Many people think bogs are just soggy and boring. They’re not – they’re wild, wet and wonderful! Crinan’s Great Moss (that’s what the Gaelic ‘moine mhor’ means) is a remarkable remnant of one of our most ancient landscapes.
The Moss began to form over 5000 years ago and once covered a vast area. In recent times, tree planting and land reclaimed for farming have eaten into it. What remains, however, is a bogland showpiece – a wild landscape of hummocks, hollows and pools, rich in spectacular wildlife. So come and explore the Great Moss – it’s another part of Kilmartin Glen you’ll never forget.
When the last Ice Age ended some 10,000 years ago, rising sea levels flooded Kilmartin Glen and covered it in heavy marine clay. Then the land, released from the weight of glaciers, began to upheave faster than the sea and a shallow estuary formed at the mouth of the Rivver Add. Saltmarsh spread near the sea as a freshwater loch formed inland where the Moine Mhor lies.
As lush plantlife died, it built up in layers and eventually filled the loch with what is now peat. This process has been hoing on for some 5000 years, and the Moss continues to rise about 1mm a year. It’s now around 4m deep and still growing, forming what’s called a ‘raised bog’.
Throughout Kilmartin Glen you can find evidence in standing stones, burial chambers and rock carvings of prehistoric people. They couldn’t live and farm on the marshy Moint Mhor but it’s likely they would have used the Moss in other ways. Boglands traditionally provided peat for fuel, dyes for clothing, berries for food, potions for medicine and heather for honey and ales.
It’s only in the last 200 years that people started farming on the bog. The Poltalloch estate needed food for the laird’s household and for the ‘new’ village of Kilmartin, built to house estate workers. They set up a tileworks and used local clay to make bricks for the buildings and pipes for draining what has always been called ‘The Moss’.
Parts of the Moine Mhor were cut to fuel the tileworks and for making charcoal. Much of the land was also drained for grazing sheep. Heather was burned off to encourage new gorwth, which in turn attracted grouse – these then attracted shooting parties. All that’s now past and the remaining bog is being returned to its natural state.
Since the moss became a nature reserve in 1987, SNH has been working to restore the bog. This involves damming the drainage channels and re-creating the [‘sponge’ effect of the peat by allowing the water levels to rise. Cattle and sheep no longer graze these flooded areas; rhododendron and birch scrub have been cleared and conifer shelterbelts removed. In time, the Great Moss will return to a near-natural state as the sphagnum moss and other typical bog plants return. In neighbouring fields, summer grazing by cattle and sheep encourages good grass to attract wintering waders and wildfowl.
The Moine Mhor is now the only example left in Britian of a landscape that changes from saltmarsh close to the sea, through freshwater peat bog, to woodland and hillside vegetation. Look out from any of the niewpoints around the Moss and you’ll see clearly how the surface of the bog has formed a huge, shallow dome as it has risen slowly over the years. By taking pollen and other samples from the peat, naturalists have identified the plants and trees that first grew on the land and began the process of forming the bog in waterlogged conditions.
Peat bogs are very acidic and the palnts that grow there don’t rot away. This is because the bacteria that help the decaying process can’t live in these conditions. As a result, when vegetation dies, it builds up in layers as new growth takes over. In time, peat forms from the squashed remains.
Peat is able to retain huge quantities of water – like the sphagnum moss growing on it – and this slows down the rate at which the stored rainwater is released. Big changes, like draining the bog, would mean the water running off quickly and choking burns, lochs and rivers downstream with peat.
The thick mass of vegetation also absorbs large amounts of carbon dioxide and stores it as peat. Disturb the bogland and the locked-up carbon would be released. So, in its own way, the Moine Mhor is helping the fight against global warming.
Take time to give the Great Moss more than a passing glance. You’ll see the soft and spongy sphagnum mosses, with their greens, browns and russet colours, and lots of other plants growing among them.
Most noticeable are the swarf shrubs (heather, cross-leaved heath) and sedges (deergrass, cottongrass). The leaves of bog-mytle give off a strong smell that makes your nostrils twitch, while the yellow star-flowers of bog asphodel light up the bogland in summer.
Ten kinds of dragonfly hunt over the bog for small insects and, in summer, they lay their eggs in the pools. You may also see the nationally rare large heath butterfly, and the Scotch argus butterfly, both of whose caterpillars feed on bog plants. Lots of other insects live here and some provide food for the sundews, which catch and digest then using their sticky leaf hairs.
The bog, its waterways and th neighbouring woods are home to many birds and other creatures. Most graceful are the hen harriers, which rost here in winter and hunt all year round for small birds and animals. Curlews with their haunting calls come here to breed, and you’ll hear and see whinchats and stonechats, meadow and tree pipits and maybe warblers by the canal. Roe deer make tracks across the bog and you may notice where they’ve nibbled young trees in the woodland. Move quietly and you might even glimpse an otter near the River Add.
You’re welcome to visit the reserve at any time but make sure you have warm and waterproof clothes and footwear with you. The wind and rain often sweep over the Moine Mhor quite unexpectedly and it can be cold on top of Dunadd Hill. Keep to marked pathways and never stray on to the bog – there are deep holes and ditches, and deer tracks can be misleading.
For the best views, climb Dunadd Hill or stroll along the canal bank at Bellanoch. For a closer experience, visit the car park and picnic area where you can pick up a leaflet and wander round the Tileworks Trail. Everyone can enjoy this 600m self-guided walk and it lets you visit the ancient bogland and the neighbouring woodland.
There are car parks 2 miles south of Kilmartin on B8025 and 6 miles north of Lochgilphead via A816
Scottish Natural Heritage
1 Kilmory Industrial Estate
Lochgilphead
PA31 8RR
Tel: 01546 603611