SYLVICULTURE 



require any more, or rather despise, the benefit of the parents' 

 presence. 



Lumbering operations are carried on — in one and the same 

 limited lot — during a number of years. 



Where the mother trees are very rapidly removed, after re- 

 seeding, from the proximity of the youngsters, the pure shelter- 

 wood types approach the types of cleared compartments, cleared 

 strips, etc. 



Where the mother trees are very slowly removed, after reseed- 

 ing, from the proximity of the youngsters, the pure shelterwood 

 types approach, or bastardize with, the advance growth types. 



The chances for success depend on: 



A. Sylvicultural talents of the forester in charge and of his staff, 

 also on the size of the ranges. 



B. Frequency of seed years and time allowed for tlie entire 

 operations. 



C. Shade-bearing character of youngsters and firmness of 

 parents. 



D. Existence of a permanent system of transportation. 



E. Configuration. 



F. Danger from storm, sleet, fire, animals, etc., locally existing. 



G. Size of timber, value of timber, percentage of debris and 

 waste. 



H. Marketability of all species or of a few, even of one species 

 only. 



According to the manner in which the forester selects the nuclei 

 for reseeding, we distinguish the following types: 



I. Uniform type, or pure shelterwood compartment type, where 

 the nuclei are geometrically and regularly distributed over the en- 

 tirety of a large area (say over twenty to two hundred acres), the 

 nuclei of the entire area being kept, during the entire progress of 

 regeneration, in or about in the, same uniform stage of development. 



II. Shelterwood strip tj'pe, where the nuclei proceed, like ad- 

 vancing skirmishers, in regular military order from the leeward 

 side to the windward side of a compartment (cove, slope, etc.). The 

 nuclei to the leeward are kept in a more advanced stage of growth 

 than those to the windward. 



III. Shelterwood group type, where the nuclei are carefully 

 selected, irrespective of geometrical arrangements, merely on the 

 basis of the fitness of the individual spot to act as a seed-bed. The 

 groups are gradually enlarged, increasing in circumference like waves 

 caused by stones thrown in the water. 



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