A Natural Regeneration Experiment

In 2022, The Prospectory and friends began an informal, natural regeneration experiment in a 3.7 acre field above Talybont on Usk in the Brecon Beacons. The field adjoins 7.6 acres of steep, mixed woodland; a combination of oak, birch, hazel and hawthorn. Until September 2021, the field was grazed by a small flock of sheep but these have now gone.

Photograph taken in 2010

Natural regeneration occurs when existing trees and shrubs release seeds that germinate successfully to produce new growth. Scrub and woodland provide the vital services of storing carbon and supporting biodiversity. As a process, natural regeneration is as old as woodland itself given it’s how trees have reproduced, unassisted by us, throughout their millions of years of evolution. Yet, when expanding woodland in the UK, planting has become the cultural norm.

I had originally considered planting trees in the field but reading around the subject and discussing with people more knowledgable than me, I decided to try a natural regeneration experiment instead. The reported advantages over tree planting are claimed to be:-

  • UK’s native tree species have a wide genetic diversity. When new generations of trees are the offspring of those already thriving in the local area, they are likely to be more resilient to a changing climate, pests and diseases.
  • Natural regeneration can create more natural landscapes and species mixes which can be far more beneficial for wildlife.
  • These trees have more beneficial mycorrhizal (root) fungi, which help with water and soil nutrient uptake, and sharing resources between trees.
  • They show adaptation to locally prevalent environmental conditions, often surviving better than planted trees.
  • Their final distribution will be determined by which seeds succeed based on the immediate soil conditions where they land rather than planting formats determined in advance.

After planting 20,000 trees in the US, one researcher remarkedThe ones that grew best were mostly ones we didn’t plant, they just grew naturally on the ground we had set aside for planting. Lots popped up all around. It was a good reminder that nature knows what it is doing.”

From my point of view, as a life long experimental psychologist (not an ecologist), there are two things which particularly appeal to me about a natural regeneration project:-

  • Enjoying unpredictable outcomes – no-one knows what exactly will happen – what diversity and what surprises will emerge? Even with the most controlled experiments I’ve ever designed, the most powerful learning has been in the surprise effects of some unintended aspect of the experiment.
  • Understanding messiness and natural diversity. Natural regeneration can elicit a negative reaction because (like unmown lawns or grass verges) people see it as “scrubby, messy, uncontrolled and uncared for”. But is what we perceive as “messy” simply a culturally determined view? Nature can be messy but in that biodiversity lies its strength and resilience – a key part of the environmental reset we need. Unfortunately, the UK government’s new biodiversity metric does not value scrubby landscapes dominated by bramble, thistle and ragwort (often key features of rewilding projects). Instead it logs them as a sign of “degradation”.

The Experimental Plan

This is still evolving and, I’m sure, will continue to do so.

The sheep have been removed and the field is now undisturbed. We have selected 4 corners of the field (next to either woodland or hedges) labelled below as Talybont Bottom Corner (TB), Talybont Top Corner (TT), Aber Bottom Corner (AB) and Aber Top Corner (AT).

We have planted hazel poles at these 4 points as markers and plan to take photographs 4 times a year: March, June, September and December to record any changes. The photographs will consist of both the view looking across the entire field from that point and a small area of ground immediately around the pole.

In addition, with the help of a friendly ecologist, we hope to document the plants and seedlings growing in each of these 4 quadrants once a year.

Warning : The experiment will certainly outlive my likely life span! Here’s one which started 60 years ago!

March 2022 – Spring photographic record – photos by Jon Dixon

July 2022 – Summer photographic record – photos by Jon Dixon

Ecological Survey & reflections

Local ecologist, Graham Cowden, carried out a species survey of the field in June 2022. The objective of the survey was to generate a baseline botanical sample of fixed locations within the meadow using a methodology that can be reliably repeated annually at set times of the year by both experienced and less experienced surveyors. The baseline can be used to detect change in the general floristic composition and character of the site following the removal of grazing management.

The survey revealed a disappointingly low level of plant diversity (5-10 different species within any meter square). This is the impact of many years of sheep grazing in the field. Diversity will improve over time but only very slowly. Several hazel and hawthorn seedlings were noted under the canopy of the hedgerow trees along the eastern boundary together with the species avoided by sheep:- bracken, nettles, foxglove and creeping thistle.

Another factor, Graham points out, is that in the absence of grazing, the lush grassy sward will gradually coarsen and develop a basal thatch as successive years of growth build up at ground level. This may further hinder floral diversity due to the suppression of new flowering plants by the thatch of dried grass. We are discussing the possibility of disturbing the ground to some degree in one area of the field to give new seeds a chance. That too would be an experiment.

From my own naive perspective, I hadn’t realised how quickly, without grazing sheep, the grass and bracken growth would seriously disrupt ready access to the wood above the field where friends, family and Stomping Space groups of children enjoy hanging out, cooking, sleeping and playing. First lesson learned is that natural regeneration is always a compromise between what people want or need to use the land for and what nature, left to its own devices, will do! Fortunately, with the help of friends, we managed to strim a path up to and into the wood so access was restored but a plan to maintain access as the experiment unfolds is going to be needed. Maybe the occasional visit by a couple of bison?? (only joking).

Stomping Space group making use of the mown path.

Graham also sent me a really helpful article by Tom Williamson ‘in British Wildlife 2022.’Rewilding: a landscape-history perspective’ . The author traces the long history of British landscape and its shaping by people’s varied activities, needs and cultural preferences at every point. There isn’t some “completely wild” past to return to, only ones we inhabited over time in different ways. This includes the many non-native animal and plant species which are now well established in our land.

Some people have asked me the aim of our particular experiment. The answer at the moment is ‘I don’t know’ beyond exploring, discovering and experiencing a differently managed natural environment in relation to our human roles within it.