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

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.

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

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

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

Rivers and Waterways

Distribution along rivers 15.6%

Roadsides and paths

Distribution along roadsides 30.1%

Distribution within 50 m of buildings 49.2%

Agricultural land

Peat bogs

Quarries and disturbed land

Heath

Coastal Cliffs

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

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

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

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

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

How to treat each plant Cut, Inject and Spray

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

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)

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