27 



NOTES TO TABLE 17. 



The table shows, what percentage on the stumpage value of 

 a tree the wood owner derives annually by allowing the tree 

 to live on at a given age. The oalculation is based entirely on 

 the data of table 15. 



Example : Where the logging and milling expenses amount 

 to $10 per 1000 feet B. M., a poplar growing under good con- 

 ditions yields by its annual increment, from the 180th to the 

 200'th year of its life, 3 per cent, interest. After that time it . 

 ought to be cut down, as the increment will fall below 3 per 

 cent. (Compare notes to table 16.) 



Kule 1. A tree is financially ripe for the axe when its an- 

 nual increment no longer yields more than 3 per cent, inter- 

 est on its stumpage value. 



2. The better the conditions of growth and the smaller 

 the logging and milling expenses are, the sooner is a tree ripe 

 for the axe. 



3. The annual interest on the stumpage value of a 

 poplar tree furnished by its annual growth is very high, whilst, 

 it is young — certainly more than 8 per cent, in the case of 

 trees less than 120 years old. 



4. With the advancing age of a tree, the annual inter- 

 est on its stumpage value decreases. It stands above zero, how- 

 ever, as long as the tree lives undamaged. 



5. The value of a tree is still increasing at the rate of at 

 least 1^ per cent, under good conditions, when the tree is 200 

 years old; under average conditions, when the tree is 250 

 years old; under poor conditions when the tree is about 300 

 years old. 



