232 The Philippine Journal of Science 



that the ground covering is composed of plants requiring more 

 moisture than those found in the dipterocarp forest. 



It does not seem probable, however, that the dwarfing of the 

 vegetation is connected with this high water content. The 

 great amount of water in the soil of the mossy forest is not due 

 to heavy rains that would cause the soil to become leached out, 

 as the rainfall here is about the same as it is in the place where 

 the soil samples were taken in the dipterocarp forest and is con- 

 siderably less than in the midmountain forest and in a large pro- 

 portion of the dipterocarp forest. The soil of the mossy forest 

 is, moreover, well drained, so that it must be well aerated, and 

 it has a springy consistency. The figures in Table I show less 

 acidity in the soil of the mossy forest than in that of the dip- 

 terocarp forest. There seems, therefore, to be no reason for 

 considering the high moisture content of the soil as harmful. 

 The moisture content of the soil of the midmountain forest would 

 certainly not seem to be high enough to be deleterious to the 

 vegetation. The fact that the trees in this situation are much 

 smaller than those in the dipterocarp forest is probably due to 

 the same factors that have resulted in the stunted vegetation 

 on the top of the mountain, the difference being that these factors 

 are more pronounced at the top. 



The above discussion indicates that the moisture contents of 

 the soil should be as favorable at high as at low altitudes and 

 so cannot be connected with the dwarfing of the vegetation as 

 higher altitudes are reached. 



SUMMARY 



The natural vegetation of Mount Maquiling becomes more and 

 more dwarfed as higher elevations are reached. There does not 

 appear to be anything in the physical or mechanical composition 

 of the soil or its moisture content which would account for this 

 fact. 



The character of the plants in the ground cover varies accord- 

 ing to the amount of moisture in the soil at different altitudes. 



