Tree-ring chronologies from Western Himalaya and their dendroclimatic potential

Abstract

Tree-ring chronologies of Himalayan conifers (viz. Pinus, Picea, Abies, Cedrus, etc.) were compiled from more than 300 tree core samples from 11 different sites covering a wide area of the Western Himalaya. Distinct annual growth and little occurrence of double or missing rings are characteristic features of Himalayan conifers. Dating of individual samples was achieved for all sites except for a few from a high elevation glacier which exhibited patches of very narrow rings and a high frequency of resin canals. Moderately high values of common variance and signal-to-noise ratio indicate their usefulness for dendroclimatic studies. Significant improvement of statistical performance is observed for all sites after removing the auto-correlation structure in the series by auto-regressive modeling. A quantitative evaluation of the growth-climate relationships based on response function analysis on a monthly and seasonal scale indicates a similar pattern across several regions of the Western Himalaya. March-April-May (pre-monsoon) climate (temperature and precipitation) is an important limiting parameter for tree growth and can be successfully reconstructed for the past few centuries.