Effects of Deer Fences in the Conservation of Erythronium Japonicum

27 Mar Effects of Deer Fences in the Conservation of Erythronium Japonicum

View Original

Abstract

1970年代にはカタクリが群生していたが,試験の開始時には著しく個体数が減少していた兵庫県佐用郡南光町船越山のコナラ二次林において,鹿防護柵の設置と落葉の除去を行った。その結果,鹿防護柵の設置区は対照区に比べ,個体数の増加と葉長の成長が上回った。また鹿防護柵の設置前は開花個体が全くみられなかったが,設置3年目以降は,開花個体が年々増加する傾向がみられた。以上のことから,ニホンジカの採食によって衰退傾向にあるカタクリ群落では,鹿防護柵の設置によって,群落を保全できる可能性が示唆された。

English Abstract

The effects of deer fences were monitored in secondary Quercus serrata forests in nko, Hyogo Prefecture, Japan. Although a large population of Erythronium japonicum occurred in this area during the 1970s, it had decreased substantially prior to this investigation. Following our experiment, the number of E. japonicum plants and their leaf lengths increased in the fenced plot, whereas both decreased in the unfenced control plot. No flowering individuals were observed prior to installing the fence, but beginning in the third year after the fence was erected, the number of flowering individuals increased annually in the fenced plot. Therefore, we suggest that deer fences provide effective protection for E. japonicum populations, which are currently declining because of browsing by sika deer (Cervus nippon).