342 



JOURNAI. 01' I'ORKSTRY 



In order to classify Recknagel's plots accurately, heights at 35 and 

 50 years for Site IV were secured by the method indicated in foot- 

 notes a and b. It is now possible to judge the position of these plots. 

 Plot 3, 50 years old, corresponds closer to the height for Site III than 

 for Site IV. Plot 6, 49 years old, is midway between the 50-year 

 heights for Site III and for Site IV. Adding the mean annual growth 

 of I foot for one year brings the plot nearest to Site III. Plot 11 is 

 only slightly below the Site III height for 35 years and far above the 

 Site IV value. 



Furthermore, Recknagel's three plots are from 26 to 55 per cent 

 below the normal stocking in number of trees for Site III, and hence 

 the heights may be expected to fall slightly below those in the yield 

 table. It is granted that the height growth is largely independent of 

 density of stocking, but what small differences in height growth may 

 exist as between normally stocked and understocked stands of ages 

 35 to 50 years tend to be in favor of the former. 



Table to Compare Density of Stocking 

 Number of trees per acre. Basal area. Average diameter. 



^ y. ^ ^ K — ^ ^ . — A ^ 



Years. g^jj j^ Recknagel Bull. 13, Recknagel Bull. 13, Recknagel 



Site III, plots. Site III. plots. Site III. plots. 



No. Sq. feet Sq. feet Inches Inches 



35 1,400 II 660 167 157 4.7 6.6 



50 3 344 ••• 106 .. 7.5 



50 764 6 565 204 134 7.0 6.6 



Since the values in a yield table represent the averages for each 

 site, Recknagel's plots would, under our practice, be considered as 

 poor examples of Site III as made in Bulletin 13. If European 



Scotch pine, Schwappach White pine. Bulletin 13 

 (1908). 



, -^ ^ , -^ s 



Site. Relative value Relative value 



Height, ' based on Height, based on 



feet. Site I values feet. Site I values 



as 100. as 100. 

 35 years 



I 45-6 lOO 53 100 



II 38.7 85 44.5 84 



III 30.8 67.5 36.0 68 



IV 23.0 50.5 27.5c 52 



50 years 

 I 62.0 100 74.5 100 



II 51.8 84 64.0 86 



III 42.6 69 S4-0 72 



IV 32.8 53 43.0a 58 



a Not taken from Bulletin 13. 



