Our trees face many threats

Tim Woodward will be writing an article about the threat posed to our woodland by disease. Hes regional rural surveyor with the CLA. (Image: Archant)

Someone once suggested to me that it was “in the blood”, given my surname. In Anglo-Saxon England, apparently, villagers used to appoint a woodward to take charge of communal woodland, and to make sure that everyone’s rights to timber and forest grazing were maintained. In the Middle Ages, private woodland owners appointed woodwards, as forest officials, to oversee forest laws and ensure that the wellbeing of the king’s deer received due priority. So ancestors of mine presumably spent a lot of their time in and around woodland.

Tim Woodward will be writing an article about the threat posed to our woodland by disease. Hes regional rural surveyor with the CLA. (Image: Archant)

Although I don’t get involved in much day-to-day woodland management these days, I used to do quite a lot earlier in my career as a rural surveyor (or land agent, as we’re sometimes known) and I found it fascinating. There’s something really satisfying about supervising the planting of an area of woodland – designing the layout, choosing the right species of trees for the area, ordering them from the nursery, overseeing the planting and the subsequent weeding – and then going back a few years later to see the young trees thriving. I know that many of those trees will be there long after I have passed on, and I feel very lucky to have played a part in that enduring legacy.

However, our trees face many threats during their long lives. Not long after I qualified as a rural surveyor, I worked in Norfolk for about two years, arriving just after the “Great Gale” of 1988 had swept through the country. I spent a good deal of time on the country estates I managed overseeing the clearing of fallen trees, selling the timber, and then organising the planting of replacement woodland. Now, more than 20 years later, it’s quite difficult to spot the areas that were devastated by the gale and, where woodland was not replanted, Nature has played its part in naturally regenerating trees and shrubs.

I can also remember the devastating impact Dutch Elm Disease had on the countryside in the 1970s, when some 20million trees were destroyed in an attempt to control the spread of the disease, and although elm suckers appear along hedges and in spinneys around my home in Suffolk, they never manage to grow on to anything approaching maturity before the beetles that carry the disease bore into them and the trees die back. Perhaps, at some stage, they may acquire resistance. I know of a solitary and magnificent English elm tree that grows beside the southbound carriageway of the A12 near the Essex-Suffolk border, probably unnoticed by most motorists, which has somehow survived.

Unfortunately, the threats to our native trees in East Anglia seem to be increasing. Two diseases in particular are causing great concern among landowners, forestry experts, and environmentalists.

The one that has received the most publicity recently is “Ash dieback disease”, which is caused by a fungus called Chalara fraxinea. Foresters often just refer to it as Chalara (pronounced “Kalara”). It first appeared as an entirely new disease in the 1990s, spreading into Eastern Europe and then to Scandinavian countries, arriving in England in March last year. Although it’s thought to have arrived with trees imported from the Netherlands, it can also be locally spread by wind-blown spores, and in infected seed.

Ash is one of the most common trees in Britain, growing in hedgerows, parks and gardens and along roads and railways, and a mature ash tree is magnificent. As a species, ash has a good deal of folklore attached to it, and was considered by our early ancestors to have magical properties. Its roots were believed to grow down into the underworld and its branches to reach up to the gods, for example, and new-born babies were given ash sap to drink. It also produces very good firewood, and first-class handles for all sorts of tools. Its name is said to derive from the Anglo-Saxon word aesc, meaning spear, as it was highly valued for spear shafts.

Research suggests that Chalara originated in the Far East, but the world timber trade now means that diseases can be transported inadvertently over long distances. Apparently, it seems to be harmless to most Asian species of Ash, but our European and British ash trees have probably not encountered it before, and most of them have no resistance to it.

It particularly affects young ash trees – big, mature trees seem to survive it in many cases –causing black, weeping lesions on the stems and branches of trees, and causing leaves to blacken and shrivel. Eventually, it will kill the tree.

Although a good deal of research is going on into Ash dieback disease, especially into genetic strains that may have a resistance to the disease, it’s very sad, given the prominent place of the ash in our landscape, ecology and folklore, to hear that current estimates suggest that in 10 years’ time, 90% of our ash trees could be infected, and up to 80% may die. I live near Suffolk Wildlife Trust’s ancient woodland at Bradfield Woods, where ancient ash stools or butts (some dating back 700) are under threat from the disease if young regrowth is affected.

Another worrying disease, increasingly common in East Anglia is “Acute Oak Decline”. There are many historic parks, often surrounding country houses, in this region, and a common feature of these parks, and of our hedges and ancient woods, are veteran oak trees. Some of these trees are relics of earlier medieval boundaries, and may be hundreds of years old. They can be immensely valuable in terms of biodiversity, as well as being of great historical interest. It can be a humbling experience to stand beside one of these venerable old trees and reflect, with a sense of awe, what has happened around that tree during its lifetime, and what it has seen.

To the Druids, the oak was a sacred tree. Despite the modern pagan ceremonies carried out at Stonehenge each Summer Solstice, and shown on TV, the ancient Druids actually carried out their rituals in oak groves, and to the Greeks, Romans, Celts and other peoples, the oak was venerated and associated with the supreme god of those they worshipped. As a source of timber, of course, it also provided fuel, shipbuilding material, and the framework of buildings; I am lucky enough to live in a 16th Century oak-framed house, and many of the timbers appear to have been re-used from earlier buildings.

Unfortunately for our old oaks, Acute Oak Decline seems to affect mature oaks which are more than 50 years old or so, and it is spreading. There are two types, as if one disease wasn’t enough for these venerable old trees to have to cope with. One causes black weeping lesions or wounds on the trunks of trees, and rotting stem cavities under the bark. It seems to be caused by bacteria, possibly carried by an otherwise lovely insect called a Jewel Beetle, but much more research is needed. The other type causes the oak tree to lose its leaves, and is probably caused by at least two types of moth. Both types of the disease can kill old trees. There is a shortage of money and resources for research, but a private fund-raising effort is under way, which has so far raised over £200,000.

Something else waiting in the wings is a disease called Chestnut Blight, which if it arrives here – if it’s not here already – would affect our Sweet Chestnuts. We are one of the few countries in Europe not to have it, and in the USA, it killed 4billion trees, practically wiping out the American chestnut. Chestnut trees are still being imported, in response to demand for chestnuts and chestnut products, and this could provide a means by which the disease could enter Britain.

Fortunately, the Government now seems to be taking plant and tree diseases more seriously, and as I walk in the ancient woods near my home, I try to feel some optimism. We need to ensure that import controls are tightened up – I find it alarming that more than half of all ash saplings planted in the UK are imported, and it’s likely that Ash dieback disease arrived in Europe from the Far East as a result of the worldwide trade in timber.

Governments must ensure that research is properly funded (especially into how diseases are spread and into finding resistant strains of trees) and we may have to adapt some of our woodland management practices.

If we can do all these things, and spot diseases in our native trees more quickly, we may be able to ensure their survival for future generations, so that they too can experience that sense of awe as they stand in front of an ancient oak tree, or walk amongst tall ash trees in an East Anglian wood.

n To become a member of The Country Land and Business Association (CLA) in the East of England, please visit www.cla.org.uk. You can also telephone 01638 590429 to speak with Tim Woodward or email Suffolk’s CLA territory manager: bernard.pentelow@cla.org.uk. Alternatively email Essex’s CLA territory manager, verity.hawkins@cla.org.uk The CLA is also on Twitter @CLAEast.