CHAPTER IX: THE ENEMIES OF TREES 



In every treetop we can read the story of a long fight. Leaf, 

 flower and fruit, bud, twig and branch, contest unceasingly for 

 room and food and sun. Underground, the roots have their own 

 struggle for the bounty of the soil. Always the struggle is un- 

 equal, the weak succumbing to the strong. Where tens succeed, 

 hundreds and thousands fail. 



In the woods the story is the same. Neighbour trees contend 

 as do neighbour branches. Nature thins and prunes, discarding 

 all but the fittest. Many people understand that the best forests 

 are those in which Nature has her own way. But only from 

 Nature's point of view. She is the great impartial all-Mother, 

 and is as much interested in the well-being of a fungus that de- 

 stroys a tree as in the tree itself. A virgin forest is a battleground 

 where varied and multitudinous natural forces meet and fight for 

 supremacy. 



The noble forests of the Cascade range in Washington and 

 Oregon best illustrate the victory of trees over all other forms 

 of vegetation. The pine forests of the Great Lakes and of the 

 South, the broad-leaved forests of the Ohio and lower Mississippi 

 Valleys, all showed how trees triumphed in days gone by over 

 inimical forces of Nature. The meagre fringe of trees along streams 

 in the arid West, the stunted growth of northernmost woods, 

 show how trees are affected by drought and cold. The dis- 

 tribution of forests and their condition are traceable to well- 

 known causes. 



Some of the enemies of the forest are natural; some are 

 attributable to man and his civilisation. In many instances 

 responsibility is divided. One enters and leaves the door open 

 for others. 



The chief enemies of forests are fires and insects. Winds, 

 frost, lightning, snow, hail; ice, drought and flood are atmospheric 

 in origin. Fungi decompose dead wood, doing the forest a service 

 by enriching the soil. But many of them menace sound trees 

 wherever their bark is broken. Grazing and wasteful lumbering 



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