Abstract: The chemical components of the volatiles from the leaves and branches of Larix principis-rupprechtii were analyzed by GC-MS, with their allelopathic effects on the seed germination and growth of L. principis-rupprechtii itself investigated. The results indicated that the volatiles contained 20 major components, and the main constituents were terpenes and their oxidized derivatives, in which, there were 5 monoterpenes and 12 sesquiterpenes. The volatiles from the leaves and branches of L. principis-rupprechtii had significant inhibitory effects on the germination rate, germination speed index, radical length, hypocotyl length, and fresh mass of L. principis-rupprechtii itself, indicating that these volatiles contained potential allelochemicals, which might be related to the higher contents of terpenes and their oxidized derivatives. The allelopathic effects of the volatiles affected the regeneration of L. principis-rupprechtii, which should be a reason for the degeneration of artificial pure L. principis-rupprechti forest.

Key words: Pinus tabuliformis, tree ring-width, climate response, climate change, climate reconstruction