When should humans intervene in rewilding sites?
Rewilding is the process of naturally restoring an ecosystem to its full functioning balanced state. Its about putting nature in the driving seat, giving the area the time and space it needs to recover. The approach prioritises dynamism and ecosystem complexity above all else, recognising that healthy ecosystems are in a constant tug of war between flora and fauna, and that this dynamism allows life, in its many forms, to flourish.
As rewilding is about leaving nature to recover, it's perhaps unsurprising that some confuse rewilding with human abandonment. After all, if you are aiming to create a robust ecosystem that can thrive without humans, what do you need humans for? On the face of it, this argument does stand up, but in practice rewilding has proven quite the opposite. On average across the UK, rewilded sites provide 54% more local employment than traditional land management. Furthermore, most rewilding sites in the UK have taken different interpretations of rewilding principles and intervene in their sites to varying extents, but almost all of them require some level of human intervention. In this piece we’ll share which factors influence the decision of when to intervene or not.
The ecological health of the rewilding site
Not all rewilding sites are born equal. After several millennia of human interaction with our landscapes, Britain’s land & seas are very far from a pre-hominid state. Indeed, early hominids are thought to have first arrived at around 800,000 BC (1). Humans are of course part of nature, and although early humans are thought to have had an impact on megafauna like sabre-toothed cats, the woolly mammoth and woolly rhinoceros, it wasn’t until around 4000 BC that homo sapiens began to alter the landscape significantly, clearing woodlands to make space for farming, rearing domesticated cattle, and introducing non-native sheep and goats (yes sheep aren’t native to the UK!). Fast forward to the 21st century, and every inch of our landscapes has been altered by human activity. We’ve drained wetlands, straightened rivers, cleared woodlands & scrub, introduced hedgerows to divide fields, removed hedgerows to make bigger fields, reclaimed land from the sea, built infrastructure and converted 70% of the UK into farmland, some of which has been heavily degraded and poisoned with pesticides and fertilisers. These changes have enabled us to occupy more space and feed a growing population, but it has come at a profound cost to our wildlife and ecosystems. This is all to say that the UK landscape is not in a natural state, and some areas are so heavily degraded that without a helping hand from humans, the journey of natural recovery would be incredibly slow and challenging.
Therefore when a rewilder is thinking about how active they should be in the process of rewilding, they first look at how degraded the landscape is. For example, they will look at the diversity, maturity and abundance of trees in the area, and even take samples of the soil to assess the diversity and quantity of native seeds laying dormant. If the seedbank is scarce and there are few mature trees nearby, then a rewilder may consider planting pockets of diverse native trees, which would then regenerate naturally across the site. Another rewilder may consider the water flows on their site. For example, do they have a naturally winding river and floodplain, or is the land drained with a straightened high-banked river? If the latter, they may consider taking some action to help the river return to a healthier, meandering state. Preferably one would use a natural solution like introducing beavers which create dams and flooded areas, but if that’s not feasible, then one may consider using a digger to create scrapes or channels from the river, rewiggling its course and re-creating a floodplain. In the short term, this can scar the landscape, but very quickly the new, healthier structure of the river would vastly improve the habitat for fish, birds, insects and amphibians, whilst improving the area’s ability to filter pollutants, retain water in times of drought and reduce flooding in surrounding areas.
An absence of predators necessitates management
The last wolves roamed Britain in the mid 1600s, and since then our ecosystems have been void of free-roaming apex predators. This has had a profound knock-on effect, as explained in our last blog, impacting the balance between flora and fauna and the landscape itself. Although Wilderkind advocates for the release of wolves in Britain, following a similar model to that of Europe, it seems unlikely that this will happen soon. In the meantime, humans can mimic the role of predators in our landscapes, albeit less effectively. In practice, this means culling certain species on rewilding sites to ensure that the population size remains at a balanced level and the tug of war between flora and fauna can continue. Too many herbivores and the vegetation will be over grazed, too few and the flora takes over.
The upside of these culls is that rewilders can sell the wild meat that is butchered, giving them a much needed revenue stream. Animals reared in a free-roaming environment feed on varied food sources and go through periods of fast and famine with the seasons, which creates some of the tastiest & most sustainable meat you can buy, as proven by the award winning Knepp Estate.
The size of the rewilding site
Another factor which will influence how passively or actively a rewilder manages their land is the size of the project. In the largest landscape-style projects with areas spanning over tens of thousands of acres, like Yellowstone National Park, one can take a much more passive approach. At this scale, the landscape can be a fully functioning ecosystem, with a wide variety of predators managing grazing pressure and instigating trophic cascades of energy passing through the food chain. Carcasses of predated animals can be left, providing a food source for scavengers, whilst large groups of herbivores can move across the wilderness freely with enough food source to sustain themselves. But even at this scale, intervention was needed in the beginning, with the introduction of wolves. Predators play a vital role in keeping these ecosystems healthy, and the impact of wolf introductions is well documented and also covered in our blog.
Mid to large scale rewilding sites, ranging roughly from 1000 - 10,000 acres, which includes the largest rewilding sites in Britain, require more human management & intervention. Many sites will introduce domesticated rare-breed species to replicate the ecosystem function that their wild ancestors produced. For example, Tamworth pigs for Wild Boar, English Longhorn Cattle for Wild Aurochs and Exmoor Ponies for Wild Horses. Although these animals live relatively wild lives without feeding & antibiotics, their well-being is still tracked and they are enclosed with fencing, albeit in a much larger area than a usual farm. When they die, their carcasses are required by law to be cleared and disposed of. Some animal introductions, like beavers, need more monitoring and are required to live within smaller fenced areas. So much as to say, no area in Britain is in a fully wild state, not even in pioneering sites like Wild Ennerdale and the Knepp Estate. In summary, in Britain some level of human management & intervention is needed to enable a rewilding site to operate within the societal, regulatory and spatial boundaries of the UK.
Smaller sites of below 1000 acres can vary in the application of rewilding principles. Below the 1000 acre threshold, the land’s holding capacity is unable to sustain many free-roaming herbivores, so rewilders may agree with a local farmer to allow some temporary mob-grazing on the site to provide some disturbance to the flora. Without the continual disturbance caused by free roaming browsers and grazers, some sites may take a more active rewilding stance, felling selected trees for deadwood creation and to allow light on the woodland floor, or creating scrapes or ponds for aquatic habitats. Others prefer a more passive approach, allowing nature to move completely in its own way without any particular outcome in mind, observing the results as they come. This balance between passive and active rewilding is surrounded in some debate and ultimately it comes down to the landowners’ perspective and the land’s unique challenges.
Conclusions
Wilderkind’s perspective on intervention is that any action should be viewed with caution, and only enacted when the evidence shows that either the site is too heavily degraded to return to a fully functioning healthy state, or that this process will happen very slowly. All interventions should be focused on kick-starting natural processes to re-create a balanced ecosystem, rather than prioritising a specific habitat or species. In all our partner rewilding sites, we suggest following ‘Rewilding Britain’s’ recommendation to wait for at least 12 months first to see how the site recovers on its own before making any intervention.
(1) British Museum