1. Controlling Gunnera tinctoria
Where are we today?
By: Cristina Armstrong and Bruce Osborne

2. Background
Gunnera tinctoria is an invasive plant to the west of Ireland.
Established on Achill Island, possibly over 100 years.
Native to Southern regions of South America, similar climatic conditions
Large herbaceaous perennial plant growing over 2m tall and with up to 2m wide leaves.

3. Outline Started in 2006 – Msc at UCD (Control & Mapping)
Greenhouse experiments
Field experiments
Mapping
Eradication?

4. Mapping Using field boundaries as a site:
Presence/absence of G. tinctoria marked out.
At each site:
Percentage cover
Stand Type‏
Size (L,M,S)‏
Habitat

5. 0.69 km2 4.2 km2 = 0.46 % = 2.9 % Total Area Invaded
Area = 55 football pitches!!

6. Rivers and Waterways

7. Distribution along rivers
15.6%

8. Roadsides and paths

9. Distribution along roadsides
30.1%

10. Distribution within 50 m of buildings
49.2%

11. Agricultural land

12. Peat bogs

13. Quarries and disturbed land

15. Heath

16. Coastal Cliffs

17. Possible means of spread
Short range dispersal
Seed falls near parent plant
Long range dispersal
Rivers and roads Habitat corridors
Disturbance
Birds

18. Greenhouse Experiments
Before
Concentration of RoundUp
RoundUp V Garlon
Leaf area
After
Recommended concentration
Garlon fast-acting
Leaf area not significant

19. Field Experiments 1. 4 x 4 m plots RoundUp Two methods of application:
Cut and Paint
Cut and Injection 2.
RoundUp V Garlon
Timing of application
Selective

20. Results
Re-application needed after 2 years!!
96%
83%
61%
75%

21. When is the best time to apply?
Early applications were not successful

23. How to treat each plant
Cut, Inject and Spray

24. Current Work Eradication on Clare Island
Biodiversity Grant (Heritage Council)
Mapping
Methods used in experiment
Island involvement
Future monitoring

25. Conclusions Main habitats invaded:
Agricultural land
Waterways
Roadsides
Disturbed land
Hypothesised that disturbance is facilitating the spread.
Re-application of treatments required
Other measures of control (physical, biological)

26. Acknowledgements Bruce Osborne for his supervision.
Javier, Angeles, Noeleen, Ale, Margherita, Mark, Lisa, Michael Bob and John for all their field assistance.
Ray for his advice on greenhouse expt.
Mayo County Council.
- Carmel & Louise in GIS
- Deirdre Cunningham
Heritage Council – Funding