THE NEW ZEALAND 
JOURNAL OF 
AND 
TECHNO LO(j ' ) 
_ _____ opf\oi 
- - ■ _ ' : 
Vol. ill. Wellington, February, 1920. No. 1. 
SCIENCE 
U > B fi A 
RATE OF GROWTH OF TREES IN RELATION TO 
FORESTRY. 
A Criticism of Mr. E. Maxwell’s Paper. 
By Sir D. E. Hutchins. 
In the text-books a broad distinction is drawn between arboriculture (the 
study of individual trees) and forestry (the production of timber from the 
culture and grouping of trees in the mass). When a student takes a course 
in forestry at a university, the basic fact that he first grasps is that arbori¬ 
culture and forestry are distinct. In one the unit of growth is per tree, 
in the other it is the volume production of timber per unit of area. 
Actually the quality and quantity of the timber depends more on 
sylviculture than on the species concerned : thus the important Southern 
Timber Association of America has decided to throw the various pitch- 
pines together and classify by annual rings and cleanness of timber. This 
means that in the timbermen’s yards one of the slowest-growing of pines, 
longleaf ( Pinus palustris), ranks the same as Pinus heterophylla (Cuban 
pine), which is one of the fastest, rivalling, as I have shown in my 
report, New Zealand Forestry , just published, insignis pine in rate of 
growth, and producing a much better timber. 
There are two good reasons why in New Zealand there must be intro¬ 
duced trees more fast-growing than the native : (1.) There is the small 
area of New Zealand and its trees, set against the trees of the rest of the 
world having a climate not too far removed from that of New Zealand. 
As will be seen later, the position is somewhat similar in the British 
Isles, and to a less extent on the Continent of Europe. It is exactly 
similar in South Africa. (2.) Certain species coming from hard conditions 
of drought or cold in their native country, transplanted into the fertile, 
forcing New Zealand climate, will, for a time at any rate, show an extra¬ 
ordinarily rapid growth. Of such are the insignis pine, the common 
macrocarpa cypress, and Pinus Torreyana, the latter as yet but little 
planted. 
Mr. Maxwell is no doubt aware of the distinction between arbori¬ 
culture and forestry, but it is not clear that he has fully realized its import¬ 
ance ; for, after giving us his experience of the rapid growth of various 
1—Science. 
