328 The Philippine Journal of Science 
is shown graphically in fig. 2\ The dipterocarps, like Podocarpus 
imhricatus, are dominant trees. It will be seen at once that 
five of the different species of dipterocarps show rates of growth 
which are very much more rapid than that of Podocarpus 
imhricatus. The sixth, Dipterocarpus grcundiflorus, also shows 
a faster rate of growth than Podocarpus imhricatus. Fig. 2 
would seem to indicate that the rate of growth of the average 
dipterocarp is about 2.5 times as rapid as that of Podocarpus 
imhricatus at the top of Mount Banahao, which is not surprising 
Yeai-s necessary for growth from a diameter of 5 centimeters to larger diameters. 
Fin. 2. Rates of growth of Podocarpus imbricatns on Mount Banahao and of dipterocarp 
species in other parts of the Philippines. 
in view of the fact that Podocarpus is subjected to conditions of 
temperature and light that are very unfavorable as compared 
with those under which the dipterocarp species are found. 
CONCLUSIONS 
Podocarpus imhricatus at the top of Mount Banahao shows 
a very slow rate of growth, a tree 60 centimeters in diameter 
being about 500 years old. The rate of growth of Podocarpus 
is very much slower than that of dominant trees at lower eleva- 
tions in the Philippines and of pines in the United States. 
