Killarney national park is Ireland’s environmental jewel, a 10,000-hectare Unesco biosphere reserve with ancient oaks and sublime landscapes that drew 1.7 million visitors last year.
It is expecting even more this summer after a star turn in David Attenborough’s documentary series Wild Isles that showed two red deer stags locked in a dramatic battle for a harem of females.
Some Irish environmentalists, however, say the park in the heart of County Kerry is also home to a much darker phenomenon: a slow-motion ecological calamity. Rhododendron, sika deer and other invasive alien species are asphyxiating the ecosystem, creating “ghost forests”, they say.
“Killarney national park is an ecological disaster zone,” said Eoghan Daltun, a rewilding activist and author who owns a nearby farm. “You have zero natural regeneration of trees. It contains what is by far Ireland’s most important remaining piece of indigenous woodland and it’s being allowed to just essentially die off.”
That may sound alarmist – but other activists as well as scientists and official reports agree there is a problem. “The great rhododendron disaster has taken place while Killarney is in the hands of the Irish nation,” Daniel Kelly, emeritus professor in botany at Trinity College Dublin, told the Irish Times in 2019.
The National Parks and Wildlife Service, which manages the park, published an independent review last year that noted “impressive improvements” but also warned of an “alarming” situation in the western woodlands.
The biggest threat is Rhododendron ponticum, a tall, hardy shrub introduced from the Mediterranean in the 19th century. In Irish and British soil it spreads rapidly, blocks the sun, smothers other plants and kills oaks. It is almost impossible to eradicate.
The dire warnings about Killarney reinforce wider concerns about Ireland’s environmental record despite its green image. In the 1980s, more than 500 rivers and lakes had pristine water, now there are just 20, according to the Environmental Protection Agency. About 250,000 hectares (620,000 acres) of wetlands have been lost in the past two decades. The European Commission has brought Ireland to the European court of justice for inadequate prevention and management of invasive alien species, among other charges.
Yet to hike through Killarney national park is glorious. Oaks soar, trout dart in streams. And if you are with Éamonn Meskell, the experience is reassuring. He is the park’s divisional manager and says his staff and contractors are prevailing.
“We’ve just turned the corner with rhododendron,” he said during a tour last week. “We are the leaders in this now. We know how to kill it. We’ve perfected our methods.”
In the first phase, workers with chainsaws topple the dense shrubs, drill into stumps and spray the controversial herbicide glyphosate.
“The rhododendron was wall to wall here,” said Meskell, in a part of the park called Reen. “We cleared a massive amount in 2007, it was like a war zone. Now look, stump,” he said, pointing at a wizened stump. “Stump,” pointing at another. “Stump, stump, stump.”
The crucial part is follow-up because almost inevitably some rhododendron will survive and within a few years bloom again, with each flower spreading up to 7,000 seeds, a task to rival that of Sisyphus. “With rhododendron there is no endgame, it’s a labour-intensive effort to keep it under control,” said Tim Cahalane, a conservation ranger.
The strategy to keep cleared areas clear is to divide the park into 53 zones, monitor them with the help of a phone app and deploy contractors and volunteers as needed. As evidence of success, Meskell pointed out seedlings of oak, beech, birch and other trees in Reen, Cloghereen, Blue Pool and other parts of the park. “It’s working. The woodland floor is coming back.”
For some critics of the National Parks and Wildlife Service this is a facade, concealing ruin.
Since 2013, Groundwork, a local environmental group, has produced surveys with geo-tagged photographs showing reinfestation in woods that had previously been cleared. “The most valuable areas of the park have been allowed to regress; now there is no single woodland in the park that is under control,” said Una Halpin, a veteran member. “The habitat is being allowed to deteriorate.”
Environmentalists want a severe cull of sika deer, whose grazing damages the forest floor and facilitates the spread of rhododendron, and greater focus on ancient woodland.
Personal dynamics complicate the science. From 1981 to 2009, Groundwork volunteers cleared rhododendron – and kept it clear – from about 350 hectares of woodland. But relations with the parks service soured when managers widened the work to other areas, allegedly at the expense of safeguarding the priority woodlands.
Amid accusation and counter-accusation, Groundwork stopped doing clearances. Meskell said he lamented the loss of its expertise and passion. “It’s awful – here we are with the same objectives.”
Paddy Woodworth, an environmentalist and former Irish Times journalist, said park service clearances focused on areas visible to tourists. “The mature trees look beautiful but if rhododendron returns and the deer graze, the trees will die and there is no generation there to replace them. What you’re looking at are ghost forests.”
Meskell rejected the accusations and said time would vindicate his strategy. In the meantime, he has another, more mundane concern: he fears amateur photographers seeking to emulate the Attenborough documentary will get too close to stags during the autumn rutting season. “People without the experience coming here chancing their arm – frightful.”
