Abstract
Twenty-two differential species of the floodplain plant communities along the lower reaches of the Sagami River, western Kanto, Japan, were examined for germination under controlled water conditions. The experimental conditions were prepared as follows: 1) wet, moist and dry conditions during seed storage, and 2) wet to dry conditions of germination beds, and 3) shallow and deep water flood conditions of them. Among the twenty-two species examined, seven species characterizing the communities with dry habitats germinated well on germination beds with moist and wet soil conditions, but germination rate was clearly suppressed by flooding. Germination of nine wet habitat species were inhibited by dry conditions, but could germinate under flood conditions. The remaining six moderate habitat species displayed intermediate germination characteristics. Thus, the suitable germination conditions of the species examined in the present study corresponded to the habitats of the plant communities to which they belonged. However, a common suitable habitat for seed storage could not be found.
