Abseilers and specialist climbers have been enlisted to help protect one of Scotland’s most spectacular gorges from invasive plant species.
The National Trust for Scotland said it had been forced to go to “extreme lengths” to tackle the problem at Corrieshalloch Gorge, south of Ullapool in the Highlands.
Conservationists are concerned that common rhododendron and Japanese knotweed are spreading rapidly along the gorge, which sits above the River Droma.
Both plants can cause the loss of local flora and fauna. Rhododendrons block out sunlight and prevent other plants from growing, while Japanese knotweed can loosen river banks with its aggressive root systems.
As well as abseiling into hard-to-reach parts of the gorge, which is almost a mile long and 60m deep, the Trust is also seeking help from a local group of “gorge scramblers”.
The pastime involves people making their way up or down a mountain river course, jumping into pools, and swimming under waterfalls.
The Trust hopes that the team will get into areas that might not otherwise be accessed by regular surveys, spotting colonies of invasive species and how they are having an impact on other plants.
Once the rhododendrons and Japanese knotweed have been identified, they can be injected or sprayed with doses of herbicide to kill them off and prevent further spread.
Conservations hope the plan will help Corrieshalloch’s diverse range of native trees – which include aspen, hazel, rowan, birch, pine, and wych elm – to thrive.
The area is also known to contain a diverse array of mosses, lichens and ferns and is often visited by wildlife including red squirrels, woodland birds, ravens and golden eagles.
Rob Dewar, one of the Trust’s nature conservation advisers, said the two invasive species being targeted were a “very serious threat” to the diversity of life in the gorge.
“The gorge scrambling community is acting as our eyes in the difficult depths and corners of Corrieshalloch,” he added. “We want to use their knowledge as much as we can to tackle colonies of the invasive plant species that may otherwise be missed – they can make a real difference to the future of the gorge, all while doing what they love.
“The work at Corrieshalloch is a great example of the extreme lengths to which we will go to protect Scotland’s natural heritage.”
The gorge, which takes its name from the Gaelic for “ugly hollow”, was formed by glacial meltwater during the last Ice Age and is regarded as one of the most striking of its type in Britain.