Southeast Scotland Basalt Outcrops IPA
Location: Scattered between Edinburgh and the Scottish English Border.
Grid Reference: NT 689 399
Southeast Scotland Basalt Outcrops IPA has been recognised as one of 165 Important Plant Areas in the UK.
The key features of this IPA are:
300 million years ago, a number of active volcanoes were to be found in this part of Scotland, and the dome-shaped hills at Hareheugh Crags, Minto Craigs, North Berwick Law, Traprain Law, Hume Castle and Smailholm Crags are all that is left of the plug of lava that once welled up within six of them.
Everything else has been eroded away by glaciation, leaving just the cone of harder material that was once deep underground. Their thin soils and underlying base-rich and acidic rocks have given rise to areas of unimproved, mineral rich grassland and an assemblage of plants that is uncommon in the area.
In a landscape where woodlands and other natural habitats have suffered from disturbance and the effects of intensive agriculture, these volcanic outcrops with their exposed rock faces form unique habitats and rare oases supporting rich communities of bryophytes and lichen assemblages of national significance.
Maiden pink, common rock-rose, meadow saxifrage and moonwort can be found amongst the species-rich grassland on the south-facing slopes, which on the north-facing slopes may include mountain pansy. Ferns, lichens, mosses and woodland plants are present on rock outcrops and ledges.
At Minto Craigs woodland has developed and an interesting and unusual lichen flora which is uncommon for the Borders area grows on the boles of mature trees as well as the rock faces. A regionally important range of higher plants occurs here, including the nationally rare fern forked spleenwort and sticky catchfly (thought to be the only remaining colony in the Borders). Locally rare plant species found include maiden pink and northern dock.
The steep sides of North Berwick Law are covered with large areas of unimproved, mineral rich grassland. Several vascular plant species indicative of base-rich conditions are to be found, including lady's bedstraw, burnet-saxifrage, wild thyme, knotted clover and maiden pink. The UK BAP priority species purple milk-vetch, not normally found inland and the Red Data List species meadow saxifrage are also known from the site, which also contains a number of rare bryophytes.
At Trapain Law the grassland supports more plant species than any other grassland of its type in East Lothian and a unique assemblage of mosses and liverworts. It is known to be the single most species-rich site for lichens in south-east Scotland.