Abstract
We controlled the ecological conditions of the irrigation pond of Sakasamaike in Manno park to regenerate of the aquatic plant community in order to inspect the effect of ecological management which was imitated the traditional methods. As a result, the improvement of the light condition of the water surface and underwater caused to the aquatic plant community expanding. And, being shallower of the water depth by the accumulation of sand mud exerted a similar influence. Similarly, the community extension speed of some aquatic plants appeared also according to the difference of the accumulation thickness of humus under the water quality being maintained in a state of poor nutrition. It was possible to recognize that the ecological character of those aquatic plant species became an indicator for evaluating the effect of community expansion.
