26 



CLIMATIC CYCLES AND TREE-GROWTH 



is desirable to see such studies applied to mature big trees and to 

 yellow pines, each in its natural home. 



Central tests — A recent test at the center of a sequoia came about 

 in this way. Stump numbered D-22, whose picture is shown in 

 Volume I, Plate 7, A, was sampled in 1918. It had over 3,000 rings, 

 but other innermost ones were missing on account of a large hole in the 

 center. The earliest ring found was 1087 b. c. The estimated radial 

 loss in wood at the center was 12 cm. (some 5 inches) or about 75 

 rings (Volume I, p. 52, table 5). The "butt" log from this stump was 

 lying not far away. In 1925, it appeared that in the upper end of this 



115 



95 



75 



55 



1 35 



I 



255 

 235 



215 ? 



195 £ 



I 

 o 



175 § 

 155 



135 



1850 60 70 80 90 1900 10 20 1850 60 70 80 90 1900 10 20 



YEARS 

 Fig. 2 — Sapwood rings in fallen sequoia; irregular growth after falling (in 1901) is shown with 

 distortion due to water-soaked condition. Scale X 7.5; horizontal line with each curve 

 represents 1 mm. growth 



log there was no hole and the rings originally filling the hole in the 

 stump might be found and measured at this point. So a special cut 

 was made crossing the center and extending a few hundred years 

 along the best radius. This direction proved to be away from the 

 original radius, but in the sequoias that practically never makes any 

 difference. This cut was 12 feet above the original cut. It was hoped 

 that the new piece would carry a record even beyond D-21, the oldest 

 of all the sequoias. But this wish was not fulfilled, although this 

 center v-cut proved very interesting. It cross-identified with perfect 

 ease and entire certainty. The central growth was in 1115 B.C. So 

 only 30 years were gained, but it thus carried a record back very nearly 

 as far as D-23 nearby, whose innermost complete ring was 1122 b. c. 



