THE ART OF THE SECOND GROWTH 



Deep root system. 



Heiglit growth slow to begin witli, rapid from seventh year on: 



Age 1 year; height 1 inch. 



Age 5 years; height 41/2 feet. 



Age 10 years; height 8 feet. 



Age 15 years; heiglit 15 feet. 



Age 20 years; height 23 feet. 



Slow cleaning of bole; very dense thickets required. 



Seed bearing from fifteenth year on. 



Subject to damage by frost and drought during first years. 



Game does not attack it; mice destroy young seedlings. 



Seeds are planted broadcast; slightly covered with, dirt; shel- 

 tered by lath screens. 



Strong seedlings three j'ears old (not transplants) are used 

 since the root system is comparatively small, whilst the stem sys- 

 tem is comparatively large. 



O. Tsuga lieterophylla: Requires strong soil; demands side 

 shade, bvit hates top shade. Cannot stand open situations. 



Root is a strong tap-root. 



Height growth good from third year on. 



Tips of the top-shoot are frequently killed by first frost, with- 

 out any apparent permanent damage. 



Use seedlings three years old, raised by broadcast sowing. 



Shelter seed-beds well. Avoid deep planting. 



Mayr prefers heterophylla to canadensis for planting in 

 Germany. 



Paragraph XXXIX. Difficulties of natural seed 

 regeneration. 



Theoretical foresters frequently make the statement that the 

 axe is the best sylvicultural tool inasmuch as its proper use secures 

 a good regeneration free of charge. This statement is misleading. It 

 is true that the density of the stand of the second growth obtain- 

 able from natural regeneration is frequently better than that ob- 

 tained from artificial planting. On the other hand, a good stand 

 cannot be obtained but under favorable conditions and at a great 

 increase of the logging expenses. While the cash expense of natural 

 reseeding might be slight, the actual expense consisting in lessened 

 receipts frequently exceeds the expenses of artificial planting. In 

 the primeval woods, additional difficulties of seed regeneration in- 

 duced by man lie in the following points: 

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