470 



The Philippine Journal of Science 



1914 



ANNUAL DIAMETER GROWTH 



Measurements were made on Parashorea plicata (bagtican- 

 lauan) growing in the forest on Mount Maquiling at an eleva- 

 tion of approximately 300 meters. The stand, as previously 

 described, is a very open one for a dipterocarp forest, and Para- 

 shorea develops a deep crown. As might be expected from these 

 conditions, the figures for Parashorea show a more rapid rate of 

 growth than do those for any of the other dipterocarps meas- 

 ured. The diameter growth from January 13, 1913, to January 



20 



W 



60 



Age in years. 



SO 100 110 



}M 



160 



180 



ZOO 



80 

 70 

 60 

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Fig. 1. Rates of growth of Parashorea plicata in forest and open. 



13, 1914, for all of the trees measured in the forest is given in 

 Table XVI. These results are plotted as one of the curves in fig. 

 1 in a form to show the age of trees of any diameter. Perhaps 

 the most remarkable point brought out by the figures and curve 

 is the very low rate of growth shown by the small individuals 

 of Parashorea. Thus, according to these figures a tree 5 centi- 

 meters in diameter is 62 years old and one 20 centimeters in 

 diameter is 44 years older. After this, as the trees get access to 

 the light, growth becomes much more rapid. 



For comparison with Parashorea there are plotted in fig, 1 



