volves a careful inspection of the trees and esti- 

 mation of the board footage or cordage, as the 

 case may be, of lumber which it will produce. In 

 the valuation of small timber tracts, all trees of 

 marketable size are measured if possible. How- 

 ever, for mass appraisal purposes of even the 

 smallest tracts this is often impractical. For this 

 reason some simpler method which will still 

 give a reasonable estimate must be followed. 

 The recommended procedure is to establish an 

 acreage value based on a typical acre in the 

 tract. To do this, a general review of a large 

 portion of the tract must first be made for de- 

 termination of species and average size of the 

 marketable trees. Sample areas of normal 

 growth and density can be selected, either small 

 measured plots (1/5 acre — circle with radius of 

 52.7 feet) or strips, and an accurate measure- 

 ment of the trees within these areas made as a 

 guide to valuation of the entire tract. Board 

 footage estimates may be made through meas- 

 urement of the diameter and usable height. The 

 diameter is measured at breast height DBH and 

 usable height from approximately one foot 

 above the ground (stump height) to about 

 where the trunk is broken by large branches or 

 where the minimum diameter is approximately 

 nine inches. 



The simplest method of measuring diameter 

 is by measuring around the tree and dividing 

 the circumference by three. (The exact division 

 is 3.1416; however, three gives an answer 

 within standards of accuracy.) 



There are several methods which can be em- 

 ployed in measuring the point at which the 

 maximum usable height of a tree occurs. One, 

 the point where the trunk either forks or is 

 broken by large branches has already been men- 

 tioned. Another method used by some estimators 

 is the formula (circumference in inches at BH 

 X .28) — 2" which will give the diameter inside 

 the bark at the top of the first sixteen foot log. 

 Deduction of two inches for each additional six- 

 teen feet of length will give the diameter at 

 the top of each additional log. For example, a 

 tree eighteen inches DBH (circumference 18 

 X 3.1416 = 56.5) is calculated as follows: 



(56.5 X .28) = 15.8 — 2 = 13.8" diam- 

 eter inside bark at top of the first 16-foot 

 log. At the top of the second log or 32 feet, 

 the diameter would be 13.8" — 2" or 11.8" 



One of the simplest methods of measuring the 

 usable height is based on similar isosceles tri- 

 angles. In measuring the height, a stick, slightly 

 longer than the arm (with arm fully extended, 

 end of stick should just touch eye) is held at 



arm's length in a vertical position. When at a 

 distance where the stump height of the tree may 

 be seen over the top of the hand, and the top 

 of the usable length of the tree can be seen over 

 the top of the stick, the distance from the tree 

 will equal the height of the tree. (NOTE: The 

 head should not be moved when sighting the 

 upper and lower limits of the tree.) 



The following sketch illustrates the use of 

 this method : 



AB and BC are equal, therefore, AY' and XY' 

 are equal. 



After the diameter and height are deter- 

 mined, the board content of the included trees 

 can be estimated by use of the following volume 

 table. This table is based on the average volume 

 in a large number of trees. The height is indi- 

 cated in half-logs or eight foot units. It is also 

 based on a minimum inside bark diameter of 

 eight inches top diameter. 



The following table may be used in estimating 

 the cordage obtainable from one acre of pole 

 timber. 



Diameter Number of trees to make one cord 



•") 

 6 

 7 

 8 

 it 

 10 



42 

 22 



14 

 10 



7 

 6 



In using the sample plot (1/5 acre) method, a 

 tally sheet which provides for recording the 

 diameters, heights and species of the trees in 

 the plot is necessary. Upon completion of the 

 measurements, the total number of trees in each 

 species of similar size are combined for easier 



37 



