摘要：The shoot diameter and shoot length extension growth studied in 10 tree species occurring between 350 to 2500 m elevation in the Kumaun Himalaya. Effects of temperature on shoot growth were studied under natural conditions. Shoot length growth was significantly affected by the temperature during shoot elongation (p<0.01). The optimum temperature for elongation was ranged from 21 to 36°C across the altitudinal gradient. The shoot elongation growth was positively correlated with the shoot diameter growth in all species. The peak activity of leafing takes place during March–April when photoperiod and temperatures are incrementing. All species showed a clear peak value of radial growth in the first few months of growing season. Over 90% of the radial growth was accomplished by the late summer season in the most species; only in a few species it was extended upto the later part of the rainy season. On the basis of successional status, early successional species show a faster shoot extension growth than late successional species.
