58 



DEVELOPMENT OF FOREST TREES. 



to the "JUlh year, before it commences falling off to any 

 considerable extent. 



Apart from species, the diameter increment depends on — 

 (a.) The quality of the locality. 



{b.) The amount of liglit which the tree receives and can 

 utilize, in other words the extent of the crown, which 

 is governed by the growing space. 

 Limited space in a crowded wood reduces the diameter 



S 10 



Silvor Fir. 

 Spruce. 



10 



L'O 



40 '.0 00 70 SO '.10 1110 110 I'JO 

 AGE, I\ YEARS. 



Fig-. 2.— Diap-am illustrating the Diameter Growth of Silver Fir, Spruce, Beech, 

 and Scotch Pine, on Localities of the First Quality. 



increment, a free position increases it ; hence height growth 

 and diameter growth demand frequently opposite con- 

 ditions. It is the business of the forester to give the most 

 profitable growing space ; in other words, to give to the 

 individual trees from time to time sufficient room to en- 

 courage diameter growth, without endangering the progress 

 of the height growth. 



The effects of a great surface of foliage and unimpeded 

 enjoyment of light are very remarkable, when licallhy trees, 



