68 GENERAL GROWTH OF STUDIES 



curves constructed interpolate. A D.B.H. growth curve mav also 

 be added l)y the method of Problem 28. 



8. Determine the dimensions of the trees — D.I.B. at the stump, and at 



the end of each section (log) and the total height — for even 10-year 

 periods beginning with 10 years, and proceeding through to the time 

 the trees were cut. Arrange in table form. 



9. From the preceding table construct a Volume Growth Table showing 



(a) the growth of the entire stem in cubic feet, and (6) the growth in 

 board feet of the merchantable stem, for each 10-year period. 

 Consider 6 inches D.I.B. for the merchantable top diameter limit. 

 Use the International Log Rule, or any other with values down to 

 6 inches top diameter for determination of board foot contents. 



PROBLEM 32. (Office.) The Determination of Maximum Growth 



Explanation. — The object of determining maximum growth is chiefly for the 

 purpose of finding out how fast all the trees in an unthinned stand would 

 grow assuming that each could be made to grow as fast as the most rapidly 

 growing trees, providing they were given the proper treatment. Thie 

 method of procedure as given in the accompanying illustration would be 

 applicable to any of the various kinds of growth studied and may be applied 

 to any of the succeeding growth exercises. The data for this exercise may 

 be obtained either by analysis of a large number of trees of different sizes, or 

 by selecting only the maximum trees for analysis. In the latter case the 

 maximum growth would be determined directly from these analyses by the 

 same method of procedure as described in Problem 26, if collected by first 

 method referred to, as described in the illustration below. 



Illustration. — To Determine the Maximum Diameter Growth at the Stump 

 in Even-aged Stands by Constructing a Maximum Diameter Growth Curve. 



Directions: 



A. Data Required. — Stump analyses and total ages of selected trees of differ- 



ent sizes. As the values are plotted exactly as in Problem 26, the 

 same sheet of cross-section paper with its plotted points may be used. 



B. Method of Procednre. 



1. Using the same sheet of cross-section paper with its plotted points 



that was used in Problem 26, draw a smooth curve as an upper 

 boundary to the main body of the plotted points, being careful to 

 exclude all points that indicate abnormally high values. 



2. Read off a table showing the diameters of the maximum trees for 



each even 10 years. 



