I.olll.oI.I.Y iHC NuKTIl I AKOI.I.NA T1XE. 63 



(,l;o\Y Til IN 1)1 \Mi 



Table 10 -ho\v- the average growth in diameter at breast height of all 

 .in -lies and over), the diameter growth of dominant trees in 

 fully stocked untliiiiiied -land-, the diameter growth of dominant tree- 

 in op. ii .-ian !>. an. I the nnniher of years required to grow one inch in 

 diameter. 



All the diameter mea-n:< Hiding tree-;, unless Otherwise 



stated, \\eie taken at a uniform height of 4 feet < inches from the 

 ground railed "breast height." Ilrea-thi^h mea-urements made outside 

 of the bark are a letter guide for determining the growth in diameter 

 than stuui| measurement-, as in this way the variations due to the 

 hi ight of the stump and butt swelling- are eliminated. 



It i- often desirable to convert diameter at stump height inside of 

 bark to diameter at hivast height outside of bark. This relation is 

 shown in Table 17. It ran be used in obtaining the breasthigh diameter 

 from stumps on rut-over land. (Also, see Table 8.) 



The culmination of the diameter growth often .takes place as early 

 as during the first decade and seldom later than in the fourth decade. 



Table 18 shows the diameter growth on stumps by decades for typical 

 groups on different sites. Column 1 shows the diameter growth of a 

 crowded group of loblolly pines mixed with hardwoods on moist stiff 

 clay soil. The growth in diameter does not culminate until between 

 the thirtieth and fortieth years; the growth is so persistent that at the 

 age of 130 years it amounts to nearly 1.5 inches for the decade. The 

 rate of diameter growth, however, is much less than that of the open 

 stand given in column 2, which shows a group of trees on loose loamy 

 soil on the edge of a pond, near Howard, Bertie County. It is an 

 excellent example of persistent and rapid diameter growth, the increase 

 between the eightieth and ninetieth years amounting to nearly 1.8 

 inches on the stump. Similar, if not better, results can probably be 

 obtained from all stands of Quality I, provided they are properly 

 thinned. (Plate IX, B.) 



