SICK SPECIMEN: A healthy ash cutting, right, next to one affected by the disease
SICK SPECIMEN: A healthy ash cutting, right, next to one affected by the disease

The devastating potential impact of ash dieback made national headlines in 2012. Nine years later, tree consultant Rodger Lowe explains his concerns about the huge loss of ash trees in Teesdale.

WHILE the news has been dominated by the Covid-19 crisis, there is another pandemic sweeping the county – ash dieback.
Virtually every hedgerow tree in Teesdale is an ash and the disease is quietly changing our landscape forever.
Since it was first identified in 2012 almost every ash tree we see around us has been infected with the fungus and with up to 95 per cent mortality rates, the consequences are enormous.
The brunt of dealing with this pandemic will be borne by landowners, particularly along highways.
From infection to hazardous tree can take as little as five years with embrittlement of the wood fibres making climbing and dismantling, and even straight felling the trees, problematic.
Such is the speed of decline and the sheer enormity of the task that felling is likely to be compressed into a ten year period, with large stretches of highways and hedgerows subject to intensive felling operations, obvious to the public at large.
This presents difficulties in finding qualified tree hazard assessors, appropriate machinery and contractors, avoiding bird and bat habitat destruction, getting contractors booked in to exploit a narrow “stumble” window, and the disposal of millions of tonnes of timber.
Much like the Dutch elm pandemic, landowners will have to carry out much of the felling and extraction themselves. (And for those who remember those days the volume of ash timber here is twice as much as elm).
The landscape consequences will be profound as Teesdale, Weardale and the Yorkshire Dales will lose a majority of its tree cover at a time when the climate change crisis demands a doubling of the tree cover in the UK. As the timber is burnt either in commercial units or domestic settings the carbon is rapidly released threatening our carbon reduction goals, and eclipsing our limited strides in increasing woodland cover.
The principal task is to identify trees with advanced infections and that pose unacceptable liabilities to land owners. Someland owners are going to have to learn to spot the tell tale signs of infection themselves and act accordingly. Allied with this task is the identification of infected trees that will need to be dealt with in the future allowing landowners to budget for tree removal in the coming years. Dealing with liabilities is one thing, restoring the landscape on this scale is another. With the loss of ash and elm, particularly on alkaline soils (East Durham), the choice of replacement species is looking slim.
Oak, beech and lime can be used in the lowlands and western Durham, but we will have to set aside our prejudices against sycamore, out of sheer necessity if nothing else, when it comes to planting up the rest of the county and the uplands.
In this regard it can only be hoped that environment and land management scheme funding can be supplied for the restoration of the landscape that we now know and love.
Roger Lowe runs Teesdale Heritage Trees in Staindrop