Friends of the Irish Environment (FIE) accused Coillte of flouting strict tree felling conditions, designed to protect the environment, on a site in north Cork.
But Coillte rejected the accusations and said it has complied with all regulations.
“No statutory body has lodged any complaints regarding environmental or other damage on the site in question,” a spokesperson said.
The state-owned forestry company is felling a Sitka spruce plantation in the Ballyhoura Mountains, near Doneraile.
The site is in the catchment of the Awbeg River, a tributary of the Blackwater.
The Awbeg is a breeding ground for otters and supports a significant population of Atlantic salmon. The river also supports a population of White-clawed crayfish, a threatened species.
FIE spokesman Tony Lowes claimed that silt traps have not been put in place on the felling site, and that special tracks to carry heavy machinery have not been provided.
“High impact clear felling of extensive plantations on sensitive upland sites combined with high rainfall is a recipe for disaster,” he said.
And this is the fifth example from the south-west that the group has reported to the Fisheries Board, the Parks and Wildlife Service, the Forest Stewardship Council and to Coillte itself in the last 18 months, he added.
FIE backed a protest outside a forestry conference in Cork yesterday, mounted by five forestry contractors concerned about the environmental damage.
Protest organiser Michael Cronin, a tree felling contractor from Ardmore, said they felt compelled to highlight the situation despite the risk of losing work.
“We are aware of huge damage being done quite unnecessarily,” he said.
“Apart from the environmental damage, it gives both the contractors and forest industry a bad name. If we complain we lose our jobs.
“Seas of mud are being washed into the rivers. There is major silt and pollution going in to rivers because proper procedures are not being adhered to.”
The protesters called for a halt to the felling until proper protection is put in to stop the environmental damage.
But Coillte said its forests have been certified by the Forest Stewardship Council (FSC) since 2001 as being managed responsibly.
“FSC certification mean that our forest management meets strict environmental, social and economic criteria,” the spokesperson said.
“Coillte recently introduced new mountain bike trails in the Ballyhoura mountains. These trails are the largest of their kind in Ireland and have provided the local community with world class recreation activities in their local forest.”
Coillte is the biggest landowner in Ireland. It owns over 445,000 hectares — about 7% of the total land cover in Ireland — of which 79% is forested.
Its net assets last year were worth an estimated €1.5 billion and its profits were €40.1m. The group employs about 1,000 people.