わが国における草本群落の二次遷移

抄録

HAYASHI Ichiroku (Sugadaira Biol. Lab. of Tokyo Kyoiku Univ.) 1976 Secondary succession of herbaceous communities in Japan. Jap. J. Ecol. 00 : 291-200. In order to explain the alternation of the dominants in secondary sucession, the life histories of the dominant species of each stage in secondary sucession were compared. In the present paper, which is the first of this series, the results of investigation of the seed weight and disseminule form of herbaceous species in relation to succession are reported. Measurements of seed weight of 167 species show that species bearing seed weighing less than 0.1 mg are most frequent. The frequency in number of species decrease rapidly with the increase of seed weight with species bearing seeds over 2.5 mg in weight being very few in number. The dominants in later stages of succession produce heavier seeds than those of earlier stages except in the case of pioneer species, which produce heavy clitochore seeds. The disseminule form of the dominant species in the winter annual stage, perennial herb stage and perennial grass stage is anemochore. A close relationship exists between the disseminule form and the seed weight in each species : anemochore seeds are light while clitochore, bolochore and zoochore seeds are heavy.