432 The Philippine Journal of Science isu 



point out such characteristics as are of interest from the stand- 

 point of management. Due probably to the pronounced dry 

 season and rough topography, the forests of Bataan are more 

 complex in composition than are the forests of northern Negros. 

 This is evident in the smaller size of the dipterocarps and in the 

 larger number of smaller-sized trees of other families which 

 enter the dominant story. The forest at various elevations is 

 dominated by different dipterocarps, although these various 

 species are represented at all elevations by scattered individuals. 

 Below 250 meters the forest is dominated chiefly by Anisoptera 

 thurifera (palosapis) , from 250 meters to 450 meters by Diptero- 

 carpus grandiflorus (apitong) and Shorea polysperma (tan- 

 guile), while above this Shorea polysperma is the commonest 

 dipterocarp in the forest. There are several other diptero- 

 carps scattered throughout the forest at all elevations, but in no 

 place do these dominate the forest. The most prominent of 

 these are Pentacme contorta (white lauan), Dipterocarpus ver- 

 nicifluus (panao), Hopea acuminata (dalindingan), and Shorea 

 guiso (guijo). At elevations of 450 meters and over, Pentacme 

 contorta occurs sometimes in sufficient numbers to give char- 

 acter to the forest, but at the same time Shorea polysperma is 

 present in larger numbers and is really the dominating species. 

 Guijo, dalindingan, and panao do not occur in sufficient numbers 

 to lend a distinctive character to the forest, and such other 

 dipterocarps as have been reported from the area occur so rarely 

 that they do not in any way affect the management of the area. 



The lower part of the forest, which lies below 250 meters and 

 in which Anisoptera thurifera is the predominant dipterocarp, 

 is more complex and less distinctively dipterocarp in character 

 than the forest of the next higher elevation. Thus, at low 

 elevations where the forest has been continuously logged for 

 many years the stand of timber is found to be an open irregular 

 one in which dipterocarps are predominant as to size but not 

 as to numbers. Due to the opening up of the area large numbers 

 of fast-growing species, such as Parkia timoriana (cupang), 

 Zizyphus zonulatus (balacat) , Albizzia procera (acleng-parang) , 

 and Lagerstroemia speciosa (banaba), have entered or become 

 more prominent, and over large areas an erect bamboo, Schizos- 

 tachyum mucronatum (boho), occurs in such profusion as to 

 give the forest anything but a dipterocarp character. 



However, as we proceed up the lower mountain slope we enter 

 a region which has been more difficult of exploitation for loggers 

 who depend upon the most primitive forms of transportation, 

 and we find the great body of the forest between elevations of 



