Rewilding

Key idea

George Monbiot first brought the theme of rewilding to many people’s attention in the UK with an eye-opening TEDx talk describing how he was ‘ecologically bored’. He describes pining for a richer and rawer life in a post-industrialised Britain. Monbiot states, in his opinion, there are two central tenants to the concept of rewilding: the mass restoration of ecosystems and the rewilding of humans.

The mass restoration of ecosystems involves the discovery of ‘trophic cascades’, interactions that control entire ecosystems from the effect of predators on their prey, propagating down food webs is a major line of argument in the rewilding movement. Ultimately trophic cascades highlight the complexity of the natural world and underscore the need for the reintroduction of predators in both the terrestrial and aquatic ecosystems.

An often-cited example of predator reintroduction is the return of grey wolves to Yellowstone National Park in 1995. Before this moment Yellowstone Elk were pushing the pushing the limits of the Yellowstone’s carrying capacity. Transformation came about due to two reasons: firstly, the wolves killed and ate some of the elk and secondly, they prevented the elk from moving freely throughout the park in large numbers. By driving the deer out of some areas, the cascade effects were enormous and are still being monitored to this day. The U.S. National Park Service even claim that rivers have changed course in this video. The underlying argument is that the natural world has great complexity. The following quote from chapter 1 of Monbiot’s rewilding book Feral neatly defines the term in his eyes:

Rewilding, to me, is about resisting the urge to control nature — and allowing it to find its own way. It involves reintroducing absent plants and animals (and in a few cases culling exotic species which cannot be contained by native wildlife), pulling down fences, blocking the drainage ditches, but otherwise stepping back. At sea it means excluding commercial fishing and other forms of exploitation. The ecosystems that result are best described not as wilderness, but as self-willed.

Rewilding is not limited to the terrestrial landscape. The planet’s oceans also rely heavily on the concept of trophic cascades. In our oceans the impact of whales is also becoming apparent. As the largest mammals on Earth, whales are incredibly important for the recycling of organic matter via their faecal plumes, representing an oceanic trophic cascade. The cycle starts with tiny marine plants, called phytoplankton, which grow and absorb carbon dioxide near the ocean surface. Phytoplankton is eaten by krill. Death, faeces, and migration move organic, carbon-rich organisms towards the ocean floor. Mammals such as the Blue whale then consume krill and defecate. These are long, flocculent (loosely clumped together) excrements, in the photic zone (the upper part of the ocean where photosynthesis takes place). Whales release excrement rich in nutrients which stimulates microscopic plant growth, called phytoplankton. Eventually this becomes a circular process known as the ‘whale pump’ — an example of recycling in the natural world. This biological cycle in the hydrosphere also underscores, in Monbiot’s words, the importance of ‘stepping back’ from certain areas to allow nature to recover i.e., by limiting krill fishing in the Southern Ocean and by enforcing fishing quotas in British territorial waters.

George Monbiot’s second central definition of rewilding is to rewild human nature itself. He describes himself as ‘ecologically bored’ from the humdrum routine of modern life and, along with many other environmentalists, argues we need to re-engage with nature for our own good, to fill our lives with adventure and surprise once more. We have arrived at the crossroads of both ideological thinking and possibility. As rewilding has grown in public awareness so too have our capabilities of turning the concept into reality. In Europe rural-to-urban migration is continuing to empty the countryside, leaving large swathes of land vacant. 30 million hectares of land in Europe will be vacated by farmers between 2000 and 2030. It is a tantalising prospect for those who argue for a wild future. However, one question sharply divides people: should we really contemplate the return of some our natural megafauna (hippopotamus, lions, hyenas) from the last great interglacial period?

Rewilding a farm

Another key book in the rewilding literature is Wilding by Isabella Tree. This take on the topic is very focused in space and place, as it is essentially a personal tale told by the Burrell family about the rewilding of the Knepp estate, from 2001 to present-day. Isabella Tree starts off with a stark summary of the last 50 years of intensive agriculture:

The number of Britain’s most endangered species have more than halved since the 1970s, with one in ten species overall threatened with extinction within our shores. The abundance of all wildlife has fallen dramatically. Insects and other invertebrates have been particularly badly hit, more than halving since 1970. Moths have declined by 88%, ground beetles 72% and butterflies 76%. Bees and other pollinating insects are in crisis. Our flora is also failing. Seed-bearing weed species — upon which turtle doves and countless other bird depend — declined by 1% every year during the twentieth century since records began in the 1940s.

