Ham Hill, Wiltshire
Ham Hill is an area of chalk downland in Wiltshire, England, on the steep banks running alongside the road from the village of Ham to Buttermere, close to the Berkshire border. A biological Site of Special Scientific Interest, notified in 1971, covers 1.5 hectares of the site; this designation is due to the site's species-rich plant and insect communities, which include some rare species. Notable among these is the musk orchid, which has been confirmed at only one other site in Wiltshire.
The site is managed as a nature reserve by Wiltshire Wildlife Trust. It is managed by grazing with sheep to prevent scrub encroachment and takeover by rank vegetation, which would otherwise crowd out the scarce plant species.Biological interest
The hillsides at this site have short, herb-rich grassland, and the flatter areas, taller vegetation. The main species in the plant communities here are upright brome, sheep's fescue, quaking-grass, and downland herbs such as burnet-saxifrage, salad-burnet, common milkwort and dwarf thistle. Other plant species found include squinancywort.
A wide range of typical chalk downland specialists are found at Ham Hill including clustered bellflower, autumn gentian, chalk milkwort, horseshoe vetch and common rockrose. Both clustered bellflower are abundant.
This is one of only two confirmed sites in Wiltshire for musk orchid. Seven other species of orchids are presented including frog orchid, burnt orchid and fragrant orchid.
Chalk-grassland bryophytes found here include the liverwort Leiocolea turbinata and the mosses Ctenidium molluscum, Dicranella varia, Weissia microstoma and Entodon concinnus.
A colony of the Duke of Burgundy butterflies is present and other butterfly species associated with chalk flora include green hairstreak, dingy skipper, dark green fritillary and chalkhill blue.
The Roman snail, the largest snail species to be found in Britain, occurs here.
