Tree ring cellulose δ18O of Fokienia hodginsii in northern Laos: A promising proxy to reconstruct ENSO?

Abstract

A tree ring cellulose δ18O chronology of Fokienia hodginsii from 1951 to 2002 is established by four cores from four different trees to explore its potential for reconstructing climatic variations in northern Laos. This chronology is the first tree ring δ18O chronology from Laos as well as the first for this species. We compare variations of tree ring cellulose δ18O and ring width between cores. The results suggest that the δ18O time series are more strongly correlated between different trees than ring width time series are. In addition, correlation analysis shows a significantly negative correlation between tree ring cellulose δ18O and the May-October Palmer Drought Severity Index (PDSI), while the tree ring width indices have a poor correlation with PDSI. The spatial correlation analysis between tree ring cellulose δ18O and global sea surface temperature and the time series correlation analysis between tree ring cellulose δ18O and the Multivariate El Niño-Southern Oscillation (ENSO) Index (MEI) during the investigated period (1951-2002) reveal that ENSO has an important effect on tree ring cellulose δ18O in Laos. Our results indicate that the tree ring cellulose δ18O of Fokienia hodginsii is a promising proxy to reconstruct PDSI in Southeast Asian countries, such as Laos, and to discuss their teleconnections with global atmospheric circulations such as ENSO. Copyright 2011 by the American Geophysical Union.