4 2 



KERRY WOODS. 



locality corresponds to Schiffel's Quality Class VIII., medium 

 density. In the diagram on p. 41 the mean height-growth curves 

 for the various quality classes (medium density of canopy) have 

 been drawn, and the height-growth curves of the sample trees 

 of Groups IA., VII., V., and VI., and IX. superimposed. The 

 height-growth curve of another sample tree (10) from a 

 group too small to measure (Plate VII. ), growing under 

 slightly better conditions, has also been added for purposes of 

 comparison. These curves show what might have been antici- 

 pated, viz., that the trees of Groups V. and VI. began to grow at 

 a greater rate than the present quality class in which they stand, 

 but as they developed and the tops became more and more exposed, 

 the height-growth began to fall off. Consideration of the curves 

 shows that Groups V. and VI. will probably fall to Quality Class 

 VII. at the age of 60 years. The probability is that the crop 

 would not stand a longer rotation than this owing to danger from 

 windfall. 



It is now necessary to consider what returns will be obtained 

 from a crop of Quality VII. 



In the following table the value to which the gross returns 

 must amount per acre on a 60 and on an 80 year rotation, in order 

 to give a specific soil rental, have been worked out, assuming the 

 cost of planting to be ^5 per acre, the upkeep 45. per acre per 

 year, and the rate of interest 3 per cent. 



The last two columns of this table also give the present value 

 of the rents per annum for the next 60 or 80 years as the case may 

 be, or, in other words, the "soil expectation value." * If the land 



* The term "soil expectation value" is used here in a restricted sense tor a 

 single rotation only and not, as is common, for perpetuity. Owing to the degree of 

 uncertainty which attaches to these calculations, the method adopted is considered 

 accurate enough for the purposes in view. A table giving the soil expectation 

 values for spruce for perpetuity will be found in Appendix D, page 64. 



