IX, A. 6 Broivn and Matheivs: Dipterocarp Forests 545 



(d) accurate data concerning the rate of growth of each species. 



The application of these conclusions to the problem of manage- 

 ment presented by the various forests which have been discussed 

 in this paper may now be briefly considered. Taking up first the 

 forest of northern Negros, which probably presents as difficult 

 a problem as any dipterocarp forest in the Islands, we find the 

 problem to be that of removing within the shortest possible rota- 

 tion a large amount of accumulated wood capital which is not 

 producing, but is perhaps deteriorating due to fungus and insect 

 attack and which is, nevertheless, so integral a part of the forest 

 that its removal endangers the very existence of the forest. 



One of the chief difficulties which stands in the way of satis- 

 factory management of such a forest is a utilization difficulty; 

 and this is due to the large size of the trees, which makes steam 

 appliances necessary for the removal of the crop. Steam logging 

 calls for large investment per unit of area, and to pay interest 

 on this investment and leave a reasonable profit for the investor 

 a large amount of timber per hectare must be removed. In order 

 to meet this necessary demand on the part of the investor, such 

 forests have in the past been regulated by a 50-centimeter diam- 

 eter limit in the hope that such a diameter limit would allow 

 the lumberman to remove the amount of timber necessary to 

 give him a return on his large investment and at the same time 

 retain sufficient timber on the ground to maintain forest condi- 

 tions and insure reproduction. The results have not been satis- 

 factory, and instead of having a regulation which leads to the 

 limitation of the cutting we have had practically a system of 

 clear cutting without any regulation whatever. 



The utilization problem, together with the necessity of remov- 

 ing the large amount of timber which has accumulated on the 

 ground and is past maturity and which in the future will become 

 less and less valuable, seems to indicate that clear cutting will be 

 the only system which can be practiced. Were the planting of 

 dipterocarps a practical proposition, a clear-cutting and planting 

 system would be preeminently the most desirable. Planting is, 

 however, entirely out of the question, and likewise any of the 

 systems which call for the existence, after logging, of a shelter 

 wood over the entire area seems impracticable. Clear cutting 

 with natural reproduction from the side seems to hold out some 

 promise of success. 



We may, therefore, consider what form of clear cutting will 

 prove the least disastrous to our forest. The clear cutting over 

 large areas, which has followed the application of an erroneous 

 diameter limit, has already proved an entire failure. This has 



