Natural regeneration and rewilding are buzzwords you’re likely to have heard in recent years – since the publication of George Monbiot’s ‘Feral’ and Isabella Tree’s ‘Wilding’, both terms have seen increasing media attention as naturalists and conservationists question whether the best approach to creating biodiverse habitats is to actually do nothing at all. 

Rewilding is broadly accepted to mean removing existing land uses such as agriculture, grazing, or even the management of nature reserves, and to allow nature to take care of itself. Some great examples have been widely discussed, such as the Knepp Wildland in East Sussex.

This naturally leads many to question the rationale for conservation projects that involve interventions like tree planting. Why not just leave the land alone and let trees, shrubs and undergrowth species naturally regenerate? 

Here at Co-forest we believe that in the right spaces, rewilding has some fascinating and hugely beneficial values and rewilded spaces have been shown to contribute valuable habitats and result in significant biodiversity. In some spaces on our sites, regeneration will be encouraged and habitats will be protected from grazing to allow them to naturally regenerate. 

However, the process of rewilding also comes with caveats, and here on our blog today we wanted to outline some of these and explain why we also need to actively plant the land that Co-forest is restoring. 

Seed source

For effective rewilding, a seed source is required to allow the establishment of trees. Some species, such as willow, have seeds that can travel large distances by wind, but many other species would be required to exist in the local area. For many ex-agricultural sites that have been grazed or cultivated for long periods of time, the seed in the ground is likely to be minimal and you are then reliant on a small number of species that may exist in hedgerows or as standard trees within fields. For our site in Almondsbury this would limit the species mixture to willows and ash. 

Species mixtures and disease

As a result of human movement between countries, we now have tree diseases in Britain that wouldn’t naturally exist. One such disease is Ash dieback, which is now widespread and impacting Ash trees across the country. Ash regenerates well, but saplings are particularly vulnerable to ash dieback and regenerated spaces reliant on ash at the moment will likely find themselves fairly sparse in the near future. 

Climate change

Another risk to current woodlands is climate change, and the predicted future temperatures for Britain by the time today’s saplings are fully grown trees. Some species that currently do well in the south of England will struggle to survive by 2080. While this seems a long way away, forests have a long lifespan and if we want future generations to have healthy forests within their landscapes, some consideration has to be given to future climate and resilient tree species. 

Pests

We can’t escape the immense impact that humans have had on Britain’s natural environment, and simply leaving nature to right itself comes with many challenges of our own creation. For example, we have removed many of the apex predators in Britain, such as lynx, wolves and bears – and without them populations of other species can spiral out of control. We have huge deer populations that do immense damage to regenerating saplings. Likewise, introduced grey squirrels strip bark from trees, killing them. They also eat vast quantities of seeds and nuts, preventing germination. Rabbits will eat the leaves of saplings. Therefore without adequate management of the populations of these species, natural regeneration of trees is compromised and as a result we see woodlands across the country aging with a lack of young trees replacing those that die. 

In conclusion, in spaces where conditions are suitable – there is a seed source, the seed source represents desired tree and shrub species, and pests and diseases can be appropriately managed – rewilding is a fantastic possibility and offers a low-cost, low-intervention way to improve landscape biodiversity. However, where these conditions are not met, regeneration will likely be very patchy, lack resilience and potentially be too slow to help tackle the biodiversity and climate crisis we are facing. In these locations, planting and landscape management, done in a ‘close-to-nature’ way that promotes biodiversity gains and future resilience, offer a more effective option. 

If you want to help us in our planting journey please join our volunteer mailing list! Drop us an email at team@coforest.co.uk to sign up.