Abstract
We aimed a rare plant species Gentiana squarrosa (biennial plant) that grows to the embankment of terraced paddy field of Oyama-Senmaida which the owner system has been introduced. We investigated the relation between the growth situation of this species of flowering season and the local vegetation management form. The population of Gentiana squarrosa in spring of 2005 was about 8500 pieces. There is Mowing of 5-8 times in Oyama-Senmaida at the ordinary year. Moreover, it investigated in 31 samples of this species of distribution regions. As a result, a lot of population were in 16 samples where mowing had been done after the rice was harvested and before planting rice of next year at the ordinary year. The situation in which sunshiny was able to be secured more at the growing period of the early spring, and it is related to this species of conservation.
