Thursday, April 29, 1999 Published at 00:58 GMT 01:58 UK
Call to save vanishing limestone
Limestone pavement in the Yorkshire Dales, created by the ice age (photo Simon Webb)
By Environment Correspondent Alex Kirby
The remaining limestone pavements in Britain - globally rare geological formations - risk being torn up for sale in garden centres.
A report by the Wildlife Trusts, the national network of 46 county trusts in England and the Isle of Man, calls for a Europe-wide ban on the trade.
The British Isles have the world's most important areas of limestone pavement, but there are fewer than 3,000 hectares left in the UK.
And the report says only 3% of them have escaped damage.
The limestone was originally formed about 300 million years ago, then scraped bare by glaciers during the Ice Age.
Exposure to the elements since the retreat of the ice has left it cracked and fissured, and home to several rare species.
A species-rich habitat
The report says: "Short of another ice age, this unique habitat is irreplaceable".
Limestone pavement plants include maidenhair spleenwort and downy currant.
And the threatened high brown and pearl-bordered fritillary butterflies feed on the pavements' vegetation.
Most limestone pavement is found in the Brecon Beacons, north Wales, north west England, Perthshire and the far north of Scotland.
The report says the main problem is the removal of stone from the pavements.
Some pavements are protected under wildlife and countryside legislation.
But once the stone reaches a garden centre, where it is in demand for building rockeries, there is no knowing whether or not it was legitimately obtained.
The trusts say gardeners should buy different products, including sandstone, granite, deep-quarried limestone, or slate.
Another problem threatening the pavements is heavy grazing by sheep, which causes serious damage to the vegetation.
The report says all livestock subsidies should be made conditional on farmers and landowners using environmentally sustainable methods to prevent over-grazing.
The director general of the Wildlife Trusts, Dr Simon Lyster, calling for a total trade ban, says the problem of the pavements is similar to that of ivory.
"But provided there is at least one pair of elephants, the species can recover.
"Once limestone pavement is lost it is gone for ever, together with all the wildlife that depends on it."