Ash Dieback

Dieback. Four weeks ago the government was contemplating an inferno of ash trees from top to bottom and east to west of the UK. The press were talking up the enemy, Chalara fraxinea, as the mother of all fungi, a Milosevic-Saddam pathogen that had to be stopped in its tracks. The trouble was that no one knew how to target the offender. The next thought, it followed, was that we should eliminate all infected trees, not just saplings imported from Europe but mature ash in British forests. Maybe even healthy trees near infected ones: deny the predator the prey.

A woodland manager in East Anglia told me he’d had TV companies on the phone wanting to know where the big bonfires were going to be (and could they be at night). That was shortly after the Daily Mail and others announced that 100,000 ash trees had already been destroyed: a bleak piece of news until it transpired that most were young trees, still in the nursery or lately planted out. The Telegraph, too, was on a roll, having brandished the same figures and threatened the long-suffering British rambler – and his dog – with a life behind closed doors in a piece it headlined: ‘Woodland walking banned as ash disease takes hold’. But then on 9 November there was a collective sigh of relief as Defra announced its considered response to C. fraxinea.

The Defra action plan has an air of sanity conspicuous by its absence from every other domain of government policy. The ban on imported ash trees remains in place; no ash is to be moved around; diseased trees in nurseries and young plantations have to be destroyed but established trees with signs of dieback need not come down: how will we identify resistant strains if every tree is felled at the first sign of infection? (C. fraxinea, Defra added, does not move directly from a diseased tree to a healthy one, but ‘only via the leaf litter’.) For the moment there is relative calm, even if the prognosis for Britain’s population of common ash (fraxinus excelsior) – perhaps 5.5 per cent of UK woodland cover, along with several million trees growing outside forests, in parks, cities and the like – is not especially good. It’s clear that the fungus is already widespread and almost everyone agrees that once it’s taken hold in a tree of any age it can’t be eliminated.

Twenty years ago I wouldn’t have known what an ash tree looked like but I knew that such a thing existed from M.R. James. ‘The Ash Tree’ is a sinister tale, set at the end of the Restoration, about a woman found cutting twigs from an ash tree, tried as a witch, hanged and buried: she migrates back to the veteran specimen of fraxinus excelsior on the land of the squire who denounced her. He is found dead and blackened in his bed and in due course so is his grandson. Later, I dabbled in John Evelyn’s Sylva. Reprehensibly perhaps, I’ve never paid as much attention to my surroundings on a country walk as I have to descriptions of the natural world in books, all the better in Sylva for its being a guide for stewards and landowners. (You don’t need a spatula to enjoy Elizabeth David.) There was an ash tree outside our house in Kentish Town: I know because I had to ask the council to lop away some of the upper growth as it came closer to the bedroom window. (The ancient tree in James’s story is uncomfortably close to the window of the room where the victims die.) But it was only when I moved to France about ten years ago that I began to notice the common ash for the marvellous thing it is.

It came about because a meadow on the property had an isolated, handsome specimen, one of the tallest in the neighbourhood, with a strapping waistline and a well-developed case of rot around the base. There was dieback at the top (nothing to do with C. fraxinea), leaving large, bare branches gesturing ominously in the summer skies. Procrastination seemed the best policy for this elderly tree in its mournful splendour: put the lower areas out of mind and see how it goes, or doesn’t. Nevertheless the idea that its life could be prolonged led me to bring in tree surgeons who took off the dead wood, shook their heads at the state of the base and announced that it could fall at any moment. With nothing in the likely path of descent, it was left to stand like a distinguished barrister, fixed in mid-argument, wig and gown beginning to fray, long after the jury had left their places and the public gallery had been cleared. Later still, when I read more about trees I got the point that it was bad taste, and environmentally incorrect, to anthropomorphise a species or a large singleton in the way I’ve just done. We were city people when we moved to the country and I still am. I’d sooner pull Francis Ponge, a scandalous anthropomorphiser, off the bookshelf than crouch by a hedgerow waiting for a rare species of bird.

