REPRODUCTION OF WESTERN YEEEOVV PINE 275 



The methods and general scope of these studies have been described 

 in detail by Woolsey,- to whose foresight during the pioneer stage of 

 forestry in this region their initiation is due. During the five years 

 since Woolsey's article was written the methods have undergone con- 

 siderable refinement. The scope has been broadened because it has been 

 found that, with little additional field work, the records can be made to 

 cover a more comprehensive field than was originally contemplated. 



The plan calls for periodic measurements and examinations on each 

 plot. Measurements and certain descriptive data will be taken at in- 

 tervals of five or ten years. Other data, such as seedling records and 

 records of seed crop, will be taken yearly on accessible plots. Special 

 studies necessary to correlate growth and reproduction with physical 

 factors are also a part of the program. 



Four "extensive" plots, each including two "intensive" plots, on the 

 Coconino and Tusayan National Forests were remeasured in 1914. 

 All of these plots were established in 1909. All are in pure yellow-pine 

 stands. 



Two types of cutting are represented, namely, standard Forest Serv- 

 ice cuttings and private cuttings. 



The cutting method^ on recent Service timber sales, as represented 

 by plots Nos. 3 and 4, is a form of the selection system sometimes 

 characterized as the group-selection system. Approximately two- 

 thirds of the volume is removed, leaving one-third in the form of 

 black jack or immature trees and a sufficient number of yellow pine 

 or mature trees to insure an adequate seed supply and to preserve for- 

 est conditions. The slash on plots 3 and 4 was piled but not burned 

 excepting on fire lines. In the old private cuttings represented by plots 

 Nos. I and 2 silviculture was left entirely out of consideration ; but 

 the character of the remaining stands was from a silvicultural point of 

 view not radically different from that of stands now left on Service 

 cuttings. The private cuttings 20 to 30 years ago resemble the modern 

 Service cuttings in that they left nearly all of the black jack and many 

 of the full-crowned yellow pine, which according to present standards 

 are considered desirable seed trees. They differ essentially from the 

 Service cuttings in that much of the overmature and defective yellow 

 pine was left. Utilization was very poor on the old cuttings and slash 



"Woolsey, Theodore S., Jr. "Permanent Sample Plots." Forestry Quarterly, 

 Vol. X, No. I, 1912. 



*On a series of plots established in 1913 four methods of cutting and two 

 methods of brush disposal are compared. Since tiiese plots have not been re- 

 measured, they are not included in this article. 



