Overview
Tony Whitbread runs rewilding safaris at Knepp Wildland. Tony’s presentation will share his experience at Knepp to help illustrate what rewilding is in practice, giving clues on how understanding the principles of rewilding might help in nature conservation more generally
Lynn’s Review
Dr Tony Whitbread, is a champion of nature in Sussex, being a conservation advocate; a spokesman for woodland issues; and for helping to introduce the Sussex Biodiversity Record Centre. He retired as Chief Executive of the Sussex Wildlife Trust in 2018, but is now president of that charity and has played a leading role in the rewilding project at the Knepp Estate where he is a trustee and where he runs safaris on rewilding. We are fortunate that he presents to us almost annually. His talks are popular with members of Science at Fishbourne.
Dr Whitbread, having spent his working life in ecology and nature began his talk by commenting that there have been many investigations and agreements around nature, conservation and planetary health, but there is still an overall decline, for example: the number of vertebrates is ¾ down on figures for 1970.
Johan Rockström and his team of scientists, in 2009, defined 9 critical environmental limits for maintaining “Intact Nature;” for caring for our planet.
The first time all 9 planetary boundaries were assessed was 2023.
In 2025 only 2 of these boundaries remain in safe global operating zones: Stratospheric Ozone Depletion and Air Pollution! The 7 others, relating to our treatment of land and water, have all been crossed.
Tony believes that Rewilding is a good place to start to address some of these problems.
Rewilding, isn’t land abandonment, it is restoring eco systems by restoring natural processes that drive the eco system.
There are 2 key natural processes that work in opposition: vegetation succession and natural disturbance.
At Knepp, with no agricultural pressure, vegetation began to gain a hold, from grasses to shrubs and trees, and within 15 years forest. Once a climax forest has been established, it will self-perpetuate, regenerating indefinitely, but the vast majority of animals don’t live in forest habitat; even oak trees grow in grassland, so some disturbance is needed.
In 1987 a storm took out many trees and so opened up woodland. Erosion, flood and tree death all play their part in maintaining biodiversity.
Big beasts used to roam the landscape: bison, deer, wild auroch; they were part of the natural environment. Today domestic proxies are used instead of wild herbivores: pigs, long horned cattle; Exmoor ponies and deer help to maintain a balance of vegetation.
We have also lost the predators which would have affected the areas used by the herbivores. Deer wouldn’t spend much time in areas where they could be hunted, as a result, river banks would keep their trees and berries, so helping specific wildlife to benefit.
At a glance, we might just think: open up the land; allow the vegetation to arrive and let in the herbivores, but it’s necessary to look at the whole landscape; to plot for different activity in different patches of land and to allow for variation over time. Domestic proxies can help with this:
A pig can plough 40 acres in a year, and, compared to a tractor, the benefits are obvious: no soil compaction; the soil micro-ecosystem is undisturbed by a pig’s snout; weed roots are eaten, the soil is fertilized, slopes are easily managed and there is no fuel cost. Pigs therefore, open up the soil for new seeds to grow.
Cattle and horses keep tall grasses down and allow smaller plants to grow.
Goats and deer eat tree shoots and shrubs, so preventing thick forest from taking over.
Beavers, by building dams, create ponds and wetlands for fish and birds.
Our use of land, through lack of careful planning, and overabundance of the same species, has led to global biodiversity decline.
A kaleidoscope of shifting habitat is needed to support wildlife diversity and monitoring the species found is a guide to the success of any rewilding project.
At Knepp, many species are reappearing as a result of the rewilding project. It has become a regional hotspot for the cuckoo, turtledove and violet dor beetle; the lesser whitethroat, nightingale and brown hairstreak butterfly. The purple emperor butterfly, depends entirely on a species of willow whose growth is helped by the action of the pigs, as is the turtle dove who benefits from the small seeded weeds that grow up on the newly ploughed land.
One way to check that the ecosystem is working, is to check the soil. At Knepp, carbon and organic matter in the soil have more than doubled over 20 years, and there is 4 times as much living material under the soil than previously thought.
Rewilding is a way of thinking. Nature changes, so objectives must change with it. There has to be a balance between careful management and working with the natural systems. Any outcomes should be seen as emergent properties rather than objectives.
Now, maybe, we might take some of these insights to the management of our gardens.
I learned much from Dr Whitbread’s talk and hopefully he will give more insights next year.
Below are links to some interesting web sites:
https://www.wwf.org.uk/sites/default/files/2023-05/WWF-Living-Planet-Report-2022.pdf
https://www.woodlandtrust.org.uk/blog/2023/04/increase-garden-biodiversity/