Conifer plantations, which are expanding around the UK to combat the climate crisis and promote biodiversity, are at risk of damaging one of the key species they were thought to protect: red squirrels.
The endangered red squirrels, driven to near extinction over most of Britain by gray squirrels, are thought to thrive in coniferous habitats, as the food sources in such forests tend to be limited to small-seeded cones, which red squirrels are better at exploiting. than the more generalistic gray squirrels. This should mean that conifer plantations turn out better for red squirrels than gray ones.
But new research raises this perception by highlighting the role of the forty-year-old. Until recently, these native predators, like the red squirrel, were in short supply. Recovery in their numbers has shown that pine nuts are generally good for red squirrel populations, at least in native broadleaf forests, because they suppress the number of gray squirrels.
The research, published in the Proceedings of the Royal Society B, found that this was not true in conifer plantations, where forty-five years lack various food sources and instead ban red squirrels, turning them from a protector into a threat.
To conduct the research, scientists from Queen’s University used Belfast and the University of St. Andrews, with Ulster Wildlife and the help of citizen researchers, traps cameras to investigate more than 700 locations in Northern Ireland over a five-year period looking for red squirrels, gray squirrels and forty-year-olds.
Dr. Joshua Twining, lead author of the research from Queen’s University in Belfast, explained the results: “In natural forest areas, there are different amounts of prey and lots of places for squirrels, so red squirrels do not become so obsolete… is planted and of uniform age, there is very little biodiversity or alternative prey and the absence of shelters, so forty years eat red squirrels to survive here. “
He said the research suggested that forest managers should reconsider whether conifer plantations should be preferred over native broad-leaved trees. “We need to adapt our strategy: if we continue to plant conifer plantations, unlike native forest, this red squirrel rescuer may cause its decline in some places,” he warned. About three-quarters of the forested area in the UK and Ireland consists of non-native timber plantations, of species such as the sitka spruce, according to the researchers.
Conifer plantations were already a cause for concern for ecologists, as they tend to be monocultures, often harvested after a few decades and may provide less diversity than native broad-leaved species. But government planting schemes in the UK and Ireland have tended to favor conifers, which are easier to plant and harvest.
A spokesman for the UK Department for Environment, Food and Rural Affairs said: “We are committed to taking steps to recover our endangered native species in England, such as the red squirrel. The planting of conifers in England is at a low level, “where our Nature for Climate Fund focuses on establishing large-scale broad-leaved forests. Together with our England Trees Action Plan, this will support the restoration of native red squirrel populations across the country.”