摘要：The effects of artificial warming on shoot elongation of alpine dwarf pine ( Pinus pumila ) was studied near Mount Shogigashira summit, central Japan, from 2001 to 2003. A nylon windshield net enclosed two experimental plots, 2 × 2 m, each year at the start of the growing season (June, but late July in 2001). The nets were removed at the end of the growing season (late September or early October). Two plots, 1.5 × 1.5 m, without a net were set as controls. In September 2001, the daily mean air temperature differed little between the experimental and control plots: compared to the control plot, the maximum was 4.3°C higher and the minimum was 1.7°C lower in the experimental plot. The annual shoot elongation differed little between the experimental and control plots in 2001 and 2002, but it was greater in the experimental than in the control plot in 2003. Shoot elongation started in June and ended in August in both experimental and control plots, but the rate of the increase was greater in the experimental than in the control plot in 2003, and so shoots had greater elongation in 2003 in the experimental plot. Thus, artificial warming promoted shoot elongation by increasing the daily maximum temperature.
