Since 2013 The Dee District Salmon Fishery Board (DDSFB) and River Dee Trust (RDT) have planted over 140,000 native trees along the river banks of the upper Dee and its tributaries, including the Geldie, Ey, Gairn, Clunie, Baddoch, Callater, Slugain, Gelder and Muick.
This vital restoration work is delivered by working closely with land owners and managers, ensuring that areas of riparian woodland do not compromise the primary land management for grouse and deer. The project works with the Estates of Mar Lodge, Mar, Invercauld and Balmoral.
The DDSFB/RDT have built up strong relationships with land managers in the upper Dee catchment, as the salmon fishery on Deeside has an important cultural and economic role to play, similar to that of grouse shooting and deer stalking. Working closely with keepers, shepherds and land managers we have designed all riparian tree planting to maximise benefits for salmon without negatively impacting the movement of deer or disrupting traditional grouse drives.
Marine Scotland predictions of climate change indicate that many upland tributaries will reach summer water temperatures that make streams uninhabitable for salmon; last year for example the Gairn reached a water temperature of 27.5C (81.5F), close to the lethal temperature for juvenile salmon. In a changing climate, a diverse ecosystem with a wide range of features, habitat types and species, is more likely to adapt to changes and ensure that the uplands can continue to be both ecologically and economically productive.
Riparian trees will lower the summer water temperatures in these important salmon nursery streams, both through direct shading of the watercourse and by cooling the ground water as it flows through the riparian zone. Riparian woodland also benefits salmon through: provision of insects for their diet; increased nutrients through leaf drop; and large trees and branches that fall into the stream will create spawning gravel and cool deep resting pools, protecting fish from predators. Trees also reduce the speed of water runoff from the surrounding land to reduce peak flood levels, and an increase in general biodiversity includes a wider variety of species such as black grouse, capercaillie and woodcock.
In June 2019 the DDSFB won funding from SNH’s Biodiversity Challenge Fund (BCF). Working with local estates the “10,000 tree” project will now continue this restoration. As the trees will take decades to mature and fall into the river, the project will also see the installation of large woody structures in the rivers Gairn and Muick to provide essential pools and spawning gravel.
To achieve a significant reduction in summer temperatures and improve upland stream habitat, this work needs to be carried out on a catchment scale. With the continued support of the estates on upper Deeside we will continue to create riparian woodland and continue to involve volunteers from the local communities. In the decades to come and with increasing climate variability the fences protecting the trees will come down and land animals will also benefit from the shade and shelter.