneration treatment to 4.5 feet in height was estimated to be 10 years for Douglas-fir trees at +1 standard deviation in the distribu- tion of heights and 16 years for grand fir.
A comparison of the yields reported by Cochran and those reported in this study is presented in figure 69. The curves for Douglas-fir are nearly identical, while for grand fir the Prognosis estimates are consistently higher. The difference in yields of grand fir seem reasonable because we expect grand fir in the Inland Empire to reach higher maximum densities than grand fir growing in eastern Oregon and Washington.
MGMT
GF-P
GF-C DF-P
DF-C
BREAST HEIGHT AGE
Figure 698—Comparison of Cochran and Prognosis yields for Douglas-fir and grand fir, site index 70. Management codes indicated on this figure are: GF-P = grand fir- Prognosis; GF-C = grand fir-Cochran; DF-P = Douglas-fir-Prognosis; DF-C =
Douglas-fir-Cochran.
55
REFERENCES
Cochran, P. H. 1979. Gross yields for even-aged stands of Douglas-fir and white or grand fir east of the Cascades in Oregon and Washington. Res. Pap. PNW-263. Port- land, OR: U.S. Department of Agriculture, Forest Serv- ice, Pacific Northwest Forest and Range Experiment Station. 17 p.
Daubenmire, R.; Daubenmire, J. 1968. Forest vegetation of eastern Washington and northern Idaho. Tech. Bull. 60. Pullman, WA: Washington Agricultural Experiment Station. 104 p.
Ferguson, D. E.; Stage, A. R.; Boyd, R. J. 1986. Predicting regeneration in the grand fir-cedar-hemlock ecosystem of the Northern Rocky Mountains. For. Sci. Monogr. 26. Washington, DC: Society of American Foresters. 41 p.
Kemp, P. D. 1956. Region 1 volume tables for cruise com- putations. Northern Region Handbook R1-2430-31. Missoula, MT: U.S. Department of Agriculture, Forest Service, Northern Region.
Stage, A. R. 1987. Progress in yield estimation: a history and prescription. In: Chappel, H. N.; Maguire, D. A., eds. Predicting forest growth and yield: current issues, future prospects. Contrib. 58. Seattle, WA: University of Washington, College of Forest Resources, Institute of Forest Resources: 61-77.
Wykoff, W. R. [In press.] Predicting Basal Area Increment for individual northern Rocky Mountain conifers. Sub- mitted to Forest Science.
Wykoff, W. R.; Crookston, N. L.; Stage, A. R. 1982. User’s guide to the Stand Prognosis Model. Gen. Tech. Rep. INT-133. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 112 p.
56
APPENDIX TABLES: INVENTORY CLASSES USED FOR SIMULATION
Table 18—Class boundaries and corresponding mnemonic codes for grand fir plantations
Table 17—Class boundaries and corresponding mnemonic codes for Douglas-fir plantations
Class Nominal Class Nominal boundary value for boundary value for Variable values class Variable values class Aspect 123-203° SE Aspect '337-157° E 204-22° NW 158-336° W Habitat type Ponderosa pine series Habitat type ABGR/XETE ABGR/XETE ee 510) Douglas-fir series except ( PSME/SYAL,PSME/CARU ABGRICLUN ou Englemann spruce series PSME/PHMA THPL/CLUN THPL/CLUN Subalpine fir series except (260) (530) ABLA/OPHO,ABLA/CLUN, TSHE/CLUN TSHE/CLUN ABLA/LIBO,ABLA/MEFE, (570) ABLA/LUHI ABLA/CLUN ABLA/CLUN (620) Dear aia — ABLA/MEFE ABLA/MEFE (670) AB CHVCEUN as ABLA/XETE ABLA/JXETE (690) THPLICLUN Mee TSME/XETE TSME/XETE 710 TSHE/CLUN TSHE/CLUN ; ee (570) National Bitterroot } Bitterroot (3) ABLA/CLUN ABLA/CLUN Forest Lolo (620) Clearwater Clearwater (5) ABLA/LIBO ABLA/LIBO Coeur d'Alene Coeur d'Alene (6) (660) Colville Colville (7) ABLA/MEFE ABLA/MEFE Flathead Flathead (10) (670) Kaniksu Kaniksu (13) TSME/MEFE TSME/MEFE Kootenai Kootenai (14) (680) Nez Perce Nez Perce (17) ABLA/LUHI ABLA/LUHI St. Joe St. Joe (18) 830 ; ( ) ‘Aspect is included in class definitions because it is a major source of variation National Bitterroot } Bitterroot (3) in Regeneration Establishment Model. Forest Lolo Clearwater Clearwater (5) Coeur d'Alene Coeur d'Alene (6) Colville Colville (7) Flathead Flathead (10) Kaniksu Kaniksu (13) Kootenai Kootenai (14) Nez Perce Nez Perce (17) St. Joe St. Joe (18)
‘Aspect is included in class definitions because it is a major source of variation in Regeneration Establishment Model.
