Matthew Oates,
An icon of the British landscape, the oak holds a special place in our hearts, says Matthew Oates, and is an important home to an astonishing diversity of species
“There is an ethereal presence, a gracefulness about oaks, which draws me in and offers feelings of sanctuary, timelessness and belonging.”
People need trees. Environmental psychology – a new academic discipline linked to the human health agenda – may in time explain our need for them, and in particular for that most iconic and heartfelt of trees, the oak. Much work still needs to be done on our relationship with trees, particularly on understanding our psychological or spiritual need for them. It may even explain our obsession with planting trees, an act that gives us tremors of immortality.
At present, our need – our love – runs deeper than words, and is simply dismissed as being unrealistically poetic, or simply spiritual. But I for one yearn to live once more in an oaken landscape, and to gaze dreamily at sentinel oaks darkening at sunset into primeval eventide. There is an ethereal presence, a gracefulness about them, which draws me in, and offers feelings of sanctuary, timelessness and belonging.
The oak has long been central to our culture and plays a key role in our history: ‘Heart of oak are our ships, heart of oak are our men…’. So runs the bellicose patriotic song scripted by David Garrick in 1759, as our navy was beginning to rule the waves – in its oak-timbered ships. The navy has had eight Royal Oak warships and there are some 500 Royal Oak pubs in England. Although Charles II only hid in one oak (in Shropshire) after the Battle of Worcester in 1651, a great many oaks are rumoured to have sheltered him. The oak, with its hidden Green Man, plays an integral part in our mythology.
There are what I term Calling Trees, which seem to call us individually, to
sit, stand and muse beside them, and feel stronger. Most of my favourites here are what we call ancient oaks (over 400 years old) or veteran oaks (150–300 years old). Other people feel similarly. This is natural, normal behaviour for which no denial is necessary. We were once forest people, then we cleared the forest. Less certain, though, is whether trees need us. They can plant themselves and rarely need our assistance, and much of what we do to them is simply wrong; if you need convincing, just look at almost any piece of tree surgery.
My favourite colour is that unnamed yellow-green of English oaks at budbreak time. The vibrancy of that colour is hard to capture, in painting, photos or words. It takes over entire landscapes at spring’s zenith, notably in the Weald of Sussex and Kent. It lasts but a short while, for by June the oaks have deepened into mid-green, and in early July their foliage takes on a sombre blue-green tone, which persists until it browns in autumn. Oaks are the last to cast their leaves.
There are two main types of oak in Britain, the English or pedunculate oak Quercus robur and the sessile oak Q. petraea, although they produce a bewildering range of hybrids. The sessile oak, distinguished primarily by its stalkless acorns, is mainly a tree of western Britain. There are also a number of non-native oak species introduced for forestry or aesthetic reasons. Of these, the holm oak Q. ilex and the Turkey oak Q. cerris are proving highly invasive in some districts and much conservation effort is being devoted to controlling them. All these incomers support far less biodiversity than our native oaks and have not been in Britain long enough to have earned the title of ancient oak.
ALL HAIL THE VETERAN TREES
The English oak is something ultraspecial, especially free-standing ancient or veteran specimens with huge spreading limbs, hollow trunks, bulges and gnarls, and character. These grow in ancient forests, old parks, pasture-woodlands, and as hedgerow and field trees, where they tell of landscapes long gone. Many grow as pollards – trees that have been cut back at head-height decades ago, a process that prolongs their life if done properly. They are all heritage trees, as important as any castle.
They are host to a remarkable range of fungi, plants and animals, including many of Britain’s and Europe’s rarest. Above all, old oaks are about fungi, especially the heart-rot fungi that steadily hollow them out and help them adjust to the ageing process, and to survive. Fungi drive their ecology: the
decomposer fungi help wood to decay and assist the recycling process, while mycorrhizal fungi form symbiotic relationships with tree-root systems – in effect, they feed each other. Over 400 species of rare fungi are associated with old trees in Britain.
Over 2,000 species of invertebrates depend on decaying wood; again, oak is a firm favourite. Most of them feed on the wood-decaying fungi, rather than on actual wood. There are earlystage feeders, which quickly colonise a dying or fallen branch; middle-stage feeders, which hollow out the redbrown heartwood, and final-stage feeders, which effectively take fallen timber underground. Then there are specialists of semi-submerged fallen wood, rotting root systems, attached dead branches, bark crevices, rot holes and cavities, sap runs, fallen branches, fungal fruiting bodies, and even bat guano in tree cavities – and their predators and parasites.
All this means there is no such thing as a dead oak tree, only trees that have not lived their full potential (largely due to our impact). An ancient oak is a tower block for a host of fungi, beetles and other invertebrates, bats and birds, with different species colonising each stage of ageing, decay and collapse. The slower a tree dies, the better.
TOWARDS A FUTURE
The oak is, of course, the national tree of England and an important feature of British natural history. The future of these amazing beings, these living green giants, depends on us understanding and valuing them more. Our duty is to give them and all they stand for a future.