APPENDIX: DERIVATION OF VALUES IN TABLE 8 



CURRENT STUDY. Used regression models and for 

 11-year height and 12-year d.b.h. models. Pretreatment 

 height growth, although not measured, was assumed to be 

 similar to the posttreatment growth of the control stands. 



JOHNSTONE (1978). Estimated height growth from 

 curves in fig. 1 and fig. 2. Used curve for 4.0 ft average 

 height, and 10 years after logging. Estimates are 8 ft at 

 10 years after logging and 4 ft at logging, so net is 4 ft, or 

 0.4 ft per year after harvest. We extrapolated curves 10 

 years prior to harvest and used the same technique. 

 (Weak, but probably reasonably accurate). Johnstone 

 had no diameter growth information for the advance 

 regeneration. 



SEDDEL (1980). Direct from table 1, line 1 (for all trees), 

 for height and diameter. Preharvest diameter growth was 

 assumed to be the same as the growth for 1975-76, the 

 period just following harvest, because he did not cut down 

 trees so he could measure preharvest growth. 



FERGUSON AND ADAMS (1980). Height estimated 

 from fig. 2, changing centimeters to feet. 



McCAUGHEY AND SCHMIDT (1982). Height esti- 

 mated from fig. 13. All four forests were similar, so we 

 chose the Dixie, which may have a little slower growth 

 than the others, but not significantly so. 



HELMS AND STANDIFORD (1985). Used data from 

 table 2, for the 20-30-cm release class. Assumed 25 cm as 

 average postrelease growth, and converted to feet. Prere- 

 lease data taken directly from table. Postrelease diame- 

 ter growth was obtained from page 9, item 2. We used 

 growth for the intermediate prerelease diameter, and 

 converted to feet. Except for reference to Standiford's MS 

 thesis, this paper contains no information on prerelease 

 diameter growth rate. 



OLD7ER (1986). Used figures in table 2. Used mean 

 value of Y for the 0-8 year period, and divided by 8 to get 

 annual diameter growth after harvest and thinning. No 

 data for preharvest diameter growth. For preharvest 

 height growth, we used table 1, and live crown pet of 70, 

 where 3-year growth = 1.39. This value was converted to 

 annual growth. For postharvest height growth, we used 

 table 2, 0-8 year period, and divided by 8 to get annual 

 mean growth of 0.29 ft. According to Oliver's data, for a 

 given type of tree, height growth rate decreased following 

 harvest and thinning. 



Carlson, Clinton E.; Schmidt, Wyman C. 1989. Influence of overstory removal and 

 western spruce budworm defoliation on growth of advance conifer regeneration in 

 Montana. Res. Pap. INT-409. Ogden, UT: U.S. Department of Agriculture, Forest 

 Service, Intermountain Research Station. 14 p. 



Twelve-year postharvest diameter growth of advance Douglas-fir, Engelmann spruce, 

 and subalpine fir regeneration and 1 1 -year height growth of Douglas-fir and subalpine fir 

 accelerated in response to decreasing competition. Competition was reflected in degree 

 of overstory removal and change in plot basal area. Notwithstanding the influence of 

 change in competition, the most influential variable affecting postharvest height and 

 diameter growth was 10-year radial growth prior to overstory removal; trees growing well 

 before harvest grew well after harvest. Postharvest mortality was greatest where about 

 50 percent of the overstory was removed. Defoliation by western spruce budworm 

 reduced growth of Douglas-fir but did not affect subalpine fir or Engelmann spruce. 



KEYWORDS: competition, stand density, insect impact, release 



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