71.^ 



WlllTFOKI*. 



;rM.MAi;Y of stand and voumi:. 



The following is a f;uininaiv of the stand and voliiiiR' tal)les given in 

 this paper. 



I'tr cent of Diptcr- 

 ocarpareae by- 



Stand. I Volume. 



Province. Luzon: 

 Liinar .._ 



Mindoro: 



Narra type 



Ilagacliac type 



Ncgros 



Zaniboanga, Mindanao: 



Yacal type. „ 



Lallan type 



Samal Island, Mindanao . 



Lcyte 



Masbate 



33.11 

 41.. 50 

 89.4 



43.7 

 45.86 



53.70 

 66.00 

 95.00 



47.00 

 46.3 



It will be seen from the above that from 33 per cent to 89 per cent 

 of the stand and 46 per cent to 95 per cent of the volume of these forests 

 are composed of species of the Dipterocarpaceae. It is estimated that at 

 least 75 per cent of the present virgin forest area comprising some 40,000 

 square miles is of like nature. Such a forest has been found in practically 

 all classes of habitats from sea level to an altitude of approximately 900 

 meters on the largest mountain masses. "Within these forests, to be sure, 

 there are local conditions such as character of soil, steepness of slope, 

 exposure to severe atmospheric conditions, and those due to artificial 

 interference, that do not favor dipterocarps at the present time. However, 

 the vegetation in many of these situations is only transitory in nature 

 and may be considered as stages in succession toward some form of the 

 most successful forest, viz, the dipterocarp forests. As mentioned here- 

 tofore it is not the intention to discuss in this paper the different types, 

 nor the different stages of succession. Briefly it can be stated that a 

 representative of a climax forest is found in Negros where the bulk reaches 

 about 429 cubic meters per hectare of wood. Here it is believed that a 

 combination of edaphic, climatic, and biotic factors have, reached the 

 optimum necessary to the establishment of most successful growth in 

 the Philippines. The climate is uniform as regards temperature, and 

 with the exception of a short dry season interspersed with showers it 

 is fairly uniform as regards humidity and rainfall. Tlie topography is 

 composed of gentle slopes so that the soil wash is not great nor in the 

 rainy season is there an accumulation of excessive moisture in the soil. 

 It is probable that originally a greater part of the area of the Philippines 



