Chalk Grassland

Chalk grassland is one of the rarest habitats in London and is restricted to the Boroughs of Sutton, Croydon and Bromley as parts of the North Downs, and a few outcrops in north-west Hillingdon. In the last 60 years much of this habitat has been lost to agriculture or has been allowed to turn to scrub or woodland through the lack of grazing or mowing management to maintain it. It is a highly biodiverse habitat and is home to numerous rare plants such as the man orchid and invertebrates like the small blue butterfly.

What is chalk grassland?
Chalk grassland is a meadow habitat that forms on soils that are alkaline and influenced by chalk or limestone. It is now often only found on steep slopes where the land is not suitable for agriculture of for development. Its plant composition is richly diverse with as many as 30 different species being found within 1 square metre. In some cases grasses can almost be absent although sheep’s fescue upright brome and quaking grass are the most common. During June this habitat can dazzle with its array of wildflowers that includes orchids, vetches, milkworts, hawkbits, bedstraws, marjoram, thymes, eyebright and many more. Management through grazing, rotational mowing, or even rotational burning, is required to maintain this habitat.

Whose habitat is it?
With such an array of wildflowers chalk grasslands attract a huge variety of invertebrates and it is well known for its butterflies with 31 species regularly found in this habitat. These include small blue, chalkhill blue, green hairstreak and grizzled and dingy skippers. The rare and protected roman snail and glow-worm also prefer this habitat. Common lizard and slow-worm are common in areas that regularly get warm, particularly south facing banks with a scattering of scrub. Chapel Bank is worth a visit in June for the heady scent of marjoram as you walk through its flower rich meadows or for its diversity of butterflies and other wildlife.

Conservation issues
Chalk grassland is predominantly under threat from scrub encroachment due to a lack of grazing or inappropriate mowing management. Soil enrichment and pollution pose other threats by reducing plant biodiversity value. Extensive scrub clearance can sometimes look devastating but is imperative to maintain and restore this rare and rich habitat.

Where can I see this habitat?
Chapel Bank
Featherbed Lane Verge
Hutchinson's Bank
Riddlesdown SSSI
Saltbox Hill SSSI
West Kent Golf Course
Farthing Downs, Old Coulsdon Downe Bank, Downe.
Coppermill Down SSSI, Harefield