INFORMATION PRODUCED 



A surfeit of detail about the tree development is available within the computer 

 data files. How to assemble this detail into information useful to the manager in 

 compact form is no small problem. Certainly, numbers of trees, their distribution by 

 size, the volume of scheduled harvests, and its species composition are essential 

 elements of the output. Stand and stock tables --arrays of numbers of trees and volumes 

 by diameter classes--are the customary means of presenting such information. However, 

 diameter-class intervals appropriate to one stage of development of a stand would 

 either provide excessive detail at later stages, or insufficient detail at earlier 

 stages. Instead, the distribution of any attribute with regard to diameter is displayed 

 by printing the lowest diameter such that a given fraction of that attribute for the 

 stand is entirely contained in trees of that diameter and larger. For example, fic r? 

 lA is a portion of the output from a lodgepole pine stand as it is expected to develop 

 from 1969 to the year 2020. In 1969 there was a total of 509 trees per acre. Of 

 these, 10 percent were larger than 8.9 inches d.b.h., 50 percent were larger than 

 6.8 inches d.b.h., and 90 percent were larger than 5.7 inches d.b.h. At the same time, 

 50 percent of the total volume (which was 4,775 cu. ft. /acre) was contained in stems 

 larger than 7.3 inches d.b.h. 



The periodic mean annual accretion (growth on surviving trees) and mortality from 

 1969 to 1980 are indicated as 100 and 61 cubic feet per acre per year, respectively. 

 The distributions of growth and mortality by size classes are provided with the same 

 interpretation described for numbers of trees and volume. In 1990 the stand was 

 thinned from below to a residual density of 300 trees per acre. Volume removed was 

 535 cu.ft. 



Species composition is indicated by displaying the percentages of the total volume 

 (cu.ft.) that represent each of the three most plentiful species. Species composition 

 is displayed for only those stand attributes that are measured in units of cubic feet. 



Yields in units of merchantable product are, of course, vital to the utility of 

 this program for management planning. Grosenbaugh (1954) and Bruce (1970) have shown 

 how summaries of the primary units of volume (cu.ft.), bole surface area (sq.ft.), and 

 bole length (ft.) can be used to predict yields when the wood is manufactured into a 

 wide variety of products. Furthermore, the conversion from the trio of primary units 

 to product yield is linear and additive. Consequently, sums of the volumes, surfaces, 

 lengths, and numbers of stems can be accumulated by species over many stands in a 

 population before the conversion is computed. 



Growth trends of the individual trees are of interest to supplement the stand 

 summaries described above. By following individual tree records through the cycles of 

 predicted growth, we can gain additional insight into the prognosis model. The second 

 output table shows the development of the five sample trees that occur at the boundaries 

 of the fractions of the initial diameter distribution (percentile). Species, d.b.h., 

 height, crown ratio, past diameter growth, and trees-per-acre associated with each of 

 the five sample tree records are shown, along with the relative density of the stand 

 (fig. IB). 



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