Environmental weeds of Christmas Island (Indian Ocean) and their management

J.T. SwarbrickA and R. HartB

A Weed Science Consultancy, Toowoomba, Queensland

B Parks Australia North, Christmas Island


The environmental weeds of Christmas Island (Indian Ocean) are mostly exotic tropical rainforest trees, shrubs and vines that persist in areas that have been rehabilitated after being mined for phosphate but which now form part of the Christmas Island National Park. Other environmental weeds occur within the rainforests, along rainforest margins and in other situations throughout the island.

The major environmental weeds of Christmas Island are Adenanthera pavonia, Aleurites moluccana. Castilla elastica, Clausena excavata, Cordia curassavica, Delonix regia, Ficus elastica, Hevea brasiliensis, Mikania micrantha, Mucuna albertisii, Pithecellobium dulce, Pterocarpus indicus, Schefflera actinophylla, Spathodea campanulata and Tecoma stans. Minor environmental weeds of the island include Antigonon leptopus, Barringtonia asiatica, Ceiba pentandra, Imperata cylindrica, Leucaena leucocephala, Muntingia calabura, Nephrolepis biserrata, Nephrolepis multiflora, Pluchea indica, Psidium guajava, Ricinus communis, Senna sulfurea and Syzigium spp.

An integrated system of environmental weed control is being developed on the island. It includes strict quarantine, the eradication of major weeds of limited distribution, the development of local legislation to prohibit the growing of certain plants, the encouragement of competition by native rainforest plants, limited physical and biological control, and progressive chemical control of the remaining weeds followed by rehabilitation with native rainforest seedlings.


Plant Protection Quarterly (2001) 16 (2) 54-57.