Back in Burnham, I'm looking at a spectacularly tilted beech, a high-wire balancing act. It's sloping away from me at an almost impossible angle, about 40 degrees to the vertical – as far as it could go, I'd say, without collapsing under its own weight. Hard to guess how it got into this position. First tilted in a gale maybe, then slowly sinking as it tried to grow itself back to uprightness. The whole core of the tree is missing, maybe discarded as useless ballast, so that the trunk is like a trough. The rims of the trough are massive tension-wood muscles, hauling it back. There is a twisting mesh of crooked branches at the top end pulling it the other way, down towards the ground, so the tree has responded with flaring root hawsers and a long single branch, both growing against the direction of the tilt. The trunk has become a lever, perfectly balancing weight with muscular tension.
I try it myself. I lean forward at the same angle as the tree, imagining my feet pinned down by straps, and trying to pick up a huge weight with my hands. It's a ludicrous posture, and I know it would break my back if I tried it for real. Unless I had tension wood up my spine, doing the pulling.
Burnham is full of humanoid trees like this Weightlifters' beech. A League of Health and Beauty tree, doing an elegant midriff twist. A Stilt-walkers' tree. A beech with a wooden Zimmer frame. All of them are exercised, like us, with the business of keeping a rather disorderly mass of tissue upright in a turbulent world. You are beyond anthropomorphism in Burnham, into a place of more mutual metaphors.
But a few of the pollards have picked up names because of another kind of human association. Gray's beech, supposedly the subject of one of the final stanzas of Thomas Gray's "Elegy Written in a Country Churchyard", went down in the 1930s. The remains of a tree called Jenny Lind, on whose roots the Swedish Nightingale used to perch when she was staying at East Burnham Cottage, is surrounded by a safety fence. Mendelssohn's tree, whose dappled shade is said to have inspired him while he was writing the incidental music for A Midsummer Night's Dream, had its top blown off in the gale of January 1990. All the old trees, including these barely living butts, have their own numbers, stamped on small aluminium plates. I like this way of registering their individuality, rather than subsuming their existence under some human's name.
Standing on a small mound, and peering at one of the labels, I can see that I'm at number 01325. It's a conventional pollard, with a decent head of branches. But the trunk's surface is beginning to break up. Some fungal infection is causing flakes of bark to lift up, like scabs, and a thin trickle of sap is running down the tree. And when I look closer I see that the bark is alive with animals. Small spiders are rushing about in zig-zag exploratory dashes. A stream of wood ants is moving against the sap current. I don't think they're drinking it, but they're collecting minute scraps of bark debris and ferrying them down the tree. I follow the thin line of downward traffic and discover, a shade embarrassingly, that I'm standing on their nest, a vast pile of tiny pieces of wood and leaves. Number 01325 is a very desirable address.
But I can't make any sense of number 01243. It makes me feel uneasy. It isn't a tree from any tradition I know, not picturesque, or noble, or intellectually amusing. It is scarcely a tree at all, just two snail-shells of wood perched on a stalk. Or the skeleton of a prehistoric bird, standing on one leg. Or a voodoo warning. Or an immense fossil embryo. I can't stop these resemblances crowding into my head. How else do you make visual sense of an illegible life form without comparing it to other living things? But is it living at all? I go close enough to touch the tree, and can read what might have happened. The shells, almost level with my eyes, are part of an immense shoulder of wood half hidden by the foliage of other trees, which itself looks like the remains of an even bigger crown. The embryonic whorls are a tangled turk's-head of tension wood and scar tissue and braces that the tree has grown to try and keep its balance while its top fell apart. And the bird's leg – a grooved tube of tension wood about 25cm wide – is the final filament of trunk that is holding up the whole extraordinary structure.
And it's working. The tree has kept its thin sheaf of branches in the light. Above me I can see its autumn leaves, with not a sign of "the condition of beech". It's covered in mast. And all around, where the collapsed crown has opened a space in the canopy, there's a forest of seedlings. I guess that in 50 years they will have shaded their parent to death, and it will sink down among them in its last rites like a crumbling megalith.
