Limestone pavements in and around Durness
Limestone pavements are one of Scotland’s most curious and rarest landforms and with their own unique geological features they also provide a unique habitat for rare arctic-alpine flora in the Durness area. The Durness pavements show excellent examples of the feature which are significantly above the threshold for SSSI (Site of Special Scientific Interest) status, hence they are legally protected and it is a criminal offence to hammer or remove rock fragments / plants from any of the sites. Because limestone is more soluble than dolostone in rainwater, the best developed pavements tend to be found on the limestone intervals of the Durness Limestone.
Flora
The limestone pavements around Durness help support an unusually diverse flora community rich in northern and arctic-alpine species. This is mainly due to the grikes between the pavement blocks which provide a relatively humid shelter from the strong winds and are also inaccessible to grazing animals.
With high levels of calcium carbonate being available within these microhabitats, the habitat is suitable only for those species that can tolerate these conditions such as Mountain Aven, Burnet Rose and the orchid Dark-red Helleborine. However, with accumulations of richer soil also developing within the shady, humid grikes, typical woodland herbs such as the Primrose and Dog's Mercury can also grow.
Other species to look out for in the pavement areas (particularly those further inland) are various varieties of fern including Hart’s tongue, Brittle bladder-fern and Hard shield-fern. Stone Brambles may also be found within some of the grikes, with the name coming from the large stones found within the red berries rather than from them clinging to the stone pavements to stop them being swept into the sea!
With high levels of calcium carbonate being available within these microhabitats, the habitat is suitable only for those species that can tolerate these conditions such as Mountain Aven, Burnet Rose and the orchid Dark-red Helleborine. However, with accumulations of richer soil also developing within the shady, humid grikes, typical woodland herbs such as the Primrose and Dog's Mercury can also grow.
Other species to look out for in the pavement areas (particularly those further inland) are various varieties of fern including Hart’s tongue, Brittle bladder-fern and Hard shield-fern. Stone Brambles may also be found within some of the grikes, with the name coming from the large stones found within the red berries rather than from them clinging to the stone pavements to stop them being swept into the sea!
Localities
The most accessible pavements are at Lerinbeg, immediately east of Sango Bay. For access (from Durness village), walk towards Smoo Cave and keep turning left along the roads / tracks after Sango Bay until you reach the disused buildings (formerly part of the WWII RAF Sango radar station). Other excellent ‘true limestone’ examples can be found just SSW of the Sangomore mobile mast (best accessed via the waterworks track just off the Bhlar Duibhe / Meadaidh walking routes). Alternatively, several can also be seen above the escarpment immediately east of Loch Borralie.
Flora reference (JNCC)
All photos © 2011-2012 Iain Greig
All photos © 2011-2012 Iain Greig