Responses of Miscanthus sinensis and Zoysia japonica to leaf clipping─interpretation of vegetational changes at a deer habitat

Abstract

The vegetation of Kinkazan Island （992 ha）, northern Japan is prevailed by forests and only small openings exist.　Many of the latter were dominated by Miscanthus sinensis, a tall tussock grass while communities of Zoysia japonica, a low growing grass, develop at the places where high density deer populations live.　This suggests that a M. sinensis community alters to a Z. japonica community as grazing intensity of the deer increases.　Although similar phenomena are known at pastures grazed by livestock, previous studies only described the phenomena.　This study intended to explain the reason of these phenomena by a clipping experiment of mixed planting of M. sinensis and Z. japonica.　Although leaf length, plant height, and productivity of M. sinensis were more intensively reduced as clipping frequency increased, those of Z. japonica were not affected.　These suggest that heavy grazing decreased M. sinensis tussocks and favored Z. japonica swards.　This clipping experiment partly explained that frequent leaf clipping caused the replacement of M. sinensis by Z. japonica on the island.