Decades ago, a well-intentioned tree planting project in Tallaght went wrong.
Sometime in the 1980s, Dublin Corporation planted beautiful Japanese cherry trees along the streets of Tallaght, says Éanna Ní Lamhna, the vice president of the Tree Council of Ireland.
But those trees have shallow roots. “They are not suitable city trees and they broke the footpaths and were causing a nuisance and had to be removed,” she says.
The council no longer plants Japanese cherry trees in the city, she says. Local authorities are switched on to the need to plant the right trees in the right places, says Ní Lamhna.
Trees that are a suitable size and a wider variety, including native trees, to encourage biodiversity, she says.
That’s one of the reasons why Dublin City Council officials are keen to get a full picture of all the trees in the city. They’re calling on the public to help create the city’s first-ever Dublin tree map.
That “will give us a complete picture of our urban forest, a visual depiction of the species diversity and distribution throughout the city”, says Dublin City Council’s tree officer, Ludovic Beaumont.
This mapping project should help the council to protect the city’s trees, too, identifying any that might be at risk, boosting biodiversity, and helping to control carbon emissions.
A spokesperson for Dublin City Council said they couldn’t put a price on getting an equivalent survey done by consultants, because no consultant would have the knowledge or access that local residents have.
“We’d never be able to get access to trees on private lands and in people’s gardens,” she says.
Local residents may know exactly when a tree was planted in their garden, or which birds nest on their streets, says the council spokesperson.
“If you know anything special about a tree such as its history or how it’s used by wildlife, that would be fantastic to share with us,” says the spokesperson.
Dubliners can help just by uploading photos of trees in their gardens, streets or local parks, using the Curio portal or the Curio-xyz mobile app.
Using the Map
“Anything to do with improving people’s awareness of nature has to be good,” says Ní Lamhna of the Tree Council of Ireland.
Looking at trees has been shown to improve mental health, she says.
But the main point of the project is to foster and build up biodiversity in light of the biodiversity and climate crisis that Dublin City Council declared in May last year, says the council spokesperson.
In other words, to help further the roll-out of the city’s biodiversity action plan. “Because of the importance of trees to our biodiversity,” she says.
Trees are essential in the city, so the council needs to know where they are and what they are doing, says the council spokesperson.
“Certain species of trees are useful for wildlife habitats, for filtering air pollution, for taking up rainwater to limit flooding and to provide pollen for bees,” she says.
Trees improve air quality and store carbon. “The value of trees to our planet’s health by storing carbon, degrading pollutants and improving soils is well acknowledged,” she says.
Felim Sheridan, secretary of the Arboricultural Association, said that “knowing the distribution of our city’s tree populations allows the council to be proactive in its management, for example against disease or infestation of harmful insects”.
The council can look at whether an area is overdependent on one species and what might happen if that species developed a disease, he says. And it can look at where to add more diversity, he said.
Back to Roots
Dublin City Council can also use the information that it gathers from the public to work out if the city has enough native trees.
“We have been increasing the number of native trees, especially in parks and open spaces which host protected species, over the past decade,” said a council spokesperson.
Native trees are better for biodiversity as local animals and insects can live in them and feed on the leaves, says Ní Lamhna.
That said, there are only 28 native species of trees in Ireland, says Ní Lamhna.
Not all of those are suitable for the city streets. “Things like oak and ash might be too large, for example,” she says.
Some non-native trees are good trees too, she says. Any trees that produce flowers can be used by bees, for example.
“Just because a tree is not native, it isn’t a total mortal sin,” she says.