CHAPTER V 

 FOREST INFLUENCES 



1. THE FOREST AS A COMMUNITY OF TREES 



The forest, known also as woodland, woodlot, timber, timberland, 

 etc., is not only an assemblage of trees. It is a living, organic, bio- 

 logical group, the units of which (trees) are constantly assisting each 

 other against natural elements and are in constant competition for 

 light (literally a place in the sun), moisture, and food. As a result of 

 this struggle, the weaker specimens may be suppressed and die; the 

 stronger trees will survive. In a planted forest where trees are 

 spaced 6 by 6 feet apart, there are 1210 trees per acre. When mature 

 or merchantable, only 100 to 400 trees per acre may remain in the 

 stand. In open fields or on logged or burned areas, thousands, often 

 hundreds of thousands, of seedlings naturally reproduced may be 

 found. When this struggle is too severe, most of the trees may suffer 

 and show slow growth and poor condition. This is why thinnings are 

 so necessary. If too open, the wood goes into the branches rather 

 than the main stem and height growth is not stimulated as in closed 

 stands. 



A stand must be kept fully stocked for most efficient results. A 

 stand too open may develop little valuable wood, whereas one too 

 dense may be a very destructive forest. 



2. SILVICS OR FOREST ECOLOGY 



Silvics, also called forest ecology, which is the relation of the 

 forest to its environment, is the foundation of silviculture. Funda- 

 mental knowledge of silvics is essential for a proper understanding of 

 silvicultural processes. It is of great importance in understanding 

 the fundamentals and best methods of cultural thinnings and of re- 

 producing the forest naturally and artificially. It is likewise of great 

 importance in the prediction of future yields and in the preparation 

 of plans for forest management. The life history of individual spe- 

 cies, or ontogeny, must be clearly comprehended in order properly to 

 understand the development of tree associations which are the basis 



61 



