REFORESTATION ON THE NATIONAL FORESTS. 59 



ciduous trees and shrubs, and with soil of nearly pure sand to a 

 great depth and somewhat lacking in moisture. Dry rocky ridges 

 and exposed slopes are included. 



Jack pine: Only one type of site is considered for this species, 

 namely, all aspects of dry areas of pure light sand of unknown depth 

 which may or may not have previously borne commercial species. 

 It may bear a light cover of grass and weeds or may include undesir- 

 able deciduous trees and shrubs. The soil may become very dry. 



Sowing is not considered advisable with any of these species. 



Nebraska Sand Hill Region. 



Jack pine: Only on the south slopes of the sand hills is it con- 

 sidered advisable to plant this species, not because it will not suc- 

 ceed on other sites, but because these are favorable to more desirable 

 species. 



Western yellow pine: The sites in order are (1) north slopes of 

 the sand hills; (2) ridge tops; (3) the bottoms or depressions be- 

 tween the hills. 



Norway pine: Only the north slopes of the sand hills are con- 

 sidered as well adapted to the planting of this species. 



No direct seeding is thought advisable in this region. 



Arizona and New Mexico. 



Western yellow pine: Approximate altitudinal limits from 7,000 

 to 8,500 feet. The sites in the order of their favorableness for plant- 

 ing or sowing are: 



1. Old cuttings on western yellow-pine land. Usually such areas 

 are practically denuded of tree growth and bear a dense growth of 

 grass. 



2. Brush land showing evidences of having been at least partly 

 forested with western yellow pine but now occupied by a moderately 

 dense growth of brush, such as oaks, mountain mahogany, and buck 

 brush or cliff rose. 



3. Untimbered parks or prairies within the range of the species. 

 Douglas fir: Approximate altitudinal limits from 8,000 to 9,500 



feet. The sites in the order of their favorableness are : 



1. Old burns grown up to moderately dense stands of aspen. 



2. Old burns bare of aspen or other shrubs but strewn with down 

 logs. 



3. Open grass lands. 



Engelmann spruce: Approximate altitudinal limits from 9,500 to 

 11,000 feet. The sites in the order of their favorableness are: 



1. Spruce burns grown up to aspen. 



2. Spruce burns not grown up to aspen but strewn with down logs. 



