Monitoring Llantysilio Mountain’s recovery from fire damage

Llantysilio Mountain, a Site of Special Scientific Interest (SSSI) and part of the wider Berwyn a Mynyddoedd De Clwyd / Berwyn and South Clwyd Mountains Special Area of Conservation (SAC), suffered a devastating wildfire in 2018 and work has been ongoing ever since to aid its recovery.

In March 2023, we shared details of a range of moorland management works that had been completed through the winter season. This was thanks to funding through the Welsh Government Nature Networks Fund and delivered in close collaboration with local landowners and colleagues from Natural Resources Wales (NRW), Denbighshire Moorland Management and Wildfire Prevention Project.

Here Bathilda Hilton-Maynes, NRW Environment Officer in the Natura 2000 Sustainable Management Berwyns project, joins us to provide valuable insight as we continue to keep close check on the mountain’s recovery.


NRW Environment Officers from the Denbighshire, Wrexham & Flintshire and North Powys Environment Teams have recently been working with the Environmental Assessment and Advice Team to carry out crucial surveillance of Llantysilio Mountain to assess its recovery following the fire damage it received in 2018.

We used metal detectors, photo-monitoring and high accuracy GPS to relocate a subset of the 60 sample points originally recorded in 2021 and 2022.

At each sample point we repeated monitoring photos and recorded information about vegetation composition and structure and ground cover. It is very important to monitor the heath following the fire to understand how outside pressures plus natural factors are affecting the recovery.

NRW officers using metal detectors, photo-monitoring and high accuracy GPS to relocate a subset.

Monitoring the progress of Llantysilio mountain allows us to keep a close eye on whether we are successful in re-establishing a healthy moorland, that will not only help restore the biodiversity of this protected site, but will have wider-reaching benefits too, such as climate change resilience, improved landscape quality, carbon sequestration, farming and grouse moor management.

The repeat surveillance takes place every year, with 50% of samples revisited in a single field-season. We aim to have revisited all samples by the end of September 2024. This will enable an assessment of the recovery across the whole area affected by the fire to help inform future management of this important moorland site.

Initial results indicate that areas of the mountain exposed to lower intensity fire in 2018 are starting to recover, with heather and bilberry reappearing and establishing good cover and associated birds such as red grouse and meadow pipit breeding and feeding there again.

However, where the fire was hotter and more intense it burnt the upper soil surface, removing the seedbank, and exposing bedrock and subsoil, leading to erosion, loss and long-terms effects on the ecology and biodiversity of the moorland.

Five years after the fire, these areas are dominated by pioneer plant species typical of disturbed or burnt ground. The surveillance has shown that amount of bare ground has reduced since 2021, and grasses and mosses appear to be increasing which should help reduce the risk of further soil erosion, but species typical of a healthy moorland are scarce and ongoing restorative management is required to ensure the heath and its associated wildlife can recover.

NRW officers monitoring Llantysilio Mountain

We would also like to take this opportunity to ask that members of the public continue to follow the countryside code and refrain from using BBQs, starting fires, dropping cigarette butts or glass to avoid potentially devastating fires.

If you wish to discuss any of the work happening on Llantysilio Mountain, please email

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