A preliminary report on phenological monitoring using experimental chambers

Abstract: To predict the influence of global warming on high-mountain plants, we have started an experiment on Mt. Kisokomagatake (2956 m), the Central Japanese Alps, using the ITEX (International Tundra Experiment) method. Four small greenhouses (OTC: open-top-chamber) were set up in May 1995 to cover two alpine species: Arctous alpinus var. japonica and Diapensia lapponica. The temperatures at plant height and the ground were measured in each OTC as well as a control plot without OTC. The average temperature in OTCs was higher than that in the control plot by 0.9OC. In accordance with the temperature enhancement, the plants in OTCs underwent some phenological changes during the summer of 1995. The duration from the leaf emergence to the beginning of coloring in OTCs was longer than that in the control plot by 33 days. Leaf wilting was also delayed in OTCs. Thus, alpine plants responded sensitively to the environmental change in the OTC. 1