Culbin's landscape: dunes and foreshore
The constant cycle of the seashore
Coastal Culbin is the perfect place to observe how nature can change a landscape, whether through catastrophic weather events, or slowly over thousands of years.
Walk the 14km length of Culbin’s ever-changing coastline and you will see saltmarsh giving way to mudflats, stretches of sand speckled with areas of shingle, and great forest-topped dunes being rapidly eroded by the highest tides.
Every element of the Culbin foreshore supports different kinds of natural life, from birds and mammals to plants and even insects, and all these species interconnect to survive on the shifting sands.
The Gut and the Bar
The Bar is a long, thin, double spit of sand-dunes attached to the mainland by a narrow and gradually eroding neck of land. On its western side it shelters a reed and sedge-bed area (including the Minister’s Pool), and to the east it protects a mud and saltmarsh bay known as The Gut, important to wading birds and seasonal migratory birdlife.
The existing Bar was formed when the River Findhorn last changed its course after an 18th century storm. It is steadily moving westwards towards Nairn where one day it may alter another river’s course.
The ever-changing coastal landscape and the forest at the edge
The Bar was once part of the estuary of the River Findhorn. A massive sandstorm in the early 18th century choked the old rivermouth, forcing it to break out into the sea along its current course to the east of the Bar. The remaining old river bed gradually changed to form an area of mudflats and saltmarsh which connect to the sea to the west of Culbin.
Every storm slightly changes the shape of the Bar, and pushes it westwards. More violent storms will almost certainly change the face of Culbin’s coast more drastically again. The sea regularly floods into Buckie Loch, the name of which recollects a time when this was indeed a small bay.
When future tides run high with a wind behind them, this area of coastal heath may well once more become a bay unprotected by the soft sand dunes which currently shelter it.
The trees, planted to stabilise the mobile sands which were blowing across the river into the village of Findhorn and other agricultural areas around Culbin, are regularly reclaimed here by the sea. The foreshore at Buckie Loch is scattered with tree roots, creating a kind of ‘elephant’s graveyard’.
If you visit Culbin regularly, it’s worth monitoring the progress of one tree near the edge in this natural cycle, and looking out for it on the shoreline after a wild storm. Mindful of the danger of timber to shipping, Forestry Commission Scotland tries to stay just ahead of the erosion, felling a strip of trees periodically before they join the beach.
Read more about tree planting at Culbin.
The biggest dune system in Britain
It’s hard now to imagine Culbin without its trees, but this image gives you some indication of the sheer extent of the sand dune systems present below the forest and beyond.
Older inhabitants of this area still recall getting lost among the featureless dunes here as children.
In all, these dunes cover 3,100 hectares and vary in height up to about 35m. Climbing Hill 99 will give you a good idea of the scale of the highest dunes.
How dunes form
Sand dunes are formed by the prevailing wind rolling sand grains along the ground (not blowing them through the air – sandstorms are in reality dust-storms, sand grains stay low!) creating banks which peak and then fall to form an ‘avalanche face’. There, the sand drops to the ground steeply at an angle of exactly 34º as the dune advances. Some dunes move fast, others slowly, all depending on wind speed and vegetation nearby.
If trees and scrub begin to grow on the sides of an advancing dune, then the avalanche face can erode backwards, creating a ‘blow out’ dune, parabolic in shape with two ‘arms’, like those to be found at Maviston.
Butte dunes (best spotted in east Culbin) are the remains of a completely vegetated dune where the sides have eroded away over time, leaving a dune which looks rather like an apple-core. In other places sand covered in vegetation has again been covered in sand, leading to layers of peaty soil sandwiched between two layers of sand.