In Japan, semi-natural grasslands have declined rapidly since 1960s. And it has been reported that the habitat about grassland plants in Satoyama areas. But it is a little known about that in suburban areas. So our study objective is to identify the habitats and the population structures of the grassland plants in suburban areas.

We selected three research sites which are located in suburban areas. At each site, we looked for 12 grassland plant species on foot and mapped their location. Based on each data set, we constructed generalized linear model with logistic regression to estimate the suitable habitat for the grassland plants. As the result, the grassland between buildings and paved road, and the forest edge were supposed to be important for the grassland plants in suburban areas.

Next, in order to understand the reproductive characteristic, we researched the population structures about three grassland plants by using stem size on the ground in some population in suburban areas. In the population structures about two species, the proportion of mature stems which can potentially produce flowers was large, but the proportion of stems actually produce flowers was small. This was because two species was affected by regularly mowing in summer. So the grassland plants was supposed to survive in habitats which was not affected by mowing.