In order to explore the potential of tree-ring components as climate proxies in Asian tropical area, we performed a systematic comparison between temporal variations in meteorological data – precipitation, relative humidity and sunlight hours – and those in treering parameters – ring width, mean earlywood vessel area and δ18O– in a sungkai disk collected from western Java, Indonesia. Ring width shows a significant positive correlation with precipitation in the last dry season prior to growth period. Ring width is also correlated inversely with sunlight hours in the last dry season. Mean earlywood vessel area shows a significant, positive correlation with precipitation and relative humidity during the rainy season of growth period. The δ18O and δ13C time series of alpha-cellulose samples, which divide each ring into three parts – earlywood, inner latewood and outer latewood – vary, furthermore, from 22‰ to 28‰ and from -28‰ to -24‰, respectively. δ13C results show distinct annual cycles, for which values of earlywood are highest, gradually followed by a decrease. Although δ18O has no such seasonal pattern, annual-averaged δ18O records show an inverse correlation with precipitation and relative humidity in the rainy season of growth period. As described above, multi-components of sungkai tree rings are expected to be useful in paleoclimate reconstruction on a seasonal scale.
An evaluation of english oak earlywood vessel area as a climate proxy in the UK
