18 THE SCHOOL BOOK OF FORESTRY 



by forest fires, cattle and sheep grazing, unfavor- 

 able soil and weather conditions, and many 

 other causes. 



Beech and chestnut trees and others of the 

 broad-leaved type reproduce by means of sprouts 

 as well as by seed. Generally, the young stumps 

 of broad-leaved trees produce more sprouts than 

 the stumps of older trees which have stood for 

 some time. Among the cone-bearing trees re- 

 production by sprouts is rare. The redwood of 

 California is one of the few exceptions. The 

 pitch pine of the Eastern States produces many 

 sprouts, few of which live and develop into mar- 

 ketable timber. 



When trees are grown in nurseries, the prac- 

 tice is to sow the seed in special beds filled with 

 rich soil. Lath screens are used as shade. They 

 protect the young seedlings from the sun just as 

 the parent trees would do in the forest. The 

 seedbeds are kept well cultivated and free of 

 weeds so that the seedlings may have the best 

 opportunities for rapid growth. Generally the 

 seeds are sown in the spring between March and 

 May. Such seeds as the elms and soft maples, 

 which ripen in the early summer, are sown as 

 soon as possible after they are gathered. Prac- 



