FAST GROWTH.

Auckland Star, Volume LIX, Issue 69, 22 March 1928, Page 8

FAST GROWTH.

BUT BOOR QUAIXTY.

IMPORTANT TESTS OP TREES.

(Special to -Star.")

WELLINGTON, this day.

It is a well-known fact that exotic trees grow in New Zealand much faster than in their original habitat. This point is of importance in connection with the extensive development of afforestation in the Dominion. That rapid growth must not be too mnch encouraged has been demonstrated by the State Forest Service, which has made tests of the strength and physical properties of redwood, an important variety for commercial forestry work in New Zealand. Comparisons have been made fin! »| a specimens of redwood grown in New Zealand, and the same timber produced for export from America, and some the results are important in their application to afforestation.

The tests lasted over a period of years, and two classes of New Zealand' grown redwood were dealt with. Out supply consisted of 21-year-old fastgrown redwood from a mixed plantation of larch and redwood growing at Whakarewarewa, near Kotorua, and set of specimens tested came from 40-year-old trees in a mixed stand of in. >ijrnis pine and redwood growing in the Botanical Gardens, Wellington. Both New Zealand timbers were contrasted with American-grown redwood, with these results s—

The fast-grown Rotorua trees save strength values very much below thorn of American redwood. While the rate of growth at Rotorua was 10 times aa fast as that of the American trees, the main strength values were only one-sixth of the American. The Wellington trees, grown more slowly, proved under test that this variation in conditions had an important influence of their use-value, the Wellington specimens, twice as old, and twice as slowly grown as the Rotorua material, proving under test to be almost four times as strong, and approximately two-thirds of the strength of the American specimens.

These results have been set out in sn official bulletin from the State Forest Service, and the conclusions noted are: "The results obtained from the locallygrown redwood prove that, unless the sivi cultural conditions are correctly regulated, a very inferior class of 'timber will be produced. If, however, the condition 8 of growth are satisfactory, it has been proved that a timber can'be produced having very similar properties to the valuable American redwood of commerce."