580 Forestry Quarterly. 



sequently a regular profile. On its borders and in natural or arti- 

 ficial openings, lianas grow in great profusion, but while lianas oc- 

 cur within the forest itself, they are reduced to a minimum in 

 numbers, and especially in size, because of the dense prevalent 

 shade. The forest floor contains a very scanty growth of herb- 

 aceous vegetation. The undergrowth of the forest is not an im- 

 penetrable jungle. One can pass through it in all directions, en- 

 countering difficulties in the way of obstructive vegetation only 

 in artificial or natural openings where light permits the jungle 

 growth. In short, the dominant trees, nearly all dipterocarps, 

 form and maintain a successful forest of trees, which produce a 

 shade so dense as to crowd out many light-demanding species. 

 These are either forced to the edge of the forest, or else exist in 

 the interior in a sickly condition, awaiting as it were the chance 

 entrance of light to permit them luxuriously to fill up the opened 

 space. Stripped of its ornaments of palms, lianas, epiphytic or- 

 chids, and ferns, whose importance is exaggerated in the eyes 

 of the inhabitants of the temperate regions, the lauan type bears 

 striking resemblance to the commercial forests of the temperate 

 zone. In simplicity of composition of the dominant trees, and 

 in volume of wood produced, it approaches in value the famous 

 coniferous forests of the more northern latitudes. 



It is not possible to estimate the area that this type of forest 

 occupies. It covers a very large part of the entire forests, and 

 probably formerly occupied extensive areas which are now in 

 cogon or second-growth forests, or under cultivation. 



Lauan-hagachac type. — This type, like the preceding, is con- 

 fined to regions where the dry season is short or wanting. It is 

 restricted to areas where the water level is near the surface of the 

 ground, reaching its best development in river bottoms, especially 

 on slightly raised deltas, and often extending in narrow strips 

 along the smaller streams through the lauan type, in which latter 

 situations it is often difficult to distinguish. 



In composition it dififers from the previous type mainly in the 

 presence of hagachac (Dipterocarpus affinis) and a much larger 

 number of co-dominant species of other families. The volume 

 of timber is seldom equal to that of the lauan type. The follow- 

 ing table is an estimation of the volume of a forest of this kind. 



