Noar Hill is a biological Site of Special Scientific Interest south of Selborne in Hampshire. It is a Nature Conservation Review site, Grade 2, and part of East Hampshire HangersSpecial Area of Conservation. An area of is a nature reserve managed by the Hampshire and Isle of Wight Wildlife Trust. It forms one of the westerly outposts of the chalk hills called the South Downs, and rises to a maximum height of about 210 metres above sea-level. The western and northern flanks slope fairly gently, but the eastern and southern flanks in places reach a gradient exceeding 60%. Gilbert White, in his Natural History of Selborne, says of Noar Hill: The western flanks and much of the summit are given over to arable fields. A smaller part of the summit, 20 hectares known as High Common, is covered with downland grasses and scrub. The northern, eastern and southern flanks are covered by deciduous woodland dominated by beech. Such beechwoods on steep hills in East Hampshire are termed "hangers". High Common is the site of mediaeval chalk-workings - chalk was dug out and spread on nearby fields as fertilizer. The excavations have left an irregular network of pits and hollows of varying size, depth, and steepness. Because the ground is so uneven, High Common remained unploughed for centuries and was only used for grazing. It retains the ancient chalk downland flora which elsewhere has largely been lost.
Flora
The chalk-diggings not only made High Common unsuitable for ploughing, but also left bare chalk exposed. The many inclines and aspects of the disused pits provide different microclimates, all of which add to the variety of the flora. Noar Hill is noted for its calcicoles. These include hairy rock-cress, dropwort, harsh downy-rose, pale flax, common milkwort, marjoram, wild thyme and mother-of-thyme ), eyebright, and clustered bellflower. Small-leaved sweet-briar was recorded in 1978. Four bushes of box growing on the landslip are considered by Dr Francis Rose to be native. Early gentian has been found on the bare chalk-scree. The parasitic knapweed broomrape is regularly recorded. Juniper thrives; and in spring there is a beautiful display of cowslip. There are occasional findings of dragon's-teeth and fern-grass. However, the chief glory of Noar Hill derives from its orchids. At least eleven species have been identified:
The colony of musk orchids runs to approximately 10,000 spikes and is of national importance. High Common, surrounded by botanically impoverished farmland, provides both a refuge for chalk downland species and a reservoir from which recolonization of nearby areas is possible. The habitat restoration being undertaken at Selborne Common may be one beneficiary.
Fauna
Noar Hill is home to the only British species of the curious fairy shrimp, which lives in puddles on the tracks and survives as an egg when the mud dries. Glow-worms are occasionally seen over the reserve on summer evenings. Grasshoppers abound, including the rufous grasshopper. The butterflies include marbled white, brown argus, Duke of Burgundy, brown hairstreak, and holly blue, besides large numbers of more common species. The reserve is a good place to look for slowworms. It supports breeding turtle doves ; and green woodpeckers, which are fond of feeding on ants, are frequent. Several pairs of common buzzards are resident in the area and the rabbits on High Common are a favourite prey. The hen harrierCircus cyaneus is an occasional winter visitor. For some reason - perhaps the abundance of rosehips - bullfinches are always to be found upon the hill.
