Cool-temperate vegetation in Japan is classified into two types. One is mixed deciduous broadleaved forest dominated by Quercus, Fagus, Acer, Magnolia, Kalopanax etc., spreading southwestern part, and another is pure beech forest, dominated by Fagus crenata, spreading widely in northern part. It has been noted that the variation in cool-temperate vegetation coincides with the snowfall regime in winter remarkably, and we have conducted many studies to reveal the controlling mechanisms of snowpack to vegetation.

Summarizing our recent studies, snowpack acts as a complex of many environmental factors;

1) heavy disturbance by snow pressure (creep and glide pressure of snow)

2) delay of leaf opening and shortening of photosynthetic period

3) alteration of the activities of seed predators (ex: rodents)

4) infection of fungi and bacteria to seed under snowpack

Quantitative analysis made it clear that each factor has strong effect on the demography of component species, and that F.crenata would be the only species that can survive the complex of stress and disturbance without serious damage.