This article gives an overview of the calcicolous grassland communities in the British National Vegetation Classification

British National Vegetation Classification

The British National Vegetation Classification or NVC is a system of classifying natural habitat types in Great Britain according to the vegetation they contain....

 system.

Introduction

The calcicolous grassland communities of the NVC were described in Volume 3 of British Plant Communities, first published in 1992, along with the mesotrophic grassland communities

Mesotrophic grasslands in the British National Vegetation Classification system

This article gives an overview of the mesotrophic grassland communities in the British National Vegetation Classification system.-Introduction:The mesotrophic grassland communities of the NVC were described in Volume 3 of British Plant Communities, first published in 1992, along with the...

 and the calcifugous grasslands and montane communities.

In total, 14 calcicolous grassland communities have been identified.

All but two of the calcicolous grassland communities fall into two broad groups:

• seven communities which group loosely together under an umbrella of "chalk grassland" and which are found on calcareous soils in the comparatively dry climatic conditions of the lowlands of southern and eastern England
  England
  England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
  
   (and also in northern and southern coastal areas of Wales
  Wales
  Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
  
  ).
• five upland calcicole communities, distributed in areas of wetter climate through the uplands of Wales, northern England and Scotland
  Scotland
  Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
  
  .

The lowlands group comprises two subgroups:

• three short-sward communities associated with heavy grazing: a widespread community (CG2
  British NVC community CG2
  NVC community CG2 is one of the calcicolous grassland communities in the British National Vegetation Classification system...
  
  ) that is regarded as "typical" chalk grassland, though it also occurs widely on limestone, and its "south-west coastal" (CG1) and "eastern" (CG7) counterparts
• four communities of rank, tussocky grassland associated with low levels of grazing (CG3, CG4
  British NVC community CG4
  NVC community CG4 is one of the calcicolous grassland communities in the British National Vegetation Classification system. It is one of four communities of rank, tussocky grassland associated with low levels of grazing, within the lowland calcicolous grassland group.It is a comparatively widely...
  
  , CG5
  British NVC community CG5
  NVC community CG5 is one of the calcicolous grassland communities in the British National Vegetation Classification system. It is one of four communities of rank, tussocky grassland associated with low levels of grazing, within the lowland calcicolous grassland group.It is a comparatively widely...
  
   and CG6
  British NVC community CG6
  NVC community CG6 is one of the calcicolous grassland communities in the British National Vegetation Classification system. It is one of four communities of rank, tussocky grassland associated with low levels of grazing, within the lowland calcicolous grassland group.It is a comparatively widely...
  
  )

The upland group comprises the following subgroups:

• a widespread short-sward community associated with heavy grazing, CG10
  British NVC community CG10
  NVC community CG10 is one of the calcicolous grassland communities in the British National Vegetation Classification system. Of the upland group of calcicolous grasslands, it is the only one with a short sward associated with heavy grazing.It is a comparatively widely distributed community in the...
  
  
• two localised communities characterised by the presence of Alpine Lady's-mantle (Alchemilla alpina), CG11 and CG12
• two localised communities characterised by the presence of Mountain Avens (Dryas octopetala), CG13 and CG14

The remaining two communities (CG8 and CG9) are characterised by the presence of Blue Moor-grass (Sesleria caerulea), both of which are localised in northern England and do not fall neatly into either of the two groups described above.

List of calcicolous grassland communities

The following is a list of the communities that make up this category:

• CG1 Festuca ovina - Carlina vulgaris grassland
  British NVC community CG1 (Festuca ovina - Carlina vulgaris grassland)
  NVC community CG1 is one of the calcicolous grassland communities in the British National Vegetation Classification system...
  
  

• CG2 Festuca ovina - Avenula pratensis grassland

• CG3 Bromus erectus grassland
  British NVC community CG3 (Bromus erectus grassland)
  NVC community CG3 is one of the calcicolous grassland communities in the British National Vegetation Classification system. It is one of four communities of rank, tussocky grassland associated with low levels of grazing, within the lowland calcicolous grassland group.It is a comparatively widely...
  
  

• CG4 Brachypodium pinnatum grassland

• CG5 Bromus erectus - Brachypodium pinnatum grassland

• CG6 Avenula pubescens grassland

• CG7 Festuca ovina - Hieracium pilosella - Thymus praecox/pulegioides grassland

• CG8 Sesleria albicans - Scabiosa columbaria grassland

• CG9 Sesleria albicans - Galium sterneri grassland

• CG10 Festuca ovina - Agrostis capillaris - Thymus praecox grassland

• CG11 Festuca ovina - Agrostis capillaris - Alchemilla alpina grass-heath

• CG12 Festuca ovina - Alchemilla alpina - Silene acaulis dwarf-herb community

• CG13 Dryas octopetala - Carex flacca heath

• CG14 Dryas octopetala - Silene acaulis ledge community