Tree ring research in India: an overview

Abstract

Dendroclimatic studies in India were taken up towards the end of 1970. Datable growth rings are found in several tree species growing in many regions of tropical forests where moisture supply acts as the limiting factor at least in some part of the growing period. The tree ring sequences from such areas reflect fluctuation in the level of monsoon. Due to difficulty in gelling sufficient replication of samples from desired species and locality, progress in tree ring analysis of hardwoods has been impeded to a great extent. Amongst the tested species teak (Tectonia grandis), because of its long age and ecological diversity, has become the pivotal species for the reconstruction of precipitation. A major breakthrough in getting 745 years long chronology of Cedrus deodara growing on moisture stressed site in Uttar Kashi has been achieved. The statistical properties such as low first order autocorrelation (0.150), high mean sensitivity (0.344) and high signal-noise ratio (20.53) point towards its suitability for the reconstruction of climatic factors, especially precipitation. The length of this chronology is not necessarily limited to the life span of living trees. Cross-dating of ring sequences from old trees with those in stumps, logs and sources of older woods from ancient buildings in the Himalayan region would permit the development of longer chronologies. Besides deodar, other conifers such as pines, spruce and fir also have shown enough potential in dendroclimatic studies.