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CHAPTER II. 



TENDING OF CROWDED WOODS AFTER 

 EARLY YOUTH. 



When the trees, which compose a wood, have become suffi- 

 ciently large to close up and form a complete leaf canopy, 

 several sources of injury disappear. Weed growth has ceased 

 to affect the trees, and dangers from frost and drought have 

 l)een reduced to a minimum. Danger from fire is not so acute 

 as during the early period of life, and in a temperate climate it 

 may disappear altogether, especially in the case of broad leaved 

 species. On the other hand, danger from insects and fungi con- 

 tinues, while strong winds, snow and rime may break or throw 

 down trees ; such damage may extend over considerable areas. 



While the forester may thus be relieved of some cares 

 peculiar to young woods, they require henceforth tending in 

 other and very important directions. He must now direct his 

 attention more particularl}^ to giving to each tree that growing 

 space best suited to its further development, without sacrificing 

 the full activity of the soil; he must also take measures to insure 

 a high technical utility to the material under production. 



The principal sylvicultural measures by which justice is 

 done to the above-mentioned requirements may be arranged 

 under the following three headings : — 



I. Eemoval of dead, injured or otherwise undesirable trees. 

 II. Pruning. 



III. Thinning. 



Section I. — Removal of Dead, Injured, or otherwise 



Undesirable Trees. 

 In every wood single trees or groups of trees sicken or die 

 from a variety of causes. Amongst these may be mentioned 



