Limestone Pavement - Nr Ingleborough - Les Binns
What are they?
A windswept and seemingly barren landscape, the bare, grey rocks of limestone pavements seem all too lonely. But take a closer look at this glacier-like landscape and the sights, sounds and smells of wildlife abound. In higher areas, ferns make their way through fissures in the rocks and rabbits hop across the cracks. Lower down, the pavements can become wooded, with ash and sycamore towering over delicate wildflowers.
There is no doubt that limestone pavements are unique habitats. Carboniferous limestone, laid down under a warm sea about 350 million years ago, became exposed as the land shifted and seas retreated. During the last Ice Age (some 10,000 years ago), this rock was deeply scoured by creeping glaciers; it has since weathered to produce solid blocks or paving stones of bare limestone (clints), separated by an intricate pattern of fissures (grikes).
Where are they found?
Less than 3,000 hectares of limestone pavement remain in the UK, most of it in the Yorkshire Dales and on the edge of the Lake District. Elsewhere in Europe, limestone pavement is found only in The Burren in Western Ireland, in the high Alps and in parts of former Yugoslavia. On a global scale, limestone pavement is rare.
Why are they important?
Far from being a rocky desert, the unique conditions on limestone pavements support many different plants and animals. Not surprisingly, plants of rocky habitats are common such as wall-rue, maidenhair spleenwort and wall lettuce. Rarer species include limestone fern, angular Solomon’s-seal, dark-red helleborine, juniper and rigid buckler-fern.
Lowland pavement is often wooded, but even on the more exposed, higher altitude pavement, many species typical of the woodland floor, such as herb-Paris and dog’s mercury, flourish in the sheltered, humid micro-climate of grikes.
A variety of insects feed on plants associated with limestone pavement including the threatened high brown and pearl-bordered fritillary butterflies and the wall mason bee (all UK BAP priority species). Birds such as skylark, wheatear, meadow pipit and chiffchaff frequent the pavements, while magnificent golden eagles soaring through the skies are a rarer, but immensely pleasing, sight.
These strange, scarred, yet hauntingly beautiful, landscapes are of great scenic appeal and a highly valuable recreational and scientific resource.
Are they threatened?
Traditional uses of limestone for walling, gateposts and agricultural improvement have had only a minor impact on limestone pavement. Much more widespread loss and destruction of this irreplaceable resource has resulted from the quarrying of ‘water-worn limestone’ to satisfy the demand for its use in garden rockeries. Intensive grazing and inappropriate management have also taken their toll.
Only 3% of the UK’s limestone pavements are thought to have escaped damage. This precious habitat, millions of years in the making, is all too easily destroyed in a matter of hours. Once gone, it is lost forever, together with the plants and animals which depend on it.
How are The Wildlife Trusts helping?
Wildlife Trusts are working to prevent further loss of our limestone pavements by looking after areas of limestone pavement as nature reserves. Wildlife Trusts also provide advice and guidance for landowners and farmers on wildlife-friendly practices in these areas.
What can I do to help?
- Most importantly, don't buy rocks for your garden that have been quarried from limestone pavements.
- Take part in conservation measures on your land – ask your local Wildlife Trust for advice on grazing and management of limestone pavement if you have some on land that you own.
- Wildlife Trusts are actively involved with the conservation and restoration of limestone pavement habitats – you can support the work of your local Wildlife Trust by becoming a member.