The difference in vegetation pattern has been pointed out between Sado Island and mainland in Niigata Pref. The purpose of this study is to clarify the difference in vegetation pattern and the cause of them in relation to weather condition

We have set 6 belt-transect along the altitudinal gradient on the ridge vegetation in cool temperate zone. We used the climate data of AMeDAS by Japan Meteorological Agency near each plots, and measured the snow depth in each plots.

In mainland, Quercus crispula (below 400m in altitude) and Fagus crenata (above 400m) were recognized as dominant canopy species. On the other hand, dominant species in Sado Island on northern area (Osado) were Q. crispula - Tilia japonica (below 400m), Q. crispula (400-700m) and Cryptomeria japonica - Pterocarya rhoifolia (700-800m). However, dominant species in Sado Island on southern area (Kosado) were Quercus salicina and Neolitsea sericea (below 100m), and Quercus serrata, Carpinus tschonoskii, Pinus densilfora and so on (above 100m). The results of Cluster analysis for each plot show the difference in species composition among three areas (Osado, Kosado and mainland). This phenomenon may result from the difference in the climate condition such as temperature, winter wind and so on.