Our countryside offers many clues to its past, writes Tony Marshall, I often lead nature rambles in the Chilterns, but I find I spend as much time pointing out other features of the countryside as I do talking about the wildlife species encountered. This is partly because our wildlife is not randomly distributed – to find particular species, you need to know the places they like to inhabit; it’s also partly because our countryside is full of interesting signs of the past that often go unrecognised by the casual passer-by. People often spot a toadstool or flower on a bank, but they seldom think about why it’s growing there, or indeed what the bank is doing there.
The most obvious features of our landscape are the result of its underlying geology and the subterranean forces that have shaped it, throwing up sea-floor deposits to form chalk hills that are rounded by weathering, and grooved by steep-sided river valleys. The products of this weathering, scouring and episodes of glacial deposits have formed the clays that survive on top of most of the hills. The clays, less warm, tending to get alternately waterlogged and dried rock hard, and leached of calcium, are less suited to agriculture, so that the usual view of the Chilterns is of pasture and arable along the valley bottoms and slopes, with wooded hilltops above. Look more closely, however, and you can usually see that the slopes aren’t uniform: just before the top, the gradient tends to increase. It’s most obvious when walking or cycling (or even, if you must, motoring) up a lane that takes you to the tops. Just as you’re tiring of the stiff climb, you suddenly reach the steepest bit of all – a killer blow! This relatively narrow steep section winds round all our hills, marking where a band of hard chalk-rock occurs near the surface. This band separates two major eras of chalk deposition, called the Middle and Upper Chalk. Being more like limestone than chalk (it used to be excavated for building), it weathers less than the layers above and below, leaving this marked contour. As most of the Upper Chalk is covered in clay, this hard band tends to be at the top of agricultural fields and close to the margin of the woods. Here, where a wide field margin is left to grass, is the best place to look for the rarer chalk flowers that can cope with its thin soils – rockrose, wild thyme, milkwort, Chiltern gentian and fairy flax.
Although geology forms the canvas of the Chilterns, the details of the picture are the result of man’s hand in more recent times, albeit going back thousands of years. Look at the components of any local Chiltern environment scene – woods, fields, hedgerows – all are man-made. Before the first Neolithic agriculturalists forests were distributed indiscriminately across the land, except for places scoured by rivers or where deep marshes inhibited trees, where lightning fires or major storms had opened glades, or where browsing wild ox, boar and red deer kept tree regrowth down and allowed grass to flourish. It was the first cultivators who felled trees and kept large areas open, creating the basis for the shapes we see today, when a continuous expanse of trees was replaced by clearly delimited woodlands, each eventually distinct enough to be given their own names. It was hunting by man, first of all for meat to supplement their domestic stock, but eventually for sport and to control competing predators, like the wolf, lynx or polecat, that changed the character of the forest.
By the late Middle Ages timber had become a crop in itself and man even began to control which trees grew where by phases of felling and replanting. Farming is nature kept under control. Barriers were needed, for instance, to exclude grazing stock from arable crops. The simplest means of achieving this was the creation of hedgerows – sometimes the survival of woodland strips left after clearance, sometimes deliberately planted, with thorny shrubs like blackthorn and hawthorn preferred. The hedges were made particularly impenetrable by laying young trees. Selected saplings were cut almost right through and laid horizontally. These would automatically produce new shoots growing vertically towards the light, providing a dense woody network. Although hedge laying is now largely a thing of the past (it’s too easy to use barbed wire nowadays), you can still see the signs of laying, abandoned since the 19th century, in any old hedgerow. Horizontal boughs of laid hornbeam, beech or hazel have grown thick and knobbly like trunks, with equally misshapen twisting boughs rising from them, a Gothic architecture of the hedgerow laid bare, the habitat of trolls too elusive ever to be seen. The oldest hedgerows, dating back to medieval times when labour was cheap, were reinforced by ditches and banks, so that these ancient monuments can still be identified, indicating where the earliest farmsteads were established.
The margins of woods were managed in the same way as hedges, with laying accompanied by a ditch and a bank – the bank inside the ditch to keep animals out of woods to protect regenerating trees; or, in the case of pasture woodland, the bank outside the ditch to keep them in. You can identify a medieval woodland boundary by looking for these signs. Usually, boundaries have hardly changed to the present day, but sometimes, where a woodland has been allowed to grow outwards, the former boundary will be marked by the same signs within the wood itself – a good example is by the footpath down from the top of Warren Wood near Little Hampden.
Not all banks are man-made, however. You often find a woodland edge marked by bank, but without a ditch. This is the result of centuries of ploughing and cropping in the neighbouring field, gradually lowering the soil level, while the wood itself is an area of soil accumulation from leaf mould. Sometimes I’ve come across a hedgerow between two fields with a similar one-sided bank. It required some research using old maps to discover that these were in fact the remains of former wood edges. There’s a very good example by the footpath going down Denner Hill (west of Great Missenden) towards Nanfan Wood. Double hedgerows with a wide ditch between them are usually a sign of an old track – a useful way of identifying those we have lost. Old pasture woodland can usually be recognised by a scattering of large, old trees (mainly beech and oak), pollarded so they sprout just above animal browsing height – Burnham Beeches for example, and, in the Chilterns proper, Little Hampden Common.
The origin of the name Denner Hill is the Anglo-Saxon denn or ‘swine-pasture’, because what are now crop fields were once oak woodland where pigs were allowed to roam and feed on acorns. Other woodlands were managed for timber, felled after one or two hundred years, leaving very few veteran trees in our woods. Smaller branches, meanwhile, were used for fence posts, tool handles and chair legs. The latter were produced by coppicing (mainly hazel, but sometimes other trees) close to ground level, so that they’d sprout dozens of straight poles that could be harvested seven to ten years later. Although discontinued at much the same time as hedge laying, the remains of these dense hazel stools, now grown into multi-stemmed trees, can be seen today in many woods and some hedgerows.
Nowadays, where you find veteran trees, you can usually see that they’ve been left as ‘markers’ indicating boundaries, especially at the corners of woods or fields. Additionally, the same corners are often marked by large sarsen stones – an even more durable sign. Trees were also valuable for fruit. Hedges were excellent places for growing fruit trees (now called ‘linear orchards’), which is why you find so many cherries, wild plums, apples and hazels still growing in them. There’s much more to be seen (I haven’t even mentioned the distinctive remains of 17th century parklands). Next time you pause to take in the view, try interpreting why the lines and features are where they are. You’ll find that even more of the countryside’s beauty begins to emerge out of the overall backdrop – a beauty ultimately, however unintentionally, of man’s creation.
Credit : Tony Marshall (originally published in Chilterns issue 227)
