24 



grasses and weeds come in and rob them of the necessary soil mois- 

 ture. A pure grove of such trees might require cultivation through- 

 out its entire life. However, since this is impracticable, the best re- 

 sults can be obtained by mixing the light- demanding with the shade- 

 enduring kinds. A proper mixture brings about a more complete use 

 of the soil, and produces a larger quantity and a better quality of 

 material. 



A general mixture of a number of different kinds of trees without 

 a knowledge of their requirements must, however, be discouraged. 

 The fewer the number of species mixed the better, provided that one 

 of them is able to shade the ground completely to an advanced age. 



The following arrangements of trees in plantations seem desirable : 



(a) For upland and bottomland. 



No. 1. No. 3. 



(4 feet by 4 feet.) (4 feet by 4 feet.) 



S S S S Wy W Wy W Wy 



s s s s 



B 8 8 8 



S S S S 



No. 2. 

 (4 feet by 4 feet) 



S W S W 



W S WS AAAAAA 



SWSW AAAAAA 



WS WS AAAAAA 



No. 5. No. 6. 



( 4 feet by 4 feet. ) (5 feet by 5 feet. ) 



BWEW CWCW 



WEWE WCWC 



EWEW CWCW 



WEWE WCWC 



S = Scotch pine. 



W = White spruce. 



E = European larch. 

 Wy = Western yellow pine. 



A = Austrian pine. 



C = Cottonwood. 

 [Clr. 145] 



