Protection of Endangered Plants From Sika Deer Herbivory Using Deer-proof Fences in the Tanzawa Mountains, Central Japan

27 Mar Protection of Endangered Plants From Sika Deer Herbivory Using Deer-proof Fences in the Tanzawa Mountains, Central Japan

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Abstract

ニホンジカの採食圧により林床植生が衰退した丹沢山地冷温帯の3タイプ(オオモミジガサ-ブナ群集,ヤマボウシ-ブナ群集,イワボタン-シオジ群集)の植物群落に設置した植生保護柵25基において,設置4年後に植物相を調査した。柵の中(3.7ha)で334種の維管束植物を確認した。その中には県の絶滅種,絶滅危惧種など12種,および県新発見種1種が含まれていた。オオモミジガサ-ブナ群集は出現種の5.1%が希少種で他の2群落よりも希少種の出現率が高かった。対象地域の過去の植物相と比較すると,シカの採食圧下で一度消失したと考えられる希少種5種が出現し,過去に未確認だった希少種も6種出現した。したがって,ニホンジカの採食圧が強い丹沢山地冷温帯において,植生保護柵の設置は単に林床植生の保護だけでなく,希少種の保護・回復にも有効な手段と考えられた。

English Abstract

Four years after establishment, we surveyed the flora in 25 herbivore exclosures constructed using deer-proof fences in three plant community types (Miricacalio-Fagetum cre tae, Corno-Fagetum cre tae, Chrysosplenio-Fraxinetum) in the cool temperate zone of the Tanzawa Mountains. The area is inhabited by a high density of sika deer (Cervus nippon Temminck). In total, we identified 334 plant species, including 12 species considered endangered in the Ka gawa Prefecture. The Miricacalio-Fagetum cre tae community had the highest proportion of endangered species (5.1%). In addition, five species that had disappeared and six previously unrecorded species were found in the exclosures. Our results suggest that deer-proof fences, which prevent deer from grazing in an area, are effective in the restoration of these plants.