Vegetation Recovery in Response to the Exclusion of Grazing by Sika Deer (Cervus nippon) in Seminatural Grassland on Mt. Kushigata, Japan

We examined the recovery of vegetation in seminatural grassland in central Japan after eliminating grazing by sika deer (Cervus nippon) by fencing. By 2012, after 5 years of fencing for exclusion of sika deer, the species composition of quadrats within the enclosure reverted to the original species composition in 1981, not browsed by sika deer. Conversely, outside the fence was different from the baseline quadrats in 1981. Iris sanguinea, a prominent flower in the area, recovered within the enclosure, while it continued to decrease with grazing outside the fence. Nevertheless, the I. sanguinea cover had not recovered to the 1981 levels in the enclosure. Fencing can effectively restore vegetation as the species composition within the enclosure gradually reverts to the original vegetation. Preventing grazing in intensively grazed seminatural grassland might lead to different successional pathways. Since I. sanguinea did not recover fully within the enclosure and the species composition differed slightly from the original vegetation, this suggests that the vegetation within the enclosure will change to an alternative state. Therefore, different management is needed to promote the correct succession pathways for ecological restoration, perhaps by enhancing the colonization of target species, to prevent restored sites from giving rise to alternative states.