Ancient oak trees in County Antrim get the halo effect
Conservationists are using a new technique to protect 500-year-old oak trees in a County Antrim wood.
It is known as haloing and entails cutting away other trees around them to give them space.
Despite their size and seniority in the forest, oaks are sensitive to crowding.
Other species growing up through their canopy cause them to retreat. In time, it may kill them.
Glenarm Wood outside the County Antrim village of the same name has probably the best oak wood in Northern Ireland.
It has between 400 and 500 specimen oaks considered "ancient or veteran".
Ancient oaks are those considered to be at least 500-years-old.
Ulster Wildlife leases the wood from the Glenarm Estate.
Reserves manager Andrew Crory says the younger trees are "basically growing up through the armpits" of the oaks.
"You can imagine if someone kept poking you again and again, you would start getting a bit annoyed," he said.
Eventually the trees start to retreat, with lower branches dying off, until the entire tree dies.
Mr Crory explained that it is not only the trees that are at risk, but the scores of species of plant, insect and animal life that live within each one.
"If an oak dies, where do all the invertebrates, the fungi, the beetles, the mosses and the lichens go?
"They need that tree at a certain stage of growth.
"So the whole ecology of those oak trees will be lost as well."