New initiative launched to save one of Scotland's most endangered tree species

It is one of Scotland’s most endangered yet most important trees for providing a habitat for rare fungi, lichens, mosses and moths.

Yet in recent years, Aspen, once common, has now largely disappeared from Scotland’s landscapes.

Now, a new initiative is underway in the Cairngorms National Park to save this endangered tree - an essential but now rare feature of the Caledonian forest.

The Scottish Wildlife Trust said it believes the species likely suffered more from deforestation than any other native tree in the country. It is also one of the most palatable species to deer.

Aspen and Suckers. Aspen provides a habitat for a wide range of rare fungi, lichens, mosses, moths | Trees for Life

The new Cairngorms Aspen Network (the Network) aims to restore aspen tree habitats by mapping, expanding and connecting fragmented stands of the rare species in the park.

Currently, aspen is mainly found in small and fragmented stands. A rare part of the Caledonian Forest, aspen (Populus tremula), with its leaves on long, flattened stalks (petioles) that flutter even in a gentle breeze, is known as the ‘tremlin tree’ in Scots. | Trees for Life

The Network, a partnership between rewilding charity Trees for Life and the Cairngorms National Park Authority (CNPA), will bring together experts, enthusiasts and land managers to take action to identify and restore the trees.

Doing so, they said, will boost the wildlife and threatened species that depend on them, and help build resilience against climate change.

A healthy, functional aspen network will help build resilience against climate change and biodiversity loss, says the Network. | Trees for Life

Niamh Byrne, aspen project officer at Trees for Life, said: “The new aspen network will offer much-needed hope for tackling the nature and climate emergencies by developing a restored, better-connected and healthier aspen network.

“By working together, we can improve the future of our aspen woodlands and the life they bring with them.”

The first stage of the project, which is being carried out by Trees for Life, will see the mapping of the location, condition and health of the existing aspens in the national park, alongside key plants and animals that depend on them.

This will be used to help identify key sites and management priorities, including growing and planting plans for creating a thriving new network of aspen.

It will also create a blueprint for an approach to aspen conservation that could be rolled out across Scotland.

Aspens, which are characterised by shimmering foliage in summer and leaves which turn golden yellow in the autumn, have been especially hard-hit by deforestation and overgrazing because they rarely flower or set seeds in Scotland, meaning that once the species is lost from an area it is unlikely to return on its own.

The deciduous trees, which can grow at elevations of up to 550 metres, today often only regenerate in the Highlands on rocky slopes or cliffs out of reach of grazing animals.

These fragmented stands, sometimes comprising only a handful of old trees growing from the same root system, are geographically isolated, meaning they are unable to provide a proper habitat for species that depend on them.

Sarah Henshall, head of conservation at CNPA, said: “Aspen is a priority species in Cairngorms National Park and hugely important resource for rare and threatened wildlife.

“Aspen also makes a significant contribution towards healthy and resilient nature networks in the National Park.”

More than 60 insect species are known to feed on aspen foliage in Scotland, while young aspen shoots provide food for caterpillars of the rare dark-bordered beauty moth, and the endangered aspen hoverfly favours aspen deadwood.

Aspens’ high rate of leaf fall and production of deadwood also enrich soils, which creates “optimum” conditions for other plants and trees, and they are said to be highly valued by beavers.

They also grow fast and die young, which the Network said means they can lock carbon away efficiently.

As the project develops, the Network hopes there will also be scope for local volunteers to get involved.

The Cairngorms Aspen Network Project is funded by a grant from the Cairngorms National Park Authority.