[MIS10-P30] Comparison between Climate and Teak Tree Ring Widths in Bago Mountains, Central Myanmar
Keywords:teak, tree ring, Myanmar
At first, we decided the age of rings by cross dating. We measured the annual ring area and derived width by “method of approximation as circle or sector” (Arai, 2016: Graduation thesis). Then we got the tree ring index by fitting using a spline curve. Comparing each tree ring index or them with the tree ring index in North Myanmar (D' Arrigo et al., 2011) and in Northwest Thailand (Pumijumnong, 2012), we decided about annual rings were started to be formed from 1906.
Next we carried out the correlation analysis among the tree ring index, amount of precipitation and PDSI (Palmar Drought Severity Index). The result shows that (1) tree ring index of three samples are positively correlated with rainfall in rainy season, (2) tree ring index of two samples and rainfall in late rainy season, especially in August and September are related to positive correlation, which is inconsistent with Pumijumnong (2012) that showed positive correlation between tree ring index and rainfall in early rainy season. On the other hand, there is no correlation between tree ring index and PDSI in three samples, which is inconsistent with D’ Arrigo et al. (2011) and Pumijumnong (2012) that showed positive correlation between tree ring index and PDSI in rainy season. Little of the seasonal variation of temperature or the river and basin system around the growing area are considered as the reason that PDSI was not reflected strongly.
In conclusion, our research confirmed that teak tree ring reflects amount of precipitation and indicated that teak will have potential for climate reconstruction in Central Myanmar. Additional data of more teak samples and using isotopes in tree rings are necessary to make the research.