In a new study, researchers have proposed that reintroducing grey wolves to the Scottish Highlands could have a transformative impact on native forests and climate goals. A study published in the Ecological Solutions and Evidence journal suggests that introducing a pack of over 160 grey wolves could lead to significant woodland regeneration, as the wolves would control the deer population, allowing forests to bloom.
Notably, Scotland's red deer population has skyrocketed to approximately 400,000, with no natural predators like grey wolves to control their numbers. As a result, deer and sheep are hindering tree sapling growth across the region. The study suggests that reintroducing large carnivores to manage deer populations could lead to significant woodland expansion, absorbing up to 1 million metric tonnes of CO2 annually. This would account for 5% of the UK's woodland carbon removal target.
"Large carnivores, including the grey wolf (Canis lupus), play an important role in the carbon cycle through modifying the behaviour and population of wild herbivores. Large carnivores have been eradicated from much of their former range and are now absent from the UK, contributing to increased herbivore populations, which can prevent the natural regeneration of trees and woodland. Reintroduction of wolves to the UK could reduce deer populations and associated browsing of tree saplings, but the potential impacts on woodland expansion and carbon sequestration have not been assessed,'' the study said.
Scientists' simulations indicate that reintroducing wolves to four key areas in Scotland could lead to a population of approximately 167 wolves. This would be sufficient to reduce deer density to four per square kilometre within two decades.
Each wolf is estimated to facilitate the regrowth of enough woodland to absorb around 6,080 metric tons of CO2 annually, valued at approximately $195,000 in today's carbon market. Over 100 years, the expanded native woodlands are projected to sequester 100 million metric tons of CO2, making a significant contribution to Scotland's 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 wrote in the study.
However, these calculations do not factor in the initial costs of reestablishing a wolf population. Additionally, the study does not explore the potential impact of altered herbivore dynamics and woodland expansion on soil carbon levels. The study's findings also raise concerns about potential conflicts with human activities, particularly livestock farming.
"We recognize that substantial and wide-ranging stakeholder and public engagement would be essential before any wolf reintroduction could be considered. Human-wildlife conflicts involving carnivores are common and must be addressed through public policies that account for people's attitudes for reintroduction to be successful," the researchers wrote.
