Rising water temperatures are one of the biggest threats facing Atlantic salmon in Scotland. On Royal Deeside, a campaign to plant one million native trees along the river and its tributaries passed the halfway mark years ahead of schedule.
The River Dee is one of Scotland’s great salmon rivers. It rises in the Cairngorms and runs east through Braemar, Ballater, Aboyne and Banchory to the sea at Aberdeen. But the river’s upper catchment has a problem that is easy to miss on a cool autumn day. It has very few trees.
Without shade, small upland burns heat up quickly in hot, dry summers. Scottish Government scientists have identified 300 kilometres of tributaries in the Dee catchment as vulnerable to dangerous warming. For Atlantic salmon, that is serious. When river temperatures rise above 23 degrees Celsius, salmon stop feeding and become more vulnerable to disease.
One Million Trees
In spring 2020 the River Dee Trust, working with the Dee District Salmon Fishery Board, launched a campaign to tackle the problem directly. The goal was to plant one million native trees along the river and its tributaries by 2035, providing partial shade over hundreds of kilometres of water. The fundraising target was set at £5.5 million.
The campaign plants only native trees, including willow, rowan, birch, alder and aspen, grown from locally sourced seed and protected with biodegradable tree guards. The Trust works with landowners to choose sites where planting will do most to lower water temperatures while fitting with how the land is used.
It has become one of the largest nature restoration efforts in the Cairngorms. Partners include the Cairngorms National Park Authority, landowners, land managers and keepers, alongside community groups, local companies, schools and individuals. Members of the public sponsor tree enclosures as birthday and anniversary gifts, or in memory of family members.
Halfway, ahead of schedule
By October 2024, more than 484,000 trees had already been planted. That month the campaign won Climate Campaign of the Year at the Holyrood Climate Action Awards, held in Edinburgh. The River Dee Trust also lobbied the Scottish Government on funding for riverside tree planting, and the government changed its policy as a result.
On 9 April 2025 the 500,000th tree went into the ground on the banks of the Allt Cholzie Burn, a tributary of the River Muick, which joins the Dee above Ballater. It was planted by two young sisters from Aboyne. The milestone came years ahead of the 2035 target, and the Trust now expects to reach one million well before then.
“It is amazing to hit this half million milestone,” said Sandy Bremner, chair of the River Dee Trust, who pledged that the Trust would scale up landscape scale restoration with its partners.
Why salmon need help
Atlantic salmon are a native species under threat, and the River Dee Trust has warned that salmon populations in some parts of the catchment are nearly gone. Dr Lorraine Hawkins, the Trust’s River Director, has said: “We are in a race against time to save endangered keystone species.”
Salmon are described as a keystone species because so much else depends on them. They are essential to the life cycle of the freshwater pearl mussel, itself endangered, and they carry marine nutrients far inland, supporting wildlife from insects to birds.
Climate change is adding to the pressure. The Dee has suffered severe floods in recent years, while summers are becoming hotter and drier. Bremner has linked rising river temperatures, droughts and floods to the pressures on biodiversity, and pointed out that floods have damaged hundreds of homes and businesses. Riverside woodland helps on both fronts, cooling the water in summer and helping to slow the flow of water off the land.
More than trees
The tree planting sits within a wider programme of river restoration across the catchment. In 2023 the River Dee Trust and the Dee District Salmon Fishery Board removed Garlogie Dam on the Dunecht Estate. The five metre high dam had been built in the 1920s to power Dunecht House and its estate workshops. Its removal, funded through the Water Environment Fund administered by SEPA for the Scottish Government, gave salmon access to around 20 kilometres of spawning habitat for the first time in more than a century.
Charlie Perfect, River Restoration Specialist at SEPA, said the fund had enabled this kind of work for ten years and that “the Garlogie Dam is its biggest weir removal to date.” Dr Hawkins said at the time that “Atlantic salmon are critically threatened throughout their range,” and that removing man made barriers is one of the most obvious ways to help them.
Other projects include the restoration of the Beltie Burn, a river and wetland scheme that won the Nature and Climate Action award at the RSPB Nature of Scotland Awards in 2021, work on the Cattie Burn at Ballogie, a river and floodplain project in Glen Clunie, and biodiversity initiatives on the Muick near Ballater. Together they show a catchment approach in action: reconnecting habitat, restoring natural river processes and building resilience to a changing climate.
Lessons for fisheries managers
For fisheries professionals, the Dee offers a powerful example of how a river trust and a fishery board can work side by side. The scale here is striking, and so is the way the campaign has engaged the public, businesses and government. Turning a technical issue such as water temperature into a story that people want to support has unlocked funding and changed national policy.
Trees take time to grow, so early action matters. Planting now means that, as summers grow hotter, more of the Dee’s headwaters will be sheltered when the fish need it most.
Sandy Bremner has described the Trust’s motivation in simple terms: “We are driven by what’s at stake for our wildlife.” With the half million mark passed in April 2025 and the campaign racing ahead of its target, the River Dee is showing what a determined, well supported catchment partnership can achieve for wild salmon.