DENDROCHRONOLOGY IN CONIFEROUS FORESTS AROUND LAKE RARA, WEST NEPAL

In two forest stands, one domonated by Abies spectabilis, and the other by Pinus wallichiana-Picea smithiana, 198 cores were taken from 105 conifers in May 1983 and the annual ring widths were measured. The annual ring widths usually had significant similarities between cores taken from the same tree and with cores taken from different trees. these similarities increased with tree size. The climatic change affected the large trees more strongly than it did the small trees. Micro environmental changes, such as canopy gap affected the small trees more strongly. Annual ring widths were also correlated with the annual precipitations at Jumla 30 km south of the plots for a recent 20 year period. A multiple regression analysis between ring width and seasonal precipitation showed that the growth of A. spectabilis was correlated primarily with the rain from May to August and secondarily with that from September to December in the previous year. © 1990 The Botanical Society of Japan.