Mapping Gunnera tinctoria on Achill and Clare Island
Last updated: 17th November 2009
Mapping of Gunnera provides an opportunity to investigate the factors
that affect their distribution, such as habitat requirements, potential dispersal mechanisms
and means of spread, along with a detailed description where it occurs at a local level. Mapping
also forms an important role for the effective management of invasive species by providing information
on the location of plants and priority habitats for the implementation of control measures.
During 2007 when Gunnera was at its full growth Achill Island and Clare Island were mapped.
Mapping was carried out using 1:5000 vector maps, which included all roads, waterways and field boundaries.
The whole area of the two islands were mapped by foot, all roads and paths were covered and additional areas
around the coast and mountain were covered roughly with the aid of binoculars.
Each field boundry, road or waterway was mapped for presence/absence of Gunnera.
If Gunnera was present an estimation of the percentage cover for that area the type
of density (single plant, clusters, large area etc), the size of the plants (large, med, small)
and the habitat type was recorded.
Map showing the distribution of Gunnera on Achill Island in blue
Map showing the distribution of Gunnera on Achill Island shown in red with rivers overlay.
Map showing the distribution of Gunnera on Achill Island in red with roads overlay.
Map showing the distribution of Gunnera on Achill Island in red with houses overlay