Domestic grazing animals such as longhorn cattle have been introduced to the Knepp Estate, which has allowed natural landscape processes to recover and enabled habitat diversification IMAGES © CHARLIE BURRELL
Rewilding is an attractive but elusive concept: if what is wild is generally defined by the absence of human intervention, what does this mean in a densely populated world, where even our most extensive nature reserves – particularly across Africa and North America – are created by humans, and are far from free of human pressures? And, if we struggle to know what is genuinely wild, defining rewilding presents even greater conceptual challenges.
There are many examples of inadvertent rewilding. The demilitarised no-go zone between North and South Korea is home to rare animals such as the red-crowned and white-naped cranes, the Amur goral, Asiatic black bear, musk deer and other species that prosper through human neglect. As another example, a silver lining to the 1986 Chernobyl nuclear reactor disaster has been the resurgence of animals, including lynx and European bison, in the exclusion zone.
However, rewilding is largely a deliberate and active process of intervention in populated landscapes, intended to support the recovery of natural species and ecosystem processes including the regeneration of soil and water systems.
We live in an era of unprecedented global monitoring and environmental literacy, with an unparalleled body of legislation and protocols relating to protection of biodiversity and the wider environment. Yet in May, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) issued a global assessment report on the status and trends in natural systems that makes sobering reading. It documents an unprecedented, dangerous decline and an accelerating rate of species extinction, between tens and hundreds of times greater than natural extinction rates, putting at risk about 1m of the estimated 8m species on earth.
Evidence in the report raises significant concerns for the viability of nature, but also for the unavoidably conjoined continuity of humanity's well-being. To quote IPBES, 'We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide'. Biodiversity loss is the direct result of human activities, and current responses are wholly inadequate. It is not too late to challenge vested interests and transform the prognosis, although, in the absence of profound socio-economic change, global aspirations for human progress – as defined by the UN Sustainable Development Goals – cannot be met. Given that around 75 per cent of the terrestrial and 66 per cent of the marine environment have been 'severely altered' by human actions, rewilding is one of the solutions posited by IPBES.
The Knepp Estate is a pioneering example of managed rewilding in the constrained, densely populated context of lowland Britain. The estate, around 8km south of Horsham in West Sussex, covers 1,400ha and has been in the same family since 1802. The landscape sits on a 320m-deep bed of Wealden clay, making for difficult farming. Furthermore, in the face of increasing intensification and chemical inputs in agriculture since the 1980s, arable and dairy farming at Knepp were becoming increasingly uncompetitive. At the same time, these input-intensive practices were contributing to precipitous declines in wildlife across all taxonomic groups. In the mid-1990s, the owners took a considered decision to pursue extensive ranching, more akin to systems in Africa.
Since 2001, the landscape has been devoted to a rewilding project emulating fully natural systems. With the introduction of domestic grazing animals such as longhorn cattle, Tamworth pigs and Exmoor ponies as surrogates for their wild forebears, along with native deer, natural landscape processes have been allowed to recover. The grazing patterns of migrating herds of animals, free to move across the unfenced estate, have been significant factors in habitat diversification. They have stimulated formation of distinct vegetated zones, varying from dense woodlands to savannah-like glades, also enabling the natural regeneration of watercourses.
Along with the cessation of pesticide use, this has resulted in rapid recovery of insect and bird populations. Some of the successes include increased numbers of scarce species such as turtle-doves, nightingales, peregrine falcons and purple emperor butterflies, as well as booming populations of more common species.
The conservation ethos at what is now the Knepp Wildland Project differs radically from conventional nature conservation. Traditional conservation approaches are generally predicated on preservation of habitats, often artificially maintained in a mid-successional state, to support particular goals and target species. However, efforts on Knepp Estate are process-led, driven by the re-establishment of a functioning ecosystem that grants nature as much freedom as possible.
Clearly, re-establishment of large predatory species lost from the British landscape, potentially feasible in remote landscapes, would not be permissible in this densely populated region of the South East of England. Consequently, managed culling of stock at Knepp is both a necessity to avoid overgrazing but also a source of revenue from meat sales. This otherwise largely hands-off approach to ecological restoration is low in cost yet still productive, applicable to many more marginal or failing areas of farmland and potentially building on and connecting networks of established nature reserves.
As Knepp is privately owned, the economics have to stack up. The culling of grazing animals supports a market in organic, pasture-fed, free-range meat, and the government's Farm Business Survey has found that economic returns for lowland grazing livestock at Knepp are significantly higher than the national average. Farm support payments, including the Basic Payment Scheme and supplementary Environmental Stewardship payments, make significant contributions. Farm labour and building needs have been substantially reduced, freeing housing and office space for rent. In addition, the estate has opened up wildlife safari, touring and camping operations. The overall result, as Savills' Rural Estate Benchmarking Survey for 2017/18 shows, is that like-for-like agricultural income at Knepp Home Farm outperforms the national average, excluding additional rental, tourism and other income.
'Rewilding efforts are driven by the re-establishment of a function ecosystem that grants nature as much freedom as possible'
Other rewilding endeavours around the world include the American Prairie Reserve's plan to rebuild one of the largest wildlife reserves in the continental USA through a combination of land acquisition and public land integration, including reintroduction of bison on private land in the Missouri Breaks. The plains are natural grassland, chiefly formed by the grazing activities of large herbivores. However, they were disastrously degraded by deep and extensive tillage driven by subsidised agricultural development during the Great Depression, inadvertently leading to the massive erosion behind the Dust Bowl that drove 3.5m people from the plains states in the 1930s and 1940s. There are similar rewilding initiatives in Europe, using reintroductions of top predator and other species, including proxy domestic strains. Other parts of the UK are also restoring ecosystem processes, giving rise to improved biodiversity, hydrology and water quality.
Rewilding can pose challenges to the established frameworks of established conservation work, which is generally predicated on individual scarce species rather than promoting dynamic ecosystem process with outcomes that are less predictable but overall more beneficial. Furthermore, an inherently ragged and dynamic rewilded landscape may not easily meet established criteria for land maintained in the good condition that is a prerequisite for farm subsidy payments. There is a pressing need for a more intelligent policy and financial environment to reward rewilding, in part or in full, recognising the multiple benefits that it can realise.
Dr Mark Everard is associate professor of ecosystem services at the University of the West of England, Bristol mark.everard@uwe.ac.uk
Related competencies include: Environmental management, Land use and diversification, Management of the natural environment and landscape