THE NORMAL KAURI FOREST, 83 
THE NORMAL CULTIVATED KAURI FOREST. 
—_—_—_— 
From REGENERATION TO THE FELLING OF THE MAIN Crop. 
Density of a Kauri Forest. 
In ordinary Kauri forest there may be seen small patches of five 
or six trees—‘‘ Kauri trees of the future ’’—with diameters not much 
above 2 f{t., standing at about 8ft. apart. These spread out above the 
lower story of forest and get the space which the Kauri (silviculturally 
a light-demander) requires. The lower story, of Tawa, Taraire, &e., 
will grow just as close, also often in patches. But between these 
patches, over perhaps three-quarters of the area, there will be nothing but 
useless undergrowth. One can perfectly reasonably suppose a stocking, 
at age 100 years, with trees averaging 12 ft. apart, or 302 trees per 
acre, of which 150 trees might be Kauri and 150 trees Totara, Rimu, 
White-pine, Taraire, Tawa, and inferior species; or such larger pro- 
portion of Kauri as silviculturally the forester may find correct. 
Number of Kauri Trees required at Regeneration. 
If there were an average of 200 Kauri standards per acre at regenera- 
tion, one could count on 150 surviving at age 100 years. Thus the 
‘* working-plan ’’ should require a minimum of 200 young Kauri trees 
before considering regeneration complete, planting where necessary to 
make up the 200; and for the inferior species perhaps as many as could 
be got without incurring the expense of planting. Where this number was 
less than 100 the planting of Rimu, Totara, Puriri, Celery-top, White- 
pine, and perhaps Tawa or Taraire, to make up the 100 could be pre- 
scribed. Of these species, Rimu might give some trouble to plant (though 
it did not on a small scale in South Africa), while the rest would 
be easy. 150 stems of the “‘ Kauri tree of the future’’ (p. 74) would 
cube 118 c. ft. x 150 = 17,700 c. ft. (gross cubage in the round), 
while the yearly yield-figure (acrim) of 100 co. ft. g.g. assumed 
(p. 98) requires only 12,500 c. ft.* to be provided for. It will be asked 
why is there so large a margin between 12,500 c. ft. estimated yield, while 
the trees, if they all matured, should give 17,700 c. ft. of Kauri and about 
half that of secondary species, or some 26,550 ft. altogether? The answer 
is that though these trees would be in the position of standards in their 
youth, as they grew up they would gradually get into the positions of high 
forest, when the weaker ones, the badly grown ones, and the inferior 
species would go out in thinnings. It is the Kauri reserves (p. 86), and 
these thinnings towards the end of the first rotation of 100 years, which 
have to be depended upon to make up the average acrim of 15 e. ft. q-g. 
of Kauri and 20 c. ft. q.g. of other timbers (p. 96, ‘‘ Balance State- 
ment ’’). 


* 12,500 c. ft. = 10,000 cubic feet quarter-girth, which is the normal “ stand’? at 
the end of 100 years. 
