INTRODUCTION. 



THE solutions of many <;f the numerous problems encountered in 

 the economic management of merchantable forests depend upon 

 the present and probable future market conditions; the present and 

 probable future cost of logging, milling and transportation; and upon 

 a definite knowledge of the quality and quantity of lumber contained 

 in trees of various sizes, along with the yearly increase in quality and 

 quantity due to growth. 



The question often arises: Is it more profitable to leave certain 

 trees standing than to cut them down and invest the profits obtained 

 thereby, or is it more profitable to allow them to grow and accumulate 

 interest in the form of wood added each year, along with a possible 

 increase in value due to change in market conditions, or perhaps to 

 future betterment of transportation facilities? Such questions can 

 not intelligently be dealt with unless at least the quality and quantity 

 of trees of different sizes, as well as yearly increase in both quality and 

 quantity of lumber contained in them, be quite definitely known. It 

 is the object of this study to make such determinations for western 

 yellow pine that can be used in the solution of the above and similar 

 problems ; also, that can be used in connection with more accurate 

 valuation surveys than have been made in the past, and which will 

 help lumbermen and timber owners in general to more economically 

 formulate their policies of handling merchantable yellow pine forests. 



The study is based upon nine hundred and nineteen trees, ranging 

 from twenty to forty-four inches in diameter breasthigh, five hundred 

 and seven of which were classified, according to outward appearances, 

 as bull pine, and four hundred and twelve as typical yellow pine. A 

 complete analysis of quality and quantity of lumber produced from 

 these trees, also from the butt logs, the best part, and the top logs, the 

 poorest part of the trees, has been made and the results arranged on 

 opposite pages throughout this bulletin, so that a comparison of the 

 two forms may be had. The values shown in the tables in Part III 

 were read from the curves shown in Part II, which were in turn plotted 

 directly from averages obtained from the original data. References 

 are made with each table, such that it is possible to trace any value 

 there recorded back to its original derivation. 



Each feature has been presented in detail and will be of direct value 

 to lumbermen operating in pine forests under similar conditions. 

 Yellow pine stands constitute the predominating forest type in Cali- 

 fornia and, consequently, this type affords a characteristic set of con- 

 ditions under which to initiate such a piece of work. Prepared thus in 