57
Table 19—Class boundaries and corresponding mnemonic codes for
western larch plantations
Variable
Aspect
Habitat type
National Forest
Class boundary values
1337-157°
158-336° Ponderosa pine series Douglas-fir series
Subalpine fir series except ABLA/OPHO, ABLA/CLUN, ABLA/LIBO,
ABLA/MEFE, ABLA/XETE,
ABLA/VAGL, ABLA/VASC
Englemann spruce series ABGR/XETE ABGR/CLUN THPL/CLUN
THPL/OPHO TSHE/CLUN ABLA/OPHO
ABLA/CLUN ABLA/LIBO
ABLA/MEFE TSHE/MEFE ABLA/XETE
TSME/XETE
ABLA/VASC
Flathead Kootenai
Lolo } Bitterroot Clearwater Coeur d’ Alene Kaniksu
Nez Perce
St. Joe
Colville }
Nominal value for class
E W
PSME/PHMA (260)
PIEN/CLUN (420) ABGR/XETE (510) ABGR/CLUN (520) THPL/CLUN (530) ABLA/OPHO (610)
ABLA/CLUN (620) ABLA/LIBO (660) TSME/MEFE (680) ABLA/XETE (690) TSME/XETE (710) ABLA/VASC (730)
Flathead (10)
Lolo (16)
Bitterroot (3) Clearwater (5)
Coeur d’ Alene (6)
Kaniksu (13)
Nez Perce (17)
St. Joe (18)
‘Aspect is included in class definitions because it is a major source of variation in Regeneration Establishment Model.
*U.S. GOVERNMENT PRINTING OFFICE:
1988-0-673-039/81006
58
Table 20—Class boundaries and corresponding mnemonic codes
for naturally regenerated stands
Variable
Aspect
Habitat type
National Forest
Class boundary values
293-113° 114-292°
ABGR/CLUN THPL/CLUN TSHE/CLUN
ABLA/CLUN
Flathead Lolo Clearwater Colville Kaniksu Kootenai Nez Perce
Bitterroot
Nominal value for class
N S
ABGR/CLUN (520) THPL/CLUN (530) TSHE/CLUN (570) ABLA/CLUN (620)
Bitterroot (3)
Clearwater (5) Colville (7) Kaniksu (13) Kootenai (14) Nez Perce (17)
Stage, Albert R.; Renner, David L.; Chapman, Roger C. 1988. Selected yield tables for plantations and natural stands in Inland Northwest Forests. Res. Pap. INT-394. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 58 p.
Yields arrayed by site index and age have been tabulated for plantations of 500 trees per acre, with five thinning regimes, for Douglas-fir, grand fir, and western larch. Yields were also tabulated for naturally regenerated stands of the grand fir-cedar-hemlock ecosystem of the Inland Empire. All yields were estimated with the Prognosis Model for Stand Development, version 5.2, including the Regeneration Establishment Model.
KEYWORDS: plantation yields, site index, Douglas-fir, grand fir, western larch, natural stand yields, thinning, growth models
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