Killarney National Park, a treasured environmental gem in Ireland, faces a slow-motion ecological crisis caused by invasive species like rhododendron and sika deer, threatening its delicate ecosystem and creating “ghost forests”.

While the park boasts ancient oaks and breathtaking landscapes that attract millions of visitors annually, concerns raised by Irish environmentalists, scientists, and official reports indicate a pressing issue that demands attention.

“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.”

The National Parks and Wildlife Service, responsible for managing the park, conducted an independent review revealing both impressive improvements and alarming situations in the western woodlands. The main culprit behind the crisis is the invasive Rhododendron ponticum, a hardy shrub introduced from the Mediterranean during the 19th century. Its rapid spread in Irish and British soil has adverse effects, blocking sunlight, suffocating other plants, and even causing oak fatalities. Unfortunately, eradicating it has proven nearly impossible.

These distressing revelations concerning Killarney reflect broader concerns about Ireland’s environmental record, despite its renowned green image. The country has seen significant degradation in its water quality, with a drastic reduction in the number of pristine rivers and lakes from the 1980s to the present day. Wetland loss has been extensive, and the European Commission has taken legal action against Ireland in the European Court of Justice for inadequate management and prevention of invasive alien species, among other charges.

“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.

Nonetheless, the experience of hiking through Killarney National Park remains awe-inspiring. Towering oaks and darting trout in streams offer a glimpse of nature’s beauty. Éamonn Meskell, the park’s divisional manager, instills confidence as he assures that his staff and contractors are actively addressing the issues.

“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.”

The strategy employed to combat the invasive species involves a multi-phase approach. Initially, workers use chainsaws to topple the dense shrubs, drill into stumps, and apply 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.”

However, the key lies in vigilant follow-up, as some rhododendron inevitably survives, capable of blooming again within a few years and producing thousands of seeds per flower, reminiscent of Sisyphus’s eternal task.

To maintain cleared areas, the park is divided into 53 zones, closely monitored through a phone app, and attended to by contractors and volunteers as required. Encouragingly, evidence of success can be seen in the emergence of oak, beech, birch, and other tree seedlings in various parts of the park, such as Reen, Cloghereen, and Blue Pool.

“It’s working. The woodland floor is coming back.”, said Meskell.

Despite the challenges, the dedicated efforts of the park’s management team and workers offer hope for preserving the natural splendour of Killarney. To protect this environmental jewel for future generations, continued vigilance, research, and collective action are necessary to combat invasive species and ensure the park’s biodiversity thrives once more.

As visitors continue to marvel at its wonders, Killarney National Park stands as a testament to the beauty and fragility of the natural world, urging us all to take responsibility for safeguarding our planet’s precious ecosystems.

Critics of the National Parks and Wildlife Service perceive it as a facade concealing devastation. Groundwork, a local environmental group, has been conducting surveys since 2013, using geo-tagged photographs to highlight the resurgence of invasive species in previously cleared woods.

“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 advocate for a substantial culling of sika deer, whose grazing harms the forest floor and aids the spread of rhododendron, while emphasising the need to prioritise ancient woodlands.

However, personal dynamics have complicated matters. Groundwork volunteers had previously cleared and maintained approximately 350 hectares of woodland from rhododendron between 1981 and 2009. But tensions arose when the park’s management extended the scope of the work to other areas, seemingly neglecting the protection of priority woodlands. Consequently, Groundwork ceased its clearances, leading to the loss of their expertise and passion.

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.”

Division and accusations abound, with both sides defending their positions. Park’s manager, Meskell, refuted the claims against him and expressed confidence that time would vindicate his strategy. In the meantime, he faces a more immediate concern: the potential risks posed by amateur photographers eager to replicate the experiences of the Attenborough documentary, particularly during the autumn rutting season when stags may become aggressive.

The situation highlights the complexity of balancing ecological preservation and human activities in a national park setting. Finding common ground and collaborative approaches are essential to ensure the long-term sustainability of Killarney National Park’s biodiversity and natural beauty.