“Put simply, without trees we could not survive,” states Andrew Swift, who, this month, looks at the devastating impact of deforestation and the vital role trees play in keeping our cities livable…
This summer’s drought and record temperatures, along with the wildfires that raged across the land, demonstrated once again – as if we needed further proof – the seriousness of our climate emergency. They also highlighted how crucial trees are in our attempts to turn things round.
Put simply, without trees we could not survive. Trees reduce pollution, absorb carbon dioxide, store carbon and produce oxygen. They also provide shade, lower ambient temperatures and, by providing habitats and green corridors for insects, birds and animals, help to slow the catastrophic decline in biodiversity.
While it is no longer possible to deny how vital trees are – not just for our wellbeing but also for our survival – the battle to halt their destruction is far from won. It isn’t just in tropical rainforests that war is still being waged; the felling of thousands of trees by council contractors, backed up by the force of law, on the streets of Sheffield in 2018 shows it is happening much closer to home.
Given the imperative to build new housing and the infrastructure associated with it, it seems inevitable that controversial fellings will continue. There is general agreement, however, that more trees need to be planted, not just to make up the losses, but also to ramp up Britain’s tree cover. What is at issue is the speed and extent of this reforestation. Recent spats over the drive to increase Bristol’s tree canopy have focused not on its necessity but on how quickly it can be achieved.
Time, however, is not on our side. Although trees are among our most important allies in the fight against climate change, some species are already falling victim to it. Ash dieback is caused by climate change, but milder, wetter winters allow the disease to spread more rapidly, while drought and high summer temperatures put the trees under stress, making them more susceptible.
In the longer term, it is feared that climate change threatens Britain’s beeches, whose shallow roots struggle to cope with drought and rising temperatures. The decline of particular species, although devastating, however, is compensated for by natural progression, as other species move in to fill up the gaps. It is the overall loss of tree cover that is the real problem.
It is estimated that, since we switched from hunter-gathering to farming the land around 12,000 years ago, the number of trees growing on our planet has fallen from around 5.8 trillion to around three trillion, with the rate of deforestation picking up speed over the past couple of centuries.
The trend in this country over the past century, however, has been in the other direction – not that we can take too much comfort from this. Only about 10% of England is covered by woodland, compared with 32% of France, 33% of Germany and 37% of Spain. A sizeable chunk of that 10% is also made up of commercial conifer plantations, far less ecologically diverse and far less effective in fighting climate change than broad-leaved woodlands.
And, although tree cover is increasing, the rate of that increase is alarmingly slow. The Climate Change Committee set up by the government in 2008 has advised that 30,000 hectares of new woodland need to be planted every year to 2050 if net zero targets are to be met. Between 2016 and 2020, however, only 7,720 hectares were planted.
Above: Avenue of Japanese cherries in Castle Park
In Bristol, too, the council has announced ambitious targets, aiming to dramatically increase tree cover in the city and prioritising planting in areas where cover is low. An increasing number of people are taking matters into their own hands, however. Community tree planting is gaining momentum all the time, and organisations, charities and individuals have racked up some impressive achievements.
The brilliant thing about planting trees is that you’re not just helping to save the planet, but also reaping more immediate dividends. Cynics may scoff at the concept of ‘forest bathing’, but so successful has the healing power of spending time in the woods proved to be that it’s now a medical prescription in Japan, while an increasing amount of research shows a correlation between exposure to the natural world and increased health and wellbeing.
You don’t need to delve into the research, though. A quicker – and more enjoyable – way of putting the idea to the test is to get out and explore the fantastic range of woods and trees on our doorstep. Bristol is fortunate in having had a slew of wealthy landowners who nabbed much of the prime real estate around the city to create private parkland, much of which now survives as green spaces for everyone to enjoy.
Most extensive is Ashton Court, where, if you head through the Clifton Lodge entrance, at the end of Bridge Road, you can walk through a magnificent avenue of limes before following the drive as it curves downhill past a succession of ancient oaks, including one known as the Domesday Oak, which was selected by the Tree Council in 2002 as one of 50 remarkable trees to commemorate the Queen’s Golden Jubilee.
Another option is to follow the wooded gorge at Coombe Dingle before climbing to Blaise Castle, an 18th-century folly hidden amid ancient woodland on the heights above. Ancient woodland – or ancient replanted woodland – also survives at Kingsweston, Oldbury Court, Stoke Park and Badock’s Wood in Southmead, along with several other sites in Bristol.
A little further off the beaten track is Bishop’s Knoll in Stoke Bishop, where the abandoned terraces and kitchen garden of a long-demolished mansion lie alongside a Victorian arboretum. Left for decades to its own devices, restoration has been limited to improving accessibility while maintaining a glorious wildness and labelling some of the rarer and more impressive trees. The largest is a Monterey Cypress with a seven-foot girth, while the oldest is a pollarded oak planted over 700 years ago as a boundary marker.
The most extensive area of ancient woodland, though, is across the Avon in Leigh Woods, where the rare Bristol Whitebeam was discovered in 1852. Along with six other kinds of whitebeam – including the Observatory Whitebeam and the Leigh Woods Whitebeam – it is endemic to the Avon Gorge, meaning that it grows wild nowhere else.
Parks such as Eastville, Grevylle Smyth, St Andrews, Victoria or St George, with its magnificent avenue of London Planes, also richly reward exploration. Some parks – such as Brandon Hill or Castle Park, with its celebrated avenue of Japanese cherries and those enormous fig trees growing out of the harbour wall – even have specially devised tree trails.
Garden cemeteries, so beloved of the Victorians, now double as wildlife havens and are also home to some spectacular trees. Arnos Vale is the most celebrated, but others well worth exploring include Greenbank in Easton, Ridgeway Park in Eastville and St Andrew’s in Clifton, where the path leading through it is shaded by a pergola of pleached limes.
With an unmistakable whiff of autumn in the air, there is no better time, as the leaves start changing colour, to get out and explore the infinite richness and variety of Bristol’s trees and woods – and, perhaps, mindful that they are our closest allies in the fight against climate change, be inspired to get planting.
Featured image: Avon Gorge
