To fully restore European wildlife and habitats, an important question must be asked: What would the ‘natural’ state of Europe be without human influence? For a long time, ecologists assumed it would mostly be a dense deciduous closed canopy forest, where trees form a dense layer blocking out most sunlight. However, new theories are rapidly changing this view where rewilding projects are put to the test.
West Sussex located roughly 15 miles south of London is an appealing English County dotted with small towns, attractive farms, and small woods.
Therefore, it may not be an area you’d expect to see Tamworth pigs, Shetland Ponies, and Longhorn Cattle roaming freely. But that’s exactly what you would find if you visited the former agricultural lands around Knepp Castle. As chronicled in the hugely successful book ‘Wilding’, farmers Isabella Tree and Charlie Burrel transformed their bankrupt farm into an ambitious biodiversity experiment. The aim of the rewilding project was to use hardy breeds of free roaming farm animals as surrogates for extinct herbivores that once roamed the prehistoric British Isles. Tamworth pigs are used to represent Wild Boar, Shetland Ponies to represent wild horses, and Longhorn Cattle to represent the extinct Aurochs (wild cattle).
The rewilding project was inspired by the radical theories of Dutch ecologist Frans Vera. He argued that the assumptions ecologists were making about the natural ecosystems across most of Europe were flawed. Without human influence, most land in Europe becomes dense woodland so it was assumed this was the ‘natural’ state of the land. But Vera challenged this with a radical new theory. Put simply, the only reason closed canopy forests tend to proliferate without human influence, is because most large, wild herbivores have been hunted to extinction in Europe, creating an unnatural system. Vera argues that to fully recreate the natural habitats of Europe, or rewilding, these herbivores must be reintroduced. These large animals would graze the land, resulting in a wide variety of habitats such as pasture, grassland and scrub, and open canopy forests alongside closed canopy forests. This mosaic of ecosystems would allow biodiversity to be maximised across a variety of ecological niches as opposed to a single, uniform habitat type.
Image credit: Wikmedia Commons
Vera’s theories seem to have successfully been put to action in Knepp. Over the course of 20 years (since 2001), numerous rare species have begun to make their home in the ‘wildland’. In 2009, 15 species that have been recognised by the UK biodiversity action plan (such as Ravens, 13 species of bats and turtle doves) were residing at Knepp and by 2016, falcons and the very rare black stork were seen in Knapp. 60 rare invertebrate species (such as the Purple Emperor butterfly) now live in the wildland.
The explosive increase in biodiversity provides evidence that the ‘closed canopy forest’ theory is flawed, as this mono-habitat is species-poor when compared with the varied, dynamic habitats found around the Knepp Castle estate.
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A similar rewilding project has been taking place in the Netherlands: Oostvaardersplassen on the coast of Holland; it has Red deer, Konik ponies, and Heck cattle (cattle bred to be superficially similar to Aurochs) as the grazers. This area has more of an emphasis of restoring wetlands than at Knapp Castle, with Eurasian spoonbill and sea eagle frequenting the reserve alongside numerous mammal species. But the same principles at Knepp still apply: with large grazers preventing natural succession to a species poor woodland.
Image credit: EM Kintzel, I Van Stokkum
However, Oostvaardersplassen has been at the centre of numerous ethical controversies. The free-roaming herbivores at the reserve were left to carry out completely natural processes and this included life and death cycles. During a harsh winter, a lack of food led to 65% of the deer, cattle, and horses being killed before they could die of starvation. Even more controversially, the carcasses were left out to rot to stimulate natural scavenging processes. These things led to passionate protests from animal rights and biological organisations and eventually led to the authorities in Flevoland (the Dutch province the site is located in) to call for a permanent reduction in the number of grazers to stop this type of mass starvation happening again. It could be argued that in a more natural ecosystem, wolves and other large predators would kill excess herbivores, thereby preventing the overpopulation issue. Unfortunately, due to the small and isolated nature of the reserve, and the intense human impact on the Netherlands, this has yet to happen.
Alongside the ethical concerns, not all ecologists are in agreement with Vera’s theories. Many still believe that the closed canopy theory of European forest is correct. However, Paleoecology is a dynamic discipline and methods such as high detail pollen records may allow ecologists to settle this question, even though trying to entangle the myriad of spatial and temporal variation alongside interactions from human and climatic factors will always be tricky.
Ultimately, the success of rewilding projects such as Keapp and Oostvaardersplassen will be pivotal in determining whether Vera’s theories are correct or not.
Featured image by: Mary and Angus Hogg/Wikimedia Commons