Floristic Composition and the Dynamics of Weeds of Sown Grassland in Japan

IV. Dynamics of Weed Communities in Sown Grasslands in Akita and Yamagata Prefectures

Abstract

In the previous paper, the classification of the weed community was presented in the sown grasslands in Akita and Yamagata prefectures. On the same grasslands, the dynamics of weed communities were studied in the present paper.
1) The dynamics of weed communities in the sown grasslands were presented with a diagram in relation to site factor (soil moisture contents) and degree of succession.
2) The direction of succession in weed communities were summarized in connection with soil moisture contents;
Mesic site: Amaranthus lividus type→Rumex obtusifolius type→Rumex acetosella type→Miscanthus sinensis type.
Xeric site: Bryum argenteum type→Hypnum plumaeforme type→Erigeron canadensis type→Petasites japonicus var. giganteus type→Miscanthus sinensis type.
Hygroric site: Carex albata type, typical community→Scirpus wichurae-community.
3) The weed communities were discussed in relation to P-A index and life form of composed weed species.