The tree was felled about six years ago. I called around to cabinet makers and timber merchants and when that failed I had it tagged for firewood. Two men arrived and cut the long sections into shorter lengths. They then cut vertically through the lower part – about the width of a paddling pool – and drove back into the meadow a few hours later with a device that was supposed to split the pieces like tofu. It was hard going. They complained of the strength of the heartwood, which simply kicked the mechanical wedge to one side: the machine groaned and bellowed and when a split was achieved it was more like a long, splintery rent, with one very stout part and another, much thinner, consisting entirely of sapwood. After a couple of hours the miracle machine gave out. But a good bit had been done and a few months later a film editor came to stay; her father had taught her to split wood in the ordinary way with a sledgehammer and metal wedges. She showed us how it was done and by the autumn the wood was stacked. By now the freshly cut cross-sections, pale cream but not as pale as hornbeam, were turning darker. We’re still sparing with these vintage logs: they’re our nuclear option in the wood-stove if the weather turns bitter.

There is more mature ash, along one side of the same meadow and the bank of the nearby river, in among the alder. (‘By the banks of sweet, and crystal rivers and streams,’ Evelyn wrote, ‘I have observ’d them to thrive infinitely.’ ) To grasp the beauty of the ash you can begin with the reflection of a tall individual in the water and work up from there to the substance of the tree, as far as the crown. The leaflets of the ash are a lovely mid-green and in summer, standing under a healthy tree with plenty of leaf, you are in a cool, lit space with a tattered sky above you and greenery round your feet: light clambers down through the foliage and plays on the ground. Constable’s ash trees – and studies by his son Lionel – reproduce this airy aspect, though even a Constable ash can absorb more light than it distributes.

The grace of the ash is reason enough to plant out more, but I was thinking mostly of its properties as a heating fuel when I dug in 120 saplings a few years ago, along with hornbeam and two varieties of oak, on a patch of land that was no good for anything except, just possibly, as a piece of wooded ground in the distant future. Evelyn, an enthusiast for the common ash, felt it should constitute a third of any planted wood. When it came through from seed, he warned, animals should be kept well away. ‘Cattel,’ he wrote, ‘are exceedingly licorish after their tops.’ Deer too. Our saplings are protected by ugly black plastic tree guards. The field looks like a plantation of fishnet stockings. Some of these little trees, now in their fourth year, are coming on nicely, but so no doubt is C. fraxinea and it’s only a matter of time before it sets in, if it isn’t present already. The fungus has been detected near the Channel and it has taken firm hold in the woodlands of the Haute-Saône in north-eastern France. The French, who are normally interventionist (they spray their oak woodlands from helicopters), have struck a fatalistic note on C. fraxinea, which arrived about five years ago. They made the same case against felling that Defra made in November, but they believe the fungus extends its territory at a rapid rate, moving at 150 km a year, against the Woodland Trust’s estimate of 20-30 km.

It’s clear that governments should have paid more attention to the disease when it was first reported but in Britain it’s only recently that we’ve paid attention to the common ash at all. In Ancient Woodland, Oliver Rackham drew up a table, under the heading ‘The Notice Which People Take of Trees’, and mapped ‘the percentage frequency with which tree species are mentioned’ in two Anglo-Saxon charters, a comprehensive list of British place names, the works of Shakespeare and a sampling of ‘British’ literature excluding Shakespeare. The ash occurs often in place names but it wasn’t much remarked by the Anglo-Saxons or anyone else. It scores zero in Shakespeare, a sucker for oak and thorn trees. That it should be such an inconspicuous tree seems odd: you could never call it unassuming. I’ve found it once in Chaucer, in The Knight’s Tale, when the time comes to build the enormous pyre for Arcete after he’s succumbed to his injuries. The poet piles the species up to the sky, with ‘ashh’ among the mountain of firewood, which also includes elm, plane, box, ‘wylugh’ and ‘whippeltree’ (dogwood). Shame the TV crew couldn’t make it.

