Isabella Tree: Ness Award 2021

As part of our celebration of this year’s medals and awards, we caught up with Isabella Tree, recipient of the Ness Award for the popularisation of geography through her writing on biodiversity and the relation between humans and the environment, to discuss the importance of rewilding, changing attitudes to conservation and her advice for getting involved in this work.

Why is rewilding so important?

Despite conservation’s best efforts, biodiversity has continued on a catastrophic decline with one in 10 species in the UK now threatened with extinction according to the 2019 State of Nature report. Conventional conservation has been hugely important, saving numerous species and rare habitats from extinction but it’s an approach that is almost impossible to apply at landscape scale. Rewilding is a way of allowing nature to restore itself, so it can work anywhere, needs little management and is therefore less costly. There are no specific targets or goals, just allowing nature to return in whatever way it chooses.

Our own rewilding project at Knepp on degraded, unprofitable agricultural land in West Sussex has shown, in less than 20 years, an astonishing uplift in biodiversity. We now have all five UK species of owl, 13 out of the 18 UK species of bats – including Bechstein’s and barbastelle, two of the rarest mammals in Europe – and numerous endangered species like nightingales and purple emperor butterflies, all of which have found us of their own accord, attracted by the burgeoning food resources and new habitats. We’re probably the only site in the UK where the number of turtle doves, a species on the verge of extinction in the UK, is actually rising.

But rewilding isn’t just about improving habitats for wildlife. It provides other vital ‘ecosystem services’ or ‘public goods’ such as soil restoration, carbon sequestration, water and air purification, flood mitigation and natural space for our mental and physical health. In one of his latest books Half Earth, the great American biologist E. O. Wilson says that if we want to retain the support systems upon which all life on Earth depends, including our own, we have to devote half the planet’s terrestrial land mass to nature. Rewilding makes that possible. We will always need land for agriculture but rewilding everything in between - and moving to regenerative agriculture on land for food production – will allow these support systems to function.

Where did the idea to rewild the Knepp Estate come from?

It was really my husband Charlie’s idea. He realised, after 17 years of trying to make the farming business profitable on our heavy Sussex clay, that we were never going to be able to compete with farms on better soils, let alone with the global market. He knew we had to give up farming and do something very different with our land – to work with it, rather than battling against it.

He and I have always been interested in nature. Ironically, we spent most of our youth travelling to the ends of the Earth to see wonderful wildlife, never thinking what we could – and should – have in our own backyard. Realising that we were responsible for the depletion of our land came as quite a shock. We’d always considered ourselves ‘nature friendly’ but, of course, intensive modern farming with ploughing and chemicals is anything but. Making the decision to give up farming not only lifted a heavy burden of debt from our shoulders, it released our minds to think imaginatively about the alternatives.

Charlie was inspired by a visit to the Oostvaardersplassen, one of the early rewilding projects in Holland and, particularly, meeting the Dutch ecologist Frans Vera (author of Grazing Ecology and Forest History) to try using free-roaming animals – proxies of the megafauna that used to roam our landscape – to drive the creation of new habitat on our land. Often people think rewilding is just about closing the farm gate, about letting go – but really it’s about kick-starting natural processes again, injecting dynamism back into the landscape. It’s like pulling the glider back into the sky. So, allowing vegetation to regenerate; restoring dynamic natural water systems; and then releasing keystone species such as large herbivores and beavers to act as the drivers of the ecosystem. Their disturbance, the different ways they graze and browse, their trampling, rootling, breaking of branches, de-barking and uprooting of trees, coppicing, puddling and wallowing, creates myriad opportunities for plants, insects and other life. Their dung and urine, and – if it’s allowed – their rotting carcasses, replenish the soil with nutrients and bacteria. They transport seeds from one place to another in their hooves, fur and gut. There are amazing rewilding projects – vast and small – happening all over Europe, now, that continue to be a huge inspiration.

During your lifetime, how have attitudes towards conservation, and rewilding in particular, changed?

We had an uphill battle in the early days, trying to persuade the Government to back our rather ambitious ‘Intention to create a biodiverse wilderness area in West Sussex’. Our neighbours, other farmers and even some conservationists accused us of being misguided and irresponsible – amongst other things. But nothing is more convincing than results and now that people can see for themselves what rewilding can do, it has become more acceptable mainstream.

It’s not always called ‘rewilding’ – some people still find the term toxic – but the principle of restoring natural processes and then letting nature take the driving seat is gaining traction. Policy makers seem to have embraced it, which is extraordinary thinking back 20 years. In the last few years, it feels like there is a much deeper public appreciation for nature – COVID-19, of course, has had an impact – but also a recognition that we’re missing so much life, that we could have so much more. Rewilding has gone from being about reintroducing wolves to a more nuanced desire to make all natural spaces wilder – from our National Parks to our gardens and roadside verges.

The huge public excitement generated by the reintroduction of species like beavers, white-tailed eagles and white storks is something I don’t think we’d have seen 20 years ago. And, thanks to the change in direction in farming subsidies, there’s now great enthusiasm for it amongst farmers and other land managers. We’ve just signed a Memorandum of Understanding with neighbouring farmers and landowners to create a corridor from Knepp to the sea, linking up with the Help the Kelp marine reserve off the south coast. It needn’t be about rewilding all your land - just recognising the benefits of connectivity and how nature, itself, can increase crop yields if you’re farming - that there’s value in allowing nature back in. The journey is just beginning!

What advice would you give to someone wanting to get involved in conservation work?

I would contact your local Wildlife Trust. They’re the heroes of nature conservation on the ground, battling to preserve endangered species and protect remaining scraps of rare habitat in all our counties. They run armies of volunteers. Their aim is to restore 30% of land and sea for nature by 2030. If you have land you are interested in rewilding, the charity Rewilding Britain has just launched the Rewilding Network offering practical guides and toolkits and connection with other rewilders.

Find out more about this year’s medal and award recipients.