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 1 2 — Yields of western larch 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 



BAJ 





Top 







MOR/ 





index 



Age 



acre 



volume 



volume 



volume 



acre 



volume 



volume 



volume 



acre 



CCF 



height 



PRO 



ACC 



year 



D 











Ft' 



ri 



Bd ft 





C"# 3 



ri-' 





ba it 



rt 





rt 



Yr 



rt 



rt 



50 



5 



500 





































3 



5 











0.0 





1 



462 



3 





Q 





















2 



g 



10 



2 





7 





20 



405 



19 

























5 



g 



16 



10 



7 







1 .4 





30 



349 



90 



Q 























13 



15 



24 



10 



18 







2.7 





40 



327 



262 



4 



14 



















28 



29 



33 



10 



30 



1 



3.9 





50 



306 



553 



95 



363 



















46 



45 



41 



10 



39 



3 



5.2 





60 



287 



918 



369 



1465 



















64 



60 



48 



10 



47 



4 



6.4 





70 



268 



1343 



868 



3545 



















81 



75 



55 



10 



53 



7 



7.5 





80 



250 



1795 



1406 



5902 



















97 



88 



61 



10 



56 



11 



8.4 





90 



233 



2248 



1945 



8334 



















110 



98 



66 



10 



56 



15 



9.3 





100 



216 



2660 



2409 



10522 



















120 



106 



72 



10 



58 



19 



10.1 





110 



198 



3050 



2830 



12595 



















128 



111 



77 



10 



57 



22 



10.9 





120 



182 



3395 



3194 



14491 



















134 



115 



81 



10 



57 



25 



11.6 





130 



167 



3712 



3522 



16329 



















138 



117 



85 



10 



54 



28 



12.3 





140 



152 



3969 



3788 



17965 



















141 



118 



89 



10 



53 



31 



13.0 





150 



139 



4189 



4015 



19451 



















142 



118 



93 















13.7 



70 



5 



500 



































1 



3 



5 



2 







0.0 





10 



465 



8 



























3 



4 



12 



10 



8 







1 





20 



420 



83 



























12 



14 



25 



10 



33 







2.3 





30 



372 



405 



30 



116 



















38 



38 



38 



10 



66 



1 



4.3 





40 



354 



1047 



407 



1621 



















73 



69 



49 



10 



87 



6 



6.2 





50 



329 



1855 



1300 



5387 



















107 



98 



58 



10 



97 



15 



7.7 





60 



299 



2677 



2265 



9701 



















134 



1 19 



67 



10 



104 



26 



9.1 





70 



266 



3464 



3139 



13885 



















153 



135 



75 



10 



100 



35 



10.3 





80 



235 



4111 



3842 



17486 



















166 



142 



82 



10 



99 



45 



11.4 





90 



206 



4645 



4402 



20645 



















173 



146 



88 



10 



94 



51 



1 P 4 





100 



180 



5071 



4848 



23490 



















176 



146 



93 



10 



91 



56 



13.4 





110 



158 



5421 



5214 



25957 



















177 



145 



99 



10 



89 



59 



14.4 





120 



138 



5717 



5522 



28175 



















177 



142 



103 



10 



85 



61 



15.3 





130 



122 



5959 



5775 



30072 



















175 



139 



108 



10 



79 



62 



16.3 





140 



108 



6129 



5955 



31427 



















173 



136 



112 



10 



77 



63 



17.2 





150 



95 



6265 



6100 



32516 



















169 



132 



116 















18.1 



80 



5 



500 



































1 



3 



5 



3 







0.0 





10 



473 



14 



























4 



5 



14 



10 



16 







1.3 





20 



437 



177 



























21 



22 



31 



10 



66 



1 



3.0 





30 



396 



833 



205 



809 



















63 



61 



45 



10 



108 



3 



5.4 





40 



376 



1880 



1208 



4999 



















110 



101 



58 



10 



126 



14 



7.3 





50 



341 



3000 



2502 



10719 



















147 



132 



68 



10 



133 



30 



8.9 





60 



301 



4030 



3650 



16135 



















172 



151 



77 



10 



137 



47 



10.3 





70 



259 



4928 



4615 



21211 



















188 



161 



85 



10 



137 



61 



11.5 





80 



221 



5685 



5410 



25918 



















197 



165 



93 



10 



130 



71 



12.8 





90 



188 



6283 



6035 



29976 



















200 



165 



100 



10 



126 



81 



14.0 





100 



160 



6734 



6506 



33319 



















200 



161 



106 



10 



117 



84 



15.1 





110 



137 



7066 



6855 



35826 



















197 



157 



112 



10 



108 



88 



16.3 





120 



117 



7261 



7065 



37422 



















192 



150 



117 



10 



107 



91 



17.3 





130 



101 



7423 



7240 



38595 



















187 



145 



122 



10 



97 



85 



18.4 





140 



88 



7544 



7372 



39451 



















182 



139 



127 



10 



92 



87 



19.5 





150 



77 



7586 



7425 



39736 



















176 



133 



131 















20.5 



41 



