582 



Forestry Quarterly. 



cupied by it is very limited in extent. In thickly settled agricul- 

 tural regions it has been entirely destroyed. 



Yacal-lauan type. — This type finds its best development in 

 regions where the dry season is short, on low coastal hills whose 

 basal rock is volcanic in structure. It occurs on headlands pro- 

 jecting into the sea, especially those at the heads of embayments. 

 These headlands usually have drier soils, lower relative humidity, 

 and less rainfall than the region back of them. It also occurs on 

 the hills bordering large river valleys that have approximately the 

 same physical conditions. 



This type, in contrast to the two dipterocarp types above men- 

 tioned, has a slight deciduous appearance during the driest por- 

 tion of the year. As it has a large number of codominant species, 

 it more nearly resembles the lauan-hegachac than the lauan type. 

 Erect palms are scattered throughout the forest, although they are 

 not nearly so numerous as in the previous mentioned dipterocarp 

 type. Climbing palms and other lianas are present, but are not es- 

 pecially abundant except in open places. The following is an 

 illustration of the volume of a fair sample of this type of forest 

 in Mindanao. 



Volume of Trees 40 Centimeters and Over in Diameter 

 In the Port Banga Region, AIindanao 



(Average of 51.17 hectares [126 acres] ). 



Volume 



Scientific name Common name 



Dipterocarpaceae : 



Hopea plagata Yacal 



Pentacme contorta White lauan 



Parashorea plicata 



Dipterocarpus sp. 



Shorea guiso 



Vatica sp. 



Shorea squamata 



Shorea furfuracea 



Vatica sp. 



Hopea sp. Malay acal 



Total Dipterocarpaceae 



per 



hectare 



{cubic 



meters) 



} 



Bagtican-lauan 



Apitong 



Guijo 



Kalunti-lauan 



Mayapis-Iauan "1 -. 



Almon-lauan \ . 



Narig 6.14 



50.37 



26.02 

 12.05 

 16.80 

 12.34 



Stand 

 per acre 

 {board 

 feet) 



5.037 



2,602 

 1,205 

 1,680 

 1,234 



946 



614 

 283 



136.01 13,601 



2.83 



