[Pboc. Roy. Soc. Victokia, 31 (N.S.), Pawt IL, 1919]. 



Art. XVIIJ. — 071 the Growth, IVeatvient and Structure of 

 some comiTRon Hardwoods. 



By R. T. PATTON, B.So. 



(Government Keisearch Scholar). 



(With Plate XXI. and Seven Text Figuies). 

 [Read I2th December, 1918]. 



One of the great surprises of the war has been the enormous, 

 consumption olj timber, but before the war the need of timber was. 

 great, and steps were taken in many countries to have supplies- 

 for future use. At the present time many believe we are faced witit 

 a timber famine in the near future, unless stepy are! taken to avert 

 it. But before we can do anything in the way of providing for the 

 future, and before we can make a definite working plan, we must 

 know what our forests are capable of yielding under efficient 

 management. 



In Australia we have no managed forests which we can study^ 

 and we have no forests of known age, and therefore in constructing, 

 any yield tables we have to devise some method by which we cai>. 

 arrive at approximate rates of growth, and from these construct 

 yield tables. 



Since the publication of my paper last year, on the rate of 

 diameter growth of Mountain Ash (E. regnans), a paper has beeii^ 

 published by the New South Wales Forestry Department on the- 

 ratei of growth of four species of Eucalyptus. 



I he method adopted by the N.S.W. Department is based on Sir- 

 William Schlich's method. An average tree is selected, and the 

 bole is cut into a numl;er of equal lengths, and the number of 

 rings counted at the end of each length. From these results graphs- 

 are constructed, Schlich's method is open to very serious objec- 

 tions. In the first place it is almost impossible to select an' 

 average tree for the purpose. In working on these trees one finds; 

 the greatest variation between two trees which externally 

 look similar. Again every variation of the single individual is-- 

 taken as typical of the forest as a whole, otherwise the study of a 

 single individual is meaningless. Tlie objection to this method" 

 is shown in Fig. 6 of Bulletin No. 13, N.S.W. Forestry Commis- 

 sion. A forest changes gradually, and lience any graph represent- 

 ing it must not show any irregularities. Another difficulty experi- 

 enced is that of countino- the rin<':s after about 90 vears. 



