584 



Forestry Quarterly, 



VoivUME OF Trees 40 Centimeters and Over in Diameter 

 In Batan Province, Luzon 



Average of 50 hectares [124 acres] ). 



Total 



285.2 28,520 



Tanguile-oak type. — The forests of this type cover the area ex- 

 tending from the upper limits of the lauan and lauan-apitong types 

 to the lower limits of the mossy-forest type in the higher portion 

 of the mountains. They have not been studied in great detail, 

 and more extended investigations are necessary to determine 

 whether more than one type exists or not. When such studies 

 have been made in many parts of the Islands, it may be found that 

 there are a number of distinctive types instead of the one here 

 considered. In the meantime, the provisional name of tanguile- 

 oak type has been adopted. Its lower limits are from 400 to 500 

 meters (1312 to 1640 feet) above sea level, and extends upward 

 to a height of between 800 and 900 meters (2624 to 2952 feet). 

 The topography is such as is usually found on mountain sides, 

 gentle to steep ridges and slopes alternating with deep ravines and 

 gorges. The evergreen character of the forests and actual meas- 

 urements show that rainfall is more evenly distributed throughout 

 the year, and the relative humidity is constantly higher than in 

 the adjacent forests of the lower altitudes. 



