Species composition and species richness were studied in the lucidophyllous forests on Yakushima Island, Kagoshima Prefecture. In total, 40 quadrates were investigated. The lucidophyllous forests were classified into Machilus type forest (Machilus thunbergii-Ficus superba Comm.), Castanopsis type forest (Hydrangeo-Castanopsietum sieboldii) and Cyclobalanopsis type forest (Illicio-Distylietum racemosum). Machilus type forest was characterized by the presence of Litsea japonica, Alocasia odora, Elaeagnus pungens and 8 other species that were resistant to salt breeze and absence of Castanopsis sieboldii and Cyclobalanopsis species. This forest was distributed on the coastal area. Castanopsis type forest was characterized by the presence of Meliosma rigida, Lasianthus fordii, Hydrangea grosseserrata and 21 other species. This forest was distributed on the lowland. Cyclobalanopsis type forest was characterized by the presence of the vascular epiphytes which were Mecodium polyanthos, Lysionotus paucifl orus, Hymenophyllum barbatum and 5 other species, and the presence of Symplocos myrtacea and others. This forest was distributed on the mountain districts. The mean number of lucidophyllous elements per quadrate (100m2), which were indicative of species richness, in Machilus type forest, Castanopsis type forest (II-2) and Cyclobalanopsis type forest were 21.4, 56.6 and 34.8, respectively. The lower species richness of Machilus type forest and Cyclobalanopsis type forest was caused by the salt breeze and the low temperature, respectively. The highest species richness of Castanopsis type forest on Yakushima Island among the lucidophyllous forests at Yakushima Island and northward was due to the high temperature.
