In total, 21 calcifugous grasslands and montane communities have been identified.
The calcifugous grasslands and montane communities consist of the following groupings:
five grass-dominated communities which group together as "sub-montane calcifugous grasslands"; two of these,
U1 and
U2 are found throughout
Britain, two more
U4 and
U5 are found throughout upland areas of
Scotland,
Wales and northern and western
England, and one,
U3, is localised in southwest England.
a sixth submontane community,
U6, dominated by
Heath RushJuncus squarrosus
four communities categorised as "calcifugous vegetation of low- and middle-alpine snow-fields", all of which are confined or nearly confined to Scotland:
U7,
U8,
U11 and
U12
two moss- and rush-heaths of low- and middle-alpine plateaus
U10, which is confined to Scotland, and
U9 which is also found in northern England and North Wales
five communities grouped together as "mesotrophic montane swards and herb-rich banks and ledges":
U13,
U14,
U15,
U16 and
U17; some of these are confined to Scotland while others extend into northern England or North Wales
four calcifuge
fern communities, one of which,
U20, is widespread; the remaining three (
U18,
U19 and
U21) are confined to upland areas of northern and western Britain
List of calcifugous grasslands and montane communities
The following is a list of the communities that make up this category: