Once again, Professor Dave Goulson helps us think our way through making our gardening more sustainable. This month he asks ‘can rewilding your garden help us to tackle climate change?’
I recently received an email from a retired Brit living in Portugal who wanted advice on how to encourage wildlife on his 10 ha of Algarve scrubland. He wants more flowers, trees, birds and insects but was most insistent that he did not want anything to do with rewilding, which he described as ‘the worst kind of eco-fascism’. It seems that rewilding has become a surprisingly controversial subject, with many passionate supporters, but perhaps just as many ardent opponents. It seems to be the conservation equivalent of Marmite. So what exactly is rewilding, why is it so controversial, and can it help us with the dire environmental problems that loom ahead?
Rewilding is not easy to precisely explain, but broadly advocates setting aside land and allowing nature to take its own course – in contrast to conventional conservation which, more often than not, involves considerable management. Where possible, rewilding often involves reintroducing lost species, such as large herbivores and their predators, which provide their own form a ‘natural’ management. The best known example is Yellowstone National Park, which through much of the twentieth century was over-run with huge populations of elk, the grazing of which was preventing forest regeneration and causing widespread soil erosion. Wolves had been shot out in the early 1900s but were successfully reintroduced in 1995, and their depredations have since reduced the elk population with widespread ecological benefits for the park, including healthier soils, more trees, more beaver, and more biodiversity. Of course Yellowstone is vast, some 3,472 square miles with no human inhabitants.
In the UK, rewilding projects are inevitably more modest. The Knepp Wildland in West Sussex is the UK’s biggest project to date, and it seems huge when you wander around, but it covers just 13.5 square miles. They have free-roaming herds of deer, cattle, pigs and ponies, but no space for predators such as wolves or lynx even if the local residents were willing to put up with them. Advocates of rewilding (of which I am one) would love to see larger projects in the more remote regions of the UK, where one might conceivably introduce predators, afforest areas currently overgrazed by deer, and introduce beavers whose dams reduce flooding downstream. So far as I am aware no-one has ever suggested that people should be evicted from such areas to make way for wolves, but nonetheless it seems to be the fear of another round of Highland clearances that is fuelling the charge of ‘eco-fascism’.
You may be wondering what all this has to do with gardening and climate change. I’m lucky in having a large garden of two acres in East Sussex, but sadly I cannot realistically consider releasing a beaver, let alone a pack of wolves. What would the neighbours say? On the other hand, I can and have made my garden a little wilder, suppressing the natural human instinct to endlessly mow, weed, hoe and tidy, and allowing nature to take its course so far as practical. I have invited nature in to live with me, and at the same time I am capturing carbon, helping in a small way to combat climate change. My efforts alone are insignificant, but we have half a million hectares of gardens in the UK, more than all our nature reserves combined. If enough of us tried to rewild our gardens, and if local authorities adopted similar approaches in communal greenspaces, roundabouts, road verges and so on, it really could make a difference. So what, specifically, am I suggesting you do, and don’t do?
- Mow less! Mowing your lawn emits carbon dioxide (unless you have a push mower), removes lawn flowers, and reduces the amount of carbon captured in the living plant material. I can’t find a figure for the UK, but the USA is estimated to use up more than 3 billion litres of petrol each year in mowing lawns.
- Recycle green waste and kitchen scraps in a compost heap, creating nutritious compost to boost your soil carbon.
- Don’t buy artificial fertilizers, the manufacture of which releases lots of CO2. You won’t need them with all that fertile compost you’ve made.
- Don’t buy peat-based composts either; peat is essentially a fossil fuel, ripped from the ground, which starts to turn into CO2 as soon as the air gets to it.
- Grow your own zero-food miles and zero-packaging fruit and veg.
- Plant as many trees as you can fit in. Fruit trees provide flowers for pollinators, and fruit for you and the birds and wasps, while steadily locking up carbon as they grow. A mature apple tree can sequester about one ton of carbon dioxide. If you have a tiny garden, plant a dwarf apple.
- Leave hedge clippings and other woody waste in brash piles to rot down rather than burning them.
It is easy to feel helpless in the face of dire environmental news, such as television footage of the Amazon burning. But all the world’s environmental woes are simply the sum of the small ‘bad’ things that we each do. The way to fix them is for us all to do our bit to help, and what better place to start than in your own back yard?