IX, A, 6 Brown and Mathews: Dipterocarp Forests 455 



grasslands there is usually a greater diversity of tree species 

 than on cleared lands. 



As the second-growth forest increases in age it becomes denser, 

 owing to the fact that the trees which grow up in it are likely 

 to be more tolerant of shade than some of those forming the 

 first stand. If the forest is not situated near a dipterocarp 

 one, it will continue to be composed of small trees of little or 

 no value in the production of lumber and only a small propor- 

 tion of which will make even good firewood. 



Despite the fact that the trees of the second-growth forest 

 are not valuable, the growth of such a forest on grasslands 

 is a decided practical advantage. The tall grasses of the grass 

 areas are coarse, and do not make good forage for animals. They 

 serve as feeding grounds for swarms of locusts, which every 

 year do great damage to cultivated crops, particularly rice, 

 sugar cane, and corn. The soil of grasslands, moreover, is very 

 unproductive, while it is much easier to put under cultivation 

 land in second-growth forest than that covered by grass, as the 

 roots of the latter are exterminated only with great difficulty. 



From a consideration of grasslands and second-growth forest 

 it is evident that if a dipterocarp area is to be kept as such, 

 it must either be logged in such a manner that the forest is not 

 destroyed or the area subsequently must be replanted. Both 

 of these methods will be discussed later. If the influence of 

 man were removed from the Archipelago, the grass areas would 

 grow up into second-growth forests and the dipterocarp forests 

 would gradually, in the course of centuries, occupy most of these 

 areas. However, this fact is of little importance from the 

 standpoint of practical forestry, as the time required would be 

 many centuries. 



The development of second-growth forests is, with the same 

 treatment, remarkably uniform over the entire Archipelago. 

 There are, however, certain minor variations. It seems wise 

 at this point to describe briefly the successions on the cut-over 

 areas of three of the forests already described, as illustrating 

 different courses of development under different conditions. 

 These results will be of interest later in connection with the 

 problem of management. 



CUT-OVER REGION IN NORTHERN NEGROS 



A lumber company has been operating for a number of years 

 in the forest previously described as occurring on the banks 

 of Himugan River in northern Negros. Trees under 50 centi- 



