Tree-ring studies in the Eastern Himalayan region: Prospects and problems

Tree-ring samples of different conifer species in various ecological settin gs from subtropical to temperate regions of the Eastern Himalayan region ha ve been evaluated for their potential for dendroclimatic reconstructions. M ost of these tree species have cross-datable growth rings except Taxus bacc ata and Tsuga dumosa where series of micro-rings and lack of variation in t hese suppressed zones make cross-dating difficult. Tree-ring chronologies h ave been established from Abies densa and Larix griffithiana, the only deci duous conifer species in the Himalayas. Tree growth-climate relationships r eveal that temperature is a determinant factor for the growth of trees at h igh elevations. Abies densa in the western part of Arunachal Pradesh shows a negative response to the July-September temperature whereas Larix griffit hiana shows a positive response to the May temperature.