THE RED SPRUCE. 



59 



to an abnormal diameter development as well as of board-foot con- 

 tents and a less-than-normal cubic and cord volume. The full effect 

 of understocking is obviously obscured by the better-than-average 

 height development of plot 17, which amounts to more than 10 feet 

 above the average and would occasion a 12 to 15 per cent increase in 

 volume. The subnormal total basal area is the best index in this 

 case. As is to be expected, the overstocked stand, plot 39, shows a 

 maximum cubic and cord volume. Plot 46 illustrates very well the 

 benefits to be derived from a slight understocking such as would be 



Fig. 3. — Effect of stocking on yield. Comparison of actual measurements of sample plots approximately 

 65 years old, with the average measurements for a 65-year-old stand in the second growth yield table. 

 All stands Quality II and measurements are for dominant (including codominant) and intermediate 

 trees only. Plottings are in percentages of the normal or average values of the different factors. 



brought about by thinning. Thus, with a normal height growth a 

 13 per cent understocking was accompanied in this instance by 

 increases of 8 per cent in basal area, 12 per cent in average diameter, 

 16 per cent in board-foot yield. 9 per cent in cubic-foot yield, an 11 

 per cent in cordwood yield. 



BRUSH DISPOSAL. 



One of the most potent sources of danger to spruce forests in general 

 is the brush and, more particularly, the lops or branch wood which 

 litter the ground after logging. The culled logs and tops from which 

 the branches have been lopped do not of themselves constitute a 



