STUDIES IN THE VEGETATION OF THE PHILIPPINES, I. 719 



which is now under cultivation or in grass, and that has physiographic 

 features similar to that of the Negros forest mentioned above had a 

 forest that contained a similar composition and volume. 



The forests of the Bataan and Port Banga regions on the other hand, 

 are handicapped by less favorable climatic and edaphic conditions. The 

 dry season is more pronounced and the topography is rough, in consequence 

 of which the bulk of the forest is much less and the composition is more 

 complex. 



Again, the delta plain of Mindoro, which has a climate similar to that 

 of northern Negros, during the. wet season is periodically flooded by rain, 

 whicli makes the soil excessively moist during a part of the year. The 

 volume of the forest is consequently much less and the forest inore 

 complex in composition. 



In temperate regions, generally speaking, the nearer success that 

 mature forest growth attains, the simpler the arboreal composition. From 

 the above the conclusion can be drawn that in this respect tropical virgin 

 forests are like those found in temperate zones. 



ECONOMIC CONSIDERATIONS. 



The economic aspect of the predominance of dipterocarp forests in 

 the Philippines is significant. The high percentage of the members of 

 one family, in many places approaching pure stands, and the comparatively 

 high bulk per unit of surface make lumbering on a large scale with 

 modern methods possible. In the previous tables the bulk per hectare 

 is given in cubic meters, regardless of whether the trees are sound or 

 decayed. Making liberal allowances for unsound timber the regions 

 investigated are conservatively estimated to run from 8,000 to 30,000 

 or more, board feet per acre. Individual acres will yield 100,000 or 

 more board feet. Including all species, the volume of the dipterocarp 

 forests in the Philippines is estimated to be about 200 billion feet of 

 lumber board measure. 



The impression is general that tropical forests yield woods that can 

 not compete with the coniferous woods of temperate regions. Fernow" 

 speaking of the lumber supplies of Australia, Brazil and other South 

 American countries states the following: 



*The valuable hardwoods of those countries, possessing excellent quality 

 besides their beauty, for which we use them at present, will never be 

 able to compete or supplant our own materials, for they occur in single 

 individuals scattered among hundreds of other species; so that to supply 

 any considerable quantity of any one kind requires culling over many 

 acres, which renders them too expensive for general use." 



What are the facts of the case as regards the Philippine forests? It is 

 true that with the exception of very limited stands of pine, the forests 



'Fernow, B. E. Economics of Forestry (1904) 34. 



