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III. Enemies of Forests. 



1. Man. 



(a) Destructive lumbering. 



(b) Excessive taxation on forest land. 



(c) Devastated lands revert to State. 



2. Animals. 



(a) Grazing. 



(1) Destruction of young trees. 



(2) Fires burning soil cover improves grass. 

 (2) Fires extend area of pasturage. 



f /ux Trampling. 

 (1) Compacting of soil. 

 (2) Destruction of young trees. 

 (3) Destruction of forest floor. 

 (4) Interference with water flow. 

 (5) Formation of flood. 

 (6) Denudation of mountain sides. 



3. Insects. 



4. Fungi. 



5. Wind. 



6. Snow. 



7. Fire. 



(a) Causes. 



(1) Negligence hunters. 



(2) Lightning. 



(3) Malice. 



(4) Berry pickers and herders. 

 Effects. 



(1) Destruction of certain species; weak perish first. 



(2) Destruction of species after species. 



(3) Change in physical condition of surface of earth. 



(4) Plains and prairies largely due to fire. 



(5) Destruction of organisms at work in soil earth worms, 



bacteria, moulds, insects. 



(6) Equilibrium in nature destroyed. 



IV. Some Important Forest Trees. 



White pine, Red juniper, 



Sugar pine, Arbor vitae, 



Cuban pine, Big-tree, 



Balsam fir, Swamp white oak, 



Noble fir, Beech, 



Hemlock, Black walnut, 



Tamarack, Pecan, 



