Trends in invasion by alien woody plants of the New England region, New South Wales
J.M.B. Smith, CRC for Weed Management Systems and School of Human and Environmental Studies, University of New England, Armidale, New South Wales 2351, Australia.
Rural roadsides in New England and six sites in the city of Armidale were surveyed for alien woody plants at intervals of 18 and 13 years respectively. Sixty-three alien woody plant species were recorded in total. In the roadside study, of the 21 species recorded at least ten times at either survey time, 15 increased their populations and range and only four became less common. In the city study, the number of species recorded increased from 26 to 30, with seven species appearing and three disappearing from the sites between surveys; of 23 species recorded at both survey times, 11 increased and only two decreased in number of sites occupied. Species whose seeds are bird-dispersed were prominent, particularly among those whose invasions appeared most advanced. By contrast, wind-dispersed species were fewer, concentrated in the category of recent invaders, and apparently remaining longer as 'sleeper' weeds. The surveys document the accelerating scale of invasion of the region by alien woody plants.
Plant Protection Quarterly (2000) 15 (3) 102-108.