98 OUR NATIONAL FORESTS 



secure the highest returns. Tables are included 

 to show the volume of the trees at different ages 

 and sizes, in cubic feet, in cords, in board feet, etc. 

 Studies are also made of the Hfe history and re- 

 quirements of important forest trees, often in con- 

 nection with commercial studies. Such studies 

 cover: local, geographical, and commercial occur- 

 rence of the species, the species which are asso- 

 ciated with it, the habit of the tree, its soil and cli- 

 matic requirements for germination and growth, 

 and the various matters connected with its repro- 

 duction. Such publications as these give the Forest 

 officers much valuable information about the trees 

 with which they are dealing, and also furnish the 

 only sources of information to students in forest 

 schools on the characteristics and requirements of 

 the trees important in forestrj^ in this country. 



Grazing Investigations. Grazing investiga- 

 tions, being intimately connected with a great 

 national industry, have received a considerable 

 amount of attention. These studies are confined 

 at present to grazing reconnoissance, the reseeding 

 of depleted mountain grazing lands, studies in the 

 best methods of handling sheep on the range, 

 studies of the effect of grazing on the forest, iden- 



