‘Wilding’ by Isabellea Tree is, I feel, a super important book…… ‘Forced to accept that intensive farming on the heavy clay of their land at Knepp was economically unsustainable, Isabella Tree and her husband Charlie Burrell made a spectacular leap of faith: they decided to step back and let nature take over. Thanks to the introduction of free-roaming cattle, ponies, pigs and deer – proxies of the large animals that once roamed Britain – the 3,500 acre project has seen extraordinary increases in wildlife numbers and diversity in little over a decade. Extremely rare species, including turtle doves, nightingales, peregrine falcons, lesser spotted woodpeckers and purple emperor butterflies, are now breeding at Knepp, and populations of other species are rocketing. The Burrells’ degraded agricultural land has become a functioning ecosystem again, heaving with life – all by itself.’

As I progressed through the book I came to realise why the Tree’s neighbours wouldn’t and didn’t like what they were doing. Letting land revert to nature meant of course that all kinds of nasties were next door to their land and would soon find their way there. I sympathised. The pictures of neat Sussex hedged fields reverting to scrub didn’t help either. From looking conventionally neat and tidy the farm now started to look like a piece of unloved wasteland. I couldn’t help but wonder whether this ‘hippy’ farming was doing any good to anyone. I was wrong.

What the Trees have done is so radical and important that it deserves huge recognition – which thanks goodness it is starting to get. The crucial moment came when Ted Green the keeper of the Royal Oaks at Windsor came to look around their farm. Peering at some sick-looking oak trees standing alone in fields and ploughed close around, he pointed out that ploughing and the use of nitrogen fertilizers was destroying the mycorrhizae which are the microscopic fungal filaments which spread out enormous distances to supply their hosts with water and nutrients. They do all kinds of other amazing things for instance acting as a communication system with other plants, and are the key natural biological system. This visit lit a lamp with the Trees and after massive amounts of research and extensive travels they got to the stage where as farmers instead of being interested in Nature and trying to slow down the inexorable decline of wildlife they were actually involved in its restoration.

But we are not just talking about wildlife. Getting back to the mycorrhizae, they, when allowed to, contribute a final compelling argument to the value of rewilding the soil – carbon sequestration. Through a very complicated process that scientists have only discovered in recent decades the mycorrhizae produce something called Glomalin which acts as ‘the superglue of the soil’ and is able to store large quantities of carbon. 82% of the carbon in the terrestrial biosphere is in the soil, and the more carbon dioxide levels increase in our atmosphere the more the Glomalin reacts – so that according to the Royal Society carbon capture by the world’s farmlands, if they were managed more naturally (as with the Trees’ lands), could total 10 billion tonnes a year, more than the annual accumulation of carbon dioxide in the atmosphere.

One estimate is that if organic matter in the world’s farmland soil was increased by as little as 1.6% the problem of climate change would be solved. Some go further….one study suggests that restoring the world’s 19 million square miles of degraded grasslands to functioning ecosystems based around our friend the mycorrhizae could return 10 or more gigatonnes of excess atmospheric carbon to the terrestrial sink annually. This could (this being the operative word I suppose) lower greenhouse-gas concentrations to pre-industrial levels in a matter of decades. Basically we are talking about a more natural and rotational system which our medieval ancestors would recognise and which they regarded as common-sense.

The book deals with lots of issues one by one such as reintroducing beavers to control flooding ( and the bete noire of Frances and myself – stopping the canalisation of rivers and allowing them back to their natural courses complete with flood-plains ), going back to pasture-fed cattle thus increasing levels of healthy fatty acids, and so much more besides. It’s a real eye-opener. Read it then campaign for change!