2020 Volume 46 Issue 2 Pages 218-225
We have discussed the response of a native wild flower Dianthus superbus var. longicalycinus to disturbances in soil caused by tsunami in the Great East Japan Earthquake. We monitored a survivor seedling and the flowering of this species for two years as of 6th or 7th year from tsunami in three types of soil disturbance intensities in the tsunami-stricken coastal forest on Sendai Bay. In an investigation area of 9 square meters, 257 seedlings were observed, out of which 105 were blighted. We treated the topsoil outflow site and the foundation earth outflow site were suffered different strength topsoil disturbance to the topsoil remains site as a control. As a result, the total number of the seedling increased in both topsoil disturbed sites significantly (Steel-test, P＜0.05). However, there were no differences in the average survival rate of seedlings by each type. As for the total number of new seedlings in each quadrat, the number of flowering plants of the neighborhood showed a weak correlation, while the cover in quadrat just before the period for investigation showed a strong correlation (r＝－0.751). Due to this result, we thought topsoil disturbance influenced the germination harder. The new seedlings showed a tendency to increase in the season when the temperature rises. One and a half years old were recorded as the shortest first flowering, but it was only 2％ of all seedling germinated in the same season. That the majority of seedlings of wild D. superbus var. longicalycinus need longer years to flowering became clear.
