IX, A, 5 Brown and Mathews: Dipterocarp Forests 465 



of undesirable weeds when a great amount of light is admitted 

 to the forest floor. 



Another condition which is appreciated as a defect both by 

 foresters and lumbermen is that the apparently very heavy stand 

 per hectare is often reduced in amount by excessive heart 

 rot. More or less defect always accompanies the development 

 of dipterocarp timber to a large size, and in the forest of 

 northern Negros where the bulk of the stand is in an over- 

 mature condition heart rot sometimes reduces the volume by 

 as much as 35 per cent. The presence of this defect in the 

 stand of timber can always be detected, but there is no pos- 

 sibility of determining its amount, except within very wide 

 limits. As a general proposition it is true that the heavier the 

 stand of timber the greater will be the percentage of defect. 



Passing now to a consideration of other dipterocarp forests 

 in the Philippines, namely, those of Bataan and northern 

 Laguna Provinces, we find that here the forest falls far below 

 the standard as represented by the managed forest of Germany. 

 Stand tables for forests of these two regions are given on 

 pages 433 and 438. Taking the forest of northern Laguna 

 as an example, we see that we have neither the same excessive 

 overmaturity that we have in the Negros forest nor the great 

 bulk. From the standpoint of the lumbermen the latter fact 

 is a very decided defect. However, looking at the forest from 

 the standpoint of the man who is to manage and reproduce it, 

 this forest presents a much easier problem than does that of 

 Negros, in as much as the total volume is distributed through 

 a smaller number of diameter classes and the bulk of the 

 volume lies in the intermediate size classes. The same statemeni) 

 may be made with reference to the forest of Bataan, where 

 the distribution by diameter classes shows a distinct concentra- 

 tion of volume at diameters of from 40 to 60 centimeters. 



Whitford ** emphasizes the fact that the best of our diptero- 

 carp forests approach purity of stand, when bulk alone is con- 

 sidered. He also brings out the fact that, if bulk is disregarded 

 and the number of species taken as the criterion, the family 

 Dipterocarpaceae is by no means so evident, as many species of 

 smaller trees are always present. From the standpoint of the 

 lumberman who desires to remove only the merchantable portion 

 of the stand, the presence of these small species is of little im- 

 portance. However, from the standpoint of the forester it de- 

 mands consideration. The dipterocarp forest contains many 



"This Journal, Sec. C (1909), 4, 699. 



