KERRY WOODS. 



which a hectare should carry at the age of 100 years. Thus a 

 spruce crop on soil of quality X. should yield 1,000 f.m. per ha. (or 

 roughly 14,300 cub. ft. per acre) at 100 years of age. 



Schiffel gives directions as to the method of estimating the 

 quality of the locality when a crop of spruce is standing on the 

 ground. It is obviously not sufficient simply to take the height 

 and age and then observe the class most nearly corresponding in 

 the tables, since such a method takes no account of the density in 

 which the crop has been grown, and it has been pointed out above 

 (a) that the spruce grows more quickly in open than in close 

 stand. Age, height, mean diameter, and number of trees per 

 unit area are at least necessary for proper classification. 



^ number of trees per unit area r , . , 



I he ratio - - - gives a useful index as 



mean diameter 



to the density in which the crop" has been grown, and is called 

 by Schiffel the crop characteristic (Besiandescharakteristik). By 

 the method of stem analysis a general view of the height develop- 

 ment of the crop can be obtained, which is of interest in comparing 

 the height-growth of the crop under consideration with the ideal 

 given in the Yield Tables. 



Comparison of Sample Plots with Schiffel's Tables. 



It will now be shown to what extent the measurements made in 

 the sample plots agree with Schiffel's Tables. 



The following abbreviations are used throughout for the sake 

 of convenience : 



H = mean height of crop, .Demean diameter, N = number of 

 stems per acre, / = form factor, A= total basal area, V = total 

 true volume per acre, C = crop characteristic = N/D, Q quality 

 class. 



GROUP I. 1,020 ft. Elevation. 



As will be seen in the comparative table above, the height 

 growth of this crop for medium canopy conditions lies between 

 qualities XI. and X. of Schiffel's Tables, but rather nearer the 

 former. The number of trees per acre, the form factor, and the 

 crop characteristic correspond very nearly with those of Class XI., 



