ALINEMENT VOLUME TABLES 



Hermann Krauch, 

 Forest Examiner, U. S. Forest Service 



In a recent number of the Journal ^ there appeared an article 

 entitled "Alinement Charts in Forest Mensuration." A footnote by 

 the editor states: "They (the charts) overcome the chief objection 

 to tables, namely, the strain on the eye after a few hours' use." 



Last winter the writer constructed a series of alinement volume 

 charts to be used in connection with the compilation of growth data 

 obtained from a number of sample plots. The elimination of eye 

 strain was one of the considerations that prompted their compilation, 

 and it therefore struck a sympathetic chord to find that the objection 

 to numerical tables is experienced by others. However, a still more 

 efficient purpose was conceived in the construction of the alinement 

 charts, as the following discussion will reveal. 



The regular volume tables ^ are constructed on the basis of even- 

 inch diameter classes and 10-inch height classes. In the compilation 

 of periodic-growth data, it is essential to consider volumes based on 

 the actual field measurements obtained. At least, this should be the 

 case in order to be consistent and scientifically exact. ^ 



To compute the corresponding volumes from the regular tables 

 would involve mathematical interpolation for values of each tree con- 

 cerned. Since these amount to several thousands, it is obvious that 

 considerable calculation is necessary. In order to obviate such com- 

 putation a series of alinement volume charts were constructed, of 

 which a small sample is shown in the accompanying figure. They were 

 made by plotting the table values on standard profile plate, 4 by 30", 

 and dividing them into fractional diameter and one-foot height classes. 



The encircled figures denote d.b.h. classes; height classes are indi- 

 cated along the corresponding oblique lines ; while volumes are shown 

 at the extremities of the horizontal (volume value) lines. For ex- 



1 Alinement Charts in Forest Mensuration, by Donald Bruce, Journal of 

 FoRKSTRY, No. 7, Vol. XVil, Novcmher, 1019. 



'Volume Tables, Yellow Pine (Pinus pondcrosa), Coconino and Tiisayan 

 National Forests, Arizona. 



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