Abstract
Epipogium roseum, the near threatened (NT) species in the Red Lists of Japanʼ s Ministry of Environment, was found on the understory of Lithocarpus edulis plantation in Mt. Ohgusu, Miura Peninsula, central Japan. L. edulis plantation and Castanopsis sieboldii forest were divided into 1 plantation, 1 association and 2 under units as follows: (I) L. edulis plantation; (Ia) E. roseum under unit; (Ib) Reineckea carnea under unit; (II) Ardisio-Castanopsietum sieboldii. The density of E. roseum was 14.0-24.0 individuals per 100m² in the E. roseum under unit. The average scape height of E. roseum was 10.6-12.2cm in the E. roseum under unit. Result of PCA analysis demonstrated that the site conditions varied between habitats and non-habitats of E. roseum. In the E. roseum under unit, the thickness of litter layer, coverage of litter layer, and soil moisture showed a higher tendency than those in the R. carnea under unit and Ardisio-Castanopsietum sieboldii. In conclusion, the abundant plant litter and abundant or excessive soil moisture will be required to maintain the habitats of E. roseum.
