Jul 16 2021

A busy summer managing Ash Dieback on the Wales Estate

Summer used to be a relatively quiet season for forestry work – not so these days! Late summer and early autumn now sees our Site Managers roaming miles of roadsides, boundaries and paths undertaking tree safety surveys, to monitor the impact of tree disease, especially ash dieback, on the health & safety of our woods.


Ash dieback, a disease caused by a fungus called Hymenoscyphus fraxineus, was first confirmed in the UK in 2012 and has since spread rapidly to all corners of the country. It causes crown dieback and bark lesions in affected trees and over time can cause trees to fail or open them up to other infections such as honey fungus.


Some ash trees can go into decline very quickly, although we remain hopeful that many will ultimately tolerate the disease and go on to produce resistant offspring. Where we can safely retain ash trees, we do so: giving the ash the chance to produce naturally regenerated seedlings is the best chance to grow on a new generation of this important native tree with some resistance to ash dieback.


Ash trees support a number of ‘obligate’ species of lower plants and invertebrates: species that depend for their survival on ash (e.g. the ash bud moth).  There are many other species, both common and threatened, that are closely associated with ash (for example the Atlantic pouncewort) . Loss of ash from the landscape would therefore be a terrible outcome for biodiversity. Here in Wales, although we are known for our oak woods, ash is a widespread tree and is particularly common as a field or hedgerow tree, whose loss would have a major impact to landscape and habitat connectivity.


However, where these trees are adjacent to infrastructure such as roads, houses, schools, railways or popular footpaths, we often need to take action to protect public safety, as there is no realistic cure for the disease. Our Site Managers undertake regular inspections, make management decisions and work with competent contractors to deliver tree safety work where absolutely necessary.


Working on infected ash trees can pose a danger to our contractors too, so we need in some case to intervene early before the decline becomes too advanced, or to use alternative methods such as Mobile Elevated Work Platforms or mechanized harvesters to ensure the trees can be felled with minimal risk to workers. We often need to liaise with the Highways Authority over road closures or traffic control too, to ensure the work can be completed safely. Of course, life is never simple and there are often other complicating factors, such as overhead electrical cables and phone lines to contend with!


This work is extremely costly, as it requires specialist equipment and a lot of man hours. In Wales, we had to spend over £100k on ash dieback work in 2020 and we expect this to increase in 2021, with major operations planned at sites including Priory Grove near Monmouth.


It also has an environmental impact, with the inevitable loss of some mature trees along woodland edges and rides. So where we can, we retain trees and in some cases we have taken the decision to close off some less well used paths for a number of years – and even whole woods where they are remote and not well-visited – to allow the disease to run its course. Woodland paths on sites including Coed Gwempa, Llwyn and Coed Aber Eden will be closed and natural processes of tree fall and decay will be allowed to create deadwood habitat and undisturbed corners for wildlife over the next few years.


See our website for some more general info on ash dieback:


For more technical info on how we manage ash dieback on our sites, visit our website: https://www.woodlandtrust.org.uk/publications/2019/10/managing-ash-dieback-on-woodland-trust-sites/


Written by Kylie Jones Mattock, Estate Manager for Wales

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