- The Secret Life of Trees: How They Live and Why They Matter by Colin Tudge
Allen Lane, 452 pp, £20.00, November 2005, ISBN 0 7139 9698 6
They are pollarding the plane trees in our street. They do it every few years: left to themselves, branches would overtop the houses by many metres and form a summer tunnel of green. In other places and at other times the lopped branches would have been a resource. In Trees and Woodland in the British Landscape (1976), Oliver Rackham makes a distinction between wood and timber. Wood, the renewable crop, the source of staves, bean poles, hurdles, fodder and firewood, is what was coppiced from the same stools or pruned from the same trunks and branches over many years, in some cases many centuries. Timber is the builders’ merchant’s solid planks and beams, which are now, in Britain, mostly imported, or cut from trees grown in plantations.
London is not woodland. We don’t fell timber, and we prune to give nature a slap on the wrist, not to provide firewood or hurdles. The knobbly extremities which result are evidence that we are in control. I know what it’s like to be challenged by a tree: I’m told that the Irish yew I planted in the front garden thirty years ago is out of hand. I’ll have it lopped, but will feel about it as I have seen others feel about having a tomcat neutered.
We may trim trees, butcher them even, but we cherish them too. British species, native and exotic, include those appropriate to the scale of narrow streets – rowan, birch, cherry and hawthorn are more recent additions to ours – and a whole range of others, some larger, some smaller, to be found not just in parks, woods, hedgerows, arboreta and botanical gardens but on wasteland, canal banks and commons.
The distress we feel when a tree goes is not always rational. Woodland regenerates, town trees can be replanted, fallen trees are good for beetles. It’s different when a whole species goes, however, as elms did in the 1970s. You can still see them full grown in the centre of Brighton, one of the few places where Dutch elm disease has been kept at bay. In the years when the disease was spreading it was hard to look out of a train window without seeing a field margin punctuated by skeletal remains. It was a dreary sight, although a long view can be taken even of epidemics: this one wasn’t the first. Rackham argues that the sudden disappearance of elm pollen in records from the Neolithic period may be evidence of an earlier fungal wipe-out, and quotes passages showing that elms have always had a reputation for being sickly. He suggests that the pathogen may go through cycles of greater and lesser virulence. Vulnerability is in part a function of variability; many of the English elms which went were clones. Monocultures don’t occur only in fields: the London plane is another species which, were the fungal infestation which killed off planes in Italy to arrive here, would be short on the genetic variation that increases the chances of resistance.
We become attached to trees, even though they can get in the way and cause anxiety when they are diseased or when they suck moisture from clay and unsettle foundations. Holy men sit under them. According to Herodotus, ‘Xerxes found a plane tree, to which for its beauty he gave an adornment of gold, and appointed that someone should have charge of it always in undying succession.’ The burden of being responsible for their well-being is justified by the rewards their presence brings. Their longevity is a reminder of the brevity of human life: we can feel that looking after them ensures, in some sense, our own continuity.