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 (497Kb)
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32,223,000 Yen (FY1995; 10,591,000 Yen)
The following studies on climatic, edaphic biological conditions, and their influences were carried out in northern and middle Japan as: estimation of snowfall by ground air temperature, modeling of melting process of snowpatch, phenological change of snowpatch vegetation, growth and distribution of Pinus pumila scrub, effects on litter decomposition rate in different forest types. We have tried to reconstruct past climatic conditions by means of alpine-subalpine meadow soil stratigraphy, which records past snow disappearance time in nivation hollows. Buried peat found on Mt. Zarumori indicates that the date of snow cover disappearance in approximately 1000 y.B.P., was earlier than in recent times. Calculations of the past snowmelt rate by the degree-day method, indicate that warming in summer and lower winter snowfall accumulation, hastened snowmelt and enabled the peat to deposit. This warmer climatic condition in north Japan corresponds to the so-called "Medieval Warm Period" of Europe and North America. It is suggested that subalpine conifers never expand into the alpine vegetation zone which P. pumila has already occupied, even under the higher temperature conditions.
climate change, alpine and subalpine vegetation, phenology, snow cover