Eradication of invasive alien plants on Lord Howe Island, NSW using three Asparagus species (Asparagus asparagoides (L.) Druce, A. plumosus Bakerand A. aethiopicus L.) as a case study
J. Le Cussan, Lord Howe Island Board, Lord Howe Island, New South Wales 2898, Australia.
Of the approximately 500 recognized alien plants on Lord Howe Island, 17 are declared noxious weeds. Following many years of dedicated but ultimately futile 'control' effort, 15 of these (including three Asparagus species) are now targeted for total eradication on all land tenures. The two other listed noxious weeds, Lilium formosanum and Ageratina adenophora are so widespread and numerous, including in totally inaccessible areas, that eradication is not planned for these species at this stage. The distribution and total population of A. plumosus is relatively limited, while A. aethiopicus and A. asparagoides are more widely distributed and more numerous. In contrast to the mainland situation, the chance of re-infestation of the island following eradication of these species is very low given the distance offshore from mainland Australia (provided effective quarantine is maintained). A close-spaced grid-search and treatment methodology within 6-8 hectare blocks has been adopted for the whole island. Management is based on a model developed by the NZ Department of Conservation for their island weed management programs.
Plant Protection Quarterly (2006) 21 (3) 117-121.