542 The Philippine Journal of Science i9u 



better suited to the conditions. This is probably truer of dip- 

 terocarps, which in youth require shade and moisture and are 

 of relatively slow growth, than of many other species. Like- 

 wise, it is truer on grasslands and in the open than in second- 

 growth areas or in openings in a high forest. Plant associa- 

 tions on cleared land throughout the Islands have already been 

 discussed, and it has been shown very clearly that the conditions 

 which exist on cleared lands, especially if those lands are of 

 considerable extent, are most unsuitable to species of the family 

 Dipterocarpaceae. 



PLANTING IN GRASSLANDS 



Attempts at the direct installation of dipterocarps in grass 

 areas must be expected to meet with failure. The moisture con- 

 ditions which exist in grasslands are unfavorable, while the 

 competition with the grass, with its dense mass of underground 

 stems, is greater than any dipterocarp which has so far been 

 studied can withstand. It is probable that only one of the dip- 

 terocarps growing in the forests discussed in this paper would 

 show as much as 1 per cent living at the end of a year, if planted 

 directly in such situations. This one exception which might 

 meet with some measure of success is Pentacme contorta (white 

 lauan), several seedlings of which have been found growing in 

 open second-growth areas. But taking into consideration the 

 high death rate of such species as Pterocarpus indicus (narra) , 

 Vitex parviflora (molave), and Albizzia procera (acleng-parang) , 

 which are among the species most suited to these conditions, it 

 is doubtful if even white lauan could succeed, and it is certain 

 that from a practical standpoint such planting of most dipte- 

 rocarps would be a failure. If it ever becomes desirable to 

 reforest grasslands with dipterocarps, cultural operations lead- 

 ing to the establishment of a second-growth forest must be 

 undertaken first. 



PLANTING. IN SECOND-GROWTH FORESTS 



The conditions in second-growth forests are very much closer 

 to those in high forests than are the conditions in grass areas. 

 The upper layers of the soil are not completely filled with under- 

 ground stems of grasses, which make the competition for such 

 soil moisture as is available too keen for the existence of broad- 

 leaved, tender dipterocarp seedlings, and the crowns of the 

 second-growth trees, while not exceptionally dense, are sufficient 

 to prevent the rapid drying of the surface of the soil in the first 



