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Invasive alien ornamental plants are a global problem, especially on oceanic islands, and can have severe impacts on native biodiversity. Pinanga coronata, is an ornamental palm tree that can form mono-dominant stands in its native habitat and is widely cultivated throughout the tropics. Here we investigate the introduction, spread, impact and management of this invasive palm in the Fiji Islands, using extensive discussions with local experts and ?eld surveys. Pinanga coronata was introduced in the 1970s to the Colo-i-Suva area, eastern Viti Levu island, Fiji´s principal island, and has since become invasive in mahogany plantations and lowland rainforest. It has also been introduced and is becoming invasive on the western side of that island. However, the distribution of P. coronata remains geographically limited to the immediate vicinity of introduction sites but it is rapidly spreading. In each location, the species has formed mono-dominant stands in the understorey and appears to be displacing native plant species, as suggested by a negative correlation of its abundance with that of native tree ferns. This highlights the need for rapid control of P. coronata in Fiji. Local experts state management should involve manual removal of seedlings and saplings, killing of adult palms by injection of herbicide, and education and legislation to prevent the further spread of the species. Based on these recommendations and ?eld data, management actions to control P. coronata are proposed and steps to develop these into a management plan are discussed. Given P. coronata threatens native biodiversity in Fiji and has the potential to invade other rainforest ecosystems in the tropics, proposed management approaches are urgent and relevant for other tropical countries.

Between 1892 and 1930, 58 percent (30 taxa) of Hawaiian endemic forest birds either were greatly reduced or became extinct. The order in which the islands experienced major declines ofseveral forest birds is Oahu (ca. 1873-1887), Hawaii (1892-1900), Mo10kai (1893-1907), Maui (18941901), Kauai (after 1900), and Lanai (1926-1932). Loss of habitat, reduced food supply, introduced avian diseases, as well as predation by man, feral cats, mongooses, and Norway rats (Rattus norvegicus) all appear to have reduced some species ofbirds, but none ofthese factors adequately explains the accelerated rates ofdecline offorest birds that occurred after 1892. Although it has been assumed that roofrats (Rattus rattus) reached Hawaii with the first European ships at the end of the 18th century, there is circumstantial evidence, independent of the bird decline data, that indicates that this rat did not arrive until after 1840, probably between 1870 and 1880. The hypothesis is advanced that after its establishment on Oahu in the 1870s, R. rattus spread to the remaining large islands in the group, resulting in a stepwise accelerated decline offorest birds on each island in turn. Hawaii thus parallels some other Pacific islands where major reductions of birds have followed the establishment of R. rattus. The need for precautions to prevent rats from reaching rat-free islands in the Hawaiian group is emphasized.