Ecology and management of invasive Poa annua on sub-Antarctic Macquarie Island
PhD candidate: Laura Williams
- 45-60 °S
- Wet, windy and cold
- Depauperate flora and faunas > isolation and harsh climate
- High conservation value > wildlife, endemics, unique environments.
Macquarie Island location
- 54°30'S, 158°57'E
- Southern Ocean
- Between Tasmania and Antarctica.
Macquarie Island — natural history
- Climate: wet, windy, cold
- Biogeography: elongated, undulating plateau, oceanic origin
- Soils: peats, dry tundra
- Flora: 42 vascular plants, many bryophytes, 3 aliens
- Fauna: seals, albatross, penguins, seabirds.
Invasive species in the sub-Antartic
- Biological invasions substantially affect the structure and function of ecosystems
- Most serious threat to the conservation of the sub-Antarctic
- Over 108 alien vascular plants
- Majority are transient/persistent and restricted, some aggressively spreading and invading
- Risk of invasion increasing.
Poa annua on Macquarie Island
- Common and widespread
- First recorded in 1873 Colonises disturbed sites
- Competes with native species for space
- Maybe outcompeted with removal of herbivores
- Most widespread sub-Antarctic weed
- Mediterranean origin > cosmopolitan
- Classified as an invasive alien
- High phenotypic and genotypic variability, high fecundity, adapted to many habitats, highly tolerant
- Infests disturbed areas.
Ecology and Management
We aim to:
- understand the ecology of Poa annua in the sub-Antarctic environment
- investigate the effectiveness of a range of management techniques
- Seed banks — seed viability, longevity, distribution
- Ecology competition between Poa annua and native grasses
- Manual removal of biomass