Cheeseman. — Age and Growth of the Kauri. 



17 



a tree, 5 ft. 11 in. in diameter, in which the disposition of the rings was 

 remarkably regular. 



Rate of Growth of Kauri-tree 11 ft. in Diameter, 

 measured on the narrowest radius (5222 in.) 

 from the pith to the circumference. (On 

 account of the scarf made in cutting down the 

 tree it would have been difficult to measure the 

 tree on the longest radius.) 



Rate of Growth of Kauri-tree 5 ft. 11 in. in Dia- 

 meter, measured on the radius of 35 92 in. 



Rings of Growth 



(equal to Years of Age), 



arranged in Groups 



of 25. 



Space in Inches 



occupied by each 



Group of Rings. 



Rings of Growth 



(equal to Years of Age), 



arranged in Groups 



of 25. 



Space in Inches 



occupied by each 



Group of Rings. 



25 

 50 

 75 

 100 

 125 

 150 

 175 

 200 

 225 

 250 

 275 

 300 

 325 

 350 

 375 

 400 

 425 

 450 

 476 



1-00 

 112 

 300 

 3-50 

 300 

 200 

 3-50 

 2-75 

 3-75 

 6-62 

 4-62 

 3-75 

 2-50 

 3-25 

 2-75 

 2-62 

 312 

 0-75 

 1-18 



25 

 50 

 75 

 100 

 125 

 150 

 175 

 200 

 225 

 250 

 275 

 300 

 320 



2-50 

 300 

 3-25 

 3-25 

 312 

 3-62 

 312 

 2-62 

 300 

 2-62 

 2-25 

 2-12 

 1-45 



Age of tree, 476 years. Average number 

 of rings per inch of radius (5 ft. 6 in.), 



7-2. 



Age of tree, 320 years. Average number 

 of rings per inch of radius (2 ft. 11 in.), 

 91. 



Comparing these two tables, the first point to notice is the great 

 difference in the rate of growth of the two trees during the first fifty years. 

 The 11 ft. tree produced only 2-12 in. of radius during this period, showing 

 an average of 23-6 rings per inch of radius ; while the smaller tree built up 

 5-5 in. of radius, with an average of 9-09 per inch, its rate of growth being 

 approximately two and a half times as great. But the rate of growth of 

 a young kauri probably depends very largely on how far it is crowded by 

 other trees. In support of this view, Mr. J. W. Hall, of Thames, has drawn 

 my attention to the different behaviour of two trees of equal age in his 

 plantation at Parawai (Nos. 5 and 6 of my tabular list). No. 5, planted in 

 an open situation, has formed 4-3 in. of radius in thirty-eight years ; No. 6, 

 much crowded by other trees, had only produced 2-8 in. in the same period. 

 The number of rings per inch of radius in these two trees works out at 8-9 

 and 13-5 respectively. 



The most interesting peculiarity disclosed by the ring measurement 

 of the 11 ft. tree is the enormous increase of growth which took place 

 between the 225th and 250th years, when no less than 6-62 in. of radius, 

 equivalent to 13-24 in. of diameter, was formed, being at the rate of 3-7 rings 

 for each inch. This is the largest rate of growth for a series of rings that 

 I have observed, although single rings are sometimes seen from half an inch 



