366 General Botany 



control water supplies for irrigation, and to prevent destructive 

 floods. They are not intended to prevent the cutting of ma- 

 ture timber or to keep suitable land from being settled and turned 

 over to agriculture. These lands are being accurately surveyed, 

 and whenever areas are found that are fitted to become farm- 

 lands they are sold to settlers to use for farming. 



The total amount of land in the national reserves is 160 million 

 acres. In addition, many of the state governments have taken 

 over smaller forest tracts within their borders for the same purpose. 

 Out of the original 822 million acres in the United States only 137 

 milhons of virgin timber remain. Only 6 billion cubic feet of tim- 

 ber are added by growth on all forested lands each year, while 

 25 billion cubic feet are being consumed. This is the same as 

 saying that in the United States we are using the timber four times 

 as fast as it is being replaced by growth. 



Reforestation. Many of the lands owned by the United States 

 and by the state governments have been partly or wholly de- 

 nuded of forests, and are worthless for agriculture. After being 

 lumbered, the tops and branches of the trees were not removed 

 and destructive fires swept away all that the lumbermen at the 

 time considered worthless. To make this land valuable, the for- 

 esters either replant the area with small trees grown in nurser- 

 ies, or plant seeds which will develop into trees where they ger- 

 minate. In areas where the forests have been only partly de- 

 stroyed, the species that remain are usually worthless for timber 

 purposes. In such places " improvement cuttings " are made ; 

 that is, the worthless trees are either cut for fuel purposes or 

 cut and burned to provide room for the young trees that will 

 make valuable timber in the course of time. Some trees, like 

 the chestnut of the East and redwood of the West, sprout from 

 the stumps when the trees are cut. Thus for several years these 

 trees make use of the roots of the parent tree and the food 

 materials stored in them. They possess a great advantage in 

 reforestation over the trees that have to start from seed. 



