BELFAST — Ecologists and land managers in Northern Ireland are trialling an unconventional approach to the region’s chronic peatland degradation problem: deploying flocks of Herdwick sheep at carefully managed densities across damaged bog surfaces, using the animals’ hooves and grazing behaviour to accelerate the re-establishment of sphagnum moss, the foundational plant that gives functioning peatlands their carbon-storing capacity.
Northern Ireland has lost an estimated 85 percent of its intact blanket bog over the past century, primarily through a combination of drainage schemes, turf cutting for fuel, overgrazing, and atmospheric nitrogen deposition from intensive agriculture. Peatlands in good condition are among the most efficient carbon stores in the natural world, capable of locking away approximately 10 times more carbon per hectare than temperate forest. Degraded peatlands, by contrast, actively emit carbon dioxide and methane, making their restoration a recognised priority under the region’s statutory climate commitments for the next decade.
The pilot programme, running across four upland sites in counties Tyrone and Fermanagh covering a combined area of roughly 340 hectares, is being led by the Moorland Regeneration Partnership in collaboration with the Agri-Food and Biosciences Institute. Researchers hypothesised that light, controlled grazing pressure from Herdwick sheep — a hardy upland breed native to the English Lake District — could mimic the trampling and disturbance patterns that historically maintained a mosaic of bare peat, pioneer vegetation, and establishing sphagnum across bog surfaces, without the overgrazing damage caused by higher-intensity livestock systems that have historically characterised upland farming in the region.
Initial results after two growing seasons are described by researchers as cautiously encouraging. Sphagnum cover at the grazed trial plots increased by an average of 14 percent compared with ungrazed control plots on the same sites, and the variety of sphagnum species present was notably higher in grazed areas. Dr. Catriona Brennan, the lead ecologist on the project, said the sheep appeared to be suppressing competitive graminoid plants such as purple moor-grass and deer grass that would otherwise outcompete establishing sphagnum for light and growing space during the critical early establishment window.
“The instinct in peatland restoration has always been to remove livestock entirely, and in many cases that is the right call,” Brennan said. “But we are seeing evidence that very light, very carefully managed grazing can actually be a tool rather than an obstacle in some degraded bog contexts. The key word is managed. This is not about putting sheep on the hill and walking away.” The trial uses GPS-tracked animals with stocking densities set at approximately 0.15 sheep per hectare, far below the regional average of around 0.9 sheep per hectare on upland grazings, and grazing windows are restricted to specific months to protect sensitive vegetative growth periods when newly planted sphagnum is most vulnerable to physical disturbance.
The programme has also attracted attention from farmers whose land borders or overlaps trial sites. Participating landowners receive a management payment under a rural agri-environment scheme, providing a modest income offset for the restrictions placed on how they use their upland grazing. Several have expressed interest in expanding involvement if results are confirmed at the end of the full three-year trial period. “It is not transformative money, but it is something, and I can see what they are trying to do with the land,” said one participating farmer from County Fermanagh who asked not to be named. “If it works, it is good for everyone, and these hills need something different from what they have had.”
Not all observers are convinced. Some peatland restoration specialists argue that any grazing pressure, however light, remains fundamentally incompatible with the conditions required for sphagnum establishment, and that the observed improvements in grazed plots may reflect site-specific variables rather than a transferable technique. The Peatland Conservation Council issued a statement urging caution in interpreting the preliminary data and called for the trial to be extended to a broader range of site conditions, including wetter raised bogs and drier marginal uplands, before any policy conclusions are drawn or the approach promoted more widely.
The partnership expects to publish a full interim report in the autumn, with a final programme assessment scheduled for early 2028. If validated, the approach could have significant implications for upland land management policy across Ireland and the wider United Kingdom, where peatland restoration targets have been set ambitiously but implementation has consistently lagged behind schedule due in part to conflicts between conservation objectives and established farming practices that have shaped rural communities for generations.