458 1'^^ Philippine Journal of Science nu 



bicolor (hamindang) , Macaranga tanarius (binunga), Mallotus 

 ricinoidea (hinlaumo), Mallotus moluccanus (alim), and Ficus 

 variegata (tangisang biawak). Up to this point the general 

 type of the vegetation on the cleared land in Bataan is very 

 similar to what has been described in Negros, although the spe- 

 cific composition is different, and the wild bananas are lacking in 

 Bataan. However, in Bataan this type is practically restricted 

 to the cutting area of the previous year, and disappears in 

 some of the older portions of this area. The areas which have 

 been logged for more than a year are all dominated by an erect 

 species of bamboo (Schizostachyum mucronatum) known locally 

 as 60^0 (Plate XI, fig. 2). Owing to heavy cutting or clearings, 

 this bamboo was scattered through the earlier cutting areas 

 before the company commenced its logging operations, and as 

 the original forest has been removed the bamboo has taken 

 its place. The flowering habits of this bamboo are not known, 

 but it probably spreads rapidly by means of underground stems. 

 When it enters an area where there are small second-growth 

 trees, it grows faster than they do and thus kills most of them 

 by shading (Plate XI, fig. 1.) This is particularly true of 

 Homalanthus populneus, which is a very small tree. This tree 

 is very scarce where the boho occurs, while Trema amboinensis, 

 a somewhat larger species, is relatively much more abundant. 

 Thus, mixed with the boho there are patches of second-growth 

 trees, old trees left from the original forest, and also rather 

 extensive patches of climbing bamboo. It is possible that, as 

 logging continues, the cutting area may be moved away from 

 the bamboo so fast that the latter will not be able to keep up 

 with it and that a second-groAvth forest will finally have a chance 

 to develop. If, however, the boho should seed, it could readily 

 enter the freshly cut-over areas and thus continue to dominate 

 all of the ground. As higher elevations are reached it may be 

 that boho will not be able to stand the environmental conditions. 



Most of the boho on the cutting areas is still immature, but 

 nearer the beach there are large forests of it which apparently 

 are practically mature. Here it occurs in large clumps from 

 3 to 4 meters apart and from 12 to 15 meters high (Plate XII). 

 Scattered in with this are dicotyledonous trees, but practically 

 no seedlings. 



In situations similar to those on which the forests of boho 

 occur, there are also extensive areas of second-growth forest. 

 From what has been observed in the recently cut-over areas, 

 it would seem that when there is a competition between the 

 boho and second-growth trees the latter largely disappear. 



