How wolf reintroduction could restore Scottish woodlands and capture carbon

Centuries have passed since a wolf’s howl echoed through the Scottish Highlands, but a group of researchers believes the time has come to reintroduce the much-maligned predators. Their simulations suggest that bringing wolves back could restore native woodland and remove carbon from the atmosphere.

Wolves and Scotland’s lost woodlands

Human hunting wiped out wolves (Canis lupus) in Scotland. According to tradition, the last wolf was killed around 250 years ago, although local myths and legends make the precise year difficult to establish.

Around the same period, the Jacobite rebellion of 1745 brought profound changes to land use across much of the country. Woodlands were cleared and large shooting estates were created.

The loss of this apex predator disrupted entire woodland ecosystems, as its prey, the red deer (Cervus elaphus), was able to multiply unchecked. Recent estimates suggest that as many as 400,000 red deer now roam Scotland, trampling and eating young tree saplings that could otherwise develop into woodland. Native woods now cover less than 4 per cent of Scotland’s land, among the lowest proportions in Europe.

The wolf is a textbook example of a ‘keystone’ predator: like a brick in an arch, it helps hold the entire structure together. Wolves have been successfully reintroduced to several nationally managed ecosystems in the US, most famously Yellowstone National Park.

In theory, bringing wolves back to Scotland’s wild places would reduce deer numbers and give woodland an opportunity to recover.

“There is an increasing acknowledgment that the climate and biodiversity crises cannot be managed in isolation,” says lead author Dominick Spracklen, an environmental scientist at the University of Leeds.

“We need to look at the potential role of natural processes such as the reintroduction of species to recover our degraded ecosystems and these in turn can deliver co-benefits for climate and nature recovery.”

Wolf reintroduction and carbon capture

The researchers’ simulations indicate that reintroducing wolves in four key areas of Scotland could support a population of around 167. Within as little as two decades, that could be enough to bring deer densities in those areas down to just four per square kilometre.

The team estimates that each wolf could enable enough woodland to return to absorb 6,080 tonnes of carbon dioxide annually. On today’s carbon market, that would be worth about US$195,000.

Their model suggests that the resulting growth in native woodland would sequester 100 million tonnes of CO₂ over 100 years, “sufficient to make an important contribution to national climate targets”.

“Large-scale expansion of woodlands, facilitated through the return of wolves, can contribute to national climate targets and could provide potential economic benefits to landowners and communities through carbon finance,” the authors write.

Safety concerns and public attitudes

There are, understandably, safety concerns to address. Wolf reintroduction is a deeply divisive subject, and with good reason.

“Human-wildlife conflicts involving carnivores are common and must be addressed through public policies that account for people's attitudes for a reintroduction to be successful,” says co-author Lee Schofield, an ecologist and farmer.

The researchers believe that lessons from wolf reintroductions in the US and Europe could help. And although wolves have a fearful reputation with some basis, ecosystem collapse and extreme climate change are hardly toothless alternatives.

“This substantial carbon sequestration and the potential financial benefit related to wolf reintroduction may influence landowner and land manager perspectives around large carnivores,” the team writes.

The research was published in Ecological Solutions and Evidence.