438 



The Philippine Journal of Science 



19U 



of the plateau. The soil, which is a deep, stiff, red clay, is rather 

 poorly drained. The forest lies some 6 or 8 kilometers to the 

 east of Laguna de Bay, and extends to the Pacific. The area 

 between the edge of the forest and the lake has been cleared to 

 permit cultivation. 



The climate throughout the area is very distinctly that of the 

 nonseasonal belt. The season of heaviest rain is from June to 

 December, but the northeast monsoon rising from the Pacific 

 over the rather abrupt elevation of the Pacific slope deposits 

 considerable rain throughout the balance of the year. During 

 the months from December to June the rainfall is heaviest on 

 the eastern side of the forest near the Pacific, becoming gradually 

 less toward the western edge of the forest. A rather heavy 

 bank of clouds lies over the forest at almost all periods of the 

 year, and is very evident on the horizon as the forest is ap- 

 proached over the cleared portion of the elevated plateau be- 

 tween the forest and the lake on the west. 



The forest is very distinctly dipterocarp in character through- 

 out the whole region. Due to the fact that changes in elevation 

 in the area are not appreciable, the composition of the forest 

 remains very similar throughout all parts of it. The dominant 

 story is composed almost entirely of dipterocarps, the two most 

 prominent being Shorea teysmanniana (tiaong) and Shorea 

 squamata (mayapis). Associated with these in the dominant 



Table VIII. — Stand table for 1 hectare {average of 6 hectares), northern 

 Laguna forest, showing number and volume of each species. 



[Volumes are grlven in cubic meters.] 



Species. 



Diameter class in centimeters. 



30. 



35. 



40. 1 50. 



1 



Trees. 



Vol- 

 ume. 



Trees. 



Vol- 

 ume. 



Trees. 



y^l-. Trees. 



! 



Vol- 

 ume. 



Shorea squamata (mayapis) 



Shorea teysma-nniana (tiaong lauan) . 

 Shorea polyspenna (tanguile) 



5.32 

 3.16 

 0.82 

 1.49 

 0.66 

 0.66 

 3.16 



2.56 

 1.55 

 0.41 

 0.72 

 0.32 

 0.32 

 1.55 



1.21 



1.15 

 1.82 



1.23 

 0.83 

 1.35 



12.83 

 7.32 

 1.14 

 1.98 

 1.82 

 0.33 

 1.15 



13.00 

 8.00 

 2.67 

 1.62 

 1.44 

 0.36 



8.66 



5.99 



. 2.65 



0.65 



17.75 



12.28 



6.36 



2.06 



LHpterocarpus sp (apitong) 



Pentaeme contorta (white lauan) 



Dipterocarpus sp (panao) 











0.16 



0.34 

 5.10 



Hopeapierrei (dalindingan isak) 



Total dipterocarps 



2.99 



2.03 



5.63 1 2,49 



15.27 

 7.82 



7.43 

 3.44 



7.17 

 4.32 



5.44 

 2.64 



26.57 32.72 20.60 

 13. 15 13. 16 3. 16 



43.89 

 6.10 



Total, all other species _- 





23.09 



10.87 



11.49 



8.08 



39.72 



45.88 



23.76 



49.99 





















