Weeds down under: invasion of the sub-Antarctic wilderness of Macquarie Island

• Main Authors: Williams, Laura, Kristiansen, Paul, Shaw, Justine, Sindel, Brian, Wilson, Susan C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Plant Protection Quarterly 2013
• Subjects: Poa annua; Alien; Weed management; World Heritage; 1102 Agronomy and Crop Science; 1108 Horticulture; 2308 Management; Monitoring; Policy and Law; 2309 Nature and Landscape Conservation; Antarctic; Major Island; Antarc*; Macquarie Island
• Online Access: https://espace.library.uq.edu.au/view/UQ:330349

The sub-Antarctic islands are some of the least inhabited and most protected ecosystems in the world. Due to their isolation and low human visitation they have escaped the worst effects of alien plant invasion. The sub-Antarctic islands are all nature reserves due to their high conservation values, and Australia's Macquarie and Heard Islands are World Heritage Areas. The sub-Antarctic climate is harsh and the vascular flora is relatively species poor, yet they support a number of endemic species. Despite the isolation of these islands, 108 alien plant species have become established since European discovery, posing threats to their biodiversity. Poa annua (L.) has quickly become widespread throughout the sub-Antarctic since its introduction and is present on all the major island groups. It is widespread on Macquarie Island, readily colonising disturbed areas and competes with native vegetation for space. The highly invasive capabilities of the grass are due to its high phenotypic and genotypic variability, wide tolerance of environmental conditions, and high fecundity. We are investigating the ecology and control of P. annua to broaden understanding of invasion biology and to assist in the development of non-native plant management in the sub-Antarctic and Antarctic region. While previous studies have shown P. annua is a successful weed, in this study we will quantify its traits and growth in the sub- Antarctic. This paper provides a background to the study of P. annua in the sub-Antarctic.