Phytosociological Status of Rheophytic Shrub Communities on Rocks

Abstract

In this study, we examined the phytosociological status of vegetation units of shrub communities established on rocks along streamsides. As a result, previously described four association: Ainsliaeo-Rhododendretum indici Suz.-Tok. 1976, Rhododendretum indici Minamikawa 1963, Rhododendretum ripensis Yamanaka & Takezaki 1959 and Spiraeetum thunbergii Ya. Sasaki & Oota 1986 were placed in newly established one class: Lespedezetea buergeri class nov. , one order: Lespedezetalia buergeri order nov. , two alliances: Rhododendrion indici alliance nov. and Spiraenion thunbergii alliance nov. These higher units are characterized by shrubs on rocks and the rheophyte. In addition, we designated the types of Rhododendretum indici Minamikawa 1963, Rhododendretum ripensis Yamanaka & Takezaki 1959, and Spiraeetum thunbergii Ya. Sasaki & Oota 1986. We also reiterate that the original description of Salicion gracilistylae has been sometimes attributed to Ohba (1973), but we again pointed out that it is Ohba (1975).