FOREST TABLES FOR WESTERN YELLOW PINE. 



INTRODUCTION. 



Forest tables for western yellow pine include Pinus ponderosa proper, 

 the variety scopulorum, and Pinus Jeffrey i. In gathering the data no 

 attempt was made to segregate the species, since the distinction is too 

 slight to be reflected in form or growth tables. The data used in the 

 construction of these tables were collected by field parties a in connec- 

 tion with various projects mainly on the National Forests; they were 

 not gathered according to a set plan, but nevertheless are sufficient for 

 the immediate requirements of exploitation and forest management. 

 Cooperation is requested in the collection of more complete measure- 

 ments for extending and revising the tables. In the National Forests, 

 technical assistants, timber-sale inspectors, and lumbermen super- 

 vising cuttings can render valuable aid in this direction. 



The widely varying factors of temperature and rainfall in different 

 parts of the western yellow pine region bring about a corresponding 

 variation in the development of the tree. This affects both the rate of 

 growth and the form, and necessitates the recognition of three regions 

 in which the tree differs widely. These regions are: the isolated 

 Black Hills region; Arizona, New Mexico, southern Colorado, and the 

 lower and drier mountains of southern California; northern Cali- 

 fornia, Oregon, Washington, and the moister parts of Montana. 



The first two regions are marked by a light rainfall; there the tree 

 makes slow growth, has a short full stem, and forms open stands. 

 The third region has a much heavier rainfall, which makes more rapid 

 growth, a more slender stem, and rather dense stands. These 

 characteristics are most conspicuous in the volume tables, but can 



« The field parties for the different regions were under the direction of the following men: 

 Prescott National Forest, Ariz, (working plan), A. E. Cohoon (1901). 

 California and Oregon (sugar pine study), R. D. Swales (1901). 

 Black Hills, S. Dak. (western yellow pine study), Coert Dubois (1902). > 

 Colfax Co., N. Mex. (study and planting plan), A. F. Hawes (1903). 

 Black Hills, S. Dak. (western yellow pine study). II. M. Curran (1904). 

 Archuleta County, Colo, (western yellow pine study), H.M. Curran (1904). 

 Butte and Madera counties, Cal. (western yellow pine study), A. W. Cooper (1904). 

 Flathead and Missoula counties, Mont, (western yellow pine study), S. J. Record (1904). 

 Stevens County, Wash, (working. plan). A. K. Chittenden (1904). 



San Francisco Mountains National Forest. Ariz, (timber sales), T. S. Woolsey, Jr. (1906). 

 [Cir. 127] 



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