362 



GROWTH OF TREES IN DIAMETER 



TABLE LV 

 Short-leaf Pine, Louisiana 

 Growth by Diameter Classes 



Fig. 75. — Method of predicting 

 future growth of trees of differ- 

 ent diameter classes based on past 

 growth in diameter and harmon- 

 ized curves. Loblolly pine, La. 



These values can be evened off 

 as described for Table LIV (p. 360). 



This assumption of unchanging 

 future diameter growth is a make- 

 shift, inaccurate under most con- 

 ditions and not as reliable as the 

 method of comparison. But by 

 measuring the growth for two or 

 three periods, which for the pur- 

 pose are preferably shortened to 

 5 years so as to bring out any 

 recent tendencies of current growth, 

 the past growth of trees of each 

 diameter class may be used to pre- 

 dict future growth by means of a 

 curve drawn through these past 

 points (Fig. 75). 



The original data, and the re- 

 sultant prediction of growth are 

 shown in Table LVI. 



The advantages of this method 

 show most distinctly with even- 

 aged stands, in which case the 

 flattening out or termination of 

 the curve of the lowest diameter 

 classes occurs successively, and in- 

 dicates the death of these smaller 

 trees by suppression. 



