SYLVICULTURE. 



felling, and unless the timber obtained is carried out either by 

 hand, or on high wheel trucks, or on a heavy cover of snow pro- 

 tecting the advance growth. Under any circumstances, fellings 

 during the period of vegetation must be avoided. 



HI. Advance growth suddenly exposed to the full influence of 

 sun, rain, snow, sleet, etc., is apt to suffer in case of sensitive species. 



IV. A minute system of permanent roads is required, the 

 advance growth usually appearing in groups or patches. 



V. if the pure types of advance growth n. s. r. were strictly 

 adhered to, a regulation of the annual cut according to the condi- 

 tions of the market would be difficult to obtain. Hypermature trees 

 would have to be left everywhere merely because young growth 

 if often slow to form on their feet. 



In such cases, artificial preparation of a seed-bed (f. i.,' by 

 uncovering the mineral soil) seems absolutely required, so as to 

 expedite the formation of advance growth. 



If the leaf canopy overhead is opened at the same time by 

 felling operations, the types bastardize with the shelterwood types 

 of n. s. r. 



According to the extent of the area covered by an advance 

 growth of suitable character we distinguish between: 



a. Advance growth compartment type of n. s. r., the areas 

 uniformly covered by advance growth measuring from twenty to 

 one hundred acres (rare). 



b. Advance growth strip type of n. s. r., the area uniformly 

 covered by advance groAvth appearing as strips measuring up to 

 500 feet in breadth (very rare). 



c. Advance growth group type of n. s. r., the groups covered 

 by advance growth having an extent of from one-tenth to three 

 acres (frequent). 



d. Advance growth selection type of n. s. r., the young seed- 

 lings and saplings appearing in scattered and small patches (very 

 common). 



Under "advance growth" is understood an aggregate (small or 

 large) ol seedlings or saplings belonging to a desirable species and 

 formed without any human intention or attention, solely by nature, 

 beneath a totally or partially untouched leaf canopy overhead. 



Spreading advance growth appearing in bunches or groups can 

 be doctored up with axe and brushhook and machetes, by an appli- 

 cation of " hairdressing." 



Where the advance growth is not freed, by one single operation, 

 from the superstructure of parents and step-parents overhead, the 

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