SYLVICULTURE 



seedlings to sprout and develop on a spot where light, humidity and 

 soil allow a single individual to make a start alone. In the primeval 

 woods, groups of advance growth formed by shade-bearing species 

 are almost invariably at hand. Even light demanders may form 

 small groups of advance growth in spite of a superstructure over- 

 head, provided tnat the soil is strong enough to support them. 



Such groups, freed from the trees superstructing them, will de- 

 velop one or a number of saplings which in turn and in course of 

 time may yield one or a few poles promising to grow into trees of 

 a loggable size. 



Very frequently the groups are formed not under the leaf canopy 

 of the parent species, but underneath another species acting as a 

 step-parent. 



Indeed, step-parents of a rather selfish kind,' inimical to the 

 children, are frequently encountered in tree life, hanaicapping and 

 killing the young progeny thirsting at their feet for light and rain. 



The endurance of advance growth living under adverse condi- 

 tions is at times remarkably great. Fir, Spruce, Beech and Maple 

 may be met grown only six feet high when 60 years old, retarded by 

 parental superstructure. 



The pure advance growth group type is frequently bastardized, 

 in Europe, with the shelterwood group type when the forester 

 uses existing groups of advance growth as nuclei to be gradually 

 enlarged, instead of using spots as nuclei for group regeneration on 

 which the soil chances to be in a conceptious condition. Further, 

 when a shelterwood group is forming, advance growth groups are 

 frequently started, under the influence of side light on seedlings 

 and humus, at a goodly distance from the shelterwood group, under- 

 neath an apparently heavy superstructure of mother trees. 



The advance growth group type pure and simple, however, 

 merely implies the freeing of chance growth from a superstructure. 

 It has nothing to do with the gradual enlargement of a group 

 by ringwise cutting around the group. 



The " hairdressing " or groups of advance growth is some- 

 times commendable. 



B. Actual Application: Systematically, this type is nowhere 

 applied in its purity. Accidentally, however, the lumbermen of 

 America happen to employ it in woods composed of Fir, Hemlock, 

 Maple, Beech, etc. 



Primeval nature employs this type quite largely (f. i., in Chest- 

 nut-oak woods at Biltmore). 



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