Calcareous Grassland

Calcareous grasslands are found on shallow, free-draining, lime-rich rendzina and brown earth soils, which, in NW England, are mostly derived from Carboniferous limestone bedrock, hence the synonym limestone grassland. In NW England these grasslands often occur in mosaics with limestone pavement (see Limestone pavement habitat statement). The majority of calcareous grasslands are grazed by sheep or cattle. Rabbits can also be significant grazers in some localities.

Calcareous grassland is a widespread habitat in the UK, but has undergone significant losses over the past century, largely due to agricultural improvement.

This Broad Habitat type includes:

• Lowland calcareous (limestone) grassland
• Upland calcareous grassland
• Calaminarion grassland.

Lowland calcareous grassland that is dominated by blue moor-grass is similar floristically to its upland counterpart but tends to support rare and scarce species that are restricted to warmer and drier lowland conditions (see below). Upland limestone grasslands will also be associated with communities that are particularly associated with cool and wet conditions such as springs and flushes, acid grasslands, blanket mire and heathland.

Calaminarion grassland is found on soils with high concentrations of heavy metals such as lead. For the most part these conditions are found on mine spoil, though they may very occasionally be found in natural situations, such as on shingle banks in rivers that have incorporated material derived from mine spoil. High concentrations of heavy metals are toxic to many plants and this, combined with the very dry nature of many spoil heaps, restricts the number of species that can grow in these conditions.

For further information please see the document for download on this page.