The value of trees in the daily lives of Ireland's earliest inhabitants is being revealed along the N6, writes CLAIRE O'CONNELL
ARCHAEOLOGICAL digs turn up exciting artefacts – jewellery, utensils and buildings that our ancestors left behind as clues to how they lived and died thousands of years ago. But as well as the man-made items, there’s another vast bank of information to be plundered: the record that nature left behind.
If you look closely, pollen, charcoal and preserved wood found at or near excavation sites can tell us how humans understood and interacted with their environment, particularly with the woodlands on which many relied for building materials and fuel.
“They really knew their trees,” says archaeologist Ellen OCarroll, who is looking at woodland use in the Midlands going as far back as the Stone Age.
“Trees were part of their life and folklore and history, and they were used to make artefacts. It’s hard for us now to appreciate just how important they were.”
To find out more about how humans used the woodlands around them, ocarroll is doing a PhD on the environmental context of 86 archaeological excavations along the N6 route between Kinnegad and Athlone.
To work out what trees were growing in the area, she analyses pollen grains laid down in sediment during that period. Changes in species’ abundance can signify human activity, she says. “When you have less oak, there were probably more people in the landscape cutting down the oak.”
But what wood did people actually choose? That’s where charcoal found at archaeological sites can help, says OCarroll, whose work at Trinity College Dublin’s botany department is supervised by Prof Fraser Mitchell. “With the charcoal, I can tell under the microscope what species it is,” she says, adding that the forest’s former inhabitants can also leave clues. “Sometimes you can see insect channels and you can tell whether people were collecting wood from the forest floor, where it was a little bit rotten, or whether they were collecting wood from the trees.”
And on the rare occasion that wood itself has been preserved at a site, rather than its burnt remains, OCarroll looks for evidence of practices like coppicing. Our ancestors often chose trees for specific functions – oak was a favourite for burning at high temperatures, while hazel was handy for building and yew was in fashion for making tankards and bowls in some periods, she says.
So far, ocarroll’s study has found changes in species’ profiles over time in the region. “My initial results suggest that in the Neolithic (Stone Age) and early Bronze Age there’s lots of oak, then as you go towards the later Bronze Age, you have more ash and hazel, so they were cutting down the trees and collecting the wood from a more open landscape.”
For the rest of her PhD, which is funded by the National Roads Authority, ocarroll plans to link environmental data with individual sites, and to develop more robust guidelines on how best to mine charcoal and pollen for information in an Irish context.
Meanwhile on the N8 route between Mitchelstown and Cashel, wood specialist Lorna O’Donnell is looking at charcoal from over 40 Bronze Age sites, including a flat cemetery at Templenoe, which houses around 76 cremation pits. At the Tipperary burial site, excavated by Martin Doody for Margaret Gowen Co, people used oak because it could burn at the high temperatures needed to cremate a human body.
But more mysteriously, some of the pyres used less suitable fruit wood, which may have been apple, pear or hawthorn, says O’Donnell, who is completing a PhD at University College Dublin’s school of archaeology.