How to reforest the UK
The experts agree: Britain needs more trees to help combat climate change. But what’s the best way to create flourishing forests for our grandchildren? Richard Baynes investigates
In Scotland’s mighty Cairngorm mountains, trees are appearing in unexpected places. On steep, heathery hillsides, on rocky outcrops and glen floors – wherever they find a toehold. In places such as the Mar Lodge Estate, Scots pine, birch, aspen and alder are popping up.
Three hundred miles to the south in the English Midlands, trees have also appeared on what was once open land. Mining sites, clay pits, quarries and other spaces – an area almost twice the size of the city of Birmingham – are now cloaked in young trees. The numbers are astonishing: nine million new trees across 200 square miles, each planted by hand. This is the National Forest, which straddles the post-industrial landscape at the junction of Staffordshire, Leicestershire and Derbyshire.
The Cairngorm projects and the National Forest are part of efforts to expand the UK’s woodlands. Trees play an important role in battling climate change by absorbing carbon – thus reducing carbon dioxide, one of the world’s most dangerous and prevalent greenhouse gases. Woodlands also boost the country’s flagging biodiversity, providing rich habitats for insects, birds and other wildlife.
Of course, there are many other benefits to reforestation. Trees produce timber, fruit, nuts and fuel. Well-placed woodlands help ease flooding. And time spent among trees even improves our mental health.
NATURE VS NURTURE
To boost forestry, 14,000 hectares of new woodland was planted in the UK in 2021–22 alone – that’s an area larger than the city of Sheffield. But some say we’re not planting enough. Compare the UK to our European neighbours: around 3.24 million hectares of the UK is woodland, 13% of the total land mass, but in France (17 million hectares) and Germany (11 million hectares) the figure is over 30% of total land mass.
Governments, scientists and conservationists agree that trees are badly needed. But the two styles of reforesting – planting and natural regeneration – could not be more different. Should we be planting trees? Or letting nature take its course and simply earmark land where trees will be allowed to flourish naturally?
On the Cairngorm estates where woodland is reappearing, landowners have simply removed grazing pressure that suppressed woodland –bluntly, culling a lot of deer – allowing trees to grow. In contrast, in the Midlands, £60 million of largely Government money has paid for 30 years of tree planting, tapping into the best research and using fencing, tree tubes, computerised mapping and years of planning. As well as the National Forest, major treeplanting schemes include the Great Northern Forest, which aims to plant 50 million trees across Cheshire, Lancashire and Yorkshire. Many estates in Scotland are increasing tree cover, while south of the border, estates such as Broughton Hall in Yorkshire, Blenheim in Oxfordshire and Doddington North in Northumberland are doing the same.
So which way is best? And what else must the nation’s foresters take into account when deciding how to go about boosting our tree cover, especially in a rapidly changing climate?
“Trees produce timber, fruit, nuts and fuel. Time spent among trees even improves our mental health”
THE CASE FOR NATURAL REGENERATION
The Cairngorm estate at Mar Lodge is owned by the National Trust for Scotland. Their director of conservation and policy, Stuart Brooks, says: “We wanted to take as noninterventionist an approach as possible.” For Brooks, problems with tree planting include the cost of putting in thousands of seedlings.
Provenance is key: even where the ‘right’ species is planted – one that should theoretically flourish in the conditions – many die. The genetic make-up of any plant species will vary naturally; plants grown, for example, from the seed of a strain of rowan tree that flourishes in lowland locations may struggle to adapt to an open Cairngorm hillside. Recent National Trust plantings in south and east England have suffered badly in the summer’s drought, losing more than 30% of saplings. If tree specimens had been sourced from more southerly climes, might they have survived the shock of the drought?
There’s another risk with planting: that trees take over land valuable for ecological or agricultural reasons. Some treeless land is already valuable as carbon sink – peat moorlands, for example. Although new rules prevent planting on deep peat, which stores more carbon than forests, foresters must still decide if they will plant on shallower peat.
The march of planted trees could also swallow up habitats valuable for biodiversity. Care must be taken, for example, that woodland does not destroy heath and meadow habitats, where rare butterflies, birds and reptiles flourish. Some farmers complain that good crop land, which may be needed in the near future due to global food shortages, is being forested, too.
“If the aim is to grow for timber, you have to plant, or a species unsuitable for timber may spring up instead”
THE CASE FOR PLANTING
So there are some downsides from planting. But according to reforesting guru John Tucker, natural regeneration sometimes just doesn’t work. Windblown birch and pine seeds may root at a significant distance from the ‘mother’ tree, but with heavier seeds, such as hornbeam and oak, natural regeneration tends to occur within just 50 metres of existing woodland. This makes natural regeneration relatively slow: trees take time to poke their heads up from the soil (see box, right).