The combination of expanding urban areas, roads severing animal movements, exploitation and climate change has led to the current emergency of both a climate crisis and a biodiversity crisis. Climate change is only just starting to show visible, long-lasting changes to our UK weather, making farming a very difficult industry to survive in, let alone profit from. Here are some climate facts for 2020 to underscore the challenge facing us:

• The last six years have been the hottest six years on record
• The last decade was confirmed by climate scientists as the warmest on record
• The Met Office says 2019 was 1.05C above the average for the period from 1850-1900 (calculated using the HadCRUT4 temperature data)
• May 2020 was the sunniest and driest calendar month ever
• Conversely, February 2020 was the wettest February on record (and the 5th wettest of any calendar month since 1862)

These records support a warning from the Environmental Agency (EA) in 2018 in the press release: ‘climate change means more frequent flooding, warns the Environmental Agency’, which scientists believe is due to changes in the Jet Stream. To learn more watch this Met Office Jet Stream YouTube video. Rewilding, it is hoped might not only protect our flora and fauna but might also be able to alter the land to absorb more surface water in the future. In Wilding there is a whole chapter devoted to the importance of ‘Rewilding the River’ and the advice from Hans Kemp, a senior policy advisor on Ecosystems and the Environment to the Dutch government, to ‘fill in the canal…and return the river to its floodplain.’ Han’s experience working with large scale ecological networks across Europe and his involvement in the Oostvaardersplassen — a rewilding project in Holland set up by the ecologist Frans Vera, made him ‘both a thinker and a doer’ with a ‘profound understanding of the behaviour of water.’

Oostvaardersplassen comes up regularly in the book and would make an excellent case study for rewilding, you can learn more about it from the Dutch website on ‘pioneering nature’.

Once the decision is made to backfill the canal on Knepp estate there is instant success. The river takes a more natural form with a shallow riverbed, banks soften to allow water to readily spill over in heavy rains and a wetland expanse full of egret, mallards, mandarin ducks, lapwings, fledglings, heron and even sea trout springs up. River re-naturalisation, as a wing of the rewilding argument, is of particular importance to the UK as the economy spends £1.1 billion a year on flooding with one in six properties in the country now at risk of flooding. This natural form of soft engineering is cheaper, safer and more resilient than hard engineering in the long-term.

In a very similar vein to the episode Siberian rewilding from the radio show 39 Ways to Save the Planet (a collaboration between BBC Radio 4 and the RGS-IBG), the big scientific ‘closed canopy’ debate is central to much of how we perceive the natural landscape (and what we should do/return it to, going forward). In the ongoing pursuit of funding from English Nature, Isabella Tree explains that the prevarications of civil servants were rooted in the controversy surrounding Frans Vera’s theory about the origins of ‘wildwood’ explained in the following perplexing paragraph:

…was Britain in the pre-Neolithic, Atlantic era, about 7,000 years ago, closed-canopy forest? Or was it a more open landscape, a mosaic of grassland, scrubland, groves and solitary trees, grazed by large numbers of herbivores? Correctly identifying Britain’s ecological past was clearly fundamental to considering how conservation should proceed…

Reintroducing key stone species

If the conclusion is that our temperate ecological zone was in the past more mosaic-like and open (which the light-demanding tree species of hazel, oak and birch all seem to suggest) then the argument for reintroducing predators arises too. Simply put, this is so that herbivore numbers are kept in check. In the UK as the appetite for hunting has slowed the deer population has become artificially high. There are 1.5 million red, roe, fallow, sika, muntjac and Chinese water deer in the UK which, without culling, are colonizing the country and preventing vegetation recovery. Two species have been suggested for reintroduction: the wolf and the lynx, both natural predators of roe.

The grey wolf has very successfully been reintroduced to Yellowstone National Park, Wyoming. It is an 8,991 km² wilderness recreation area and since the return of wolves there has been a ‘trophic cascade of ecological change’. Watch this video on How wolves change rivers to understand the impact on beavers and elk in the National Park.

The beaver is already a success story of the UK rewilding movement. It was first successfully released in Scotland, in Argyll and around the Tay and Forth river catchments between 2009-2014. This was followed in England by the River Otter Beaver Trial (ROBT) in the lower reaches of the river Otter, Devon. Robin and Merlin Hanbury-Tenison have also been fundraising since April 2020 to return beavers to Bodmin Moor through the Cabilla Beaver Project, supported by the Cornwall Wildlife Trust and the Cornish Beaver Trust. In total 6 young beavers will be released to a tributary of the Warleggan River, Cornwall. Their reintroduction is widely celebrated as beavers help mitigate against river flooding due to their dam-building and channel-digging. They have been absent from the UK for 500 years.