Pollination systems in the cool temperate mixed coniferous and broad-leaved forest zone of Yakushima Island

Animal pollination was observed in a cool temperate mixed coniferous and broadleaved forest, and in shrubby vegetation on a mountain summit, on Yakushima Island (30.2°N, 130.3°E), to the south of Kyushu, Japan. In the mixed forest, two groups of plants were recognized: exclusively canopy-flowering species, and understory-flowering species. All of the canopy-flowering species had dish-shaped flowers or flowers without petals, were visited by opportunist insects, and most of them showed a mass-flowering pattern. Each segregated its flowering time from those of the others. On the other hand, most of the understory-flowering species had bell-or funnel-shaped flowers which were pollinated by birds or bumble bees, and showed an extended flowering pattern. Their phenological flowering series (exceptCamellia japonica that was pollinated by birds), without a break, coincided very well with the active period of a bumble bee species,Bombus ardens. In the shrubby vegetation on the mountain summit, two types of species were recognized: one type also grew in the forest, whereas the other type only grew in the shrubby vegetation. The former type of species in this vegetation was visited by a more diverse range of insects than that in the forest. In particular, species visited mainly by bumble bees in the forest attracted many opportunist insects. All but one of the species that only grew in the shrubby vegetation were visited only by opportunist insects and never by bumble bees.