A rare lichen has been discovered in a Carmarthenshire park.

The endangered lobaria pulmonaria lichen was found on several trees in Dinefwr Park including the Wildlife Trust of South and West Wales' Castle Woods nature reserve and the National Trust's Bog Woods.

The discovery of the lichen, an endangered species in Europe, is a sign of environmental recovery.

This type of lichen was almost wiped out in the UK during the Industrial Revolution and only survives in areas with clean air, humid, and still conditions.

There are only around 600 trees in Wales known to have lobaria lichen on them, with around 40 sites across Wales holding just one or two trees with lobaria lichen.

The discovery of a tiny population at Dinefwr, the only population within Carmarthenshire, signifies it has survived thanks to the clean air and it being sheltered from airborne nutrients from agriculture.

The National Trust, the Wildlife Trust of South and West Wales, and Natural Resources Wales (NRW) are working together on a conservation project to protect and nurture the lobaria lichen population found there, ensuring shelter where possible and attempting translocation of lichen to other parts of the forest to encourage its growth there.

Hayley Barrett, NRW's environment team leader, said: "I’m really proud of the team and the work they have been doing in the Dinefwr Estate, working with partners from the National Trust and The Wildlife Trust to preserve this charismatic species that tells a story or survival and restoration, as one of the few sites left in Wales of this wonderful species.

"It’s fantastic to see the lichen thriving on the trees that remain here and hopefully we will see it spread further under the sympathetic management that we’re undertaking here."

Lobaria lichen had previously been spotted on ash trees in the National Trust’s Bog Woods, but was more recently discovered on the oldest tree in Dinefwr - the Castle Oak - which is estimated to be at least 800 years old.

Dai Hart, countryside manager for Carmarthenshire and Ceredigion at the National Trust, said: "Lobaria lichen has been observed on the largest and oldest oak we have on site.

"The fact that lobaria lichen exists on this ancient tree is really something quite special and I am delighted not only that the lichen has been found at Dinefwr, but also with the work being carried out to ensure it is given every opportunity to flourish here."