FORESTRY 533 



a point has been reached when it is difficult to get lumber 

 of good quality for many of the most important purposes for 

 which it is used. In some parts of the country timber is a 

 profitable crop to raise, even if it has to be planted and cared 

 for while growing. The science and art of growing timber and 

 caring for tracts of wooded land is called forestry. Much atten- 

 tion has long been paid to it in the most enlightened countries 

 of Europe, but the subject is a comparatively new one in the 

 United States. The importance of maintaining a suitable pro- 

 portion of wooded land in any region does not depend merely 

 on the desirability of a supply of timber. The water supply of 

 lakes and streams, the retention of the cultivable layer of loam 

 on the earth's surface, the climate of any region, at least so far 

 as the prevention of severe winds is concerned, all are depend- 

 ent on the presence of considerable forest areas. 



The principles of forestry cannot be laid down in a few words, 

 and forest management requires years of study in the woods 

 themselves. The literature on the subject is extensive, and 

 courses in forestry are now given in a good many universities. 

 Evidently it is a topic of growing importance in this country. 

 A few useful rules can be given here. 



1. Tree cutting should generally be managed on the prin- 

 ciple of selecting only mature trees and leaving the others to 

 grow up to replace those cut. 



2. Forest fires should be prevented. 



3. Destructive fungi should be exterminated wherever found. 



4. Insect enemies of trees, such as the seventeen-year locust, 

 the various caterpillars, and boring insects, should be destroyed. 



5. Sheep and cattle should never be pastured in woods where 

 they can do harm by killing young seedling trees or other 

 useful undergrowth. 



6. Tree planting should be carried on whenever it can be 

 made to utilize lands not needed for other purposes, and the 

 species planted should be chosen with extreme care to meet the 

 requirements of the soil and climate. 



