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Nob End is a 9.4-hectare (23.2 acres) Local Nature ReserveStatutory designation allowing principal local authorities to protect areas containing wildlife or geological features of particular local interest. (LNR) and biological Site of Special Scientific Interest (SSSI) on the outskirts of the villageSmall rural collection of buildings with a church. of Little Lever, about 4.5 km (2.8 mi) from Bolton, in Greater Manchester.[1][2] It is owned by Bolton Metropolitan Borough Council.[1]
The site stands at the confluence of the River Irwell and River Croal. It consists of a flat topped, steep-sided tip of toxic alkali waste from the production of sodium carbonate (soda ash), dumped there between 1850 and 1870.[2] The waste was a blue sludge dominated by calcium sulphide,[3] which subsequent weathering has converted to calcium carbonate, allowing the site to be colonised by calcicolous vegetation, plants that thrive on lime-rich soil.[2]
Habitats
Although most of the site consists of limestone grassland, there are a few small patches of acidic grassland where boiler-ash has been spread over the surface of the toxic waste. In addition, the water table lies close to the surface towards the north of the site, where areas of marshy grassland have developed. There are also small areas of sycamore woodland and patches of hawthorn scrub.[2]
Flora and fauna
Carline thistle Carlina vulgaris, blue fleabane Erigeron acer, purging flax Linum catharticum and rough hawkbit Leontodon hispidus are among the herbs typical of natural limestone grassland to be found at Nob End. Several species of orchid also occur in large numbers, including the fragrant orchid Gymnadenia conopsea, northern marsh orchid Dactylorhiza purpurella and early marsh orchid Dactylorhiza incarnata.[2]
The habitat diversity of the site is reflected in the large populations of burnet moths and common blue butterflies Polyommatus icarus.[2]