Abstract
Succession and the number of species were investigated in wet, abandoned paddies, undergoing various treatments (mowing once or twice a year, plowing, and surface soil padding) in the Tama Hills (western Tokyo). Phragmites acstralis was dominant before such management was performed in these paddies. In plowed plots, most of the P. australis disappeared. In padded plots, in addition to P. australis, other dominant species such as Isachne globosa and Polygonum thunbergii also disappeared, and erect stem paddy-weeds became dominant. In mowed plots, the density of P. australis gradually decreased with increasing mowing frequency, and prostrated or rhizome paddy-weeds increased. The number of species in the plots mowed once was sometimes higher than that in the plots mowed twice.
