Vessel Chronologies from Teak in Northern Thailand and their Climatic Signal

Abstract

Five teak trees in northem Thailand were selected for the study of vessels in terms of dendroclimatology. The tree rings were divided into earlywood and latewood, and fourparameters (average vessel area, average vessel diameter, average conductive area, and vessel density) were measured by automatie image analysis technique to obtain 50-year (1947-1996) time series. Two questions were addressed: 1) How strongly are the vessel characteristics related to climate and 2) are these relationships different from those of ring widths? All vessel parameters of the total ring and of the earlywood were negatively correlated with precipitation during the transitional period between the dry and the wet season. The latewood vessel parameters, however, are negatively correlated with J une temperature. The climatic signals of the vessel parameters and of the tree-ring width are different from each other.