440 ^^6 Philippine Journal of Science isw 



puted from valuation surveys on 6 hectares at different points 

 in the area, are fairly typical of the stand in this forest. 



A review of Table VIII shows that this forest differs from 

 those previously discussed in that, although it is dipterocarp in 

 composition, it is a forest of smaller-sized trees and is very dis- 

 tinctly not overmature. Due to the elevation at which the forest 

 occurs and to the presence of rather heavy clouds over the area 

 at almost all seasons, the site as a whole is less desirable than 

 that of Negros for the development of a large forest, and the 

 result has been that although dipterocarps have claimed the area 

 almost to the exclusion of other dominant species they have not 

 been able to dominate it sufficiently to produce an even-aged 

 forest of but a few species. Each species in the area is rep- 

 resented more by trees of the smaller diameter classes than 

 by large overmature specimens. 



The main canopy is even more irregular and open than that 

 of tke better parts of the forest of Bataan, and this has resulted 

 in a very well-developed lower story and a dense undergrowth 

 (Plate VIII, fig. 1) . The undergrowth is made up almost entirely 

 of tree seedlings, to a very large extent of those of dipterocarps. 

 The excessively moist soil and high relative humidity furnish the 

 dipterocarps excellent conditions for germination, and over large 

 areas dipterocarp seedlings, particularly those of Hopea pierrei, 

 a meter or less in height, form dense thickets. 



As is true in all forests, certain patches may be found through- 

 out the area where the situation is more favorable to the develop- 

 ment of the predominant group, the dipterocarps, and in these 

 patches the forest approaches the overmature character of the 

 other forests discussed, but in no place does this become suf- 

 ficiently pronounced to necessitate serious consideration in the 

 management of the area. The data in Table IX, from a patch 

 of forest of 44,100 square meters, illustrate the best development 

 attained by the forest of this region. 



Certain portions of this forest lying within easy logging dis- 

 tance of large wood-using communities have been continuously 

 logged over for many years in a desultory manner with a 

 diameter-limit regulation of 40 centimeters. Practically the 

 only effect of this operation on the forest has been to reduce the 

 percentage of large specimens of the more desirable species, 

 such as dalindingan isak, macaasim, tanguile, and baticulin — 

 the dipterocarp character of the forest being little changed. 

 This is, of course, largely due to the fact that the logging itself 

 has been very selective in character and has not sought diptero- 

 carps as the main product. However, the satisfactory distri- 



