IX. A, 6 Brotvn and Mathews : Dipterocarp Forests 543 



two or three days of sunny weather. Where second-growth 

 species occur in sufficient density to prevent the establishment 

 of a thick ground cover of succulent grasses and herbs, the 

 mineral soil is often sufficiently moist to furnish a fairly satis- 

 factory seed bed for some dipterocarp species. Such satisfac- 

 tory conditions are sometimes found where pure stands of Homa- 

 lanthus populnevs or Trema amboinensis exist in moist regions. 

 On burned-over areas at high elevations within the recent log- 

 ging area on Mount Mariveles, Bataan, such stands of Homa- 

 lanthus are claiming large areas. This species does not produce 

 such a dense crown cover as to prevent the development of 

 seedlings once they are established, and seedlings of Pentacme 

 contorta (white lauan) have been found entering such areas to 

 an extent of 1 to each 25 square meters within six months after 

 the area has been logged over. These areas of Homalanthus 

 thus give some promise of going over to a stand of Pentacme 

 contorta within a short period if Homalanthus is able to main- 

 tain itself, as Pentacme seedlings under such conditions grow 

 at a very rapid rate for dipterocarps. It must be said, how- 

 ever, that Pentacme contorta is the only species of dipterocarp 

 in Bataan which has shown the ability to seed in second-growth 

 forests. Although no other species of dipterocarp has been 

 found entering such areas, it must be remembered that the white 

 lauan has established itself by seeds alone. Since this species 

 is able to seed in naturally, it seems reasonable to expect that 

 other dipterocarps could be planted in the area with success. 



With most of our dipterocarps the rate of growth in youth 

 under the second-growth conditions, which are necessary to 

 make growth possible, is so slow and the cost of seed collection 

 and of the establishment of plantations is so great that from 

 the standpoint of a commercial planting operation the financial 

 returns which could be expected would not warrant the invest- 

 ment. In general, it is safe to say that if planting operations 

 are conducted in the Philippines at all the species chosen must 

 be ones like Tectona grandis (teak) , Pterocarpus indicus (narra) , 

 or Vitex parviflora (molave), which have already given a fair 

 measure of success in plantations and which are more suited 

 naturally to the conditions existing in the areas to be reforested. 

 Also, species such as these produce timber of a greater value 

 than do the dipterocarps and apparently grow more rapidly; 

 therefore, more money can be spent in the establishment of the 

 plantations with the expectation of a reasonable return on the 

 investment. 



