24 
Indian Forest Records. 
[VOL. Ill. 
forest with Dendrocalamus strictus as the prevailing bamboo, forest of 
this type is absent in Gwethe, where Bambusa polymorpha is the chief 
bamboo in the teak areas, and the forest is considerably moister than in 
the Ziyaing-Mehaw reserves. 
Considering the proximity of these reserves to each other, and the 
fact that both are situated on the same hill range and are similar in geolo¬ 
gical formation, the difference in rate of growth is striking, as the follow¬ 
ing statement shows :— 
Average age of tree of girth 
of 
Reserve. 
3' 
4' 6" 
6' 
7' 
Ziyaing-Mehaw ..... 
62 
112 
153 
190 
Gwethe •••••• 
57 
86 
117 
139 
Some difference might perhaps be expected from the fact that in the 
case of the Gwethe reserve the figures were obtained chiefly, but not 
entirely, by Pressler’s borer, whereas in the case of Ziyaing-Mehaw the 
counting of rings, on stumps was more largely carried out. This, how¬ 
ever, cannot account for such a large difference, particularly as in Gwethe 
reserve the age of a tree 7 feet in girth as deduced from ring-countings 
corresponds exactly with the age as determined by borings. The 
difference is no doubt due largely to the fact that the Ziyaing-Mehaw 
forests are of a drier type than the Gwethe forest. 
Although the slower rate of growth and smaller size at maturity 
of teak trees grown on poor dry localities as 
Exceptions to general rule. compared with those grown on r i c h moist 
localities is almost axiomatic, this difference is not always so apparent 
in the younger age-classes. There are, in fact, one or two instances 
where the rate of growth is even faster in the drier than in the moister 
localities during the first half of the life of the tree : where this occurs, 
it is no doubt to be explained by the fact that in the richer localities 
teak suffers more from suppression during its earlier stages than in the 
poorer localities where the forest is more open. 
[24] 
