Ancient woodlands lie buried, but trees return
Shetland seems bare and bleak to many visitors. Glaciated sloping hills, exposed cliffs and miles of moorland contrast with familiar comfortable landscapes of tree lined roads, hedges and woods, Scottish forests and tall, tree filled public parks. It is hard for them to picture the thick brush wood, dense, low tree covered acres of ancient Shetland, evidenced by the bark and branches preserved in much of the islands’ peat deposits.
Today species common to Shetland’s earliest settlers, birch, aspen, willow, hazel, honey- suckle and wild rose, are being planted again in growing numbers. Fragments of small woods are rising slowly from the low profiles, shaking out season’s colour-changing leaves along sheltered burn-sides and around houses and gardens, creating copses where blackbirds can nest.
Fragments of prehistoric trees in peat are usually extremely damp, soft and fragile. A layer of bark may still have the sheen on it; traces of knots, side branch scars and bark markings may be clearly visible, but leave it for a few hours and the traces will begin to fade and the surfaces crumble. They are far too old to retain their features, once they begin to dry out.
Archaeologists have special treatments with which to preserve the appearance of wooden items. Wooden floors of ancient buildings, wooden tools, wooden boats and oars, preserved where lochs once existed, can all be found where they have lain for centuries, preserved by the ensuing quirky conditions of wet and chemistry in the surrounding soils, muds or peat.
I found a chunk of ancient birch, which was in the bottom of an exposed peat bank in Northmavine, over 20 years ago. I was so keen to save it from crumbling away that I tried desperate measures.
I filled an empty five litre ice cream tub with PVA glue and set in the chunk of branch, which vanished beneath the thick, white gunge.
I placed the container, with its lid loosely on top, on a high shelf in the garage and left it.
About five years later I came across the box and looked inside. Water in the glue had evaporated considerably, reducing the level of the glue, which was nowhere near as opaque as it had been. The wood was slightly shrunken in size, but clearly visible, as were all the marks and surface features. Eventually the glue became crystal clear and hard, leaving the whole ancient chunk high and dry and rock solid.
But there are ancient woodlands, which are not buried several feet below ground. They are still flourishing and I went for a walk in one of Britain’s oldest ones just a week ago. Hempstead Wood, in north east Essex, is currently used for private pheasant shooting and has severely restricted public access. Luckily for me I know a local botanist who has permission to walk here whenever they need to, for study and survey purposes.
The wood, surrounded on all sides by miles and miles of arable, with almost all fields now exposed, as the majority of hedgerows have been torn out in order to exploit every available inch for cultivation. Hempstead Wood stands like an island in a sea of rape, sugar beet and wheat fields. Thought to be part of a 380 acre wood recorded in a 14th century document, now reduced in size to 178 acres, it retains a species pedigree that stretches back to post-glacial times.
Woods in Britain after the Holocene (or last Ice Age) began to return about 12,000 years ago when the climate warmed sufficiently for tree seedlings to germinate, grow and mature. Since then, first birch and pine, then hazel too came in, followed by oak, alder and lime. Beech and ash, maple, elm and lower growing hawthorn, dogwood, wild plum, cherry and crab apple, willows and blackthorn came back, along with yew, mistletoe, spindle, wayfaring tree and guelder rose. Under their shelter, and in the glades between them, flowering plants too spread and flourished.
Until the 1970s, Hempstead Wood contained Britain’s largest population of the rare oxlip, a tall, multi-headed relative of the cowslip and primrose. This exquisite, scented flower has been almost eaten out of the wood now by swelling numbers of deer and the gradual water logging, but small groups of the flowers can still be found in May. Hempstead Wood, assessed by the famous tree expert Dr Oliver Rackham, was heading rapidly for SSSI status until a serious hatchet job during the Thatcher era cut drastically the number of protected sites.
A high bank and deep ditch survive all round the perimeter of the wood. One mild, clear evening last week saw us enter the wood and take the “Fair Mile” track into ancient shadowy depths of this very special fragment of relict woodland. Winter still held back the leaf growth on the millions of bare branches, but catkins hung in curtains from the slimmer twigs of the hornbeams and hazels. All manner of small birds sang from the shadows.
Deer tracks threaded the damp, leaf quilted undulations of the woodland floor and now and then a pheasant called, flapping off with a clatter at our approach. Once the wooded area was soft to the feet and open soil was limited to the coarse broken ground around a fallen tree, or a fox’s earth. Now the whole feel and appearance is much changed, due to the introduction of pheasant shooting.
Heavy machinery is brought in regularly, carting in feed or shelters for the doomed birds, their enclosures and feed bins. The ancient leaf carpet and underbrush has been crushed repeatedly, so that water lies in deep, clayey ruts and backs up in formerly free draining channels, altering the local flora. But it wasn’t the flowers, or the wild animal life which drew our attention on this particular visit, it was the hornbeams.
Related to hazel and beech, this tree is native to south eastern England, where it was a vital element in local culture. In much of the open areas within the wood, massive, gnarled hornbeam trunk bases, or “stools” survive, resembling the upper torsos of gnomes and goblins. From these, tall new trees are sprouting from the original rootstock, after the main tree was cut, or “coppiced”.
Coppicing was practised for hundreds of years, generating steady, renewable supplies of timber for fencing, tool making and fuel. Individual hornbeams can thus survive for centuries, constantly sprouting new growth from the old tree. The wood was part of my childhood and it saddens me to see it degenerating, through ignorance and carelessness. But it has been an education too and an on-going one.
Jill Slee Blackadder