When we’ve given it any thought, we’ve ascribed magical properties to the ash: it Googles as the tree of life, but the ailments it’s said to heal have had a way of tainting the tree by association, which is why M.R. James could have such fun with his ash tree, hollowed out like a burial vault from which monstrous spider forms, the size of human heads, begin to issue when it goes up in flames at the end of the story, revealing the remains of a woman in the dead embers. Ash trees were sometimes opened up and prised apart with wedges as a healing snug for children with a birth deformity (‘ruptured children’). Evelyn tells us this, and in The Natural History of Selborne Gilbert White repeats it, describing the procedure in detail: if the gash in the tree healed, so would the infant. White also talks about a ‘shrew ash’ in the parish, which was used to cure lameness in livestock. If a horse was lame, it was probably because a shrew had come into contact with the limb in question. A hole was dug in an ash tree and a ‘poor devoted shrew-mouse thrust in alive, and plugged in, no doubt’. You then took a twig or a branch from the tree – as the witch in James was first seen doing – and applied it to the game leg.

Elizabeth Kent, a charming Georgian plagiarist, clocks both these procedures in Sylvan Sketches and adds a third from the Highlands, where newborn children were not allowed to suckle until the nurse had taken ‘a green stick of Ash, one end of which she puts into the fire, and, while it is burning, receives in a spoon the sap that oozes from the other, which she administers to the child as its first food’. On its travels in the human imagination, the ash has acquired an unsavoury connection with infant disability, sickness in livestock, and a sinister masculine precedence over the mother’s breast. Why shouldn’t the ash be a den of demon arachnoids that turn a squire and his descendant black in their beds? Why not blame the ash tree for C. fraxinea?

Just now it’s easier to blame government. Woodland experts and conservationists are still furious at its slothful response to ash dieback when it was identified in 2009. They’re also furious about the Tories’ attempts to stick public woodland on eBay, along with everything else. But they all acknowledge that sickness in trees is on the rise, from Australia to the Americas, via Asia and Northern Europe, spreading as a result of international trade. Plants have always been moved about – it’s a point Rackham makes – but a voyage on a sailing ship was long enough for a pathogen to die, or kill the specimen, before arrival. On a steamship the odds of survival improved. C. fraxinea is one of many globetrotter diseases attacking oak, chestnut, alder, Corsican pine, new generations of elm and several other species, in a world of 24-hour deliveries.

One approach is to advocate deeper restrictions on the movement of flora and hope this will slow up the rate and extent of diffusion. We’d be better off, it’s said, growing our own trees in our own time in our own nurseries. We’ve been too inclined to say that the plantation conceived today must be realised tomorrow and if we haven’t got the stock to do it now, we’ll wave our cash at the global market, where it’s cheaper anyhow. Another view has it that global trade is fine provided there is proper inspection of what comes in or goes out. But employing hundreds of plant pathologists at UK customs to examine saplings from Poland, Lithuania or Denmark as they quake in their little punnets is unaffordable. Besides there is the wind. No one is ruling out the possibility that the spores of C. fraxinea, like the midges that carry Bluetongue, may well cover long distances in the right circumstances – a good breeze over a mass of warm water, between the Dutch coast and the coast of Suffolk, say. Finally the fungus is not easy to identify: it is a close relative, or possibly a pathogenic phase, of another fungus that doesn’t harm the tree. Only DNA tests can establish the difference.

