Ash Dieback aka Chalara has taken hold of our Ash trees at Rushmore which is a great shame as they form much of our woodland structure and contribute to the local landscape. Whilst we are aware that genetics forms an essential part of tree resistance, we also know that whilst some trees do not have this trait, they still manage to remain healthy. Why is this? And can it help us manage our Ash trees to increase their chances of survival?

We are two years into a PhD study looking investigating these alternative factors. Whilst we are at early stages, we can see the following:

• Smaller trees, particularly when densely packed, are very vulnerable.
• Medium to larger trees in more open stands with an understorey are much less affected.
• There appear to be individual trees of all sizes which have significant genetic tolerance;

We hope this research will be invaluable for informing our management into the future, for instance selective harvesting to remove intolerant, or retain tolerant individuals will increase stand resilience through natural regeneration over time.  It seems lower densities of Ash per ha are preferable, which in turn suggests that irregular stand structures and mixtures of Ash and other species would be most resilient, and also better for biodiversity (which links to other research carried out on Rushmore investigating the link between woodland stand complexity and biodiversity).