Rising to the challenge of ash die-back disease
NOTTINGHAMSHIRE Wildlife Trust’s nature reserves provide a unique free resource for the public to see, enjoy and get close to nature but balancing the needs of wildlife and people on our cherished sites with limited resources has always been a challenge.
Ensuring our woodlands stay havens for wildlife whilst keeping visitors safe in the face of the growing threat posed by Ash dieback, gives the challenge a very different complexion.
Ash dieback is a disease that affects Ash trees, caused by a fungus called Hymenoscyphus fraxineus – also known as ‘Chalara.’ The fungus blocks water transport in the tree, leading to lesions in the bark, leaf loss and dieback of the crown.
It is believed to have originated in Asia and was first discovered in Europe in Poland in 1992.
It is now found across the continent and since the first UK case in 2012, it has spread across England to Scotland, Wales, Northern Ireland, and the Isle of Man. Up to 80% of ash trees across the UK could be lost to the disease at a cost to the UK economy of as much as £7 billion by 2030.
Once a tree is infected the disease is usually fatal, either directly, or indirectly by weakening the tree to the point it succumbs to attacks by other pests or pathogens, such as honey fungus. Ash dieback causes trees to slowly die, drop limbs, collapse or fall.
Where infected trees grow beside roads and footpaths, they can pose a threat to public safety and infected trees may be felled to reduce the risk. In these cases, ecological surveys are important to check for the presence of protected species such as bats and dormice.
Sadly, but not surprisingly, tree safety surveys show that Ash trees on some of our nature reserves are affected by the disease.
This can pose a risk to the safety of visitors, neighbouring properties, and highways. We are currently removing potentially dangerous trees and closing off a small number of paths and tracks at three of our reserves to keep people safe whilst limiting the impact on wildlife.
Whilst we are still learning about the impacts of ash dieback, and the challenge is significant, we are fighting back.
We keep a close eye on the health of trees in all our woods. Health and safety considerations are central to our woodland management decisions, alongside maximising opportunities to turn the challenge of ash dieback into an opportunity to help wildlife.
As we face up to the combined ecological and climate crisis it is vital the resilience of our woodland habitats is improved over time so they can resist and recover from pest and disease outbreaks. As well as tackling dangerous trees where necessary, we are also looking for opportunities to help the wildlife on our nature reserves.
On larger sites where paths can be diverted or in less visited areas away from footpaths, we keep affected trees wherever possible, to give nature time and space to respond rather than intervening.
Allowing nature this space can offer the opportunity for potentially tolerant ash to naturally regenerate and for affected ash trees to become valuable deadwood habitat.
Replanting or encouraging natural regeneration of native tree species helps offset some of the impact of the loss of Ash trees.
We estimate that the cost of tackling Ash dieback on our nature reserves will run to tens of thousands of pounds a year for many years to come. However, the cost of not tackling it head on could be the closure of some of our cherished woodlands to visitors should the risks posed by dead and dying trees becomes too high.
Over the past 18 months we’ve reviewed and refined our approach – seeking to minimise disturbance and other impacts on wildlife whilst reducing the risk posed by affected trees.
With our new approach now being applied across our nature reserves we are confident that with the support of members and donors and the understanding of visitors, we can tackle Ash dieback whilst ensuring our woodland areas go on being havens for people and nature.