QUAD bikes and scrambler motorcycles have been banned from more than 160,000 hectares of mountain, beach and forest lands.
And Environment Minister John Gormley has also banned camping and lighting of fires in Knocksink Woods, near Enniskerry in Co Wicklow, under new regulations signed into law last week.
The move was taken to protect 14 sensitive nature sites which were being damaged because of recreational off-roading. The ban extends to the Wicklow Mountains, Slieve Bloom Mountains in Laois and Offaly and Galtee Mountains in Limerick and Tipperary.
Owners of quad bikes, scramblers and 4x4 vehicles who flout the law face fines of up to €5,000.
"Unrestrained use of these vehicles can cause the destruction of upland vegetation leading to erosion, the disturbance of ground-nesting birds and destruction of their nests, and permanent damage to sand dune systems," Mr Gormley said.
"The object of these directions is not to restrict people's legitimate enjoyment of outdoor recreational activities. Along with other EU States, Ireland has designated certain areas for nature protection and, in those areas, that must be our priority. Many people, indeed, find recreation in the enjoyment of undisturbed nature."
Affected landowners can appeal the decision and seek an exemption if they can prove that the scale of activities will not damage a protected site or pose a threat to protected species.
The regulations are aimed at certain activities including the unregulated use of scramblers, trail-bikes, quad bikes and off-road vehicles. Use of these vehicles for legitimate purposes such as agriculture or by the emergency services will not be impacted.
Camping will also be restricted on one site where it is causing damage to the habitat of the area -- Knocksink Woods in Co Wicklow.
The ban on off-road vehicles applies to The Raven in Wexford; Wicklow Mountains; Kilpatrick Sandhills in Wicklow/Dublin; Cahore Dunes and Polder and Cahore Marshes (Wexford); Slieve Bloom (Laois/Offaly); Carlingford Mountain (Louth); Ballyness Bay (Donegal); Gweedore Bay and Islands (Donegal); Castlemaine Harbour including Inch Strand (Kerry); Galtee Mountains (Limerick/Tipperary); Slieve Bearnagh (Clare) and Slieve Aughty (Galway/Clare).