In Northern Ireland , this type of terrain only covers 0.4 % of the total land area .
In Northern Ireland , this type of terrain only has decreased by 18 % over the last ten years mainly due to the 21 % decrease in Fermanagh coverage .
In Northern Ireland , this type of terrain only covers 0.4 % of the total land area and has decreased by 18 % over the last ten years mainly due to the 21 % decrease in Fermanagh coverage .