The Government's plan to cover 24 per cent of Ireland with trees by 2030 is under threat - from squirrels. American grey squirrels to be precise.
A recent seminar held at Tullamore, Co Offaly highlighted that young woodland areas can be damaged by grazing deer herds. However, once the trees are established, it is the grey squirrel which is the biggest danger.
Unlike the smaller and woodland-friendly native red squirrels, the grey squirrels have a habit of stripping the outer bark from trees in order to eat the soft inner tissue.
Director of the European Squirrel Initiative, Mr Charles Dutton, said in severe cases up to 25 per cent of the crop can be lost completely, "resulting in destruction of habitat and substantial financial loss".
Grey squirrels also drive out the native reds and in Britain have succeeded in almost wiping out the species altogether. They also carry a disease, Parapox Virus, which is deadly to the reds.
Mr Michael Carey, a former chief director of Coillte, described the American interlopers as "tree rats".