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Rewilding the Downs

Friends of the South Downs have been asked for our view on rewilding, especially in relation to the sensitive landscape of the South Downs. Glynn Jones has approached this controversial subject.

Photo by Richard Reed: Coombe Hill Scarp, July

Rewilding the Downs is a complex issue, mainly because the Downs as we know and love them are entirely unnatural and a product of human interference.  We also need to consider our reasons for rewilding. What outcome are we seeking?

The “climax vegetation” of most of the British Isles is woodland. Put simply, if you take an area of land and do absolutely nothing to it, it will turn into woodland. That’s what would have covered the Downs when Neolithic people visited in the warmer months to hunt. But then as the climate improved, they decided to settle there. There would have been a few places where the geology, geomorphology, grazing and aspect prevented the development of forest, areas sometimes referred to as “Refugia”.  These areas harboured some of the plants that had colonised the area as the “Tundra” of the last ice age retreated.

The downland forest was sitting on deep “Forest Brown Earth” soils that had developed over thousands of years from the insoluble impurities in the chalk that had slowly dissolved away. During the Neolithic period, the first farmers started to clear the woodland on the best drained, lighter and shallower soils (the Downs) using “Slash and Burn” technology.

As time passed the newly exposed soils would have lost their fertility and been eroded away on the slopes. Those early farmers just moved on and cleared more forest. They left behind wild animals  and their own, domesticated animals to graze the vegetation now spreading across these abandoned cultivations. Many of these colonising plants came from the “Refugia” and eventually they were selected to form the vegetation we think of as Chalk Downland. This was selection, not evolution, as the plants themselves did not change.

This persisted for thousands of years until the two World Wars, when the need to feed the nation led to the development of artificial fertilisers and the spread of arable farming. The reduction of sheep farming and finally the introduction of Myxomatosis in 1953 removed the grazing pressure and coarser vegetation developed, including woody plants. Most of the current population of the south of England now know and accept the downland as a partially or fully wooded landscape. Today’s woodland is a very different and less diverse type when compared with that which our early ancestors found. Most importantly, the Forest Brown Earth soils have gone. It would take thousands of years of tree cover for them to redevelop to the point where they could support the type of woodland our forebears destroyed.

To a degree, it could be argued that we have been practising “rewilding” on the steep slopes of the Downs for some time. Most of the scarp slope pasture has been abandoned and the once scattered “open-armed” spreading yew trees are now absorbed into a, largely, pioneering ash woodland with trees thrusting upward in the competition for light. The primary grazing animals are now Roe, Fallow and Muntjac deer together with Brown Hare. The new ash woodland is itself now threatened by the spread of “Ash Die Back” and we do not really know what will replace it. Whatever comes next, even if it’s Rewilding the Downs, it will lack the diversity of the Ancient Woodland cover and will not support more than a fraction of the wildlife interest of the ancient woodland or succeeding grassland.

Glynn Jones, Trustee

2 thoughts on “Rewilding the Downs

  1. Hi,
    I disagree that the “climax vegetation” of most of the British Isles is woodland. This view assumes that the British Isles did not include large native Herbivores, we know it did. Our climax vegetation is more likely to be a mosaic of woodland, grassland and scrub. A rich and varied habitat structure would hugely increase the biodiversity of the Downs. The use of proxy large herbivores in very extensive grazing systems is essential to achieving more nature from our National Parks.
    A move away from a farmed landscapes to something that provides a more interesting naturalistic habitat mosaic would be very exciting.
    Matt

    1. Matt is, of course, correct in what he says and I share his vision for a richer downland.
      There is always a problem trying to express complex ideas in simple language for a fixed length article. We might differ in our definition of what constitutes a “Woodland” but I think we agree on more than Matt realises.
      It is a fact that, where we have suitable soils, tree cover is the final stage in natural succession. It is equally true that factors other than the vegetation will shape our woodlands and grazing pressure is a significant example, one that I made a passing reference to in the article.
      A healthy woodland should exhibit age class and species diversity along with structural diversity and grassland and scrub are part of that. There is a distinction between “Natural” grazing pressures which contribute to the climax vegetation and grazing controlled or modified by human activity. In the latter case what we get are Plagioclimaxes and our historic, extensive, herb rich downland sheepwalks are a local example.

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