SHORT-TERM EFFECTS OF WIND SHIELD ON PHENOLOGY AND GROWTH OF ALPINE PLANTS IN MOUNT KISO-KOMAGATAKE, CENTRAL JAPAN (19th Symposium on Polar Biology)

摘要

To determine the effect of wind on alpine plants, we set up five wind-shields (called WS) on a wind-blown alpine dwarf shrub community on Mount Kiso-komagatake (2956m), in the Central Japanese Alps, in June 1996. Air temperature at vegetation height, soil temperature, and relative humidity on the windward side of the WS plots and control plots were recorded. Phenological observations and growth measurements of five species, Diapensia lapponica var. obovata, Empetrum mgrum var. japonicum, Loiseleuria procumbens, Arctous alpinus var. japonicus and Vaccmium uligmosum, were conducted from June to October. By setting up the WSs, the daily mean temperature did not change significantly in comparison with the control plots. Growth periods of four species, except for D lapponica var. obovata, were extended at the WS plots, and E. nigrum var. japonicum, L procumbens and V. uliginosum bloomed earlier at the WS plots. Annual shoot length of E. nigrum var. japonicum, L procumbens and V. uligmosum was longer at the WS plots. These results suggest that one of the important effects of wind on the alpine plants was the restriction of shoot growth, probably due to decreasing leaf temperature. The effect of the wind shield was not significant for D lapponica var. obovata, which has a mat-shaped growth form.