The Forests of the Philippines. 589 



a merchantable length of 18.3 meters (60 feet). It is estimated 

 that the swamps of the Islands will show an average volume of 

 20 cubic meters per hectare (2000 board feet per acre) of trees 

 over 20 centimeters (8 inches) in diameter, and if, as is usually 

 the case, the branches and large twigs are used, this amount will be 

 exceeded. 



The forest itself has rather an even top profile. The canopy 

 is fairly well closed, and the forest is practically clear of under- 

 growth, except at its inner edge. The presence of a complex sys- 

 tem of stilt roots, as high as 3 meters (10 feet) and wide spread- 

 ing, of the two species of Rhisophora presents a tangle through 

 which one can make his way with difficulty. A number of the 

 species, such as pagatpat and api-api, show characteristic aerial 

 roots. The leaves of all are hard and leathery in texture. The 

 seeds of the Rhizophoraceas begin to germinate on the trees, finally 

 drop, and are distributed by the tides until they find a favorable 

 lodging place, where they continue their development. 



Beach Type. 



Sandy beaches above high-tide limits are found throughout the 

 Philippines. They are favorite places for settlements and so the 

 original vegetation has been greatly modified. In those places 

 where it has kept its original form, it presents a distinct type. 

 Usually the frontal zone has a tangle of vegetation in which pan- 

 dans (species of Pandanus) form a conspicuous part. The princi- 

 pal trees are as follows: Talisay (Termiiialia catappa), dapdap, 

 (Erythrina indica), botong (Barringtonia speciosa), mulbago 

 (Hibiscus tiliaceus), bani (Pongamia glabra), banalo (Thespesia 

 populnea), dongon-late, palo maria (Calophylluni inophyllum), 

 agoho (Casitarina equisetifolia), tawalis (Osbornia octodonta), 

 and Dantigi (Pemphis a idula). In some places ipil, narra, bansa- 

 laguin, and other valuable trees are encountered. Talisay often 

 occurs in patches of pure stands in rich river bottoms. On sandy 

 flood plains of large rivers, in various parts of the Islands, agoho 

 often forms small pure forests. 



Behind the frontal line, the vegetation partakes more of the 

 nature of other types. Series of old beaches sometimes cover 

 quite extensive areas, on which the lauan-hagachac type usually is 



