President Mary McAleese helped local schoolchildren to plant a holly tree in Phoenix Park today to mark the start of National Tree Week.
The theme of this year's National Tree Week, "Harvesting an Ocean of Air", reflects concerns about global warming and, it is hoped, will encourage tree planting as a local step towards combating this worldwide problem.
"The ceremony of planting the holly tree symbolises what we would like to see happen all over the State," said Executive Director of the Tree Council Of Ireland John McLaughlin. "It also symbolises the danger to holly trees from indiscriminate cutting for decorations."
Organisers of National Tree Week have provided 15,000 trees to be distributed by local authorities to community groups and schools.
Mr McLaughlin said: "If we all planted a tree this week that would add 3.5 million to four million trees - that would make a significant difference to our tree cover."
Over 300 other events have been organised all nationwide, include forest walks, tree-planting ceremonies, workshops, talks and competitions.