THE TREE AND ITS FORMS. 



29 



GROWTH. 



The hickories are comparatively slow-growing, especially the true 

 hickories. Pecan grows rather rapidly, is long-lived, and is persistent 

 in its growth; the bitternut grows rapidly at the start, though it rarely 

 reaches large size. The true hickories, however, are even slower-grow- 

 ing than white oak. A 200-year-old white oak growing under the 

 same conditions of light and soil as a shagbark or pignut of the same 

 age often will have almost twice the diameter and will yield from two 

 to four times as much .merchantable material. No growth figures 

 were secured for pecan, water, or nutmeg hickory, since they are unim- 

 portant commercially, and no cuttings were found. Figures for the 

 other species were taken for typical situations in five different regions. 



As previously shown, the hickories are generally suppressed in early 

 life. Therefore, to secure figures that would be applicable to trees 

 grown under forest management, the periods of suppression have been 

 disregarded in the preparation of Table 3, which gives the time 

 required for a normal tree to increase 1 inch in diameter. 



TABLE 3. Time required by trees of various diameters to make 1 inch of diameter growth. 



