146. 



m. The behaviour of the tree in the stand is partly good and 

 partly badT Trees help each other: 



1) They protect the site for each other. 



2) They protect each other from the wind, snow and frost. 



I) Treee force each other to take on betexf form, a/ cleaner 

 bole and higher ounlity. The tree itself cares nothing about the last 

 point; the first two only are important to the tree itself. Here the 

 forest is * grert factor of site; they help each other, and afford 

 mutual protect if- . 



Trees hurt "each other: 



1) Competition for soil, moisture and light. 



2} Retard, each other's growth, fruiting or reproduction, and 

 in very dense stands 'whey fti&l&Ik diminish each other's vigor and safety. 



3} Smaller individual ^rov/th a longer time elapses before 

 they are valuable to nrm. 



n. The edge of the stand presents important peculiarities, yet 

 they hr.ve never "been dealt with extenoively. Mayr was the first to treat 

 of thin point. It has "been stmdied by practioners but not much by 

 writers. It forms a line of contact of dissimilar elements. 



Two trees close together force the development of one* sided 

 crowns. This is of universal occurrence* 



The 0ame if true of the spreading tree in the forest. It affects 

 others unpleasantly and injuriously. 



The edtfe of an opening in the woods: develops poorly cleaned 

 timber; it ifTa border where the trees differ from those within, with al. 

 species. They are lirnby all the way down, are one-sided, and therefore 

 there sre no sstrc-i/->it Voles, But the border is valuable and necessary to 

 the stand. You^ trees on the edge have to grow outward to get a fighting 

 chance, as for intBC, the fight between oak and Scotch pine, or 



tween birch and spruce or whit pine, they are whipped, crowded, and 

 dief igur 



Such edges are more injurious with mixed stands on opposite sides 

 less injurious vdth pure stands on opposite sides. Hardwoods are more 



-ressive than conifers, especially beech. The condition along the 

 r'dge are aggravated with respect to the north and south aides. They are 

 worse on the north or shady side than on the sunny or south side; the 

 fight is e?sier on the south side. 



In general the edge of a group, line or point of contact of lar- 

 i*r or Dissimilar elements or stiff results in a difference in develop- 



it, injures growth, fora, and quality, just as with small groups. 

 is less growth per acre, more deformed and less perfectly cleaned timber 

 This is important, and is well appreciate- by European practitiensrs. 

 They often cut young balsam clear off of an area to avoid such trouble. 



Fire lines and compartment lines also present the above difficul- 

 ties, as does the strip system forest. Choose the least of several evils 

 According to whether you want the timber or the reproduction, etc. 



The edge in the foreat is one of the important silvicultural 

 phases with which the forester must deal. 



