156 PHILIPPINES 



character. The great evaporation and rapid runoff produce con- 

 ditions which are not favorable to either dense growth, rapid 

 growth or great individual development. The traces are short 

 and far apart. Commercially, however, this has been and is an 

 important type because of its accessibility and the great demand 

 for the hard, durable woods Hke molave, narra, trudalo, acle, 

 banuyo, etc. Hence, altho the average stand under virgin con- 

 ditions is only 3M per acre the type has been heavily exploited. 



Mangrove Type. — ^Another type which has relatively low'stands 

 per acre but which has been heavily exploited by reason of its 

 accessibility and the special value of its products is the man- 

 grove type which fringes the shore line of protected salt waters. 

 The trees cannot stand heavy surf but form a low dense growth 

 in such relatively sheltered locations as the muddy flats at the 

 mouths of the larger streams. Under virgin conditions the stand 

 per acre has been found to run as high as 13M board feet of 

 saw limiber altho this included a relatively small proportion of 

 the trees. The type has been principally exploited for firewood 

 and for tanbark and stands of five cords per acre or 10 tons of 

 bark are not unusual. Growth is fairly rapid so that the same 

 area may be cut over for fuel and bark at intervals of at least 

 20 years. 



Pine Type. — Stands of pine averaging 7M per acre and made 

 up of trees 100 feet high and 30 inches in diameter occur in the 

 high plateau region of northern and central Luzon at elevations 

 ranging from 3000 to 5000 feet above sea level. The climate is 

 distinctly cooler than at se'a level so that growth is fairly rapid 

 in spite of the long dry season. Unlike many species of pine 

 these stands can stand considerable burning and are able to hold 

 then: own against the encroachments of the grass in spite of the 

 frequent fires. 



Beach Type. — On the sandy beaches above tide water which 

 have not been preempted for settlement and consequently had 

 their original vegetation much modified there are Kght stands not 

 exceeding 3M board feet per acre of such durable woods as ipil, 

 narra, dungon, palo maria and agoho scattered among less val- 

 uable species. 



