212 PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 



are situated at an altitude of 3,000-4,000 feet, and the 

 climate is therefore temperate. They only differ in general 

 character from those at lower levels further north, where the 

 climate is suhtropical, in containing less undergrowth. The 

 less luxuriant types of rain forest often grow in poor soils, 

 especially where the rainfall is high. This fact is exemplified 

 at places such as flyer's Ferry, south of Southport, where 

 a rain forest of the lighter kind flourishes in the sandy soil 

 adjacent to the ocean beach. The soil in this and similar 

 localities is composed of grains of silica in very high pro- 

 portions, and plant food must be present in low percentages. 

 In cases of this kind it appears obvious that a heavy rainfall 

 {oD inches in this instance) is a very decisive factor in , 

 determining the character of the forest. On the other hand, 

 in localities where the soil is fertile a rain forest of the 

 lighter type is generally the result of a light rainfall. These 

 conditions are seen in the light rain forests in the neigh- 

 bourhood of Theebine (Kilkivan Junction), where the 

 average annual rainfall is 40 inches and where the fertility of 

 the soil is exhibited by the good crops grown in the felled 

 areas. 



SIZE OF KAIN-FOREST TREES. 



Queensland rain-forest trees do not often exceed 160 

 feet in height and 6 feet in barrel diameter when measured 

 above the basal flanges or plank buttresses. The fig trees 

 {FicHS spp.), Queensland kauri pines {Agathis spp.), scrub 

 box (TrislMuia conferta), and some species of Eucalypts 

 .such as the messmate (Eucalyptus Cloeziana) and the 

 flooded gum {E. saligna), when growing in the luxuriant 

 rain forests sometimes exceed 6 feet in barrel diameter. The 

 Eucalypts which sometimes grow in the rain forests or on 

 their margins often exceed the true rain-forest trees in 

 height, but they do not grow beyond 200 ft. in height, so far 

 as the writer is aware. The common form of rain-forest tree 

 has a long barrel bearing a shorter canopy of branches and 

 foliage. In .some cases the barrels attain 80 or 90 ft. in 

 height before they branch. In the light rain forests the size 

 of the trees is sometimes reduced so that the general height 

 is brought down to about 40 or 50 feet, and the barrel 

 diameter of the larger trees to 12 or 18 inches. 



