SYLVICULTURE. 



Paragraph XXXIX. Difficulties of natural seed regeneration. 



American 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 

 obtained from artificial planting. On the other hand, such a stand 

 can only be obtained under favorable conditions and at a great 

 increase of 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 

 tne primeval woods additional difficulties of seed regeneration lie 

 in the following points: 



A. Overaged trees have poor seeds. 



B. Interference with the leaf canopy overhead at once invites 

 danger from fire, increased by the debris on the ground, and by 

 the impossibility of battling against fires in the underbrush. 



C. In the primeval forest, the age classes are usually mixed in 

 an irregular manner; hence uniform measures for reproduction are 

 out of the question. The forester cannot generalize; he must 

 individualize a very expensive procedure in the face of low stump- 

 age values. 



D. The virgin forest usually contains a mixture of species; the 

 best ones only are removable; the weeds and worthless species are 

 left on the ground; and from this fact arise additional difficulties 

 to propagate the most valuable kinds. To this must be added the 

 difficulty of properly gauging light and shade according to the 

 individualities of the species mixed. 



E. In America the lack of a permanent system of transporta- 

 tion necessitates the operations to extend at one stroke over large 

 areas, whilst natural seed regeneration requires the gradual removal 

 of mother trees, in imitation of nature's own way of proceeding, 

 on small and restricted areas only. 



As a matter of fact, the lack of permanent means of transporta- 

 tion in primeval woods is the most serious obstacle to regeneration 

 from self-sown seed conscious of its aim and its effect. 



F. Natural seed regeneration requires cutting, according to the 

 occurrence of seed years and according to the development and 

 requirements of young growth. Hence the axe must be inde- 

 pendent from the fluctuations of market or mill requirements, an 

 impossibility in the United States at the present time. 



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