REVIEW OF THE PHYTOSOCIOLOGICAL VEGETATION SYSTEM OF JAPANESE ALDER SWAMP WOODS

Abstract

Various types of swamp woods dominated by the Japanese alder (Alnus japonica) are occasionally found in wetlands occurring in the cool and warm-temperate zones of the Japanese Archipelago. The vegetation of these Japanese alder swamp woods is azonal and they are a terminal community maintained under certain natural environmental conditions. The authors reviewed the phytosociological vegetation units (i.e., syntaxa) and reorganized their vegetation systems based on the phytosociological data previously published. These alder woods occurring in several habitats (waterside-marshes, fens, spring-wetlands, and back-swamps) were classified into six associations in the cool-temperate zone and three associations in the warm-temperate zone. These syntaxa were unified in three alliances (Fraxino mandshuricae-Alnion japonicae, Fraxinion japonicae, and Ligustro obtusifolii-Alnion japonicae) belonging to the order Alnetalia japonicae and to the class Alnetea japonicae.