In the National Forest, industrial-scale tree planting was needed, says Forest company development director David Bourque. “In the early days of the Forest, there weren’t many mature woodlands to act as reservoirs of species to colonise nearby land.” If the aim is to grow for timber, you have to plant, or a species unsuitable for timber may spring up instead.
Everyone involved in developing new woodlands, however, agrees the single biggest task is to get landowners and communities on board. Government grants have helped the National Forest to spread its message, and Luke Barley, the National Trust’s senior woodland adviser, agrees it’s the way forward. “Once farmers start to see that their neighbours are coining it from woodland creation, that cultural resistance starts to be eroded,” he says. “You do see a snowball effect, where more and more people get interested.”
POWER OF PLANNING
Ultimately, when it comes to the question of how to plant these forests, a hybrid approach may be the solution. According to John Tucker, sometimes natural regeneration is right, sometimes planting is needed, and sometimes a mixture of both is required. “The key things are to know what you want from a [reforesting] scheme, and to know as much about the site as possible before you start,” he explains. “If you want something to be around for 100 years or more it’s vital to plan.”
The past summer underlines the importance of planning. Climate change is making reforestation more challenging, says Luke Barley. “What we have is a multiplier effect – we want to establish trees to help mitigate climate change but it’s becoming harder to establish trees because of the impacts of climate change.”
For Barley, it’s time to get wise. Instead of just replacing dead trees that are on the driest ground, more trees could be planted elsewhere, where others have flourished. He will also look at using more drought-resistant varieties of trees – such as oak, beech and hazel – grown from the seedlings of trees that have flourished further south, in England, or even in continental Europe.
Thankfully, organisations such as the Woodland Trust and the National Forest, and people such as John Tucker, David Bourque and Luke Barley, have built up a wealth of experience. Now, says Tucker, we need to tap into that expertise and develop more woodland: “Government and its agencies have recognised the scale of the challenge and some steps have been put in place, but much, much more needs to be done.”
MAKING TREES PAY
The key to getting landowners to reforest is to convince them they can benefit from it, according to John Tucker of the Woodland Trust charity.
He stretches reforesting to include schemes such as that on Whitehall Farm in Cambridgeshire. Here, farmer Stephen Briggs has set apple trees in three-metre-wide biodiversity corridors between strips of cereal and vegetable crops across 52 hectares. The 24-metre strips of arable crops are wide enough for two runs of a combine harvester.
Tree roots allow run-off from the fields to soak into the ground, benefiting crops, and sales of apples are now a valuable income stream, too. Without these orchards, the fields would have remained treeless prairies. Bees, butterflies and other plant species also thrive in the tree strips.
Other benefits to farmers of reforesting include shelter for livestock, timber, crops, plus the psychological benefits of trees. Briggs says: “The trees make it just a nicer place.”
HOW FORESTS ARE REBORN NATURALLY
The process by which open land naturally reverts to woodland over time is called ecological succession. The land goes through a series of stages. On open land covered in topsoil, grasses and wildflowers will give way to brambles and shrubs, before trees spring up, either from seeds already hidden in the soil, or from seed imported on the wind or buried by animals, such as jays and squirrels. Woodlands may take between 80 and 160 years to develop; young, growing woodlands soak up carbon more quickly than mature ones.
SUSTAINABLE SPECIES
Three key trees for the future
1 Wild service tree (Sorbus torminalis) This relatively rare native tree is more common in Europe, the odd name stems from the Latin for beer – ‘cervisiam’ – because its fruits were used to brew alcohol. It has high-quality timber and could be more drought resistant than more common species.
2 Sycamore (Acer pseudoplatanus) It’s said this species was introduced from Europe by the Romans, or in late medieval times. Although it is a non-native, research has shown that sycamore can fill a big part of the gap left in woodland ecosystems by the loss of ash trees to the fungal disease, ash dieback.
3 Lime (Tilia x europaea) A native species, the common lime tree became scarce here when increased management of woodlands for timber coincided with a change to a damper, colder climate – to which limes were ill-suited – 350 years ago. Limes are now rare, but may make a comeback as the climate warms.
Richard Baynes is a multi-media freelance journalist based in Glasgow who specialises in the outdoors and the environment. He develops content for radio, newspapers, online and TV.