The organisation also wants a programme to research the suitability of the tree species that were native to Ireland before the most recent ice age in order to enhance biodiversity and resilience to future climate change.
This raises an important topic for debate. Ireland has a little more than 20 species of tree classified as 'native', making us one of the poorest countries in the temperate world for the number of native species, and therefore for biodiversity.
In contrast, Malaysia, a country I was fortunate enough to visit in recent months, has more than 2,500 species of native tree.
This trip brought home to me the paucity of native trees at home. Yes, in many ways the two regions are not comparable. Malaysia is a tropical country with areas of forest that are more than 130 million years old. But it does drive home the importance of all countries enhancing what biodiversity they possess as much as possible.
This time last year, Crann lobbied the Government to change its attitude to what constitutes a native tree. Crann's director, Diarmuid McAree, argued that in the year of The Gathering it was appropriate to welcome back home the tree natives that had been banished from the island of Ireland by the ice ages.
"These were trees that were driven to extinction on this island," he said.
"They are now looked down upon as being somehow inferior in status to the other tree species that are regarded as native.
"In the interests of biodiversity, we are calling on the Department of Arts, Heritage and the Gaeltacht to widen its concept of native trees to embrace these one-time natives. Until there is a change in official outlook on this issue, Ireland will remain on the list of relatively impoverished countries in terms of biodiversity.
"Ireland has just 24 native tree species," Mr McAree said. "Western Europe is somewhat more biodiverse with about 100 natives, but it is still very far behind North America with its estimated 1,000 species.
"The reason for this huge difference lies in the geography of the mountain ranges on the two continents. The east-west geography of Western Europe's mountains prevented tree species from finding refuge to the south to escape from the effects of the ice ages. By contrast, North America – where the main mountain ranges run north-south – was a much luckier place for tree species, which were able to retreat southwards," he said.
"In the geological period immediately before the ice ages, Ireland had a much greater diversity of tree species. These included fir, maple, sweet chestnut, swamp cypress, beech, walnut, tulip tree, sweetgum, sourgum, pines, spruce, Japanese umbrella pine, wingnut, redwood and hemlock," said Mr McAree, who also serves on the United Nations committee on forest management. Prior to his retirement, he served for a number of years as chief inspector with the Forest Service.
Some of these species are no strangers to foresters, but the more purist environmental and ecological scientists amongst us sometimes still argue against their inclusion in planting programmes.
Perhaps if more people appreciated that only a few thousand years ago these species were in fact natives, attitudes might change.
Acceptance of these previous native tree species as part of our heritage would not be a threat to existing natives, but would enhance Ireland's biodiversity and the richness of our landscapes. Crann, which this year will celebrate the 21st anniversary of its joint Oak Glen plantation with Coillte, remains very much in favour of increased planting of native trees.
However, Ireland has one of the lowest levels of tree cover in Europe and there is plenty of room for both current natives and previous natives.
For further details visit Crann's website www.crann.ie or email Crann at email@example.com
William Merivale is national secretary of PEFC Ireland and a forestry consultant based in Cork