62 OUTLINES OF FORESTRY. 



natural conditions of the locality, that it will grow 

 and multiply so rapidly as to choke out of exist- 

 ence all other forms. Even such forms, however, 

 will continue to exist only as long as the condi- 

 tions continue favorahle for their existence. 



The dependence of plant life on climatic condi- 

 tions is, perhaps, more marked in the higher 

 forms of the vegetable world. Trees may, in a 

 certain sense, be regarded as of the highest type of 

 plant life. They rigorously depend on conditions 

 of soil and climate for their continued existence. 

 It is true that when a forest is once formed, and its 

 vigorous growth has almost completely shut out 

 the light from the soil in which it is growing, that 

 the numerous forms of vegetable life which lie 

 ready to spring up, should the sun's rays find free 

 access to them, are prevented from growing. Even 

 if they did appear, and the climatic conditions 

 remained as before, the same struggle for existence 

 would again occur, and the same forest would in 

 all probability finally be reproduced. If, however, 

 the character of the soil be altered, or the climatic 

 or other conditions be changed, the forests would 

 either disappear or be replaced by trees of another 

 character. 



The forest has many enemies that are ready at 



