3886 Philippine Journal of Science 1920 
prominence in the markets, but the number of species that are 
of no value for lumber is so much greater that the timber trees 
seem few in comparison. On any given tract the merchant- 
able kinds of trees are not likely to exceed twenty. While a 
tract may contain two hundred tree species, nine-tenths of them 
will be of species that never reach a size suitable for lumber. 
Whitford says that “the largest tree measured to date shows 61 
meters (200 feet). Very few species will reach a diameter 
of more than 180 centimeters (6 feet), measured above the root 
buttresses.” 
The species of trees in the Philippines and in the Tropics in 
general are very different from those of temperate-zone forests. 
Conifers appear only with elevation. In the Philippines the 
pine type of vegetation is estimated to be only 5 per cent of 
the total forested area; it is confined to parts of Luzon and 
of Mindoro. 
A very large area of the forests, about 75 per cent, is charac- 
terized by various species of dipterocarps. The trees of this 
family yield a great variety of commercial wood suitable for 
many purposes. Whitford says: 
Throughout the work [Whitford’s book] emphasis has been laid on the 
importance of the dipterocarp family; for in spite of the richness of the 
Philippines in fine furniture wood, the real wealth of their forests consists 
of construction timbers, such as are represented by the lauans, apitongs, 
and yacals—all belonging to the dipterocarp family.” It is estimated that 
the dipterocarps include about 144 out of a total of the 200 billion board 
feet of standing timber in the Islands. Not only is the total amount 
great, but the members of this family occur in stands sufficiently heavy 
to be exploited by the use of machinery. The predominance of this 
family needs emphasis because it is the general belief that the Philippines 
and the Tropics in general produce only wood of the mahogany and teak 
grades. [p. 9.] 
Whitford recognizes six major types of forest, each of which 
is characterized by certain tree species. In abstracting the 
characters of these types as given by Whitford I have omitted 
much of the detail and have treated his five dipterocarp types 
as one. I have also arranged the types in what seems a logical 
order, beginning with the mangrove and ending with the mossy 
forest. Each of the six types is characterized by certain con- 
spicuous species of plants. There are forests that do not have 
the characters of any one type, but in general these divisions 
“See Foxworthy, F. W., Philip. Journ. Sci. § C 6 (1911) 231-287, pls. 
34-44, and 13 (1918) 163-197, for the classification of Philippine dip- 
terocarps. 
