The trees distributed by the Tree Council of Ireland for National tree week included the Silver Birch and the Rowan Tree – also known as the mountain ash.
These are native Irish trees – we have a total of 28 different species of native tree.
What is a native Tree? It all goes back to the end of the ice-age, ten thousand years ago when the ice and snow covering Ireland to a depth of several kilometres final melted exposing a bare country. It was still joined to Britain and continental Europe as sea levels were much lower than they are today. So as the climate warmed up the trees that had been growing south of the ice covered regions could spread north again. There were no people to bring them so it was the wind and the birds and the mammals that moved the seeds. Trees like birch, alder and willow have light wind-blown seeds so these blew north and self-sowed. And as these trees grew they provided perches for birds.
These birds were feeding on berries from trees that grew further south so as they voided the seeds of the berries when they perched in the trees new trees such as holly, mountain ash, elder, hawthorn, spindle, guilder rose, blackthorn, wild cherry, crab apple could all spread north. The insects and invertebrates associated with these trees spread too and the forests advanced.
Trees with nuts as seeds moved slower as they depended on mammals but oak and hazel managed to arrive in the thousand years that it took for the ocean to rise enough to cut Ireland off from Britain and the rest of Europe.
So in all 28 different species of tree made it here naturally with their own associated fauna so these are particularly rich in biodiversity. For example there are 280 species of insects associated with the oak tree.
All the rest of the many, many types of tree that grow so well here were introduced by humans. Beech, sycamore, Horse Chestnut, lime are all introduced species as are the forests of Sitka spruce that cover our mountainsides.
Our native trees are:
- Oak – 2 species
- Scots Pine
- Birch (2 species)
- Willow (4 species)
- Mountain Ash
- Guelder Rose
- Wild Cherry (2 species)
- Crab Apple