46 graves: place of forestry among sciences 



foresters could leave wholly to botanists the working out of the 

 basic facts about the life of the forest which are needed in the 

 practice of forestry. When the general science of plant associa- 

 tions has reached a higher state of development, the two may 

 possibly merge, but not until then. 



In developing the science of tree associations, the forester has 

 been unquestionably favored by the fact that the forests, being 

 the highest expression of social plant life, aiford the best oppor- 

 tunity for observing it. 



The reason for the ability of forest trees to form most highly 

 organized plant societies lies in their mode of growth. Each 

 annual ring of growth, together with the new leaves that appear 

 every year, is in reality new colonies of cells. Some of the cells 

 'die toward the end of the vegetative season; others continue to 

 live for a number of years. When the conditions of life in a 

 forest have changed for a certain tree, when, for instance, from a 

 dominant tree it became a suppressed one, the new colonies of 

 cells formed during that year, and which sustain the life of that 

 tree, are naturally adapted to these new conditions. The same 

 is true when a suppressed tree, through some accident to its 

 neighbors comes into full enjoyment of light. The last annual 

 growth is at once capable of taking advantage of the new situa- 

 tion created in the forest. Therefore, as long as a tree can form 

 annual rings, it possesses the elasticity and adaptability essential 

 for trees living in dense stands. It is only when a tree is sup- 

 pressed to a point when it can not form new growth that it dies 

 and is eliminated from a stand. 



Because of the fact that the forest is the highest expression of 

 social plant life, the foresters occupy the stragetic position from 

 which they command vistas accessible only with difficulty to other 

 naturalists. In this lies the strength of forestry, its peculiar 

 beauty, and the debt which natural science owes to it. It is a 

 significant fact, although, of course, only of historic importance, 

 that, according to Charles Darwin^ himself, it was ''an obscure 

 writer on forest trees who, in 1830, in Scotland (that is, 29 years 

 before the Origin of Species was published), most expressly and 



^ Origin of species. 