Until the spring there’s little to be done in the way of new identifications and nothing in the air, except perhaps a feeling of optimism. Rackham, who has been to Denmark, is sure that the country’s ‘90 per cent’ losses reported by the press are too high. The naturalist and author Richard Mabey believes that resistance in the Danish ash population is 5-10 per cent and probably higher in Lithuania. I noticed this upbeat tone too in Julian Roughton, chief executive of the Suffolk Woodland Trust, as he showed me around Arger Fen, a stretch of woodland acquired by the trust in 2008. There is dieback here, but like other conservationists Roughton felt that with the genetic diversity of Britain’s common ash there was sure to be hardy resistance. We were making our way through the wood to another of the trust’s properties, a forty-acre holding known as Hullback’s Grove, which they’d obtained in 2005. Most of this land, which adjoins Arger Fen, was stubble field at the time and the trust let it lie.

Mabey has written about the extensive habits of the ash. In Beechcombings (2007) he recalls his early attempts to coax the wood he’d purchased in the Chilterns back to a ‘natural’ state. After careful clearing and tweaking he found that ‘ashlings sprung up everywhere, voting themselves in as the wood’s next dominant species.’ Even where I live, a good distance from natural woodland, ash has a way of popping up by the roads and along the river. But at Hullback’s Grove the growth was astonishing. These young trees were packed together like maize, acre on acre, without a single planting having been done. Roughton put the total at half a million. Around the edge there was evidence of dieback and further in, he directed my gaze to lozenge-shaped openings in the bark of several trees whose stems had died and fallen off. With half a million flourishing ash, he felt a 10 per cent survival rate would be good news.

Wait-and-see has prevailed over a policy of widespread felling, but another line of argument will open up in the spring and summer as existing damage becomes visible and the disease makes seasonal headway. The idea that C. fraxinea can be zapped with a clever chemical is not fashionable: conservationists don’t like it, scientists doubt it can be done and governments are uncertain what products it’s appropriate to license. But there are people in favour, including Dr Glynn Percival, a plant physiologist at Bartlett Tree Experts (Bartlett, a US company, got a foothold in Britain in the 1990s). Percival works at an experimental field site at Reading University, where the company funds a couple of research projects. He doesn’t like the estimates for resistance in Britain’s population of common ash. ‘Five per cent?’ he asked me in his prefab as the rain drove down on Reading and we drank our tea. ‘That’s 76 million ash trees lost and four million left.’ He and his colleagues believe it’s time to get stuck in with treatments and ‘pre-treatments’: they talk up complex products, organic and synthetic, that can boost a tree’s defences against the fungus. They invoke earlier successes with other sicknesses, in oak especially.

I suggested to Percival that this was the voice of the private sector, eager for business. How agreeable for Bartlett’s to make its way around the UK with fungal treatments supplied by the pharmaceutical companies who could afford to license the products he’d be trying out next spring. But he assured me there was far more money in felling than curing and seemed genuinely appalled by the losses in the US to the emerald ash borer, an insect that got across from Asia in a wooden crate in the 1990s and has since done for 20 or 30 million ash trees of several species. It wasn’t just the pest that dismayed Percival; it was the draconian felling, driven by ‘sanitation’ programmes that took out battalions of treatable trees: a policy that’s since given way to remedial treatment. It’s a different killer this time, tougher no doubt, ‘but this is the 21st century: do we just sit back, let it happen and start felling?’

It took me a while to grasp that Percival has no pretensions to forestry. He’s interested in the 12 million ash trees that continue to survive in Britain’s cities, suburbs, public thoroughfares and private gardens: the mature tree at the junction of a busy ring road which will cost the council thousands of pounds to remove, the veteran in a city park whose absence will tear a hole in the shared geography, or the avenue that has to come down tree by tree, as avenues of elm have come down all over Britain. In this view, intervention in landscape beyond the forest’s edge is worth a go. The ravages of C. fraxinea are not confined to charismatic woodlands like Arger Fen, or Bradfield Woods near Bury St Edmunds, where Rackham has identified 1000-year-old ash. We have to see the trees for the wood. Most Britons live in built environments where nature has full diplomatic status. Trees are its great ambassadors: the oak and the ash and magnificent domesticated foreigners like the London plane. By the summer of 2013, people in cities miles away from Hullback’s Grove will be the first to notice the decline of the common ash.