SYSTEMS OF CLEAR-CUTTING 111 



from 3 to 5 trees per acre. More often, from 5 to 10 

 trees per acre are necessary for good reproduction. 



Character of Seed-Trees. Seed-trees are chosen 

 for reproduction, and they must be capable of performing 

 that function. A satisfactory seed-tree is a wind-firm 

 tree, with a full, thrifty crown. Generally the tree with 

 a full, thrifty crown is the most wind-firm of the stand, 

 since root and crown develop in harmony. A good 

 working rule is to select, when possible, trees whose 

 crowns take up at least 50 per cent, of the full height of 

 the tree. 



In selecting seed-trees one must consider constantly 

 the question of the investment. If the trees are to be 

 sacrificed to reproduction, and probably will not be util- 

 ized later, one chooses the least valuable trees which will 

 serve the purpose. The forester, therefore, selects the 

 smallest trees which will be satisfactory distributers of 

 seed. They must, however, have full, thrifty crowns. 

 Suppressed trees, trees with long boles and short crowns, 

 or dominant trees with dying crowns, will not answer the 

 purpose. If small seed-trees are wanting, larger and more 

 valuable ones must be left in proper locations. 



There are certain defects which unfit a tree for high- 

 grade lumber, but do not affect its reproductive power. 

 A knotty or a crooked tree may be fully as good a seed- 

 tree as a straight one. In fact, a knotty tree may be the 

 best possible seed-tree, because it usually has a full 

 crown. Other defects, like cat-face, seams, sun-scald, 

 etc., do not injure a tree for reproduction. 



