Response of cellulose oxygen isotope values of teak trees in differing monsoon environments to monsoon rainfall

Results of interannual variations in cellulose oxygen isotopic composition (δ18O) of four teak (Tectona grandis L.F.) trees (one from western India, two from central India and one from southern India) are presented. Cellulose δ18O of teak trees from western and central India show a significant positive correlation with the amount of rainfall, which is contrary to expectation. We propose that this correlation is caused by longer duration of the growing season in years of higher rainfall. Teak from southern India shows a significant negative correlation with the amount of rainfall and this relationship is used to reconstruct rainfall back to A.D. 1743, extending the existing regional and local rainfall records by 70 and 128 years, respectively. The reconstructed series reveals higher rainfall for the period 1743–1830 than for the later periods.