ササ群落の生態学的研究 V

Abstract

Influence of light intensity, snow depth and temperature upon dry matter production of Sasa kurilensis community especially at Mt. Waisuhorun, southern Hokkaido, was analyzed.1. The relatively high shade tolerance of Sasa kurilensis is attributable to the characters of photosynthesis, the increased longevity of leaves and the increased ratio of total leaf area to total leaf weight with decrease of light intensity, the constant distribution ratio for new leaves independent of light conditions, and the maintenance of active productive structure for full utilization of growing season, though the species has a disadvantageous character of large respiration loss.2. The standing crop of the community was decreased with the decrease in snow depth. This is mainly caused by the shortening of the life of culms and the depression of gross and net production caused by the shortening of the life and decrease in amount of leaves.3. The maximum standing crop is expected at the locality where the annual temperature is 4.4°, which is really observed at the station concerned. If higher than 4.4°, the standing crop decreases with increase of respiration loss, and if lower than this temperature, it decreases with decreases of gross production caused by short growing period.