AGE OF KAURI TREES.

New Zealand Herald, Volume LXVII, Issue 20620, 19 July 1930, Page 14

AGE OF KAURI TREES.

Sir, —While the cross-sec'ion of kauri log at the. Winter Show is vtiry interesting it is misleading to the uninitiated as >t gives the impression that tho ago of a tree can be told by counting its number of rings. This is correct only so far as the period of growth is concerned. A healthy kauri tree, like everything vegetable or animal, has a period of vigorous growth, in which rings are formed. Tins is followed by a much longer period of maturity, in which very little growth takes place and few if any rings are added to its bulk. This in turn is followed by a long period of decline. For example, tako a kauri 'lft. thick. Its upright branches will make from 2ft. of growth in a season, with six rings to the inch, up to 10ft. with two or three ring' to the inch. As the tree gets toward maturity Jes® and less growth is made till 2in. to 6iu. on the main branches will be a seasons growth. Tn the period of recline, which is known by tho bark peeling from tho topmost spire, a tightenin ;-up pieces* takes place. The wood g-ts firm an hard and rings that were three to tne inch are now 12, and those that were are now 20 or more. \ot sui lcjcnt giowt ' is made to replace the fallen leaves am the tree becomes bald on ihe crown, t us gradually working down til! '.he last B'"'' leaf falls from the lowest branch, then death. The tree will now be very much less in girth than it was at the end of the first period. A cross-section ot sin a tree. 10ft. thick, shows an average ot It) rings to the inch a growing peno < dot) years. - Allowing twice this maturity and once tor dec*mo 1 3SJO years as the age of this monarcl a verv 'conservative estimate. 'I he section at tlie. Winter Show has grown on ruggc*. wind-swept country , t lie grain "l « > nnd would be dillicult to sp i • wood is hard and wel> matured A the rings are close the tightening uj. | , has taken place And its age miK J* put at anvthing over three times !.. g mg ppriod. Nothing but reniur.es of r. ful tabulated measurements -an determine the age and growth of kauri trees. ° Woodpecker ii