SYLVICULTURE 



C. Advantages: The advantages of the type are identical with 

 those given under C, I, II and IV, in paragraph LIV. In addition, 

 this type may often allow the forester to favor a desirable species 

 of shade-bearing character. 



Under sylviciiltural care, it renders regeneration an absolute 

 certainty. The trees forming the superstructure frequently happen 

 to be of a marketable size. The tj-pe does not require much sylvi- 

 cultural understanding. 



D. Disadvantages: 



I. Border trees to the leeward of advance growth are subject 

 to windfall and sun scald. 



II. Advance growth groups continue to be badly suppressed, 

 along the edge of the group, by border trees. 



III. The logging operations are scattering, and an intricate 

 system of permanent roads is required. 



IV. Only intense shade bearers can be properly managed under 

 this type; light demanders found in mixture with shade bearers 

 must gradually disappear from the mixture. The shade bearers will 

 readily form groups of advance growth underneath light demanders; 

 but hot vice versa. 



Paragraph LVI. The advance growth selection type of natural seed 

 regeneration. 



A. This type is usually bastardized with the cleared and with 

 the shelterwood selection type. 



The selection by the forester of trees to be cut might be either 

 by single trees or by very small bunches of trees underlaid with 

 a carpet of advance growth covering about one one-hundredth acre 

 of gi'ound. 



The logging operations, as in all selection types, are exceed- 

 ingly scattering; indeed, they ought to continuously extend, as a 

 matter of theoretical principle, over the entire forest. 



Only shade bearers, notably Fir, Hemlock and Spruce, are well 

 adapted to the type of advance growth selection. 



The type, like the cleared and the shelterwood selection type, 

 renders the construction of an intricate network of roads neces- 

 sary. Every tree, so to speak — not every strip or every compart- 

 ment — must be continuously accessible. 



It might be necessary to prepare the soil, in scattered patches, 

 where the layer of humus is too deep, and wnere the soil is so 

 hardened or so covered with weeds as to prevent any chance of 

 n. s. r. 



123 



