Impacts of streaked shearwater (Calonectris leucomelas) on tree seedling regeneration in a warm-temperate evergreen forest on Kanmurijima Island, Japan

摘要: The ground vegetation of an evergreen broad-leaved Persea thunbergii-dominated forest on Kanmurijima Island has been heavily damaged by a ground-burrowing seabird, the streaked shearwater (Calonectris leucomelas). To clarify effects seabird trampling and burrowing recruitment tree seedlings, 22 paired quadrats, protected unprotected against seabirds, were laid out under various degrees canopy coverage, ranging from heavy- to light-shade. Protection activities resulted in increase species richness seedlings. Seabird had significant effect seedling diversity, while coverage was shown be important for herbaceous diversity. Though emergence thunbergii, dominant, not affected that Mallotus japonicus, deciduous pioneer tree, negatively both factors. heavy-shade survivorship species. Low seedlings may doom present-day warm-temperate thunbergii island. Mechanical impacts resulting soil erosion play role regeneration dynamics.