I'm seeing it through a mist now, astonished that I could be so moved by a vegetable. I back away a little, and look at it through my binoculars. I'm trying to frame it as a picture, the old Picturesque discipline. But the bony pterodactyl in its halo of green does not look like any ancient landscape painting. It's defiantly Modernist. It could be a Miró squiggle, or a bizarre Surrealist coupling, or abstract Expressionism gone three-dimensional. It could be one of Maurice Cockrill's doors, with the new green forms emerging from the shadowed pit. But mostly it makes me think of the paintings van Gogh made in the last months of his life, those total immersions in the chaotic creativity of nature that make no concessions to our tidy-minded perceptions. It insists that natural systems are never completed, not contained within fixed time frames. Uvedale Price was right to connect the grammar of painting with the grammar of nature, but not to suggest that we need the first to appreciate the second.
What 01243 says is primitive, empathetic, universally recognisable. It's both reality and metaphor, a living instance of nature's resilience, and of the graciousness of survival. Simon Schama, in his uncompromising TV series Power of Art, said that art is about learning what it means to be human. In the more inclusive arena where we're now trying to live, art – and the natural forms that spontaneously aspire to it – could also be said to be about learning what it means to simply be alive.
This is an edited extract from Beechcombings: The Narratives of Trees, by Richard Mabey (£20), published by Chatto and Windus on 4 October. To order a copy for £18 (free P&P) call Independent Books Direct on 0870 079 8897, or visit www.independentbooks direct.co.uk
Britain's sylvan beauties
Ash - Fraxinus excelsior
A native tree that provides strong, hard timber, yet its height and grey bark are more elegant than the oak. In both Celtic and Norse mythology, the ash was viewed as sacred. Its single-winged fruits, growing in bunches, are known as ash keys.
Silver birch - Betula pendula
One of the first trees to colonise any piece of ground left untended, and one of the first to recolonise Britain when the great ice sheets retreated about 10,000 years ago. Its delicate appearance belies its hardiness: it appears higher up mountains than any other tree. It's also the national tree of the Finns, who use its boughs to beat themselves in the sauna.
Sycamore - Acer pseudoplatanus
The biggest member of the maple family in Europe is not a British native, its home range being in the central and southern parts of the Continent. It is uncertain when it was introduced: it may have been by the Romans. Its creamy-white wood can make beautiful furniture – look for Art Deco examples. The double-winged seeds descend like helicopters and have long been autumn toys for children.
Horse chestnut - Aesculus hippocastanum
The conker tree, beloved of schoolboys, was introduced to Britain from the Balkans around 500 years ago. It looks most spectacular in the spring when it is covered in tall white blossoms called "Roman candles" (which can also be red). In the last two years horse chestnuts in Britain have been widely attacked by an insect pest, the leaf-miner moth, which shrivels the leaves towards the end of the summer.
Elm - Ulmus procera
The tall, stately English elm traditionally provided solitary sentinels for hedgerows and guards of honour for paths to the church, but all were devastated when Dutch elm disease came to Britain in the Sixties. The disease, a fungus carried by the elm bark beetle, has now wiped out most of the mature elms in the country: it's thought to up to 25 million trees have perished.
Yew - Taxus baccata
The second of our native conifers (the third is the juniper), the yew is associated with churchyards, where trees of great age can be found (some 1,000 years old). The wood is very flexible and was used for making the longbows with which English archers defeated the French in the Hundred Years' War. The bark is poisonous.
London plane - Platanus x hispanica
One of the few trees that was able to survive the smog-laden atmosphere of London before the Clean Air Act of 1955, this is the tall tree that appears in London's squares – as well as the one that lines those straight country roads in France. The trunk often appears mottled because the tree occasionally sheds large pieces of its own bark, a process that may help it to survive in heavily polluted environments.
Beech - Fagus sylvatica
The beech provides much softer wood than oak or ash, and was often discounted or even despised, as Richard Mabey makes clear in his paean of praise to the tree. It has come to be much loved, however, especially for the woodlands it forms in areas such as the Chilterns, when the tall, straight trunks, combined with the light falling between them, give the appearance of leafy cathedrals.
Oak - Quercus robur
England's emblematic tree. The building material of the Royal Navy, from the Armada to Nelson – "hearts of oak are our ships" – the wood is famed for its enduring toughness. But the tree has other identities. It was sacred to the Druids, and it has an outstanding conservation value: up to 500 species of insects and other organisms can live on a single oak tree.
Scots pine - Pinus sylvestris
One of only three native British conifers, the Scots pine's home range is confined to Scotland. Only 17,000ha remain of the great Caledonian pine forest, and it is best seen in Rothiemurchus in the Cairngorms. It has been planted extensively in other areas, including the Brecklands of Norfolk. Outside Britain, it is the world's most widely distributed conifer.Reuse content