Oak (All About)
The oak tree is described as the king of the woods. It was greatly valued in olden times in Ireland and was considered to be one of the “nobles of the wood”. It is the canopy tree in our native oak woodlands that have been here since the end of the last Ice Age ten thousand years ago. Oak trees are one of the last trees in Ireland to get their leaves each year — it is usually the end of April before they emerge from their brown buds.Read moreRead less
Oak leaves are particularly prized by all sorts of insects who feed on them. The caterpillars of the purple hairstreak butterfly depend on them, as do many species of greenflies, shield bugs, moths etc. It fact it has been estimated that some 286 species of insects and other invertebrates feed on the leaves of the oak. All this eating of fresh oak leaves in May and June leaves the tree somewhat depleted. But the tree fights back, producing a new growth of leaves with lots of unpalatable tannin in them and quite browny-purple in colour at the end of July. These are called “Lammas Growth “, Lammas being the time of year between July and August.
Catkin-like flowers are produced by the tree in early April before the leaves are formed. This is because they are wind pollinated and the presence of leaves would get in the way of the blowing pollen. Acorns are formed from the fertilised flowers and ripen in autumn. These are prized as a source of food by birds such as jays and rooks, squirrels and by mice. Grey squirrels are able to eat unripe acorns, red squirrels must wait until they are fully ripe, by which time if there are grey squirrels in the area the acorns may be all gone, leaving the red squirrel short of food and unable to compete with the grey.
New oak trees will emerge from acorns which may have been buried and not
retrieved by their owner later in the winter. There are two native oak species
— the pedunculate oak whose acorns are borne on stalks and the sessile oak
whose acorns have no stalks. Both are very long-living trees and can survive
for well over five hundred years in ideal circumstances. The Irish name is dair
and many places in Ireland reflect this. Counties Kildare and Derry are called
after the oak as are all the place names beginning with Derry such as
Derrynaflan and Derrynane.
Oak trees produce tannins so oak bark was much in demand by the leather tanning industry. Its timber was excellent for shipbuilding and for use as charcoal. So it was no wonder at the time of the plantations — particularly the Cromwellian plantation in the 1650s when soldiers were paid in land rather than money — that the first thing the planter did was strip the land of its timber in case their tenure there didn’t last very long.
Things to do
1. Find an oak tree that the children can be brought to see. Collect leaves and acorns.
2. Back in class get the pupils to draw outlines of the leaves so that they will learn their characteristic shape.
3. The acorns can be sown in pots of compost and planted out the following summer when the seedlings have emerged.