British NVC community CG7 explained

NVC community CG7 (Festuca ovina - Hieracium pilosella - Thymus praecox/pulegioides grassland) is one of the calcicolous grassland communities in the British National Vegetation Classification system. It is one of three short-sward communities associated with heavy grazing, within the lowland calcicolous grassland group, and is regarded as the eastern counterpart of "typical" chalk grassland (community CG2).

It is a comparatively widely distributed community. There are five subcommunities.

Community composition

The following constant species are found in this community:

• Sheep's Fescue (Festuca ovina)
• Mouse-ear Hawkweed (Hieracium pilosella)
• Rough Hawkbit (Leontodon hispidus)
• Wild Thyme (Thymus praecox) / Large Thyme (T. pulegioides)
• Cypress-leaved Plait-moss (Hypnum cupressiforme)

The following rare species are also associated with the community:

• Field Wormwood (Artemisia campestris)
• Purple Milk-vetch (Astragalus danicus)
• Rare Spring-sedge (Carex ericetorum)
• Wall Bedstraw (Galium parisiense)
• Lizard Orchid (Himantoglossum hircinum)
• Hutchinsia (Hornungia petraea)
• Bur Medick (Medicago minima)
• Sickle Medick (Medicago falcata)
• Sand Lucerne (Medicago sativa ssp. varia)
• Fine-leaved Sandwort (Minuartia hybrida)
• Purple-stem Cat's-tail (Phleum phleoides)
• Spring Cinquefoil (Potentilla neumanniana)
• Sand Catchfly (Silene conica)
• Spanish Catchfly (Silene otites)
• Breckland Thyme (Thymus serpyllum)
• Spiked Speedwell (Veronica spicata)
• Spring Speedwell (Veronica verna)
• Side-fruited Crisp-moss Pleurochaeta squarrosa
• the lichen Bacidia muscorum
• the lichen Buellia epigaea
• the lichen Diploschistes scrupsos var. bryophilus
• the lichen Fulgensia fulgens
• the lichen Lecidea decipiens
• the lichen Squamaria lentigera
• the lichen Toximia caerulea var. nigricans
• the lichen Toximia lobulata

Distribution

This community is found scattered throughout chalk grassland sites in southern England, particularly in The Brecks on the Norfolk/Suffolk border, with outlying clusters in the Yorkshire Wolds (also on chalk), and on Carboniferous limestone in Derbyshire and Mendip Hills.

Subcommunities

There are five subcommunities:

• the Koeleria macrantha subcommunity
• the Cladonia spp. subcommunity
• the Ditrichum flexicaule - Diploschistes scruposus var. bryophilus subcommunity
• the Fragaria vesca - Erigeron acer subcommunity
• the Medicago lupulina - Rumex acetosa subcommunity

References

• Rodwell, J. S. (1992) British Plant Communities Volume 3 - Grasslands and montane communities (hardback), (paperback)