Resistance to Decay of Fijian Timber — Osborne 
549 
as does Pseudotsuga menztesit . However, those 
species which are comparable with the highly 
susceptible Pinus radiata sapwood would be un- 
suitable for external use in humid climatic 
conditions, unless they were impregnated with 
a preservative. 
Specimens of almost 20 of the species in the 
present test are, or have been, in graveyard 
stake tests in Fiji. Although these tests are not 
complete some comparison can be made be- 
tween the laboratory and field results (Alston, 
1966). In general, there is good agreement be- 
tween the results of the two types of tests, the 
timber species ranking in approximately the 
same order, with only a few exceptions. Speci- 
mens of Garcinia myrtifolia, Palaquium fid- 
jiense , and Swietema macrophylla, when com- 
pared with the other timber species, all showed 
higher decay resistance in the laboratory tests 
than they did in the field tests. The reason for 
this discrepancy is not clear but could possibly be 
related to rate of wetting. S. macrophylla, al- 
though not native to Fiji, is an important 
plantation timber in Fiji, and it is therefore 
particularly important to note that for this 
species field test results are not as favourable 
as laboratory results. 
In conclusion, it should be stressed that the 
relationships obtained in the present tests for 
the tropical rain forest timbers of Fiji are very 
similar to those obtained for a group of com- 
parable timbers of New Guinea: notably, that 
less dense timber species tend to be more sus- 
ceptible to fungal decay, but, more particularly, 
that timbers which are highly water-absorbent 
are more susceptible. It is possible, therefore, 
that a knowledge of the density of a rain 
forest timber of which little else is known may 
be a rough guide to its durability. Again, a 
majority of trees was shown to have more 
durable heartwood in the outer zone than in 
the inner position, although the percentage was 
not as high as for the New Guinea timbers 
(70% cf. 86%). 
ACKNOWLEDGMENTS 
The author wishes to acknowledge the col- 
laboration of the Department of Forestry, Fiji 
in collecting material for this investigation, of 
the Royal Botanic Gardens, Kew in identifying 
specimens, and of Miss Nell Ditchburne in 
carrying out the statistical analyses. Thanks are 
due also to Mr. E. W. B. Da Costa for valuable 
discussion and to Mr. J. M. Stephenson and 
Miss Maureen A. Tighe for technical assistance. 
REFERENCES 
Alston, A. S. 1966. Natural Heartwood Dura- 
bility. Fiji Timbers and Their Uses, No. 2. 
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Da Costa, E. W. B., and Lynette D. Os- 
borne. 1967. Comparative decay resistance 
of 26 New Guinea timber species in accel- 
erated laboratory tests. Commonw. For. Rev. 
46(1) : 63-74. 
Findlay, W. P. K. 1956. Timber decay — a 
survey of recent work. For. Abstr. 17:317— 
327, 477-486. 
Hansen, H. N., and W. C. Snyder. 1947. 
Gaseous sterilization of biological materials 
for use as culture media. Phytopathology 
37 (5) : 369—371. 
Rudman, P. 1964. The causes of natural dura- 
bility in timber. Pt. 16. The causes of varia- 
tion in decay resistance in jarrah (Eucalyptus 
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and E. W. B. Da Costa. 1959. Varia- 
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in heartwood of Tectona grandis L.f. J. Inst. 
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Scheffer, T. C, and Catherine G. Duncan. 
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