Acorns collected last weekend from the Charleville estate outside Tullamore, Co Offaly, will be used to plant the National Millennium Forest, where an oak tree will be planted for every household in the State.
The harvest on the 2,000acre estate was organised by Crann, based at Crank House, Main Street, Banagher, Co Offaly.
The Millennium Forest project will involve planting more than one million trees in the State. In the coming weeks every household will receive a letter detailing the scheme.
Crann has been scouring the remaining oak woods of Ireland to collect native acorns for planting.
Founded in 1986 by Jan Alexander, the non-governmental, non-profit making organisation aims to reverse the situation where only 1 per cent of Ireland is under broadleaf trees.
It also wants to maintain and protect the few remaining native broadleaf forests and to substitute native timber supplies for the large quantities of imported tropical hardwoods.
Explaining the background to acorn collection, Mr Peter Madden, information officer for the organisation, said that last year 30 tonnes of acorns were imported from abroad to meet the demand for broadleaf planting by Coillte and other companies.
"Seed-buyers in Ireland have difficulty in obtaining a consistent supply of large quantities of native acorns. The vagaries of our climate cause large fluctuations in the crop and they do not keep well for greater than 12 months." He said the crop of acorns was heavily dependent on weather conditions during the flowering time for the tree in April and May. Adverse conditions such as heavy rain washed the pollen down to the ground, reducing quality of fertilisation and resulting in small crops.
Good crops came only every four or five years, he added.
"What we are attempting to do is to substitute these imports with as many native species as possible. Last year we managed to pick up nearly five tonnes of acorns," he said.
"We hope to surpass this figure this year because of the huge demand for the Government's millennium forest programme which will involve planting a tree for every homestead in the country.
"As part of Feile Shamhna na gCrann, the autumn festival of trees, we went out to the great oak forest in Charleville to pick as many acorns as we could for the event," he said.
"Charleville is special because what is reputed to be the oldest oak tree in Ireland, the Great Oak of Charleville, estimated to be at least 800 years old, is at the entrance to the estate.
"Chances are the other great oaks in the forest are descendants of this great tree and we hope they will form a major part of the millennium programme."
He said that last year at Charleville, volunteers collected over three-quarters of a tonne of native acorns, which would result in the planting of a quarter of a million native Irish oak trees.
"This year the young people who took part were paid for their efforts and they will use the money for charities and to fund their own organisations." He said this year was disappointing because of the poor weather in May. The production of acorns was very poor, unlike further south, in Kerry.
"The volunteers who braved the poor weather did manage to come up with 60 kg of acorns, which was far below our expectation and much lower than last year's harvest," he said.
"However, we always have next year to look forward to and we were very satisfied with the harvest from Killarney, where 700 kg was collected some weeks ago. "There is a growing interest in our heritage and that was very evident on Sunday. It was wonderful to see so many young people out there collecting for us," he said.
"It is a great source of satisfaction to us that more broadleaf trees are being planted and that this is being done with native Irish seed," he said.
Charleville wood is under threat, according to local councillors, because of a plan to build a £28 million bypass through part of it.
The council officials are to hold a public meeting to hear objections from local people about the council's preferred route for the bypass. This would go through part of the woods, which lie less than a mile to the south of the town.