A single 500-year-old oak is a whole ecosystem – ten thousand 200-year-old oaks is not. Professor Oliver Rackham
By strange coincidence, I heard this arresting quote twice in one day recently. It sparked a cascade of thoughts, ranging from humankind’s indomitable presence on this planet and the pressures that we inflict on our landscape, through to the massive loss of habitat for thousands of species in recent years. It struck me how crucial it is to look at the wider picture, to relax our grip on our environment to give it breathing space, in whatever small way possible.
The current custodians of the Knepp Estate in Sussex have done just that. In an incredibly brave move, they turned their failing arable and dairy farm over to nature, ‘rewilding’ their 3,500-acres to become, after a time, a thriving area of biodiversity. The story of that incredible journey is told by Isabella Tree in her book ‘Wilding’ and it makes for compelling reading. She reminds us that the UK has lost 75,000 miles of native hedgerows, 90% of our wetlands and 97% of our wildflower meadows since the Second World War. Many of us are aware that the landscape in the UK has changed dramatically over the past century, especially the loss of our hedgerows and the wildlife that they supported, but these figures still gave me a jolt. Our intensively farmed, pesticide choked, and overpopulated land makes us one of the most nature-depleted countries in the world.
Knepp’s regeneration experiment is a triumph of conservation, with the return of a profusion of wild species, both plant and animal, rarely seen in Southeast Britain. This includes the turtle dove, which I have only ever seen on a Christmas card! Free-roaming red deer, longhorn cattle, Tamworth pigs and Exmoor ponies co-exist at Knepp – they are left to their own devices and in long, harsh winters they must fend for themselves, and do so, very successfully. The experiment shows that if you remove human intervention in the land and introduce the right balance of animals - grazers, foragers, browsers, rootlers (I may have made that word up!), it is possible to set off a chain of complementary events that result in a perfectly balanced eco-system.
I was fascinated to read about the importance of indigenous thorny scrubland, so often reviled and removed from the margins of our gardens. The trees that grow in this type of environment have a myriad of uses and are harvested widely to make tools, baskets, medicines, preserves and to flavour wine and gin. In medieval times it was said that the ‘thorn is the mother of the oak’, protecting the young saplings from attack by animals until established. Given light and open ground Quercus robur, Britain’s indigenous oak, will grow to its iconic wide-girthed, broccoli-headed splendour. It is a long-lived tree, with some surviving 0ver 1,500 years. A mature oak can support a huge diversity of life forms, with somewhere in the region of two thousand species living on a single tree, including 300 species of lichen. The tree supports as many as 280 invertebrate species, who in turn provide food for a variety of birds nesting in the wide branches or in holes in the trunk. Bats will roost under loose or cracked bark or in deserted woodpecker holes. Acorns are beloved green jewels of nourishment to jays, rooks, squirrels, deer, badger, mice and pheasants, and birds of prey, who nest in the high branches of the tree, will hunt many of these animals. I love this image of the mighty oak - the high-rise block and nurturer of the natural world.