1919.] Maxwell. — Growth of Trees in New Zealand. 373 
There may be instances, where the native forest occupies poor and 
extremely rough areas, and where the continuous maintenance of the forest 
covering is essential for climatic and other reasons, in which it might answer 
to maintain such as a forest for production of native timber, assisting natural 
regeneration ; but even in such cases it is hard to believe that from an 
economic point of view it could possibly be profitable to wait 174 years 
(vide Cheeseman’s article) to grow a kauri 3 ft. in diameter, when a red¬ 
wood would grow the size in 35 years. For, even taking the monetary 
aspect and leaving out of count the fact that we cannot afford, for many 
reasons, to wait such a time, if, allowing an absurd margin in favour of the 
kauri, it would produce the same quantity of Timber in 100 years as the 
redwood would in 35, the position would be as follows (charging no cost 
for establishment against either, but 8s. per acre per annum to cover all 
annual costs, including value of land, rental, fencing, fire-protection, &c.): 
Kauri, 100 years at 8s. per acre per annum, compounded at 4 per cent., 
£495 ; and redwood, 100 years at 8s. per acre per annum, compounded at 
4 per cent., £29 9s. 
Cheeseman says in the last paragraph of his paper on “ The Age and 
Growth of the Kauri/’* “ Although the kauri is not so excessively slow 
in its growth as has been supposed, it is much slower than most trees of 
economic value. A tree of 2 ft. in diameter would have an average age 
of 116 years ; one of 3 ft., 174 years ; and one of 4 ft. would be 232 years 
old. Periods like these are much too long to offer any hope of monetary 
return from the planting of kauri even if there were not other reasons to 
advance against such an undertaking.” 
The information with reference to the redwood, contained in table F, 
is very remarkable in that it shows extraordinary evenness in rate of 
growth of all trees measured, notwithstanding the considerable difference 
in climatic'conditions under which they have grown and the difference in 
age. Measurements are of trees in the Wairarapa, at Tauranga, and at 
Rotorua, and of ages from 16 to 35 years. The averages of years to 12 in. 
of diameter are, for the different places, 13-99, 13-68, and 13-21. This 
fact and the great rapidity of growth under dissimilar climatic conditions 
indicate, so far as the writer knows, for the first time that the redwood 
is destined to play a very important part in future forestry operations in 
this country. 
Note regarding Measurements .—All measurements made by the writer 
for the purpose of finding the rate of diameter-growth of standing trees 
were made 4 ft. from the ground, of felled trees 4 ft. from the butt, and 
of mill-logs at the lower saw-cut. 
For the purpose of ascertaining the degree of taper the writer made 
measurements at every 10 ft. from the butt to the end of the stem. In a 
number of cases trees cut into mill-logs were measured at every saw-cut. 
The computations of rates of diameter-growth from data such as con¬ 
tained in Mr. Cheeseman’s paper and the work of the late Mr. W. N. Blair, 
are, of course, mostly from the number of annual rings to the inch. 
Height-measurements : The writer made exact measurements, at every 
opportunity, of trees felled for milling purposes and of trees brought down 
by gales, such as at Mokoia, where a number of trees planted in 1878 were 
brought down by a gale in 1917. Measurements of standing trees were in 
some instances made with the aid of an instrument, in others were judged 
by various methods of estimating. 
* T. F, Cheeseman, Trans. N.Z. Inst., vol. 46, pp. 9-19, 1914. 
